Second try gsxr conversion

[smarzinski]

Im trying to figure out how to mount the rear caliper on my bike. Its an 83 GS750E and the wheels are 89 GSXR750. I switched the bearings so I could use my stock axle but now I dont know how to mount the rear caliper. Just wondering what everyone else has done. I have a katana 600 mount that came with the caliper im using, I also have the stock mount and the gsxr750 mount that goes with the rims. I am using the katana caliper so I can keep it located where the stock one was. Thanks posplayer for informing me about the jack! This is all new to me...

 

[posplayr]

Im trying to figure out how to mount the rear caliper on my bike. Its an 83 GS750E and the wheels are 89 GSXR750. I switched the bearings so I could use my stock axle but now I dont know how to mount the rear caliper. Just wondering what everyone else has done. I have a katana 600 mount that came with the caliper im using, I also have the stock mount and the gsxr750 mount that goes with the rims. I am using the katana caliper so I can keep it located where the stock one was. Thanks posplayer for informing me about the jack! This is all new to me...

Part of the brake arm (where the axle goes) will knock out. Maybe a machine shop can make you a new one that is a smaller ID. You only have 3mm to deal with so I'm not sure is a 1.5mm bushing is really thick enough if you went that route.

 

[smarzinski]

Yea I just talked to my buddy (whos a machinist) he said he could make a bushing that fit inside the gsxr mount. Im hoping that does the trick. The sprocket and hub I have are off of a suzui bandit also. I havent even looked to see if the sprockets lined up. I guess I will cross that road when I get to it. Thanks for your help. I appreciate it.

 

[posplayr]

Yea I just talked to my buddy (whos a machinist) he said he could make a bushing that fit inside the gsxr mount. Im hoping that does the trick. The sprocket and hub I have are off of a suzui bandit also. I havent even looked to see if the sprockets lined up. I guess I will cross that road when I get to it. Thanks for your help. I appreciate it.

Normally people use a GS1100E sprocket carrier with a 17x5.5" wheel as it has less offset. The GSXR sprocket carriers are more outboard for chain clearance but the GS that puts the chain too far from the tire and into the frame. What wheel you have and tire you plan to run?

Salty Monk just did a 17x5.5" with 170/60-17

 

[smarzinski]

I have the 4.5" rim and am planning on running a 160 rear

 

[salty_monk]

That combo will give you loads of room relatively speaking... Dan

 

[smarzinski]

I have a sprocket carrier and sprocket off of a 91 katana 600. it fits the rim but now im wondering if it will line up. I dont know how to tell other then by just looking at it. Maybe I should pick up the 1100e carrier?

 

[smarzinski]

Did any of you guys have to spread your swingarm arms? Im thinking of putting a bottle jack in there and spreading them a lil.

 

[salty_monk]

I used a longer axle & spread mine more than an inch.

I also converted it to take a 20mm axle using the GS1150 swingarm as a template (Swingarm ends are the same so I just removed the same amount of material).

I did mine with a scissor jack but make sure it's fitted to the bike or there is something V strong between the front pivots if you do it or you will squash the front in (swingarm is basically an X shape if you look at it so widening the back narrows the front if you do it off the bike).

 

[smarzinski]

Alright, got the rear wheel in. Used the stock rear axle and different bearings to fit the gsxr wheel. Next thing I need to figure out is how to tell how far I need to move my front sprocket to match the rear. How do I measure that? From what I read, I can get spacers from Z1 enterprises?

 

[smarzinski]

I know the caliper is off. I am waiting on tires to see if it will clear with the angle I have the bar bent at.

 

[smarzinski]

 

[salty_monk]

With a straight edge, laser or string off of the back sprocket. You need to check the wheel alignment against the front wheel first though to make sure it's straight in the swingarm.

 

[smarzinski]

Got it, thanks Dan.

 

[salty_monk]

Looking at that you might find an offset sprocket is what you need... Do a search there is a good source for them posted on here somewhere. Think 80GS1000 posted it last.

I used a 6mm Z1 spacer with a 520/530 conversion sprocket but I'm also using a 520 sprocket set & chain to buy a little extra clearance.

Is your cush drive in that wheel a 5 rubber or a 6 rubber? That sprocket holder looks really tall! You don't look like you have enough room to clear the frame. You may find you need to use the GS sprocket drive if it's 6 rubber or one from a GS500 (the newer model twin) if it's a 5 rubber. These should move the sprocket in closer to the hub.

The "net" movement on my front sprocket is 8mm further out. (i.e. there is 6mm spacer & a 2mm lump on the sprocket). 3/8" offset sprocket is one of the "standard" sizes so you should be able to go with that (although they are about $70 - just to warn you).

Dan

 

[posplayr]

With a straight edge, laser or string off of the back sprocket. You need to check the wheel alignment against the front wheel first though to make sure it's straight in the swingarm.

I think the proper order is:

Step #1 Center the rear wheel in the frame
(taking into acount swing arm offset measure spacing of wheel in swing arm forks) (approx 1-2mm)

Step #2 Align front wheel with rear (e.g. string method) (approx 2-3mm)

Step #3 Check chain alignment and adjust as required. (1-2mm)

 

[Billy Ricks]

Since you're using the smaller axle and bearings what did you do about the bearing support inside the hub of the wheel? It needs to be there and the same length as the GSXR part to keep the bearings centered within themselves. I used my stock part which was too short but I added a length of tubular steel the right inner diameter to make up the difference. I didn't bother welding the two together, just used some epoxy putty to hold things together for assembly.

 

[Guest]

I just went out and did some measuring.... I have an 1100 six paddle/rubber wheel, my sons 600 kat has the same five/five sprocket holder that josh is trying to use with his 750 wheel. From outer edge of the carrier to outer edge of the inside of the sprocket (same width of sprocket on both) is the same 1 3/4 in. I'm using the stock 750es sprocket side spacer, my swingarm is only 1/4 of an inch wider than my spare unmodified bare swingarm. I have a regular countershaft (but 16 tooth) sprocket with an 1/8th inch spacer on the inside of it. I use a stock gs axle with no washer inside the nut, also using a shorter flange style castle nut on the axle, i don't know what bike it's from i wish i did it was something i had laying around in my stash. Looking at the picture it sure looks like that spocket is really far out from the wheel. How wide is that wheel at the hub, and how far from the outer edge of the rim? i wonder if it's different from my 1100 wheel?

 

[Guest]

Since you're using the smaller axle and bearings what did you do about the bearing support inside the hub of the wheel? It needs to be there and the same length as the GSXR part to keep the bearings centered within themselves. I used my stock part which was too short but I added a length of tubular steel the right inner diameter to make up the difference. I didn't bother welding the two together, just used some epoxy putty to hold things together for assembly.

Ive got one from an early 600 kat in mine. Same one i used with the 600 wheel i got from you.

 

[gearhead13]

I have the 4.5" rim and am planning on running a 160 rear

WOW looks like a lot of headache, I am getting a 3.5" 1150 wheel to run a 150 tire and it basically just bolts right in