Need some advice on extending the existing hole in my frame so that I can mount and recess the handle for an adjustable backrest. I bought backrest second hand and it didn't have the handle mount. There is an oval hole already in the frame, its just about 1/2" too small to fit handle. IMO this is the best way to mount handle- recessed and out of the way. Not sure how to cut/shave the opening bigger though. See red line in pic.. Any ideas appreciated

 

I can't give you any advice, but I damm sure wouldn't cut on my frame...but that's me...

 

I wouldn't be considering it if there weren't already the almost exact right size oval opening that just needs to be opened a half inch or so. Makes more sense to me than the exposed bracket mount these typically affix to..

 

I would use a die grinder and a burr bit.

 

Good luck with the burr bit...I bought a burr bit set at Harbor Freight (maybe that's the problem) and tried to use one to enlarge the wire exit hole on my new bars. The burrs were gone from the bit within 30 seconds....

 

Cut a bunch of straight cuts up ward towards the red oval line you have drawn then start breaking the tabs of, then finish with a die grinder...spray a little rustoleum and your good...that little bit won't hurt the integrety of the frame.

 

A die grinder is definitely the way to go. You could use a dremel (and it would work) but would take a lot longer.

 

Is the handle mount available for purchase separately?

 

If not, maybe fab a bracket out of some aluminum or thin steel?

Just hate the thought of cutting into the frame.

 

If you look in that hole, on the right side runs one of the frame tubes. That may block the handle from fitting in there correctly, but I have not seen one of those handles so I don't know that for sure. Regardless, do not cut into that frame tube as that could very much weaken the frame in that area. I don't know if cutting the sheet metal will harm anything, but that area is a potential place to burn your hand with the hot cylinder and primary right there. I would look somewhere else to put that handle.