Hi, I recently bought a Montesa 200 frame for a project and now that i look at it closely i am not sure if one of the downtubes is bent or it is meant to have a kink in it to allow exhaust routing or similar, its the right hand tube,  Could any with more knowledge offer some advice, cheers Ian

That’s bent.  The exhaust exits centrally so kink shouldn’t be there. 

Definitely bent.

Put a trolley jack in between the two downtubes, heat up the bent one and it will straighten quite easily. To check if the frame is out of line set on a stand and use a spirit level to get the swinging arm arm spindle level, then check that the forks are vertical. My gut feel is that it will be ok.

Thanks for the replies, as im going to fit a Ducati 160 motor i will just cut off above the bent and weld in new tubes to suit engine, many thanks

 

Hi, I just saw this. Did you get any further with this project? I too have most of an extra Ducati 160 and thought of building a trials bike with it but the sump would dictate mounting the engine quite high. I'm curious to see what you've come up with.

Cheers