How to get REGEN braking from your geared hub motor. Lock that clutch!

[@juste96669]

seriously ??? I was looking for exactly that video for a week ! and you created it! Thank you

[@knoxieman]

Good to see you Justin, I had one of the very first geared BMC motors 20 or so years ago now and still have it, used it on my electric BMX, we used to weld the clutches on some of the higher powered builds using this motor but we would then find that the nylon gears would shred, then we fitted steel gears which were noisy and then you could use the motor a bit more aggressively but then the motor would overheat, we would have phase wires solder joints un solder themselves, hall sensors cooking, magnet glue letting go, in the end we went back to using clutches, using a gentle throttle curve and limiting the power to no more than 1800W, we found the sweet spot to be 52V and 35A max, you dont have to go much over that to start having problems, if you get a good clutch the the benefits of freewheel far outweigh the regen benefits, when you take the losses in to account you dont regen enough to make it worth it as there is little mass to generate enough energy back, also the wheel nuts loosening and having to run 2 x troque arms is a pain, on my steel MTB I dont need to run any torque arms at all and have done 40,000 miles over 20 years with it like that LOL, amazing little motors but if you handle them properly and are realistic you dont need to weld the clutch.

[@GrinTechnologies]

Hey Knoxie and thanks for sharing your field experience. FWIW you almost always 'gain back' more than you loose having regen vs freewheeling, see kzbin.info/www/bejne/nYqmm2eXqNVspqc bewteen the 10 to 15 minute mark. The torque arm / nuts loosening situation is for sure the most annoying downside with modding motors for regen. It's a consequence of all generic hubs using lame axle flats rather than a spline for the TA interface, but this here does the trick to solve this with a single arm: ebikes.ca/v7-regen-torque-arm-12mm.html We all think you should have another crack at this in spite of your experiences from years ago :-)

[@Kactapuss]

Appreciate your post about the drawbacks of this type of mod.

[@Sir_TwiggusRandomannequin]

Oh look a solution to the freewheeling problem of my unicycle CVT unicycle idea, thanks Justin. You have all the unicycle CVT solutions don’t you?

[@briannugent5518]

Very nice idea for single speed geared hub motors. I have a XiongDa 2 speed hub motor that freewheels only apparently like a 1 speed motor. However I believe this clever 2 speed design is not a candidate for this REGEN mod. It cleverly uses a pair of opposing roller clutches that take power by clutching to whichever is forward rotating be it the sun gear (normal 1:16 gear) or the ring gear (slow 1:32) as determined by the rotors electronically select-able direction. Its planet cage is fixed and driven by a first stage gear reduction.

[@GrinTechnologies]

Your take is correct. Freewheeling is a critical component of retro-direct transmissions, and so regen and reverse will never be in the picture.

[@dg9bfc]

I did not know that 2 gears reduction motors exist with switching between gears...

[@SkyGizmmo]

Meticulously thorough. Great that you are pioneering the definitely worth it. My scenario is trail riding up to high altitudes. What goes consistently up ...yes... must come back down.

[@rickw3785]

I can see where regen would be critical when using an ebike in a hilly area. Excellent video. Thanks

[@ianhickson2693]

In place of welding could you just drill and and screw the clutch with a magnet to catch shards of metal?

[@GrinTechnologies]

You could try, but be mindful of the torque levels at play and the shear strength of your screw.

[@LuisLabastida]

Justin did not like those snap ring pliers

[@GrinTechnologies]

We spared you the 5 minutes of struggling before they finally did the trick!

[@thedon2703]

😂😂😂

[@EBikeBuilder_]

😂😂😂🎉

[@eliprotiva222]

@@GrinTechnologies KNIPEX Tools - 6 Piece Circlip Pliers are amazing

[@pickleballhi]

Aloha from Hawaii it seems i have a dead clutch (shenghi DLK074-60-1) freewheels in both directions and thinking about this mod as i cant source it. Where do you get the prelocked clutch for shenghi from your first example?? Mahalo for all your interesting work!

[@GrinTechnologies]

The prelocked ones are from eZee bicycle. For Shengyi they don't have that as an option, in spite of us doing many requests. Welding yours shut isn't a bad way to turn a nonworking motor into a working motor at least.

[@pickleballhi]

@@GrinTechnologies as an alternative do you know if u can swap other clutches? Is it just a matter of moving over the 30t planetary gears if the OD and ID of the clutch match? Or is there more to it than that?

[@GrinTechnologies]

There's nothing off the shelf that will have the same planet carrier pins at the same location. It's not a generic part, it's something specifically engineered by Shengyi.

[@dg9bfc]

I guess a good metal shop can build whatever you need ... so I think it is possible to build a fixed gear holder for ANY motor

[@Funermen]

Good to know about this for the g062. Dont know if I'm gonna go with this tho since I'm planning on going dual 60v battery on my radrunner with a diode battery blender. You mentioned temp sensors back on the radrunner upgrade videos. Will said temp sensor video also work for the g062 motor (when video releases)

[@GrinTechnologies]

Yeah if you have a diode you won't be able to do regen, but you really don't need a diode with parallel connected batteries. Just charge them independently and plug them together for discharging and they're is very little risk. The temp sensor upgrade depends on the controller, but on those that can take a multiplexed speed and temp signal is pretty straightforward.

