Rad Factory Ebike Hack, Part 3. Adding Regenerative Braking with a Welded Clutch

[@bensmith3304]

One nice feature of the new regen speed limit is if you set it to 0 MPH, it effectively permanently parks the bike. This is great if you need to run inside for a few seconds, as if anyone tries to hop on the bike and steal it, they will need to overcome 750W of regen to go anywhere.

[@williamaungleyraud]

Forgive my ignorance, but won't the regen braking prevent the bike to move forward in that scenario, but how about moving it backwards? 🤔

[@bensmith3304]

@@williamaungleyraud Someone awkwardly trying to walk my cargo bike away backward while the alarm is screaming is of little concern, as a stroll would let me catch up. Someone jumping on the bike and trying to ride away is a much bigger concern. When both the alarm goes off and regen grinds them to a halt, they are going to be far more inclined to ditch the bike for an easier target rather than sit there for a while trying to figure out the best way to circumvent the issue. If someone is smart enough to circumvent both an alarm and ebike system, they are a professional thief and even a U-lock and a garage won't stop them. This comes from first-hand experience.

[@chrisE815]

@@bensmith3304 🤣 I don't know why your response has got me cracking up.

[@hiandhello4183]

@@chrisE815 i wouldnt count on it, what if all it takes is for the motor to be disconnected?

[@fraserthomson5766]

This is why I love my Wellgo quick release pedals, and I can run really fast. :D

[@jeffhsiao3106]

Amazing to discover such brilliant engineering minds from my hometown. I wish to one day work for you guys.

[@Matanumi]

oh sick you used a radmini- my favorite bike from this company such a nice look for a folder

[@JohnDoe-mf5db]

This is an awesome hack can't wait to try it on my e-bike.

[@brendentrethewey8154]

New torque arm! can't wait to get one for my older direct drive rear hub (MXUS 3005)

[@bradarmstrong1656]

Grin is great!

[@brantgoose]

Thank you so much for the tutorial. When I posted your first video in our Elf group quite the drama and regenerative braking debate 😂

[@tamholt3494]

I hate to complain because GRIN is making things no other company will, like the BaseRunner ESC. But here it goes: I wish they had an alternative display using a modern tiny 128x64 OLED screen rather than the dot matrix calculator style. I wish GRIN had another lower-profile option for the screen. Even if it's just a little rectangle with the entire back side taken up by the wire loom.

[@GrinTechnologies]

You and at least 10,000 or so other people! Don't worry we know. :-)

[@MathieuTechMoto]

Or like Bafang you can program everything with a usb cable on your phone

[@AmerAhmed91]

I look forward to each video. They're so helpful as a collective

[@michelecatufa]

what about pairing a rigenerative (welded clutch) mid drive engine with a fixed gear back wheel? wouldn't enable regenerative braking with mid drive too?

[@GrinTechnologies]

Yup, but you would loose all the benefits of a mid drive since it works just be single speed, while retaining all the disadvantages. But if it's the only motor you got and fixie is how you like to ride, then buy all means this will work

[@michelecatufa]

@@GrinTechnologies by adding a rear wheel with integrated hub gear then I would have a bike which has central motor, with energy recovery, with a shift that could be even used to modulate the braking torque! Isn t it?

[@CamiloSantana]

have you tried a rear axle with a hole drilled through the threaded end to stick a cotter pin through it to hold the nut in place or at least some kind of safety wire? that's the common solution for motorcycles.

[@GrinTechnologies]

Yes, that's commonly used in aviation too and you are welcome to do it. The axles are hardened steel and a bit of a pain to drill through, and in many cases there is an electrical cable running through the axle as well.

[@kitesailor]

Awesome torque arm. Hope to see them for sale soon! I have been wondering about welding the clutch and if the weight of the spot welds would throw the balance of the motor off, just a thought. Is than an issue here?

[@GrinTechnologies]

Once welded The clutch does not rotate anymore, so there is nothing to throw off balance even if that was hypothetically a concern.

[@kitesailor]

@@GrinTechnologies More and more i just see no downsides.

[@jimmyBurnett]

I don't want regen braking. How do i remove it from my hub so i can add another battery?

[@manp1039]

i am wondering if i connected the cycle analist to a golden motor magic pie 2 hub motor and its internal motor controller.. could i activate and use back pedal brake regen ?

[@GrinTechnologies]

Only if the internal controller can be configured to do regen when the throttle voltage drops below 0.8V, with maximum regen at 0.0V.

[@Puppybreth242]

Awesome videos and looking forward to adding regen to my system with the new torque arm!

[@hampusbergman4604]

Would it be possible to weld the clutch in a mid motor like Bafang M620 to get regen and REVERSE? Of course I need a fixed gear on the wheel.

