TOPIC:

Were do you strenten a frame on a 77 650. I've looked around a little and sofar only found one place. It is were the two down tubes are on the back of the engine. is this the only place?
I herd that the chissis flexes at high speeds I wont to keep this at a minimum.

I would look at a gusset welded at headtube, a cross piece between front downtubes and really thick engine mount plates. The bikes are old (tech wise) and frame flex on round tube frames is an issue, especially with high HP motors. Don't recall any major issues with 650 flexing too too bad. A Z1 style steering dampener should suffice. Swingarms are the same issue being simple round tube. Ensure your swingarm pivot busshing are good, same with steering head bearings.

Snakebyte wrote:

Were do you strenten a frame on a 77 650. I've looked around a little and sofar only found one place. It is were the two down tubes are on the back of the engine. is this the only place?
I herd that the chissis flexes at high speeds I wont to keep this at a minimum.

You could gusset pretty much anywhere on the frame that you wanted if you feet like it.

I'm gonna make a gusset kit for my bike for this same reason. It will include a few different gussets that will need to be welded in. You just kinda have to look at the bikes frame and imagine if, under load, the upper mainbar flexes what else it will move too?

Adding the upper shock mount helps for the rear a lot. If couldn't hurt to throw one across the front. 2 between the upper tubes and the main drop bar (angled makes more sense to me, as it would give you more rigidity... I'll explain this later sometime), 2 on the back corners from the top bars to the back set bars, and then extra plates to go with a bunch of these.

I was looking through the archives and found this for the Z1, it should give you some ideas. img.photobucket.com/albums/v12/wiredgeorge/frame_drawing.jpg

Wow thats great info, thanks felas:)

You can buy that whole gusset kit- wierd part to me- it is chrome moly- not exactly easy to weld to the old metal Z1 frame.