[@dg9bfc]

​@@GrinTechnologiesI have 2x 25Ah with 52v direct in parallel,(no blender or diode) both packs have an inline diode in charge port so with an y splitter cable on my charger I can charge them together and both voltages are absolute in sync to the last tenth of a volt... charger charges both packs but one pack does not see the other (current only can go inside charge port but not out) .. it's even safe if you accidently poke your keys in the charge port or if you short circuit the charge cable

[@mattmatolcsi6457]

Hey Grin, thanks for another awesome video! One thing that caught me off-guard was the addition of loctite between the planet carrier and the axle. I'm guessing this is not necessary for the GMAC? And not applicable to a DD like the RH212 because the stator is already very tightly coupled to the axle? Would really appreciate your thoughts, I'm using both of these motors. :-)

[@GrinTechnologies]

Correct. The GMAC uses a larger axle diameter on and a thicker tight fitting key stock and hasn't shown any issues in this regard. For the G60/G62 motors, the verdict is still out on how hard you can push it with just the stock key. You can definitely feel the little bit of play and 'clunk' sound when the core switches modes, and it slowly gets worse over time. But so far none of the units on the field have gotten so bad that it either trips up the controller or causes mechanical failure. Everything feels a lot nicer with zero play though so we'd recommend using the 648 retaining compound regardless. For the RH212 of course there is no need as the stator is quite literally welded to the axle.

[@chickeee]

GMAC regen is huge !

[@StartledPancake]

Id love to see some tests comparing the efficiency of a direct drive regen vs a freewheeling geared motor over various riding conditions. After driving 10s of thousands of kms in an electric car its pretty clear that you get best efficiency by turning regen up in town, but turning regen off (and using efficient driving techniques) out on open country roads. This is backed up by many other electric car drivers experiences also.

[@GrinTechnologies]

Speaking from seeing 100's of thousands of km of logged ebike ride data, I can tell you that the only situation with an ebike where a freehweeling motor will get you more range than a regen capable motor is when your riding style involves a majority (>> 50%) of the distance pedaling without using the motor and don't have any significant stop and go or long downhill stretches. In that case the extra drag from the wheel has more of a negative effect than the gains from regen. Even in the case of coasting fast down a hill and building up momentum, vs going slower and collecting regen energy, you will generally go much farther powering on the flats from the saved regen energy than you would from the extra inertia of the higher downhill velocity achieved through coasting. Storing energy via inertia is 100% efficient, but the quadratic rise of air drag with speed very quickly negates any benefits.

[@StartledPancake]

@@GrinTechnologies Thank you for the detailed reply, very much appreciate it. The work you guys do on bringing electric vehicles forward as practical transport is admirable and your enthusiasm for the technology behind them is genuinely infectious. Wish you and Grin every success.

[@andrewstephens2687]

Any idea what the strength of the weld needs to be? Any chance a future-glue like dp420/490 could suffice with their shear strength being upwards of 1500psi?

[@GrinTechnologies]

We've seen the welds fail when done poorly, so the glue would have to be pretty tough. Plus it's quite hard to clean out all the grease to get a glueable surface. No reason you can't try though if you think you have a viable approach

[@BruceTheSniper]

The disadvantage to welding up the clutch is if your battery goes dead, pedaling the bike becomes much harder as you are now fighting the motor resistance. Also, if you like to catch air, your landings will almost guarantee breaking the planetary gears, as I see this happen all the time when the rider stays on power airborne. Now you will need to worry about letting off too much throttle, as you can strip the gears due to the motor turning too slow. The amount of battery gain you get from regen will never make up the range from the coasting ability from the clutch.

[@GrinTechnologies]

Hey Bruce, it's true that there is more drag when pedaling without a battery (similar to the rolling resistance of your tires if you want to quantify it). But you are dead wrong about regen gains being less the coasting benefits. See kzbin.info/www/bejne/nYqmm2eXqNVspqc. We've been selling non-freewheeling geared motors with the GMAC system for nearly 5 years no, with no instances of people breaking gears from being airborne or doing small jumps. I could see the sudden change in RPM causing a shock load on the gears due to the motor's inertia beyond what you'd normally get from motor torque, but I wouldn't universally say this will break gears as a blanket statement.

[@DennisLeeyeet]

For Shengyi SX motor, do you know what steel is being used for the planet carrier plate, the center of the clutch where it connect with the motor axle, and the gear axles, if I want to make my own locked clutch gear set? (or for the GMAC/eZee gear set, what material is used there?) Do you plan on offering a locked clutch gear set, or only plan on offering the mod for the foreseeable future?

[@maximumchargeEV]

What type of grease is best for these types of motors? I hear good things about mobil 28 since lithium grease will eat away at nylon gears.

[@Zombifan122]

Would it make sense to loctite now before welding the clutch so theres no risk of it not fitting? Just thinking you could avoid the reaming step. Just not sure if the heat would undo the loctite and when it cools it resticks.

[@GrinTechnologies]

It's a good question actually. We were worried that the heat would damage the loctite but it's usually possible especialy with steel to keep the heat quite localized just to the weld area. Worth an experiment for sure.

[@Zombifan122]

@@GrinTechnologies I couldn't get it off the shaft anyways and didn't want to try a puller, so I'll just wait a bit and see if it loosens up on its own and then loctite it.

[@SB-fe4gt]

Pretty goood welding for a spark chaser :). Did MAC ever make a solid part to replace the clutc in the MAC motors that would allow it to have regen like the GMAC?

[@Chris-bn1bn]

I don't have hands on experience with planetary hub motor wheels, but in general, is spot welding a viable option to lessen possible damage? I'm picturing, if there's a clutch mechanism, there's most likely an overlap of some sort. Am I assuming correctly?

[@nicod974]

Silly question, does that mod affects the pedaling?

[@GrinTechnologies]

Not in any meaningful way, no. The pedal drive chain is unaffected, but there is now a bit of motor drag (0.5-1Nm) to overcome while pedalling without assistance.

[@nicod974]

Thank you for replying

[@DennisLeeyeet]

The weld looks kinda jank lol, I'm wondering if I can find some machine shop to manufacture the planet carrier if I draw it in cad. Just not sure about the exact type of steel used in the original sx gear set. Also for the sx gear set, it looks like there is quite a bit of axial play even after the C ring is attached. I saw there's a broken o-ring under 1 of the gear bearings, but none on the other 2, on the replacement gear set I got from your shop. If I put the o-oring back under it seems to fit tighter. I'm guessing they are using the o-ring to fill up the gap/preload the bearing? Would the bidirectional axial forces from regen cause the gears to move back and forth axially and grind up the shafts? Another thing unrelated to regen (but related to what you mentioned about ensuring no noise from motor after welding), I sometimes hear a noise from the front wheel that could be described as a sloshing sound, or maybe the sound of some fabric tearing, for a split second. That probably happens most often when I go from accelerating to coasting, but I don't remember for sure (could be from when I start accelerating if I got it backwards). Could that be from the freewheel or is it more likely to be from the fenders? Is that a normal sound if it's coming from the freewheel?

