How many X5 owners run torque arms?

[knoxie]

Hello

I have a 5304 I am going to run for fun at 72V 25A on my main ride for a while, it will be fitted to the rear of my Trek, the frame is ally but does have substantial drop outs, I don't have a torque arm for this motor but I can make one up.

Do any of you run the X5 on the rear with a torque arm? front forks would be recommended of course but on the rear?

Once I have run the X5 for a few months the draper conversion is going in!

Cheers guys

Knoxie

 

[Ypedal]

only 25 amps ? sissy...

On the rear i have not bothered yet, but if you go 72v i'd seriously consider it if you have the means to do it ... the derailer side usually has a SS insert wich is pretty tough.. I'd say make one for peace of mind.

 

[knoxie]

25A!

Ha ha yes well I can adjust it you see I can run 35A if I want to ha ha yes the one side has the SS insert, I think an old spanner then something more permanent for sure will be a good Idea, the X5 should run well at 72V, must sort the brakes out now! ha ha.

Thanks for your input, anyone else?

P

 

[xyster]

Rear 5304 on a 7005-series aluminum comfort bike frame. 80v 35a. No torque arms. No problems so far.

 

[Doctorbass]

I have a 5305( the Brute!) rear hub motor, presently no torque arm, only had to tightened the bolt one time.

110nm torque would be equal to around 10kg of force at 1 meter radius.

It become 180 times higher at 5,5mm radius(the 11mm bolt)

=1800kg =4000lbs of force applied at 5.5mm radius from the center of the bolt...(in case it would not be tightnened)...

I understand it's enough to cause some dammage on the dropouts!

Doc

 

[knoxie]

Hi Guys

Thanks again! I think it should be ok, I will try it anyway, how do you find the rolling no power resistance of the X5? I may fit a switch so I can disconnect the controller to reduce the back emf resistance, how do you find it?

I can of course run this rig at 120V 35A as well!! ha ha think I will start low and work high! ha ha

More vidoes to come, I need to burn up some mopeds!

Cheers

P

 

[xyster]

how do you find the rolling no power resistance of the X5?

For me, only noticeable above 10mph. I can pedal my free-wheelin' Currie about 2mph faster on average.

 

[fechter]

I've never exactly figured out why you get resistance with the controller connected. When the throttle is off, there shouldn't be any path for the current unless you're going fast enough to generate the full battery voltage, then it would start to regen.

If you turn off the power switch, then the low side FETs will also stay off, which would eliminate any possible current through them.

 

[Lowell]

No torque arms here. I run a washer on each side and the factory nut, and then torque on a Porsche wheel nut. Has never budged in over 3000km, and no signs of movement inside the dropouts. The closed end Porsche nuts make good thread protectors as well.

 

[solarbbq2003]

i send out x5 motors with a torque washer for each side and a torque arm for each side!! just to be on safe side

 

[Instant Karma]

Rear 5304 on a 7005-series aluminum comfort bike frame. 80v 35a. No torque arms. No problems so far.

Aluminum bicycle frame, no torque arm, high voltage=high speed, huge heavy hub motor- the question must be asked- Are you nuts??? Same goes for Lowell and his setup.

 

[xyster]

Rear 5304 on a 7005-series aluminum comfort bike frame. 80v 35a. No torque arms. No problems so far.

Aluminum bicycle frame, no torque arm, high voltage=high speed, huge heavy hub motor- the question must be asked- Are you nuts??? Same goes for Lowell and his setup.

Not nuts. The rear dropouts are much beefier, and already have a torque arm to resist twisting forces in the form of the rear triangle. The weight of the motor is immaterial since the bike frame rests on top of it. The amount of torque produced is the salient consideration. There's been cases of lighter 4xx series hubmotors ripping apart front steel dropouts. Steel seems no better than aluminum in this regard, though steel provides more warning of impending failure.
Did you see Lowell's vid of him doing burn-outs? I was surprised his rear dropouts lived through that.

 

[Lowell]

Rear 5304 on a 7005-series aluminum comfort bike frame. 80v 35a. No torque arms. No problems so far.

Aluminum bicycle frame, no torque arm, high voltage=high speed, huge heavy hub motor- the question must be asked- Are you nuts??? Same goes for Lowell and his setup.

Do you have pics of any rear mountain bike dropouts that have spun?

 

[DeeL2003]

I want to put a torque arm on my S750 TF rear dropouts, esp if I plan to go X5 but don't have the expertise or equipment to do it. Know of anyone that can fab me a piece?

I think might give EVTech a call and see if I can buy some from them. They sell torque arms for their BMC kits I believe.

 

[Toorbough ULL-Zeveigh]

I want to put a torque arm on my S750 TF rear dropouts, esp if I plan to go X5 but don't have the expertise or equipment to do it. Know of anyone that can fab me a piece?

I think might give EVTech a call and see if I can buy some from them. They sell torque arms for their BMC kits I believe.

Their torque arm is fabricated specifically to mount onto the rear of the TF frame so it should work perfect.

 

[d]

beware, this is what can happen with an aluminum fork, x5305, 72V, no torque arm, INSTANTANEOUSLY on the first throttle depression:
(I now use a heavy-duty custom built steel fork with huge thick dropouts)

 

[Eric G]

Holy Crap...THAT'S SCARY !!!! Hopefully you came through unscathed.

Eric

 

[Doctorbass]

... I have a x-5305 ... at 72V

installed rear with steel dropout but.... I seriously begin to doubt about keeping that without torque arm!

Doc

 

[Nimbuzz]

I have an EV Tech torque arm on my rear 5304 and couldn't relax without it. My Montague frame has heavy Alum dropouts but I must feel safe riding mountain roads at high speed = 20 -- 40mph. I'm only at 36v but want to go to 72 when I get controller.

Anyone have a 72v 30 or 35a controller for sale?

thanks,