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