[@GrinTechnologies]

With access to CNC You can definitely custom machine your own planet carrier and make it much lighter since it doesn't have a clutch mechanism. A bit of axial play in the planet gears is of no consequence. The noise you hear is probably the motor simply winding down from it's own inertia after you let go of the throttle.

[@DennisLeeyeet]

@@GrinTechnologies do you happen to know what kind of steel they are using for the planet carrier?

[@BigDanDCNation]

May I ask potentially silly question? While looking at all the grease on the planetary gears and thinking of the potential high heat and wear on these motors, why isn't graphite used as a lubricant?

[@GrinTechnologies]

The motor heat is not high at all by grease standards (like 100-110 oC max) and electrically conductive graphite dust floating around the motor can very much mess up hall signaling, the same way water in the motor can cause leakage currents. There is almost no wear on the insides of the motors, and with the nylon gears we honestly are not convinced grease is even needed at all.

[@WimHagens]

Hi Justin Grin, Great, I want this with my bike too. I appreciate your work very much. Have you already thought of drilling the torq handle vertically together with the shaft, I was thinking of 4 mm. Of course on the side where there is no electrical wire. When mounting, the shaft can then be blocked against Torq forces with a 4 mm bolt and screw. One of hardened steel that can take more. Have you already tried this? kind regards Wim.

[@GrinTechnologies]

A 4mm bolt will have nowhere near the strength to resist the rotating forces on a axle. 80 Nm of torque at the surface of an 12mm axle is about 3000 pounds of shear force.

[@WimHagens]

Ok,that is more then I expected, thank you for the Info.😊

[@tuckfrudeau8665]

Am I correct to think that regen will fatigue the frame and fork faster than freewheeling? I know Grin says that adding hub motors should be safe for any frame designed for the stresses of normal, unassisted, use but are there not more fatigue loading cycles introduced by having hub motors and regen that have a detrimental effect on the overall life of the bike? I'm especially curious about bikes predating the 90s and how they handle this kind of loading, long term. BTW, you guys are the best. I wish more manufacturers and suppliers would be this transparent about the engineering going on with their products. Keep up the good work!

[@GrinTechnologies]

The easiest way to understand why this is not an issue or concern at all is to realize that the forces present on the frame from regen braking are identical to those on the frame or fork from disk brakes brakes. Only disk brakes can put upwards off 200-300 Nm of torque, while regen is rarely able to hit more than~80 Nm. If bikes aren't falling apart from fatigue with disk brakes, they definitely won't from regen either

[@tuckfrudeau8665]

@@GrinTechnologies I've heard about some vintage bikes that shouldn't be upgraded to disc brakes and figured it would be the same for hub motors, but I didn't realize the motors are actually gentler than the brakes. Thanks for clearing that up!

[@andyjackson3414]

Would the main advantage of a braking motor be the reduction of wear and tear of the friction brake system? And I I can see how such a system could make descending long grades safer.

[@GrinTechnologies]

That is definitely the primary advantage. The secondary advantages are totally consistent braking in all weather conditions and and extra 5-10% back into the battery depending mostly on how much stop and go there is in your commute as well as the terrain.

[@dg9bfc]

​@@GrinTechnologiesI live in a very flat area so not much to gain down hill ... only in the city with a lot of stop and go Regen would gain a tiny bit back.. so my guess is I would not gain much (or in other words I stay on freewheel)

[@henrievery-3eye]

Excellent guide thank you once again!

[@1managainsttheworld]

How do they work after the welding? Is there less torque and more rpm than before? Doesn't the gear ratio change when you do this conversion?

[@GrinTechnologies]

No and no, as a motor it works and behaves exactly the same. There is no change to the gear ratio as its the same set of gears.

[@1managainsttheworld]

@@GrinTechnologies Oh yes, now I get it. The ratio would change if the gears would not spin. It only affects the freewheeling clutch.

[@pianojazz4975]

Hello, I have a 1000 watt Bafang motor from the front of an Arial grizzly 52V ebike. It is making a noise like a bee. It has everything new inside, the new bearings, the new clutch and it continues that noise like a bee. Can you shed light on that for me? noise?

[@ivaylodimitrov7186]

I guess it is possible to do that with a normal Mac motor to work like the Gmac ? Any other hidden tips beside the one in the video like using -Loctite , Many thanks

[@GrinTechnologies]

It is indeed possible. MAC motors have an extra complexity that the motor stator is also a bit loose on the axle, and not just the planet carrier. So you may need to loctite 648 on the actual stator too as that will wear down from back and forth torques in a normal MAC. We had to have the stator core material in the GMAC's modified with a steel sleeve insert as the stock stator core that was all aluminum would eventually get quite loose.

[@Rozbujnik_Rumcajs]

Can I fry my controller if it don't support regen? I want to weld clutch because its slipping under the load. Little bit more drag don't bother me.

[@GrinTechnologies]

The controller almost for sure will be fine with the clutch disabled.

[@insertgoodname4809]

4:48 first time I ever heard Justin cuss. LOL!

[@UberLew]

Will this allow me to "lock" the motor in place when i join all the phase wires together

[@GrinTechnologies]

Yes, pretty effectively.

[@UberLew]

@@GrinTechnologies could you please test this out and show how effective it is please, thx for when we are locking the bike to protect from thieves

[@noonly777]

Hello , do i just need to weld the clutch? Do i need something special like a display for it to work ?

