Twisted headstock

Previously wrote:

As You may have seen in my 750 strip thread, my headstock is twisted out of the vertical axis with the centre line of the headstock being about 7.5mm to the left of the frame centreline at front iso bolt level. The frame is so flimsy being made of 1" dia mild steel tube, I would think that appling a bending force to bring it back into line would be almost impossible without causing some serious distortion to the rest of the frame. The strongest part of the frame is probably the welded joint beween headstock and spine and the other three tubes that are joined to the headstock. Anybody got any thoughts on straightening this twist?

Dave E

Give Martin Russell at Rustler Racing a ring.He worked at BSA and is a chassis specialist, tel 0121 784 8266. If it's fixable, then Martin can fix it.

sam

Previously wrote:

As You may have seen in my 750 strip thread, my headstock is twisted out of the vertical axis with the centre line of the headstock being about 7.5mm to the left of the frame centreline at front iso bolt level. The frame is so flimsy being made of 1" dia mild steel tube, I would think that appling a bending force to bring it back into line would be almost impossible without causing some serious distortion to the rest of the frame. The strongest part of the frame is probably the welded joint beween headstock and spine and the other three tubes that are joined to the headstock. Anybody got any thoughts on straightening this twist?

Dave E

How did you establish this Dave?

Previously wrote:

Simon, I set the rear Iso bolt and top of the seat loop (close to the top damper mounts) horizontal left to right. Set a steel straight edge down the centre of the frame ie centre between rear iso lugs and also centre of front iso lugs. fit bearings and 25mm steel rod in headstock. note the fact that the edge of the straight edge does not line up with the centre of the rod. finally compare with another frame.

Thanks Sam I'll give him a call

You don't state what you used as vertical and horizontal datums to check your measurements against in two planes.

You will find this article interesting on the worlds straightest Commando:

http://www.vintagenet.us/phantom/wsc.html

Skip Brolund

Wow. Skip - that's serious work being done there. Now I realise why I sold my Commando and kept my Dominator. Though someone is bound to point out all the faults in a featherbed frame. Gordon.

Thats good news David, at least you haven't spent any extra money. I also prefer paint to powder coat on frames, I've seen instances where water gets in behind a crack in the the powder and corrodes frame tubes.

sam