review these no weld clamping aluminum dropouts

[auraslip]

This air hardened tool steel frame. The derailleur hanger and rear portion of drop outs will be trimmed.

Two piece design. Torque plate will be bolted to rack mounts and possibly epoxied.

Arm clamps to frame with u-bolts. The arm is attached to the torque plate with bolts.

I wanted to use docs torque plates, but I was worried about the drop outs themselves failing at the weld. I choose to use aluminum here because it's 1/2" an inch thick and should be able to handle the torque when clamped. That's a total of an inch of clamping force on the axle. Besides, the axle these hub motors come with are made from soft steel, so there is little to gain from using hard steel in drop outs. Additionally, aluminum is much easier to work with. And cheap as well. The cost for the metal is only $15 + shipping.

Hopefully I can work this design as a standard horizontal drop out and not need a chain tensioner.

I'm pretty sure this design will work, but I'm not a machine head so I was hoping I could get some feed back.

 

[liveforphysics]

Your dropout weldments to the tubing will not tear out, the radius is too far from the thing applying torque to be much stress by that point.

IMHO, Doc's would be a more elegant solution that you simply wouldn't be able to break.

That said... It's also always fun to make your own designs. Squeezing aluminum is never very satisfying like squeezing steel in my experience.

 

[amberwolf]

Probably would work, but wont' know till you try it.

Don't forget this part, in red; a slot for flexure/closure of the gap when clamping, and a hole at the end of the slot to prevent fatigue cracking beyond it.



Personally, I'd leave the existing dropouts and stuff, and use bolts thru them along wiht the accessory mountpoints and disc mountpoints to bolt new dropout plates to, that extend backfrom the rear edge of the existing dropouts. The wheel would wind up about 1/2" to 1" or so back from it's designed spot on the frame, but that shouldnt' be an issue, other than also making you have to put disc mountpoints on the new plates, offset back by the same amount the axle will be, assuming you'll be using rear disc. If using rear rim brakes, it might cause them to be too far forward to be usable--depends on how adjustable your pad slots are on the arms.

Keep in mind you'll run into the same problem of brake alignment using horizontal dropouts for tensioning even if you use the plates you've got in your drawing exactly as you plan to do right now.

 

[izeman]

me too would buy some 6mm stainless steel. take a plasma cutter (in case you don't have any - a cutting wheel will do the job fine) and cut out the shape needed. then drill a 10mm hole where the dropouts are and use a file to make the hole perfect. i would use the 2 holes for the fender to screw the torque plates to the frame.

the whole procedure should not take more than 2 hours depending of the tools you have available.

 

[auraslip]

Cool cool cool. I guess I really just wanted someone to tell me that I could use docs torque arms on a high powered bike.

Epoxy is easy. Just got to tap them so I don't have to worry about nuts.

like this but with out the backing plate.