[@GrinTechnologies]

Uh, you definitely need a motor controller that can do regenerative braking via some input or another, you need a torque arm that can handle bidirectional torque, and you need to ensure that your planter carrier is affixed to the shaft such that the back and forth rocking won't shear the keystock.

[@noonly777]

@@GrinTechnologies alright thanks

[@noonly777]

@@GrinTechnologies can i send u somewhere a DM?

[@jimj2683]

How can I enable regen during winter when the battery is cold? Could you add a dump load or something?

[@GrinTechnologies]

It's best to start your ride with a warm battery by keeping it indoors till you head out on the ride. You get better performance on discharge (lower internal resistance and much less voltage sag) and no problem handling high regen currents either.

[@dg9bfc]

and during the ride the current (and an isolation "jacket") may keep it warm enough

[@sandroz321]

I would like to solve the opposite problem, on a 750watt hub motor with freewheel, after I go up a hill and the engine is slightly hot, if immediately afterwards I go downhill I feel the engine as if it were slightly braked, when the engine is cold I don't From this problem, do I have to replace the freewheel or could there be another problem?

[@GrinTechnologies]

Potentially. You can tell if the freewheel is working or not by unplugging the motor controller and then spin the wheel by hand forwards and backwards. If the drag feels the same both ways then you don't have a freewheel, while if there is more drag in reverse then it means your freewheel is working.

[@HeroRickyGames]

The truth is that the part that turns falsely when we put it in reverse is something that is kind of useless if we stop to think about it. My bike once broke the cover on the ratchet part, I ended up realizing that it worked for a few minutes until it returned to normal. With this tip, she will definitely have the regenerative brake!

[@olafberend8837]

Has anybode tried to build a temporary lock, that is engaged/disengaged during drving (with power) to enable regen? May we keep it simple as it is made in Bosch (e.g. 6000 Pro) Hedgesaw safety freewheeling...

[@djsolstice8964]

I'm wanting to convert to front hub to get regen (currently using a midrive Bafang BBS01). What's the best to buy up front, a geared hub which I would mod, like this video describes. Or buy a direct drive motor?

[@GrinTechnologies]

Direct drive is far easier and blue reliable. But if lightweight is most paramount for you, then geared is the way to go. Shengyi SX1 is a really good option for that

[@antonmaier2263]

Is it possible to switch to oil lubrication? Or would it leak?

[@dg9bfc]

I have seen a video here on YT where a guy added ATF oil for lube the gears and bearings and to let the oil transport the heat from the coils to the outer case... if I remember right he added about 100ml and he added some sealing to the motor

[@WimHagens]

Hi Justin Grin, Now I also have another question. There are warnings about this subject all over the internet. The battery is not charged in a conventional way, but via the cables that normally supply the motor. The power that comes back could damage the battery BMS circuit board. It is also said that during downhill driving the battery can be overcharged and overheated. I would really appreciate to hear your opinion on this? Can the BMS circuit board be modified for this? Is it true that the battery can be overcharged, is this not secured? Can this be checked via the display and, if necessary, remove the battery during the descent. But then the engine probably won't brake anymore. What do you advise?

[@GrinTechnologies]

We've discussed this topic in various presentations and videos about regen. In general, it's not an issue at all. You'll always be drawing much more than putting back in. In some special situations (like you live at the top of a mountain and start every trip with a really long downhill), then you are aware of the situation and simply charge your battery to like 85 or 90% so that it has a reserve for regen out of the gate. If you have a programmable controller, then you set the max regen voltage to not exceed the full charge battery voltage and the regen will automatically roll back as required. Single port BMS circuits will cut off regen, dual port BMS circuits won't. Neither will get fried from regen unless they are terribly designed BMS boards.

[@dg9bfc]

and it only works with a Regen capable Controller and in the settings of the controller you set max voltage of the pack.. no way to overcharge

[@C0deH0wler]

Good to hear that the eZee is... well, easy to modify.

[@jrobpat0154]

The Shengyi SX1 motor appears to have slightly angled gear teeth, does this cause side thrust issues ?

[@GrinTechnologies]

It does, but luckily it also has a pair of deep groove radial ball bearings in each planet gear that can cope with the thrust no problem. This is what makes it quite one of a kind. No other heroism gear hub motor we've seen on the market would be regen compatible this way

[@1bottlefed]

While it might seem like a good idea on paper if you consider the amount aero drag+friction vs mass+velocity it will soon become apparent that the capture of energy through regen will be minor compared to say a Tesla. Hence when you factor in the typical velocity vs deceleration required when riding a typical Ebike, that on most roads with all but the most high powered heavy Ebikes, being ridden very aggressively in stop and go traffic the gains will never surpass the loss when comparing regen to a freewheel. In general you are a lot better off just riding like you would normally and coasting up to the red light and applying the brakes at the last moment to scrub off the last 5-10 mph. Now if you used a small magnetic clutch to replace the one way clutch and had it paired with a variable regen lever that would IMHO be an ideal (best of both worlds) solution.

[@GrinTechnologies]

This isn't just a hypothetically good idea on paper. We have firsthand data from over 20 years of actively using regen on ebikes in all kinds of conditions to back up the merits! The actual numbers show that in the majority of riding situations you get more energy back from regen than you expend from lack of freewheeling. Usually it's a factor or 2-4 times or higher. City riding in Vancouver on my normal bike I average between 1 to 1.5 Wh/km of energy repacture from regen. The energy lost to motor drag when pedaling without the motor running is no more than 0.3-0.5 Wh/km. But even that's mostly beside the point because it's 100% worth it just to have the benefits of electronic braking with no mechanical wear of the brake pads. The primary scenario where there is a net benefit to freewheeling over regen is people who are doing long distance riding in flat terrain without any stop and go and where the motor is used sparingly, like bike touring in the countryside and only saving the motor for occasional headwinds etc. For more details, watch: kzbin.info/www/bejne/nYqmm2eXqNVspqc or read: endless-sphere.com/sphere/threads/analysis-of-regen-on-an-ebike.7891/ A controlled rather than overrunning clutch of course gets you both (freewheeling and regen), but it comes with a lot of complexity if you work on all the mechanical and electrical details of implementing one. That is likely the primary reason why no actively clutched hub motors have every made it to market yet, though there is nothing stopping someone from building one!

