Hub motors & torque arms

[DieselTech]

Everybody I recently ordered a ebike & have been seeing guys talk about putting torque arms on hub motors. Extra insurance type prevention.

That bike I ordered dont have torque arms on the front or rear motors. Do I need these?

I really dont want a motor to spin & yank my wiring out.

What do I need to know to order to order torque arm kits. Also is there a brand better preferred?

Thanks

 

[Sidewinder Jerry]

My first immediate thought on these are use 2 per wheel and steel ones instead of aluminum ones.

 

[HumanPerson]

For sure get steel ones.

These are said to be the best in the market: https://www.amazon.com/Grin-Technol...hvlocphy=&hvtargid=pla-4583932715376017&psc=1

 

[HumanPerson]

My first immediate thought on these are use 2 per wheel and steel ones instead of aluminum ones.

For sure, 2 on the front wheel and 1 on the rear wheel.

 

[Gordy]

I didn't even know that was a possibility

 

[HumanPerson]

I didn't even know that was a possibility

oh yeah, crazy amounts of torque and twist when not assembled properly.
Seen some dropouts wollered out due to lack of torque arm and front forks the same way.

Sometimes it just tears all the wiring out of the hub motor , sometimes it just wollers out the dropouts/fork axle areas.

Well worth the money and time to install

 

[HumanPerson]

@DieselTech

This is one of the things a friend wrote, this is m@robertsons writing on dual hub motor ebikes.

Dual Motor AWD Electric Bikes – Case Study: Twin Geared Hub Commuter

A big bruiser geared specifically to be pedaled hard at 32-34 mph, this is my commuter workout-workhorse. Don’t want to sweat? Just relax and pedal easy… at 28 mph.

talesontwowheels.com

Here is a quote from that writing, concerning torque arms.

""Torque Arms (!)

I’m not going to get too deep into the specifics of this topic, but I will say if you use hub motors you have to use torque arms. Gotta do it. Thats for any motor that has ‘flats’ on its axle to allow their use (which is almost all of them). It is true many motors do not need torque arms because they are of such low power. I will say having suffered the consequences of not using one, its WAY better to be safe than sorry and just go ahead and install them regardless of motor power.

What could happen? If you don’t use a torque arm, the force of the motor will overwhelm your bicycle’s dropouts and the motor will “spin out”. That means your steel dropouts will not be able to contain the motor’s axle, which will spin (instead of the motor casing spinning) and when that happens the dropouts spread. Your frame or fork is effectively destroyed and unsalvageable at that point. These 750w, 80Nm motors are right on the edge of demanding two torque arms. For sure they need one. I have used two on the front motor and one on the rear, where the stronger rear dropouts are much less likely to have an issue."" (End Quote)

 

[DieselTech]

For sure get steel ones.

These are said to be the best in the market: https://www.amazon.com/Grin-Technol...hvlocphy=&hvtargid=pla-4583932715376017&psc=1

Do I need to order 4 of them GRIN technology torque arms? Or is there different models for front & rear torque arm applications. Thanks.

 

[HumanPerson]

For what you have, i'd personally use 2 from grin/amazon.
1 for the front and one for the rear.

or 4 of these: https://www.ebay.com/itm/4043725554...LxrEpiJahyub8qayuJw7M50g==|tkp:Bk9SR7KO0e3IYg

 

[HumanPerson]

Do I need to order 4 of them GRIN technology torque arms? Or is there different models for front & rear torque arm applications. Thanks.

ok so i tinker alot and make s**t work when some say it shouldnt LOL
so i'd prolly just use the same for front and rear, i'd make it work...
not saying that is what people should do, just sayin