early 1900's clone

[cyclone]

Just took a recip saw to my mountain bike frame. Going to sleeve the top tube, and bolt dual small tubes from the seat tower & chainstay area to what remains of the down tube. To provide room to mount a 3.5 hp edger motor.Next I will figure out how to transfer power to the rear wheel. I was told the bolts would be better than welding due to vibration.

 

[deacon]

I haven't tried welding on the frame yet but I will be trying it this week. I do know if you bolt it on check your bolts and nuts often,,,

 

[cyclone]

Going to use hardened bolts and loctite. My welding skills are rusty, and I don't want to remove the temper from the frame. Would brazing be sturdy enough to join frame parts? And yes, I plan to check the bolts before every ride.

 

[deacon]

Good with that intention you might remember it once in a while lol. I had an engine fall off last week.

 

[rgvkid]

Brazing is not a good idea for a frame. Im pretty sure most good steel and aluminum frames are tig welded, which looks like really small beads or dimes layed in a row. Cheaper steel bikes will be Mig welded, which has a bigger bead and a good weld should look like nickles layed next to each other. A cheap bead will look like just like one long bead with no circles in it and may be in consistent in shape. Most frames are really thin so if you try welding you have to make sure your not to hot or it will blow through the material and maybe weaken it.

 

[deacon]

I'll keep all that in mind but all i want to do is tack onto the two small arms of the wishbone behind the seat to keep my mount from moving around. A bolt will be holding the mount onto the frame but they tend to let the engine move a little in a twisting action.

A couple of small beads and that will prevent the twist. It should also take some stress off the scissor hinge as well.