[@dg9bfc]

look for FREGEN (FREEGEN?) video in KZbin... they mounted the brake to the freewheel clutch (call it a new motor design) and as more you brake as more Regen you have ... I guess THAT would make a perfect design (best of both worlds) ...

[@johngalt97]

My folding ebike came with a no-clutch geared hubmotor and I like the regen.

[@GrinTechnologies]

That's neat to hear, what is the brand of the bike? It's pretty rare to see this on a factory ebike.

[@johngalt97]

@@GrinTechnologies It’s one of those old Currie folders with small diameter wheels and 24V of lead-acid batteries. They are suitable only for low-speed operation, and the regen makes speed modulation easy enough that brakes aren’t needed most of the time. Btw, I’m an OG from endless-sphere forum. You guys at GRIN are the GOATS!

[@pekkavalkonen1973]

I didnt watch all this clip but why my Bafang 250W freewheel slip? motor working but no drive...

[@GrinTechnologies]

Either your gears are stripped or your freewheel clutch is not engaging and is slipping instead. Open it up to have a look and see which it is!

[@pekkavalkonen1973]

@@GrinTechnologies I opened but i cant find solution, everything looks good, freewheel rolls and strings..

[@lookoutleo]

I've done that to my 36v motor but how do I get it to regen my battery , the clutch failed a few years ago so I welded it but it doesn't regen at mo. What's your thoughts

[@GrinTechnologies]

You need a regen capable motor controller.

[@lookoutleo]

@@GrinTechnologies can you think of a 36v 250w one that has it

[@ScottAce-Macgyver]

Hiya can you suggest any upgrades that can be made on himo z16 electric bike? Thanks scott

[@cargobk]

Is it possible to use a GMAC clutch assembly on a Mac motor to get an easy regen upgrade like the eZee?

[@GrinTechnologies]

We went with a wider / stronger keyway on the GMAC planet carrier than the regular MAC motors, so it wouldn't be quite as straightforward.

[@spencerlambert1498]

With the removal of the clutch on the ezee motor for Regen does this open the possibility for running in reverse?

[@GrinTechnologies]

Yes indeed, those two things go hand in hand. In fact, the only reason that ezee had a stock carrier without a clutch is because they had a high volume customer that required reverse mode. Regen wasn't part of the picture.

[@captainchaos3053]

What if I have a motor which can reverse? I wonder can the motor still be made to regenerate?

[@GrinTechnologies]

Yes, almost by definition a motor that can run in reverse can also regenerate, as it doesn't have a clutch and can apply backwards torque to the wheel.

[@captainchaos3053]

@@GrinTechnologies cool just need to figure how to make it charge the battery

[@czgunner]

Is this a possible conversion with the Ride1UP bikes?

[@GrinTechnologies]

In principle you can do this with most geared hub motors, but it's risky and complicated and not something we would recommend for 99% of people.

[@NikoxD93]

I was wondering if we could have both Direct Drive and Freewheeling possible on the same hub motor by using a clutch that can engage or disengage like most ICE vehicles? That would be the best of both worlds: You have Regen, but you can also disengage the motor using a lever or a switch, to reach a higher top speed downhill or to decrease resistance. I wanted to contact Justin to see if he had already thought about this possibility, if it is feasible and how could it be achieved? Edit: that question was asked and answered in an other comment already :)

[@edgefx1]

are the nylon gears put under extras stress from doing this?

[@GrinTechnologies]

Zero indications or signs of that so far, and there isn't any reason why the nylon gears would care which direction the torque is in. So far all the 'issues' stem from metal components that slip or wiggle a bit when alternating torque direction, and that includes the planet carrier/key stock and axle itself when secured with just a normal torque arm. Both of those are addressed in this video.

[@edgefx1]

@@GrinTechnologies ohhh that's good to know, I'm opening a repair shop of my own after working as a repair tech for this mom and pop shop for the last 3 years, and recently there's been a spade of ig hubs coming back with planetary gear stripping, i assume it's cuz of the lack of grease cuz wen i service them is bone dry inside

[@GrinTechnologies]

@@edgefx1 We've not seen any correlation between greasing and gear damage, nylon is largely self lubricating after all. We have seen batch-to-batch variations when clearly one batch of gears had poor process control in the plastic injection molding or whatever and was more prone to failure when previous lots of the same hub held up just fine. And of course issues with people putting more torque in the motor than it can sustain. If the motor is run quite hot, the plastic gets correspondingly weaker, and most gear stripping happens during a long climb or other heavy usage situations where the motor is toasty.

[@edgefx1]

@@GrinTechnologies hopefully that's the issue, a batch of bad gears causing a bunch of costumers to come in for such repairs🫣, if it's just a bad batch then id love to be able to offer this service without the customers coming back saying their gears stripped

[@gigifrana940]

Use a mig welder mate 😉 it's a "colder" weld enough for the needs and doesn't modify the shape of the piece 👍 Tig is to 🥵

[@GrinTechnologies]

Agreed, if we had a mig we'd have used it for sure.

[@bobdebouwer7835]

Do you think welding this is even viable? Doesn't it warp the planet carrier? I'd assume that even the slightest warp will have extra wear on the gears long term? Wouldn't it be better to drill a few holes and pour in some resin or something like JB weld?

[@kitesailor]

Can the Bafang G063.1000.D be welded? I have this motor on my AR X-Class bike.

[@GrinTechnologies]

That is exactly the same as the G062 shown in this video. So yes. But you will most likely need to change the controller on your ebike to take advantage of the regen

[@kitesailor]

@@GrinTechnologies If the controller is left unchanged then you still get the braking, but not power back into the battery, correct?