[@GrinTechnologies]

If your bike is a fixie bike then in principle yes, but then you also loose the primary advantage of a mid-drive while retaining all the disadvantages. ie no ability to change the motor gearing, but still having all the chain wear and transmission drivetrain issues.

[@vikferreira2137]

I have a Lankeleisi T750, thinking about upgrading to a G-Mack motor with the Franklin Runner controller kit. What would it cost me ? How much extra if you can build me a new rim with the motor?

[@vikferreira2137]

Are most hub motors capable of having Regen ? What if my motor 's cable is the smaller 6 pin type? Not sure of the cable type. However its a 1000W hub similar to the Bafang.

[@GrinTechnologies]

If it has straight cut gears then in principle it can do regen just fine if you eliminate the freewheeling clutch, noting the caveats in this video. You will obviously need to terminate your motor cable with a connector that matches what is the new regen capable motor controller, or visa versa. 6 pin cables would be for motors that lack actual motor hall sensor but which have an internal speedometer sensor, and that means you'd need a sensorless capable motor controller.

[@JK-zl7vv]

If the electrical system failed, and you had to ride the bike like a regular pedal bike, wouldnt this bike be extremely hard to pedal and ride with this conversion?

[@GrinTechnologies]

These are already pretty crumby bike platforms to ride without assist regardless of that. But yes there is additional drag for turning the motor, quantitatively it is notably less than the rolling drag of the low psi fat bike tires.

[@daveheyrman]

Can I do this with a fiido M21? I don't understand the settings you setup... 😢

[@GrinTechnologies]

In theory yes. In practice it all depends on your skill set and ability to figure things out and solve problems. For a few people it's a great project, for most others it'd be a nightmare to take on.

[@Jahmall841]

How do you replace the plastic gears once it’s welded?

[@GrinTechnologies]

The same way as a non-welded clutch. You just remove the planet carrier and gears from the motor axle with a gear puller, then remove the snapring from the stubby planet axle and slide off and slide on a new planet gear.

[@roop298]

which CA do you need for regen braking?

[@chrisE815]

Hey Grin, Anything on the horizon for modulating regen brake levers or is back pedaling still the only option?

[@GrinTechnologies]

Backpedaling isn't the only option, there is also throttle modulation with a digital ebrake lever, and using the Digi aux input for digital regen control at any point. But to answer your question. Yes.

[@bonzobanana1]

How does it feel without the freewheel function unassisted. On a direct drive hub motor its a slight drag but I imagine it would feel worse than this with a geared hub motor hence why it is not commonly done. I'm also wondering for someone like me who is heavy but with strong legs I find the DD drag very small and don't care about it on flats and I only use assistance for hills as a sort of bailout option when hills get too tough. What sort of level of regen can I expect when I would regen down all hills, just cycle on flats and need assistance on all but the smallest hills? I don't have a controller that can simulate freewheeling by providing a small amount of current to the motor. I just wonder if anyone has any figures for how different configurations compare? If I'm regenning down all hills and use assistance perhaps for 3/4 of hills while still pedaling what percentage of regen could I expect compared to lets say a ebike with a freewheeling geared hub motor which is only used for hills but has no regen. I realise there are so many variables I just wondered if anyone had any experience of what I might expect as rough estimate. I'm wondering if I would see a significant increase in range?

[@GrinTechnologies]

You can directly tell how much drag a motor has by looking at the energy needed to run it unloaded. Large geared motors like the ezee or GMAC typically have about double the drag of a good direct drive hub. For small geared motors like the sx1 it's about the same. Most people get 5-10% and your described use isn't really any different. Wondering how much it will increase your range shouldn't be the main interest, your motive should be about the desire for consitent braking without any wear and tear on your mechanical brakes. The range boost is just an extra bonus on top.

[@bonzobanana1]

@@GrinTechnologies If you regen as much as possible and only use the motor for the steeper hills won't you massively increase your range? On a geared hub motor with clutch only operated by a throttle and only occasionally I've read of someone getting 200 miles out of the battery charge mainly because it was used so sparingly in reality they may have only got 10 miles of assistance up steeper hills only and they would have assisted that with pedaling too. Isn't there a similar situation with a regen hub motor where the reduction in charge in the battery is very slow because you keep topping it up and only use the motor sparingly. What I'm saying is there must be some people who put in much more regen than others compared to using using assistance. If I ride for 100 miles of which 1 mile is assistance going up only the steeper hills but 5 miles are using regen going down steeper hills. Is that 5-10% purely braking or do people use regen going down steep hills by pedaling at the same time? Is regen braking only or can you regen by pedaling or coasting down steep hills? I've not seen exactly where and when you can regen I assumed for steeper hills you could have long sections of regen where you wouldn't stop because you keep pedalling. A sort of flatworld mode where you regen down hills, use no assistance for flat roads and slight inclines and use assistance for steep hills so you average out the required power from the rider so in a way downhill may not be any easier than up hill but you end up with a huge range.

