Chopping off rear of frame..?

Im wanting to cut off the upper rear portion of the frame about 1-2 inches behind the upper shock mount. Would a crossbar need to be welded in inbetween the shock mounts, or would the frame still be plenty rigid with the already existing factory crossbar that is really close to the shock mounts?

Im wanting to either run fenderless in the rear or make my own fender and have it swingarm mounted. And with the solo seat pan im making...the rear portion of the frame sticks out like a sore thumb.

I know Dutchz did about the same exact thing on his bike, so if you could chime in on any extra structure you added....i would appreciate it.

I didn't weld in a brace as of yet. I probably will later this year because I'm planning a strip down to gusset the rest of the frame.

So your not having any flex problems with just the factory brace? If not, thats good. I was kind of only wanting to fill in the void between where im cutting and the factory brace with a peice of 3/16" plate to keep it a lower profile for more room on my seat.

Im kinda wanting to do what you have done in the rear, but with a different tail light setup and different cowl. Im also thinking about making a flat top fender to mount to the swingarm, so i can get it as close as possible to the tire and not worry about anything if i do decide to keep the rear shocks inplace of struts.

If its strong enough to ride the way you have it though, it takes my mind of having to TIG in a crossbar....i can just MIG in a peice of plate and do it three times as fast than having to bend, notch, and TIG in a peice of tubing. Thanks for the info man...it appears that your about the only other person on this site thats done this. I could be wrong though.

Well no turning back now. The sawzall had a run in with the back of the bike, and the grinder got a little action on the seat brackets, seat lock, and helmet hook. I might get some pics up tomorrow, i still need to weld in some filler peices on the ends of the frame. I ended up cutting the rear portion off where it slid inside and welded to the larger diameter tubing on the frame.

I plan on getting a sealed battery and moving the electronics a little inboard. Im going to make my seat pan one peice with flat sidecovers that countour with the bend in the forward tube that the rear master cylinder mounts to.

I've also got another question. Would it hurt the rigidness of the bar the rear master cylinder is mounted to if i cut off the bars that come off the frame that the passenger footpegs mount too? Im only going to be running a straight header with a turn out, so i don't need a exhaust mount and i think it will clean up the bike a little without it. I would have to leave a little bit of the bar for the MC to mount too, but it sure would tidy some stuff up a bit.

heh it's a Z... I got flex problems EVERYWHERE :laugh:

So i take it that gusseting the frame is almost a necessity on these bikes? I've got about 12 sq. ft. of 3/16" plate so i might just go ahead and do that while i've got the welder out.

I've seen a couple of other bikes on here with the exhaust/foot peg bars cut off. So im guessing its nothing structural to loose. Now i just need to find a stretched swingarm

Torch wrote:

Would it hurt the rigidness of the bar the rear master cylinder is mounted to if i cut off the bars that come off the frame that the passenger footpegs mount too?

Nope, chop away.

dutchz wrote:

Torch wrote:

Would it hurt the rigidness of the bar the rear master cylinder is mounted to if i cut off the bars that come off the frame that the passenger footpegs mount too?

Nope, chop away.

Saaaweeeeeeettttt!!!! Well, i wasn't going to work on the bike tonight...but since i found something else i can chop off. Hell why not make a night of it.

Seems you have started something here Dutchz. I am still working on my chop and thinking constantly. I should scan and send you some of my planning. It should be quite different in its own way. Cheers bro...