[@Kotofosonline]

@@kitesailor No, no regen, no braking.

[@robertovaldes6232]

can mid-drives have regen too?

[@GrinTechnologies]

In theory yes but in practice not very easily and not with normal bicycle drivechain hardware.

[@grindz145]

Such an important topic! Ever tried epoxy for affixing the clutch?

[@GrinTechnologies]

Yup. Several times and it never came close to doing the trick, even when we tried to completely fill all the gap space in the keystock. Epoxy does not bond to metal very well, nor does it have much strength as a general gap filler to take up play.

[@3737HH]

Would loctite 684 maybe bond strongly enough to the metal for this?

[@GrinTechnologies]

@@3737HHOh I see, you are talking about using a glue/adhesives inside the clutch assembly to prevent it from freewheeling, rather than using it as a bonding agent between the planet carrier and the axle to prevent play. No, we have not tried this. The clutch is full of grease and rivetted together, so you can't really get at it to clean and flush out the inside of all grease so that a glue would stick. That said, we HAVE seen some clutches on old motors with water damage where the rust itself caused the clutch to become seized. So perhaps a strategic soaking in salt water could do for those without access to welding supplies. We have also tried drilling holes and pinning the clutch mechanically, but without being able to see the inner workings it's hard to do this with proper effect.

[@jimmyBurnett]

I want to remove regen braking. How do I do that? I don't need it or want it.

[@GrinTechnologies]

You just do all the steps shown here in reverse.

[@chuyskywlk]

Hol'up -- what happened to torque arm v5 and v6?

[@detacheddad3396]

My direct drive broke in the hub and I had a hell of a time pedaling back. Whatever broke had far more resistance than normal. Normals not bad at all. It wasn’t one of your motors. I think riding it off road on bumpy trails shook something loose.

[@GrinTechnologies]

Any short between the phase wires will cause very high drag to turn the wheel. This is common if the cable gets severed or torn as the exposed phase wires can come in contact

[@profitgreenly5991]

Very cool. For the addendum couldn’t you also just weld the axle to the carrier? I guess that would make future servicing difficult/impossible. I wonder if solder would give a strong enough bond and be easier to do along with your initial weld and remove for future repairs?

[@GrinTechnologies]

You totally could, but then as you say it means future servicing of the motor gears is impossible, and you would also distort the axle with weld bead right near where the ball bearing of the shell needs to fit. It would have to be a tight job or one that is ground down after the fact. Brazing would likley be better.

[@nicholasfairburn7113]

Would a geared hub motor provide more Regen than a direct drive motor?

[@GrinTechnologies]

A geared hub motor of the same power class generally will, yes, since they have lower winding resistance for a given KV, so less of the regen energy is absorbed by the copper winding and more is available to go back into the battery pack.

[@GreenGrid]

Would this affect peddling?

[@GrinTechnologies]

No the pedaling system is totally unaffected by this. However, locking the clutch will result in a small amount of resistance to turn the motor. Depending on the model of hub it can be anywhere from 0.5 to 1.5 Newton-meters. It's roughly comparable to the rolling drag of the tires on the ground.

[@redsandokan]

Any know of a geared hub with integrated torque sensor?

[@GrinTechnologies]

There's been more than a few that have come and gone over the years, but these aren't usually available as separate parts, more typically it's part of a proprietary system.

[@oplkfdhgk]

how many watts of parasitic drag is there on direct drive hub?

[@GrinTechnologies]

It depends on the speed. Most DD hubs have 0.5-0.8 Nm of drag loss, so you can multiply that by your RPM ( but in rad/sec) to get a watts value at any given wheel speed.

[@oplkfdhgk]

@@GrinTechnologies that's not too bad. I was expecting it to be like double that. 🙂

[@GrinTechnologies]

@@oplkfdhgk Well some hubs are about double that, like the big honking Crysatlyte motors were like 1.5 Nm. One of the lowest we measured was the original BionX PL350's, at about 0.4 Nm.

[@olitonottero7620]

super helpful thank you

[@giuseppegalione1388]

Ciao, ottima la modifica..ma non tutte le centraline hanno il sistema "rigenerante" Portare elettricità dalla ruota verso la batteria... può portare a guasti alla batteria (BMS) o centralina.👍🙋

[@JamiePineappleWyatt]

Now for the next complex idea, a clutch that operates based on whether a lever or switch is pulled/pressed or not, so that you can freewheel and regen when necessary. Sounds dumb but would give you more of the benefits of both worlds? P.S I have an old Bafang BPM1 hub, any chance you guys know where to get a new planet carrier assembly, preferably with metal gears 100v melted the gears after a year and I want to do more dumb stuff with that hub.

[@GrinTechnologies]

Not dumb, but so far any implementation idea that gets hashed out seems to add enough complexity to be "not worth it". Especially when the drag losses are pretty insignificant -much less than the energy you get back into the system from regen-. The more sensible approach to reducing the drag losses to almost zero would be switching from permananent magnet motors a technology without PM's, like induction or switched reluctance, or go ironless like maxon motors. Without magnets moving over iron, the unpowered motor can spin freely without resistance, yet still stay always engaged for regen.

[@JamiePineappleWyatt]

@@GrinTechnologies Oh I didnt mention the dumb stuff I wanted to do, I was talking more pushing over 120v through it again now that I have amassed quite a few 60v batteries. Although, you make a great point, I thought it would add too much complexity, but then I started thinking about the Rholoff Hubs and the way they work and thought eh why not, one day we might be able to solve that riddle more simply. If you ever see any hubs running induction motors I would be very happy to see them, my Escooters would be much less of a pain to walk home when I get flats then. Thanks for the response :)

[@JamiePineappleWyatt]

@@GrinTechnologies Btw, I very much do need a replacement for my BPM clutch assembly and have been having one hell of a time trying to find one.