[@shawnio]

hey, update on my issue, I took it all apart, tested the phase wires, it was the yellow phase wire, it was shorted, opened it up lol everything absolutely toast, I think when I crimped my brake disc and bunged up the wheel it must of been in between that phase and it just gave up the ghost, I mean inside the controller, my motors good, hall sensors should be good, I hope. Im ordering a backup medkit for my ebike and a new controller, I have a 500 w continuous motor, these imported from China controllers are all 500w to 1000w on them, would they be ok to use? 60 bucks compared to a 110 at the bike shop, it would help, thanks again Im subscribing

[@GrinTechnologies]

If you have the means of figuring out all the connectors and wiring then you could likely make the random china controllers work, just don't expect to get much help from the sellers to figure things out.

[@manp1039]

backup medkit?

[@Zombifan122]

So I welded my clutch on a RadRunner and I have a 35A controller installed by Bolton (sorry cycle analyst screen is keeping me away...) Anyways i notice now when I'm going faster and coasting and go to use PAS or throttle it kind of lurches like its going into Regen and then speeds up. Is this likely a controller issue or is this normal without the clutch?

[@GrinTechnologies]

This has nothing to do intrinsically with a clutch or no clutch, and everything to do with the startup behavior your motor controller. By chance is it running sensorless?

[@skwerleyz]

So simply welding that together ads Regen?

[@GrinTechnologies]

As long as your motor controller supports it, then yes

[@thomashenden71]

Wouldn’t a locked clutch increase the wear on the cogwheels a lot, as they now constantly engage, instead of only when the bike get assisted power from the motor? Not saying the hack isn’t nice, just wondering about this. Regen obviously is nice.

[@GrinTechnologies]

Believe it or not the cogs are always engaged and spinning whether the clutch is locked or not. The freewheeling clutch stops the rotor from spinning but not the gears. The bidirectional forces on the cogwheels could change their wear dynamic but nothing that we have seen so far, and that's with quite a few years of experience with the GMAC motors.

[@UWMailing]

Interesting video but I'm wondering, with this hub it looks like you can't remove/replace the freewheel without cutting off the plug connected to the wire that enters the drive side of the hub. Is that correct?

[@GrinTechnologies]

You can in principle remove the freewheel just fine, as it is much larger in ID than the nut and connector. What you can't easily do is use a standard freewheel removal tool to start the unscrewing process. You'd have to modify one by boring it out to fit over the nut

[@UWMailing]

@@GrinTechnologies Ah, ok, that makes sense. Thanks for the reply.

[@BobSmith-zx4jy]

@@UWMailing Rad actually makes a FW tool that will take off the gears.

[@UWMailing]

@@BobSmith-zx4jy Good to know. Thanks!

[@musicly9028]

How much torque can this handle exactly?

[@GrinTechnologies]

Are you asking about the torque arm or the motor itself?

[@musicly9028]

@@GrinTechnologies torque arm

[@GrinTechnologies]

It is stronger than the axle. Hollow axles with cables in the middle will shear around 70-100 Nm, solid axles will shear off between 150-200 Nm typically. The torque arm will survive all of that just fine.

[@HappyCampersRescueRanch]

Link to buy torque arm please 🙏

[@GrinTechnologies]

Kinda where you'd expect to find it! ebikes.ca/shop/electric-bicycle-parts/torque-arms.html

[@Altema22]

Love the torque arm, and may get one even if I don't go to regen. I currently have a RadMini with the Bafang G63 tuned to 2.6kw, and use double torque washers on the left, and one torque washer with the mini torque plate on the right. Never had anything come loose yet, BUT, I preload the axle so it's already bottomed in the direction it wants to go. I expect that setup to be less than effective if I go to regen though 😉. One question: Are there other methods of engaging regen, like a bidirectional half twist throttle, or a thumb throttle used for proportional regen braking? Asking because I ride mountain bike trails on occasion, and rotating the pedals backwards to position them for clearance is common. It could get weird if regen engages in that situation!

[@GrinTechnologies]

Yes all those ways and many more. See kzbin.info/www/bejne/nYqmm2eXqNVspqc

[@namenotshown9277]

small point, turn bike upside down to mount wheel, much easier

[@muntasirmahmood4374]

Man you guys should really make bionx BMS boards. I’m sure they’d be very popular as the original ones keep dying including mine. The same goes for the consoles as well which also keep failing. You guys already had previous relations with bionx and I think it would be brilliant for the many bionx customers out there to have access to these parts to keep their bikes going considering how expensive they were. Bionx has been dead for years so who’s stopping Grin Tech to continue the legacy of bionx.

