Installing an Ebike Torque Arm with 1000W Rear hub electric bike motor [DIY EBIKE]

[@ThunderbolttheFox]

Gonna use this as reference for installing my 2 torque arm kit on my walmart bike that I am converting into a 1000w e-bike when the parts get here next weekend. Since the kit has 2 arms, I'm gonna put one on each side

[@expedition-electric3549]

Nice! What brand of kit did you go with? What size battery did you get? Sounds fun!

[@ThunderbolttheFox]

@@expedition-electric3549 A CSCbike 1000w rear hub kit, and a 48v 14AH battery. It's kinda on the cheap end since I had a budget of about $500

[@expedition-electric3549]

@@ThunderbolttheFox Nice! I’ve made many similar bikes! It may be difficult to install the 2nd torque arm because of the motor wire harness being larger than the hole of the torque arm. Send me pic when complete!

[@ThunderbolttheFox]

@@expedition-electric3549 I got the kit today but haven't installed it due to the battery still shipping, no point in adding a ton of weight to an unpowered bicycle. Anyways the cable comes out of the end of the bolt itself, so I was able to remove the pins from the plug at the end with some pliers, and then slip on the torque bracket. When I do finally install the kit, I will be able to use both torque arms, one on each side.

[@expedition-electric3549]

@@ThunderbolttheFox Oh nice! well hopefully that battery arrives soon so you get rollin!

[@capitalnguyen5624]

Hello, I have a bike with 26inch wheel. I want to upgrade a motor like yours. My rear dropout bike is 135mm wide. I wonder the 1000w motor can fit it with a 7s or 8s thread freewheel? Could you make it clear? I appreciate it.

[@TheAmbitiousCitizen]

Will this actually help? My rear wheel is also not fitting a lot exactly like the way ur axle doesnt fit a whole lot into the frame

[@expedition-electric3549]

Some say yes, some say no. I think it's a good backup with one or two torque arms that could prevent a wheel from just completely flying off.

[@azuolasmk3510]

It's actually better to install the torque arm from the bottom because the direction of torque is opposite from that which the wheel is turning. So seeing how you have installed it is only as strong as the hose clamp holding it, which isn't that good

[@girlsdrinkfeck]

some people cant though due to the bike design, if one has to use a clamp they wanna use a O clamp or something which is solid metal

[@expedition-electric3549]

I've installed double

[@expedition-electric3549]

No

[@sotheamam1244]

Hi does it metter how the motor turn for the torque arm to work correctly.

[@69tytyhar]

Hello I have a 1200 kit it came with 2 of those styles torque arms do I have to put one on each side or is it extra for when lost

[@expedition-electric3549]

I would install both of them.

[@trollingc.1132]

Do we need this for left side of the bike?

[@expedition-electric3549]

Yes

[@ItZFlipz]

i dont get it so its held on by a metal zip tie thing clamp, you never screwed the torque arm into the brakes that how its done right

[@expedition-electric3549]

Were you able to solve?

[@ItZFlipz]

yes my friend i have built 5 e bike for my friends now all same method i created my own way to make work without torque arms or anything up to 5000w @@expedition-electric3549

[@myscreen2urs]

I've seen some people or the torque arm from the bottom. Does it make a difference? Do you get better torque transfer if it's coming from the top? I've always thought so myself

[@girlsdrinkfeck]

yes its better if the torque arm can rest against the frame but for some people it dosnt align up that way

[@expedition-electric3549]

Heard both ways

[@expedition-electric3549]

Geat tip!

[@myscreen2urs]

I've since come to the conclusion that it's better to have the torque arms from the bottom. When the wheel spins forward, the torque in the motor is actually going backwards in order to drive you forward. It's best to have that torque travel up and directly into the frame. Otherwise, you're just relying on the hose clamp to hold up. That's just how I understand it and I could be wrong

[@ripp3rjak934]

Uhh would these torque arms work with a horizontal drop out?