[@NikoxD93]

Lol I just finished writing my comment and I had the same exact question!

[@NikoxD93]

​@@GrinTechnologies Interesting, I had the same question! That answers it. So it's hard to imagine a simple mechanical solution to offer this actionnable mechanism. The benefit would be greater for heavier direct drive motors but their stators are solidly fixed to the axle, so it sounds unplausible to find an elegant solution to disengage heavy PM motors mechanically. I've personally experienced running out of battery it on my commute, and would have benefited from this solution in that case :)

[@HighVoltageKits]

Cool! Now do it for the BBSHD? ;)

[@GrinTechnologies]

There's one on my desk for just this purpose! Of course, locking the clutch on the BBSHD turns it into a pedal generator not into a regen brake that can slow down the bicycle. But you can eliminate the drivechain completely and just pedal to charge the battery if you want.

[@educosta21]

What if we lock the freewheel on the rear cassette? Well I guess this will only work on a fixie bike, without a rear derailleur... That S curve on the chain would snap... Has anyone used a BBSHD on a fixie?

[@namenotshown9277]

cloth soaked with water to cool down welds faster, reduce damage to grease in freewheel

[@GrinTechnologies]

That is true, but the grease inside the freewheel no longer serves any function because it's no longer a rotating component that can benefit from lube. So damaged or not damaged doesn't really matter.

[@namenotshown9277]

@@GrinTechnologies might reduce warping also not sure though, I've used that technique to cool quite a bit, its effective

[@move88888]

can you help me install that？

[@GrinTechnologies]

Nope. It's totally a DIY project, not something that we or anyone else we are aware of offers as a paid service. So if it's outside of your comfort zone to do this kind of work yourself you would be better off just purchasing a ready made factory ebike that already had regenerative braking well implemented. An used but good condition BionX system is a good bet in that regards.

[@PilliBisiklet]

I think there should be a magnetic lock mechanism in the clutch which will can be induced by the brake lever. Welding the clucth and losing all freewheeling advantage just for some regen? no thanks!

[@antonmaier2263]

Is the motor driving the Planets or the sun? Am i right that the pedal is driving the planets and the motor is driving the sun?

[@GrinTechnologies]

The motor drives the sun in this topology. The pedals aren't connected to the gearing at all, they drive the hub shell directly.

[@thedon2703]

Justin is a Nikola Tesla of the DIY ebike community 🎉

[@LaLaLand.Germany]

No, he´s not. Just a bloke pressing his agenda.

[@ambiorixcastillocina2730]

How much regen can I get?

[@GrinTechnologies]

kzbin.info/www/bejne/nYqmm2eXqNVspqc At the 12 minute mark

[@ambiorixcastillocina2730]

@GrinTechnologies Hi Grin, I really love the work you do, I wish I could learn from you; I don't know much about technical stuff but I would at your place for free just to learn.

[@TrCic]

what kind of energy recovery are we talking about here? 🤔

[@GrinTechnologies]

kzbin.info/www/bejne/nYqmm2eXqNVspqc Obviously it depends, but here in Vancouver we typically see between 5% to 15% depending on the user, terrain, and riding style.

[@XavierBetoN]

There's much easier way, any 3-phase (BLDC) motor can switch rotation by switching 2 of 3 wires (most healthily the 2 wires with the same resistance), switch the wires, reverse the motor, install the motor in reverse direction too, and clutch mechanism will be cancelled. edit: won't work on disc brakes

[@GrinTechnologies]

That only works to reverse direction with sensorless systems, that doesn't work on controller that uses hall sensors, and this isn't the same as regen, it's motor direction reversal. If you do that (swap the phases) while the motor is running at speed in the forwards direction you will usually just pop and fry the controller mosfets.

[@XavierBetoN]

@@GrinTechnologies You're right for off-the-shelf packs, you're so right about not recommending it btw I happen to be an engineer who designed my own motor, didn't have time to disassemble the off-the-shelf ebike motors and kits, but they must all have hall sensors. Mine is no-hall motor, bio-oil cooled (so the windings are thinner and motor is lighter, and bio-oil doesn't degrade plastic shielding of electricals over time unlike synthetic oil) [can use linseed or hemp oil for wide range of application temperature] and roughly speaking, if air cooled motor 24v continuous limit is at given size, you can pack oil cooled 43v 12s and thinner wirings. Hall sensor is required on low rpm motors, high rpm motors synchronize after a few milliseconds automagically, in a way of speaking. And yes, I got a reductor too, but not geared, disc-contact (with NBR sleeve) for silent operation. Everybody use timing belt or gears in e-bike motors, but I think timing is unnecesary, it just has to give power, and slip tolerance lower than the wheels, that's all.

[@XavierBetoN]

And motor part is separate from reductor part because Alu-NBR roller pulleys run dry unlike the conventional gears. Downside, I will have to make new rubber rings in 2 years like a tire-change.

[@XavierBetoN]

@@GrinTechnologies Back to topic, my 500w 36v controller is free-gen on default, when you short the cables without throttle (nor PAS signal) it flows the kinetic energy on 3-phase side to electrical on 2-polar side, and a clutch system by wire to engage/disengage the wheel. The clutch mechanism is still on work tho, but the idea of freegen is, again, best of both worlds. I just couldn't find one built ready in market.

[@dg9bfc]

and without a locked clutch your reversed motor spins backwards and does NOTHING.. just spins free.. in the wrong direction 😂😂😂

[@mrcleanisin]

Your engineering skills are amazing, but your audio quality needs to improve.

