Torque Arms

General Discussion about electric bicycles.
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markz   100 GW

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Torque Arms

Post by markz » Mar 12 2018 4:36pm

Take a look at this, mxus 3kw, sunwin cont, 48V, 375lbs 'ish, daily rider

No Torque Arms!
The rear derailleur hanger is my torque arm.
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Noticed a hall wire broken, that explains the issues I been having. Still works!
Maybe next rear tire issue I fix that wire.

markz   100 GW

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Re: Torque Arms and other stuff

Post by markz » Mar 13 2018 5:04pm

I wanted to see how long it would last without t.a.

I do have the scrap steel ready to go. The side with no hangar is a bit gouged, can see the aluminum bunching up.

Since its warmer weather I am doing more and more.

Gave the bike a good washing and washed out the garage & driveway.

The chain is rusted very badly, but like I say I hardly pedal. Got an "Anti-Rust" chain ready to go.

Also needed is a r.d. & shifter and r.brake, its funny bc the rim is disc only, and the bikes rear is V-brake.

Today I picked up a 16 x 1.60 SR244 and tube for my conversion to moto rim.

John in CR   100 GW

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Re: Torque Arms and other stuff

Post by John in CR » Mar 14 2018 12:14am

markz wrote:
Mar 13 2018 5:04pm
I wanted to see how long it would last without t.a.
That's the craziest thing I've seen posted on the forum. The nature of failures with aluminum are catastrophic, and when you're talking about the aluminum that holds the motor on the bike, which is also the wheel, then you're looking at a failure resulting in the wheel separating from the bike.

markz   100 GW

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Re: Torque Arms

Post by markz » Mar 14 2018 1:50pm

TBH I forgot at the beginning to put t.a. on when I swapped over the motor to that bike. It wasnt until a month or two later, when I got a flat tire, that I realized I rode so long without t.a. so I inspected the dropouts. I did not have any t.a. as they were on the other bike with a diff motor on it. So I immediately went out, bought some steel and used the grinder but I didnt have a tap & die set to secure them. So I rode until my next flat, realized hey wtf, ordered a tap & die set. And rode again without t.a.
So you see how that all went down.

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dogman dan   100 GW

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Re: Torque Arms

Post by dogman dan » Mar 15 2018 7:25am

No, you just never got loose enough nuts. If it had tried to spin, that shape would not retain it, it would just lever itself out of the notch. Justins tests showed just tight nuts resists an amazing amount of torque. But once loose, no resistance to spinning, or levering out of a shallow notch.

Sometimes a derailleur hanger can be converted into a practical torque arm. The bolt on type that are used on cheap steel bikes can be welded on, and the weld then deepens the notch creating an effective torque arm from the combined thickness of the steel hanger, and the steel frame.

In your case, sure, the hanger is stronger than alu. but its too shallow to effectively contain an axle that wants to rotate out.

markz   100 GW

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Re: Torque Arms

Post by markz » Jun 03 2018 10:05pm

Thanks dogman dan, it is a good read.

viewtopic.php?f=2&t=14195&p=211396&hili ... ms#p211386

e-beach   100 MW

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Re: Torque Arms

Post by e-beach » Jun 03 2018 10:22pm

dogman dan wrote:
Mar 15 2018 7:25am
No, you just never got loose enough nuts. ......
Commando jokes aside, I have been tightening my motor nuts to 55nm for years, and, I have been running with a broken alloy dropout for months using 55nm pressure. It's been working great.

:D
Favorite Quote: "This is L.A., sugar. There is no 'over the top." --- Chris Erskine

Current build: Liahona w/ cheap front suspension and suspension seat post. Yescomusa 36v 800w generic front hub motor. 15ah Headway triangle mounted pack. Tronsung 30 amp,

Previous Build:1992 Trek Antelope 800 - Bone Crusher (no suspension) - Yescomusa 800 watt 36 volt front wheel kit. Don't do it! Get suspension!!!

markz   100 GW

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Re: Torque Arms

Post by markz » Jun 03 2018 10:26pm

e-beach wrote:
Jun 03 2018 10:22pm
dogman dan wrote:
Mar 15 2018 7:25am
No, you just never got loose enough nuts. ......
Commando jokes aside, I have been tightening my motor nuts to 55nm for years, and, I have been running with a broken alloy dropout for months using 55nm pressure. It's been working great.

:D
Just lawyers lips no T.A.'s?

e-beach   100 MW

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Re: Torque Arms

Post by e-beach » Jun 03 2018 10:42pm

Sorry, my bad. Yes TA's for 8000+ miles before it cracked. TA's now and a broken dropout plus 55Nm to keep it in place.

:D
Favorite Quote: "This is L.A., sugar. There is no 'over the top." --- Chris Erskine

Current build: Liahona w/ cheap front suspension and suspension seat post. Yescomusa 36v 800w generic front hub motor. 15ah Headway triangle mounted pack. Tronsung 30 amp,

Previous Build:1992 Trek Antelope 800 - Bone Crusher (no suspension) - Yescomusa 800 watt 36 volt front wheel kit. Don't do it! Get suspension!!!

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dogman dan   100 GW

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Re: Torque Arms

Post by dogman dan » Jun 07 2018 8:26am

FWIW, proper fitted washers tend to result in nuts staying tight, allowing just the nut pressure to do most of the work.

Many of those who cracked an alloy frame or fork had some kind of mis fit, where an unseen air gap behind a washer puts uneven pressure on the dropout, cracking it as soon as the nut was tightened. Or, similarly, the gap means the nut was never truly tight. The washer bends, and now the nut is loose.

This is why Justin created the c washer, for proper fit on typical front forks.

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MadRhino   100 GW

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Re: Torque Arms

Post by MadRhino » Jun 07 2018 4:39pm

The strength required is proportional to power fed in acceleration. My dirt bike did open 1/4 thick steel torque plates each side. Now it has 1/2’’ each side and I have no doubt they are safe.

Since then, I prefer overbuilding them torque plates.
Make it fool-proof, and I will make a better fool.
Current bikes
Street: https://s20.postimg.org/ewrvugywt/Session_04_2015.jpg
Dirt: https://s20.postimg.org/lbqwr55ml/IMG_0157.jpg

markz   100 GW

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Re: Torque Arms

Post by markz » Jun 10 2018 6:37pm

My new setup, redid my battery, repositioned the bottle cage and controller, and yes some hillybilly torque arms.
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spinningmagnets   100 GW

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Re: Torque Arms

Post by spinningmagnets » Jun 10 2018 7:16pm

Those TA's may not be pretty, but...you have two of them, and they look STRONG!

I approve...

markz   100 GW

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Re: Torque Arms

Post by markz » Jun 13 2018 8:38pm

spinningmagnets wrote:
Jun 10 2018 7:16pm
Those TA's may not be pretty, but...you have two of them, and they look STRONG!

I approve...
I am quite fond of them, I used a wide thick cutoff wheel on a grinder and was a bit off. Would have been better to use a thin one to cut the sides, then the wide one to get the rest.

Just now, after 65km ride out to Cochrane AB from the Tuscany Train to do some fishing, I noticed my left pedal is frocked. My brand new pedal from CRC. Luckily I have spare crank arms and pedals.

Another thing is noise is coming from the motor. I am thinking it is the axle bearings but am unsure because when I start off walking it, no noise. Add 375lbs go slow, no noise. Started happening right after my axle spinout. Its very preculiar. I move wheel by hand sideways and dont feel no movement. And sometimes when I start from stop, the halls give mixed signals, go forward a inch, then its reversed. So, I am thinking wires are touching the conductor, so cut/shaved insulation perhaps on the phase.

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