Best front torque arm?

[Jonah]

What is the best torque arm to fit to my Thorn steel forks? I’m going to be using the small Xiongda YTW-06 Motor which I ordered yesterday.

 

[Deleted member 4366]

I'd use a Cyclezee one from Ebay or the BMSBattery type. Just use the bit that goes on the axle, and make your own tie-bar out of 2mm steel strip (cut to length and drill two holes) to fix it to your mudguard stay mount. Alternatively, if you have an angle-grinder and 5% cobalt drill, you can cut down and re-drill the supplied tie-bar. They're hardened, so don't waste your time trying to hacksaw one or drill it with a HSS drill bit.

 

[Jonah]

Thanks for that. Looking at the cycleeze ones I discovered there are different versions for 12 or 14mm axles. So now I’m feeling pretty stupid because I don’t know what the axle diameter is on the Xiongda and I can’t see this measurement on the website tech spec. Potentially worse is that my dropouts are 9mm. Have I made a terrible mistake?

 

[Benchie]

Thanks for that. Looking at the cycleeze ones I discovered there are different versions for 12 or 14mm axles. So now I’m feeling pretty stupid because I don’t know what the axle diameter is on the Xiongda and I can’t see this measurement on the website tech spec. Potentially worse is that my dropouts are 9mm. Have I made a terrible mistake?

Hi Jonah, the YTW-06 that I'm using has a 12mm diameter axle with 10mm across flats. I simply filed out my quick release drop outs to a 10mm slot and made the slot deeper to get the axle back on centre line. But I had plenty of metal around the slot to play with, whereas your fork looks very narrow.

I'm not sure if this is true, but I'm pretty sure that Panda ebikes are using the same motor in their swytch kit, and the order survey offered an option to match an 8 or 9mm quick release drop out (I've ordered one for my wife's bike). Maybe ask Bonnie at Xiongda if they can offer an axle diameter to match your fork? If you send her the same photo as in your original post then I'm sure she will see the issue. I doubt if they have made up and despatched your order yet.

 

[Jonah]

Thanks for the info Benchie. I’ll send Bonnie a quick message.

 

[Deleted member 4366]

The axle is standard. they can't change it. All the ebike motors we use have 12mm axles with 10mm flats. The bigger ones, like the 500w+ direct drive motors, MACs and (IIRC) Ezee all have 14mm axles with 10mm flats.

 

[Cyclezee]

To the best of my knowledge all front hub motors including eZee have a 12mm diameter axle, i.e. measured across the threaded part.
The majority of rear hub motors but not 100% have 14mm axles.
'Flats' are always 10mm.
I hope that helps.

 

[Jonah]

Thanks again. So I guess that means filing the dropouts. I wanted to interchange the motor wheel with the original wheel but I guess this won’t be possible once I file the dropouts?

Are all quick release hubs 9mm or have I just been unlucky?

Is there some coating that can be applied after filing to prevent corrosion or is this not necessary?

 

[Jonah]

Would it be possible / stupid to file the motor axle flats?

 

[Nealh]

12 x 10 for most rear geared hubs, the exception is the 14 x10 one's that d8veh has mentioned.

Bafang/8fun , Aikema, Xiongda and the Bafang copies Mxus, Yose etc etc,all use the 12 x 10 axle.

 

[Deleted member 4366]

It's no problem to use your 9mm QR axle with 10mm drop-outs. Many bikes are like that already.

 

[Jonah]

It's no problem to use your 9mm QR axle with 10mm drop-outs. Many bikes are like that already.

That’s good news. How about filing the axle flats?

 

[Deleted member 4366]

How about filing the axle flats?

Definitely not.