M
makenzie71
Guest
(1981 GS750E, by the way)
...I do a YZF600 rear. Wheel matches and it's 5X17. I can finally run a 160 again...110/160 being my favorite combination, and something I think is perfect for the bike's wheelbase and power.
Anyway, I'm running Yamaha FZR600 forks, triples, brakes, wheel, etc up front...as I've discussed before, it's almost a straight bolt-on, with the only major thing needed is a 5mm shim under the lower bearing.
I have been running a 3.5X17 GS500 wheel in the back, but the 130 just isn't offering the traction and stability I want in a machine...it might be more because the tire is about as bald as can be, but I can't even change lanes without the bike getting fishy when it rolls across the lane divider paint. But, I digress...
The FZR has an 3.5X18 rear wheel. If you swap out the bearings for 20mm pieces instead of the 17mm ID it comes with you can run it in the 750, but you need the YZF600R caliper hanger, caliper, and axle spacers to make it work properly. You're still limited to, at most, a 150mm tire...and 18" wheels are getting scarce, which means that the good tires cost more.
I opted to do a YZF600R rear wheel instead. The bare minimum you need here are the wheel, YZF axle spacers, YZF caliper hanger, sprocket carrier, and cush. Clearance is TIGHT, though, and you WILL have to shave a lot of the caliper hanger off to get everything to fit. It's too tight for this swingarm, really.
So I widened mine by 1.25". It's a little wider than the stock YZF600R swingarm, but if I ever get to do the engine swap I want to do I'll end up needing a 6" rear wheel and more room.
What I did was cut the stock swingarm twice...first to separate the spars from the pivot, and second to split the spars. The first cut needs to be done by a professional. I have access to proper machines and measuring gadgets to get it done...but to keep the project simple YOU HAVE TO HAVE THAT FIRST CUT 100% TRUE! If your cut is even a few degrees off from parallel to the pivot, everything will get more complicated.
The second cut you can do with your eyes closed in the dark with a machete.
Have your machinist mark your center and mark where your limbs will be relocated to for the welder. In my case, everything got moved .75" off center. From here I tacked everything back together, then placed a few cuts along the parts of the spars that protruded so that it could be bent back in easily. With luck your gaps should be fairly small...unless you went WIDE...and you won't have much to reinforce. If you go any wider than I did you'll need to do a lot of reinforcing.
After I got it all tacked up I built a brace...very simple "U" with some flipped ends connected to the pivot by two legs. As some of you will undoubtedly be able to tell, that is EMT tubing I made the brace from. I feel that it's strong enough...however, this is my first jaunt at doing this and it took me six attempts to get the horseshoe right. Now I have a good jig and established measurements...I will be making another soon using iconel tubing. I may actually try my hand at doing the FULL swingarm.
Anyway...
Ignore the mess in the background.
My caliper hanger may bolt to the subframe, I think...it was an idea I had after I had it all together, but I really didn't design the subframe with it in mind and am unsure if it's up to the task.
Upper shock mounts will have to be extended by half an inch and the rear brake master will have to be relocated.
That's all I can think to say right now. I go to have that gap in the middle and the joints properly welded this weekend. Hopefully I'll have a carrier in this coming week and can install it next weekend.
...I do a YZF600 rear. Wheel matches and it's 5X17. I can finally run a 160 again...110/160 being my favorite combination, and something I think is perfect for the bike's wheelbase and power.
Anyway, I'm running Yamaha FZR600 forks, triples, brakes, wheel, etc up front...as I've discussed before, it's almost a straight bolt-on, with the only major thing needed is a 5mm shim under the lower bearing.
I have been running a 3.5X17 GS500 wheel in the back, but the 130 just isn't offering the traction and stability I want in a machine...it might be more because the tire is about as bald as can be, but I can't even change lanes without the bike getting fishy when it rolls across the lane divider paint. But, I digress...
The FZR has an 3.5X18 rear wheel. If you swap out the bearings for 20mm pieces instead of the 17mm ID it comes with you can run it in the 750, but you need the YZF600R caliper hanger, caliper, and axle spacers to make it work properly. You're still limited to, at most, a 150mm tire...and 18" wheels are getting scarce, which means that the good tires cost more.
I opted to do a YZF600R rear wheel instead. The bare minimum you need here are the wheel, YZF axle spacers, YZF caliper hanger, sprocket carrier, and cush. Clearance is TIGHT, though, and you WILL have to shave a lot of the caliper hanger off to get everything to fit. It's too tight for this swingarm, really.
So I widened mine by 1.25". It's a little wider than the stock YZF600R swingarm, but if I ever get to do the engine swap I want to do I'll end up needing a 6" rear wheel and more room.
What I did was cut the stock swingarm twice...first to separate the spars from the pivot, and second to split the spars. The first cut needs to be done by a professional. I have access to proper machines and measuring gadgets to get it done...but to keep the project simple YOU HAVE TO HAVE THAT FIRST CUT 100% TRUE! If your cut is even a few degrees off from parallel to the pivot, everything will get more complicated.
The second cut you can do with your eyes closed in the dark with a machete.
Have your machinist mark your center and mark where your limbs will be relocated to for the welder. In my case, everything got moved .75" off center. From here I tacked everything back together, then placed a few cuts along the parts of the spars that protruded so that it could be bent back in easily. With luck your gaps should be fairly small...unless you went WIDE...and you won't have much to reinforce. If you go any wider than I did you'll need to do a lot of reinforcing.
After I got it all tacked up I built a brace...very simple "U" with some flipped ends connected to the pivot by two legs. As some of you will undoubtedly be able to tell, that is EMT tubing I made the brace from. I feel that it's strong enough...however, this is my first jaunt at doing this and it took me six attempts to get the horseshoe right. Now I have a good jig and established measurements...I will be making another soon using iconel tubing. I may actually try my hand at doing the FULL swingarm.
Anyway...
Ignore the mess in the background.
My caliper hanger may bolt to the subframe, I think...it was an idea I had after I had it all together, but I really didn't design the subframe with it in mind and am unsure if it's up to the task.
Upper shock mounts will have to be extended by half an inch and the rear brake master will have to be relocated.
That's all I can think to say right now. I go to have that gap in the middle and the joints properly welded this weekend. Hopefully I'll have a carrier in this coming week and can install it next weekend.