[@mariopic]

it possible to swap axel out on the motor to new ones

[@GrinTechnologies]

On principle yes but it is both nearly impossible to source replacement axles of a given motor type, and the actual swap is a royal pita since everything (wiring, soldering, interference press fitting etc) needs to be redone

[@TheGreatDadoo]

this is very cool but, in reality, over normal biking, you're lucky to get 3% to 5% back ... and the reason it's not worth this small amount back is because you can't coast without careful throttle control - like a Tesla. The difference is the Tesla gets like 25-30% back since it's so drag efficient compared to - ya know - a bike. So, yeah --- cool but totally not worth it unless you live in San Francisco ... and even then it's iffy. I mean, you do save a little on brake replacement but brakes are much, much, cheaper than your previous videos touted... like 75% less expensive on Amazon... but, very cool none the less :)

[@GrinTechnologies]

3-5% is still more energy you got back than you ever expended overcoming the small amount of motor drag when pedaling without the motor. Not sure what you mean by throttle control, you can coast just like any normal bike by not using the throttle, and if the ~0.5-1Nm of torque is an issue then you can use the "virtual electronic freewheeling" feature of the Phaserunner/baserunner controller to automatically cancel that with a small amount of current injection from the battery pack. As we've been showing since 2008 or so, that is more than covered by what you get from the "small" amount of regen. Remind us what is the downside that makes it "not worth it" ? Definitely with higher weight to drag ratio vehicles you get higher and higher regen percentages. Cargo ebikes are routinely in the 15% + regen realm even in just stop and go riding without major hills.

[@TheGreatDadoo]

@@GrinTechnologies I dunno what ebikes with regen are like, but with my Tesla once you stop accelerating you let back on the "gas" peddle just enough to coast... but if you let back too much - like all the way - the regen kicks in and it starts to slow you down. This is how I assume regen bikes work. If not, then maybe you coast as with normal vehicles when not accelerating but since regen recovers energy by slowing you down the only other way to do it I can see is by activating the regen system (thus slowing you down) through the brakes or some other notification system. All in all I'd rather be able to let off the gas and coast and then begin regen once I touch the brakes and actually engage the brakes once I push far/hard enough. Now, if this is the way regen ebike brakes work and they're not heavy and not expensive and have no draw-backs then sign me up. Also, can regen braking be set-up on my cheap-o 1000w or 3000w Chinese ebike conversions? If so, how are they implemented, how much do they weigh and how much do they cost? You mentioned a controller --- is that all I need? Thanks

[@dg9bfc]

you need a Regen capable controller I would connect the brake light contacts to the regen input ... so if you let the throttle go.. no Regen if you brake .. Regen is engaged brake switch should be set to close earlier as the brakes to pull hard so a slight braking activates Regen but not letting off the throttle

[@marxman00]

unless your using it for entirely for electronic breaking... you cannot add any meaningfull charge to a battery on something as low mass as an ebike, Also you need to generate a higher voltage than the battery currently has or the volts cannot charge it ! Cars have mass that takes energy to slow down and energy to accelerate .. even then 10 seconds or ten minutes of regen is negligable , the only benfit is less wear and toxic dust from breakpads.

[@GrinTechnologies]

>> you cannot add any meaningfull charge to a battery on something as low mass as an ebike I guess that depends on your definition of meaningful. The % recapture rate on a bike is not as high as a on heavy dense vehicle like a car, but it is still north of 10% or more in most situations with an ebike in either stop and go riding or riding with lots of hills. It's better of course with loaded cargo bikes.

[@noobulon4334]

You don't actually need to generate a higher voltage than the battery if you are using a well designed bldc controller. Also, not having as much mass is kind of a moot point because the energy used for accelerating and decelerating are proportional to mass

[@marxman00]

@@noobulon4334If you charge your battery with your mains powered battery charger for 4 minutes ...how much have you charged it ?.... 4 minutes of regen cannot give you anywhere near a constant 2 amps like your battery charger ... Mass inertia is the only stored energy you have . so it only makes sense on locomotives .. On a low mass vehicle Why not just call them magnetic breaks. Calling them "regen" is just a marketing slogan , As I said before ,who is going "fast" downhill with their breaks on ?? you are just wasting efficient momentum and turning into inefficiently milli amps ...that is actually wasting energy ! I will connect my solar charge monitor to my battery output and go down the longest hill I know with my "regen breaks "on and give you the current ,speed,,duration data ...when it stops raining.

[@noobulon4334]

@@marxman00 you're barking up the wrong tree here and for two reasons. First is that we *have* batteries that can charge in excess of 20C, (so 0-80% in less than 3min) the particular chemistry is Lithium Titanate Oxide (LTO), and as long as you have a big enough battery it can take in whatever current you need it to Secondly the magnitude of energy in the system is irrelevant, what matters is how efficiently you can take in energy and release it. Lots of bikers don't like to stop or slow down even when they really should for their own safety because it is a pain to have to build speed again. If you can efficiently put that energy into the battery and use it to get back up to speed then you basically eliminate the physical penalty of stopping or slowing without killing your range

[@marxman00]

@@noobulon4334 Dream on, What slice of the total energy pie are you using ?accelerating and decelerating is not a journey ..if what you said worked every electric vehicle would already never need to charge ..because the start inertia would magically last forever .we dont live in a frictionless vacuum , perhaps you are suggesting dream power,..without all the nasty physics getting in the way.

[@jaysonwallker1648]

Forget the world, unless it's JB weld.

[@bobdebouwer7835]

Would JB weld be better to squeeze in after drilling some holes?

[@TheSnowLeopard]

Or this is what you do if the clutch keeps failing...

[@GrinTechnologies]

That too. Sometimes the clutches even fail in a way that they are locked, and then you get the mod for free!

[@TadeuszTarka-so2dt]

Proszę o napisy w języku polskim

[@cryptonitor9855]

plastic gears on a motor?! WTF thats a piece of shit motor

[@GrinTechnologies]

Your obviously not very familiar with ebike hub motors or the many benefits of nylon VS all metal gearing in that context.

[@davidcarr2649]

Are you guys too busy to deal with Australian customers?

[@heyheynowinga9972]

fantastic video

[@GrinTechnologies]

Thank you! 😃

[@mairavanhun5402]

Where is ur shop att?