[@expedition-electric3549]

it depends on which direction the dropouts face

[@ripp3rjak934]

@@expedition-electric3549 yeah they’re horizontal. My bike is called the Redline Slant 2004 model.

[@Mikeb8134]

I'm very new to ebikes and you have been my go to source. You have so much good stuff out there. If you have 10 seconds I have a quick question sir; if someone was running 2 hub motors and their combined max current from the controllers was 60 amps, and you used a battery with 50amp BMS (52v 20ah), what would happen? If you ran WOT you may trip the BMS of the battery and it come back on after a few seconds? Or something worse? Thank you!

[@haks_123]

that depends on the c rating of the cells being used on the battery, every battery has a maximum constant discharge rate; check the manufacturers reccommendation. In theory as long as you stay within the range the battery will be fine, for your application though it seems overkill for the batteries and you might have to invest in a higher discharge battery or resort to LIPO batteries as they are generally have much higher C rating than Lion batteries

[@expedition-electric3549]

Hello Mike, Sorry but I somehow completely missed this comment. Were you able to find the solution to your question?

[@expedition-electric3549]

Thanks!

[@yourfavouritescepticx8969]

Should I put two torque arms or will one do ?

[@expedition-electric3549]

I would recommend two if you can get them to fit.

[@yourfavouritescepticx8969]

@@expedition-electric3549 thank you

[@expedition-electric3549]

@@yourfavouritescepticx8969 you're welcome

[@andylin6560]

you are going to round that bolt out in no time

[@expedition-electric3549]

Need some better tools

[@TheAmbitiousCitizen]

Does it matter wich side I install the torque arm?

[@expedition-electric3549]

Either, or both sides would be correct.

[@paule.maurice1521]

I'd use a coaster brake wheel lstay clamp looks slicker

[@expedition-electric3549]

what's a coaster brake?

[@siyamislam5821]

Is it enough to install just one side?

[@expedition-electric3549]

I would try to install two of them if your electric motor is over 750Watts.

[@davidward1274]

Those wire clippers is a adjustable wrench.

[@expedition-electric3549]

Good call!

[@josmty9]

DonI need to install these ones on both sides? Or with one side is enough?

[@brandinojam24]

I installed torque arms on both sides of the rear axle for extra measure.

[@expedition-electric3549]

I would install double.

[@dannym470]

This is wrong. All of the work is being done by the hose clamp. The torque is going backward. As for the arm not fitting on in the right direction, you needed to flip it around to get it lined up. You only rotated the piece and selected from one of two direction. The item is not symmetrical - you need to flip it around and try those directions.

[@expedition-electric3549]

You're right, a hose clamp shouldn't be the primary source of torque. It's designed for sealing, not holding things together under force. Is there a way to use a proper bolt or bracket for a more secure fit?

[@gettingluckytrading999]

Good information! You’re a pro fo sho!

[@expedition-electric3549]

Thanks!

[@simonashmead3162]

I’ve just purchased a fiido m21 with a m12 Axle and 175mm drop out it runs 500watt rear hub but I’d like to fit a 1000 Or more powerful motor any advice please it’s for usage on private land in U.K.

[@expedition-electric3549]

Were you able to get the bike?

[@unclebirdman]

Isn't it backwards?

[@expedition-electric3549]

So I've seen quite a few posts lately on this topic in diy ebike forums. Some people would say that it is backwards. Some say that it is correct. This is pretty much the only way that it would fit on this bike with the wheel axle.

[@unclebirdman]

@@expedition-electric3549 Eventually I found it on web archive Grin V1, web.archive.org/web/20140305043627/ebikes.ca/product-info/grin-products/torque-arms.html

[@expedition-electric3549]

@@unclebirdman Good find!

[@WhatWorks-DIY]

I promise there's no way it can fit on my frame, I'll have to cut the hall sensor wire

[@expedition-electric3549]

Can you install a torque arm on one side and then on the other side the motor wires are in the way?

[@WhatWorks-DIY]

@@expedition-electric3549 , yes man, it won't fit on the chain side, and in the other side there's is the motor cable in the way, but no big deal, I have to install new discs, pads an tires, so I'll take the chance to put the torque arm on. keep up the good work!!

