Thanks for the advise ill do the minimum
This is a discussion on Yamaha xj900p 2008 within the Project Builds forums, part of the Caferacer.net Forums category; Do whatever you feel like. #1 it doesnt sound like u are interested in the warnings from the group #2 it's the subframe, as long ...
Do whatever you feel like.
#1 it doesnt sound like u are interested in the warnings from the group
#2 it's the subframe, as long as you arent 300 pounds or your girlfriend/boyfriend isn't, anything reasonable as support other than a simple cantilevered loop should do fine. The subframe does add some structural support to the main frame, but if you are welding, i would throw some well placed frame bracing in there at the same time.
You see the issue here is by your questions you reveal your general lack of mechanical knowledge. No offense, but it's like a regular joe asking at a doctors conference if he should remove an appendix by an up and down incision or a sideways incision.
OK maybe I was a little premature with the whatever comment. Look where your monoshock mounts to.
You need to make sure that is as well braced as original or you WILL have issues.
Going out for a ride right now, but I will compare the pics when I get back...
Last edited by jcw; 05-05-2019 at 11:30 AM.
so i cut of the unwanted part and left the top bar to the length i require have to shorten it to include the hoop. after having space n a being able to see how the rear swing arm n suspension work i came up with 3 options again lol.
1. would be to just put a supporting bar extending the existing bottom bar to the middle of the seat option
2. would be to use bars but totally eliminating the existing bottom bar and creating a new one like the xj600 design and putting a bar across (blue bar) the top of the shock mount to give it that extra strength
3. would be the same as option 2 but instead of using round bars i would use 5mm thick plate to create the support. Sort of the the xj600 major lazer by wretch kings. of course my will have a bigger plate but similar concept. Making sort of a box with thick plate and using the bottom plate (blue plate) of the box to reinforce the top mount of the shock
Of course the side plate n bottom plate would extend to make the seat base
Last edited by kumailrashid; 05-05-2019 at 02:19 PM.
Ok, so ideally you should have cut the frame with the weight off the rear shock. Even cut and weld with the frame in some kind of frame jig.
This thread is a whole bunch of fail...
I suspect when you cut it the frame went boooooiiiiingggg and the upper shock mount moved. Thats just changed critical geometry points on the bike.
These are things you just should know before starting...
Last edited by jcw; 05-05-2019 at 05:06 PM.
Courage is knowing it might hurt, and doing it anyway.
Stupidity is the same...
...and that is why life is hard.
I'm out. Let us know when the "for sale" ad is posted of the unfinished project
I have not cut the supports for the shock I only edited the pic. I will finish it and won't be for sale. I'll let you guys know it goes
you need to support those two tubes you cut the tops off, as they provide the rear support to the top shock mount. that plate will need some structure under it at least. the way it was would have been the most effective strength vs weight vs packaging wise.