dropouts - new steel ones on a aluminium frame?

[izeman]

hi

i plan to install a 2-3kw 9c in an aluminium frame. unfortunately the frame's dropouts are extremly weak (see pictures)

i would cut the whole part off and weld new steel ones to the remaining frame triangle. but as we all know soldering/welding aluminium and steel just ain't work. so what other solustions to i have?

dp420 is NOT my favorite choice. and torque arms aren't either. i'd like to have a clean solutions, where i can easily remove the rear wheel - no problem if it's labor intensive.

ideas welcome

 

[Spicerack]

Get some decent ali dropout plates welded on then add steel torque arms as well. You really have f@rk all metal to play with there!

 

[izeman]

so you mean: weld an alu plate to the frame, and then eg. screw steel dropout to them?

i also thought of making a totally new rear triangle out of steel. this would be a hell of work, but i could also increase wheel base and add some space to install the controller or battery.

 

[Spicerack]

I was thinking of cutting the existing dropouts out, making new ones which are substantially bigger and welding those in. Then make up steel dropouts which fit over the top and are held on by a couple of screws (and the motor axle nuts of course). Fair bit of work unfortunately, especially if you don't have an acdc tig welder and milling machine.

I guess another possibility is to make steel dropouts which extend up the tubular swingarm frames for a bit to give it a bit more strength, but you'll need to clamp them on somehow. Might end up looking pretty shit. Overall it's really not a good frame design to start with for an ebike conversion. Certainly not insurmountable, just harder than most.

 

[izeman]

machines are not a problem. i have all equipment for welding aluminium and steels, as well as a cnc lathe and a mill.
i guess welding a new all steel triangle would be easier. i don't like it to look sh*tty

 

[MadRhino]

Open the alu tubing with a grinder and leave as much as possible of the original dropout. Make steel dopouts that are inserted long enough into the actual tubing of the bike, to make a strong connection. Use epoxy in the insertion, both to make the connection stronger and to limit direct contact between alu and steel. Bolt the new steel dropout to the remaining part of the original alu dropout.

 

[neptronix]

You could always get another frame.

Some frames are better for installing a torque plate than others ( these are pics of torque plates i made for a Mid 2000's Trek 4500..

 

[Drunkskunk]

Make a steel triangle. There just isn't enough material on those dropouts to attach anything to them. Any hybrid solution of making a steel dropout that clamped or bolted to the end and was as strong as the original would probably be as almost heavy and as labor intensive as just making a new steel triangle.

 

[botz244]

start with a frame with removable dropout like my Ti Muk

 

[izeman]

@botz244: thanks for your reply - i know what to do with other frames, but i WANT to use the frame i have
i know this is difficult, and me be impossible to do, but that's the challenge. converting a frame with removable dropouts i straight forward, and i've done that before.
i think i will go drunkskunk's route and make a new triangle. shouldn't be that hard.