[@GrinTechnologies]

It's really a dead end path to keep a propriety system propped up. Best to open things up with a new controller as we describe in the bionx hack video and forever be free.

[@vaxt]

In Part 4 are you going to show us how to add a temp sensor?

[@GrinTechnologies]

That IS the plan indeed. And then there isn't really much left to do so we'll probably end it at Part 4. It's now got a powerful field oriented controller, a top speed boost due to field weakening, twice the torque off the line, a torque sensing button bracket, and regenerative braking. The temp sensor is the final ticket to ensure that no matter how hard the system gets pushed, it will still automatically limit power to stay in a safe operating zone. This is becomes more important with regen where the hub won't always have the same opportunities to cool down on the downhill stretches.

[@vaxt]

@@GrinTechnologies amazing thank you!!!

[@chuyskywlk]

protip; almost all of these geared hub motors have (on basic models like this) 4 halls; three for phases and one for a speedomagnet on the shell of the hub. I will often just steal the wire used for the speedo and use it on an NTC probe instead so I don't have to rewire the motor. It's much easier to add an external speedo magnet on the wheel spokes than to rewire the motor entirely just to get one extra wire inside.

[@vaxt]

@@chuyskywlk what about for a temperature sensor?

[@kitesailor]

Do you have a link to the torque arm on your website yet?

[@GrinTechnologies]

Yup

[@omo7945]

How much is the whole kit?

[@GrinTechnologies]

There isn't a kit shown in the video. It's a set of discrete part replacements. Controller pricing is here: ebikes.ca/shop/electric-bicycle-parts/controllers.html Torque sensing BB pricing is here: ebikes.ca/shop/electric-bicycle-parts/torque-sensors.html etc.

[@solarEbike]

8:55 Regarding "how much braking torque do I need?", I have mine set to 69 Nm which is enough to bring the bike to a stop. I intuitively learned to begin braking a little sooner than I would with friction brakes and typically only engage the friction brakes after I've come to a full stop to keep the bike from rolling.

[@allanboyd3799]

I love the idea of reusing my old bike and turning it into an Ebike. The June 1st $300 - $1400. Rebate to purchase an Ebike seems to be only for a new Ebike. I wish that this would also include GRIN KITS. SAD!

[@GrinTechnologies]

It is sad. We've tried hard to make them see the light but they are dug in in their intransigence

[@omo7945]

​@@GrinTechnologies Are there any other $2000~$2500 'barebone' ebikes compatible with this kit that are a little better than a Rad? I currently have the $1400 rebate ready to go but they all don't seem to have the power I need.

[@ambiorixcastillocina2730]

How much regen can you get?

[@GrinTechnologies]

m.kzbin.info/www/bejne/nYqmm2eXqNVspqc&pp=ygUcQWxsIGFib3V0IHJlZ2VuIGViaWtlIGp1c3Rpbg%3D%3D Go to 12:27

[@phototristan]

While they make good products here, their customer service is quite lacking. When you email them with a question, sometimes they reply but sometimes they just ignore you. They need to do a lot better. If they're going to sell products, they need to provide some level of acceptable customer support for said products.

[@xmtxx]

Well, I've had perfect customer support from now on. And I've been a pain in the ass with my clumsiness.

[@TheBicycleTherapist]

Cooool

[@vaxt]

Awesome!

[@geemy9675]

I love the smart back pedalling control on the Regen but if I was given the choice, I'd pick blended Regen like ev brakes on the back brake lever for the simplicity of just using your regular brake lever to brake.o

[@GrinTechnologies]

Yup that's basically a given and it's present on almost all the systems (including this one) too.

[@Zombifan122]

You'd think so but the trade off is you have to be sooooo careful not to brake too much. To use the lever you have to back your brakes off so they won't be as effective or they come on too soon and make Regen useless.

[@ThomasMcFarland]

Heck yeah!

[@anthonyrstrawbridge]

The top tube orientation was painfully confusing as a lad but now I'm good with it.

[@phillyd2018]

9:58 what 💀💀

[@山間777]

Please put torque arm on both end of shaft, otherwise, it will twist.

[@GrinTechnologies]

That would require cutting off the electrical connector and resoldering the wires, as the plug is much larger than 10mm diameter. And the cable side of the axle is a lot weaker too due to being hollowed out. In cases where you can there is no harm in doing this, but it's not necessary either.

[@lufknuht5960]

What is this "schoolgirl" stuff?

[@heyheynowinga9972]

hahahahaha a young school girl