Dropout Mod for 1500w

[500w_Of_Power]

Hi, I'm building a 1500w e-bike on 48v and the dropouts are aluminum, they just barely go over the axle. I was thinking of machining some 1/4in 304 stainless steel from SendCutSend to make extended dropouts, then adding a torque arm. I would bolt them on, and use JB Weld Steel epoxy for added strength. You can see my cardboard and paper mock-ups. Is this a good idea, or should I look for a steel frame? This frame is a DimondBack Overdrive 27.5 large frame: https://www.costco.com/diamondback-overdrive-27.5"-bike.product.100744715.html

 

[ElHegpah]

What you are describing is excellent if you want to make your life insurance policy a good investment for your next of kin.

STEEL.

 

[500w_Of_Power]

I don't know, everybody else on the forums thought it was fine... also I'm using 3/8in steel.

 

[Hootz]

From what I can see the dropout depth is the average size seen on most bikes. Can you show a picture of the hub axle to be used placed in the dropout? I would not recommend the modification shown; the dropout does not normally need to be so deep.

 

[500w_Of_Power]

Sure! The hub motor I'm using in this photo is old and chewed up, but the new one is the same axel, and much better fitting. I have talked to framebuilders and they think it would hold 3 times the power.

 

[Hootz]

Your main concern is trying to prevent the axle from spinning in the dropouts. Designing deeper dropouts is not the answer. Your best option is a pinch torque arm on both sides. Don't be tempted to cheap out; buy quality torque arms and be done with it.
https://ebikes.ca/shop/electric-bicycle-parts/torque-arms/v7-regen-torque-arm-12mm.html

 

[500w_Of_Power]

I got some good torque arms, so I'm good. That steel is never breakin'!