[@expedition-electric3549]

@@WhatWorks-DIY There's always some project on a DIY ebike!

[@gotnoshoes99]

That is because torque arms are intended to be used on front forks which have weaker dropouts. I have yet to see a torque arm intended for rear forks.

[@jornmulder]

somebody told me it's getting the bolt off..

[@gotnoshoes99]

The reason it fits awkwardly is because they are intended to be used on front forks which have weaker drop outs. I have yet to see a torque arm intended for a rear fork.

[@expedition-electric3549]

Someone needs to start making them!

[@mdemartile]

I've got the bike, waiting on the electrinics to show up and in the mean time I've been searching for a one piece torque arm. I don't understand the pivot / hose clamp design being sold as a torque arm.

[@expedition-electric3549]

@@mdemartile If you find one piece torque arm, let me know! What bike and kit you going with?

[@eternaloptimist2840]

@@mdemartile What don't you understand about it? The torque arm itself engages with the axle flats, the anchor strap attaches the torque arm to the frame to stop the arm rotating. Ideally the arm and strap should join at around 90 degrees so the strap best resists arm movement. Just make sure you have it set up so the anchor strap is in tension so it actually resists the axle turning - it's not designed to work in compression. An alternative configuration is a one-piece torque arm that presses directly on the frame - this works in compression rather than tension so is mounted on the other side of the frame tube or fork leg. Just remember that the force the torque arm is resisting is the opposite to forward wheel rotation, so the torque arm must be pushed or pulled in the same direction as the wheel rotation.

[@eternaloptimist2840]

@@expedition-electric3549 A one-piece torque arm would be a lot less "universal" than the two piece type, but easy enough to make your own with basic metalworking tools. It does need to be quite thick hard steel to hold the axle without getting chewed up, so tedious to make if you're using hand tools.

[@firewall8039]

You installed the torque arm in the wrong direction. Just lol.

[@expedition-electric3549]

Dont know.

[@kezbrassington8587]

Broke my bike doing this shit

[@expedition-electric3549]

Some bikes might be stronger than others.

[@firewall8039]

You are supposed to install the torque arm, against the torque. You have it backwards. The only thing holding your torque arm on is the hose clamp. You really should think about what you post - this installation is very dangerous not to only you (OP,) but others who are installing it wrong.

[@liljawden620]

What is the right way then I need help I don’t want it coming off during my ride

[@expedition-electric3549]

I've found videos that show both..

[@DecentralEyes]

Personally I would avoid hose clips (jubilee clips) if at all possible! For a start they look amateur.

[@expedition-electric3549]

What do you use instead?

[@TheAviation101]

You're using a fake, chinese clone of torque arm that will snap over time

[@expedition-electric3549]

Where do you get yours from?

[@TheAviation101]

@@expedition-electric3549 ebikes.ca/product-info/grin-products/torque-arms.html These are the original torque arm developers, they talk about how the chinese cloned their flawed v1. Only v2 and above will actually help in the long run. I recommend you read the FAQs on the bottom of this link. However, they're a Canadian based company so I got mine on ebay from a reputable UK seller. 3mm (low power only and should have one on each side), 5mm and 10mm thick stainless steel options. Mine bolts directly to a fender eyelet which is ideal but they have designs for other types of configurations

[@expedition-electric3549]

@@TheAviation101 They don't seem very interested in selling on ebay or amazon. I haven't been able to find. Only the same ones used in this video.

[@TheAviation101]

@@expedition-electric3549 Yes just get good life insurance instead, no big deal

[@TheAviation101]

@@expedition-electric3549 One user died after this chinese torque arm snapped, the dropouts spread wide open, the rear wheel came off whilst shorting the phase wires and he went uncontrollably in to oncoming traffic and hit a truck. Splat, got cut in half.

[@chestersebastien7881]

It doesn't work its a stupid product

[@expedition-electric3549]

Did you install it on your bike?