Fatter wheels for my GSX 750 SD

[Anonymous]

Hello,

Ive read most of the questions about putting fatter wheels on my Kat, so I apologise in advance if this has been dealt with and I missed it.

Now my understanding is that the back wheel (upto a 180) will go straight in with an offset front sproket. And almost any GSXR front end will bolt staight on.

I am still just beginning this project so I have a couple of preliminary questions (i'm sure there'll be more later :roll: ) and would be grateful of any assistance.
1). What will I attach the rear torque arm to as looks like it will be in the way?
2). I am on a bugdet so it would be good if I can do a little bit at a time, so.
a-does front and back wheel have to be done at the same time?
b-is there any reason why I cant get GSXR(or other) yokes that will make my stantions further apart to take the bigger front wheel, while still keeping my front end as stock as possible.
3). how will this effect my speedo and how do i get my speedo to tell me the right speed with a different size front wheel

Also if you could point me in the direction of any resources for this type of work I'd be greatful.
Thanking you all in advance.
Nathan

 

[Billy Ricks]

I'll give you some tips later this evening when I have more time. Real quick though, start with the front. You don't want to run a radial rear with a bias ply front. Radial front with a bias rear is okay.

 

[Anonymous]

Cool no problems I'm not in a huge hurry; still researching and collecting all the necessary parts.

Nathan

 

[Billy Ricks]

Okay, I'll try to steer you in the right direction here. Up front the easiest thing is to replace the entire front end. Unless you have the ability to machine brackets and caliper hangers and such then it's more cost effective to just get forks and all from the same year donor bike. The only thing you have to watch on the forks is that they use tapered head bearings. And don't use anything earlier than '89.

One problem you run into immediately trying to adapt a GSXR wheel to a GS front end is wheel bearing problems. Yours may be different, but my stock front wheel used smaller outer diameter bearings than the rear of my bike. The rear outer diameters are the same on the GS and the GSXR. So you just swap out bearings to be able to use your stock axle if the inner diameters are different. You can't do that up front. You would have to make some precision spacers with a slight amount of crush to them to use the GS bearings in a GSXR wheel.

Then you run into caliper alignment problems. GS calipers won't work with a GSXR wheel. The inside of the caliper will hit the spokes of the wheel. So you would have to adapt GSXR calipers using custom hangers. And it may not all fit within your fork. An 1150 triple might help if it is indeed wider. But for what you are going to pay for a triple you can damn near buy a complete Gixxer unit.

When you shop for a front end look for one as complete as possible. You can pick up axles cheap, but make sure the entire triple comes with it.

For guages I'm using GSXR units from about a '90 model. If you decide to do the same I can tell you how to hook the tach up to your stock wiring.

In the rear it's easier to stick to a 4.5" wheel from the '88 and '89 models. You'll have less clearance and sprocket alignment problems and a 160 is plenty of tire. I was able to get by grinding down an old sprocket to use as a spacer behind the countershaft sprocket. You could also just use multiple sprocket lock washers. It brought it close to straight but was a little off. I left it that way until I was ready to do a 520 conversion. I just did that and the fact that the outside edge of the rear sprocket is closer in and reversing the new countershaft sprocket put everything in alignment. Worked out great.

What parts to use in the rear depends on your axle size. On my '85 700 the GS axle is smaller diameter than the GSXR. Guys that have swapped wheels on older 1100s have found that their axle diameter is the same as the GSXR. So the first thing to do in the rear is get a wheel with bearings to check the axle size. Then you can start picking up what you need to make it work.

 

[Anonymous]

Thanks for the reply.

I've already committed to the 180, I've bought the wheels in an absolute bargain off ebay (and the girlfriend has her heart set on them ). Still waiting for the wheels to show up then I'll do some measurement

Was looking at USD forks was just thinking maybe I could get away with delaying the purchase with wider yokes, but if not will go the whole hog.

Have also found somewhere to get the offset sproket from and i imagine spacers are easy to come by, but what will happen to the taorque arm?

 

[Billy Ricks]

You'll probably end up having to move the torque arm to the bottom of the swingarm. You can put a bend in it to clear the wheel then weld a mounting tab to the bottom of the swingarm for the torque arm.

 

[QuaiChangKane]

There's a lot of info on suspension swaps at Old Skool Suzuki:

http://www.oldskoolsuzuki.info/

Lots of details on 7/11 swaps, frame bracing, etc. - especially for Kats and GS-EFE's.


I've actually seen torque arms on old Kats anchored directly to the frame during swingarm swaps....


Post some pictures of your progress!!


-Q!

 

[Anonymous]

Thought the torque arm would have to go there

QuaichangKane..... is.... that your's???

Ok will set up a website to document my victories and tragedies on the upcoming project, but till then here's a couple of pics of how she is now.
http://www.thegsresources.com/_forum/viewtopic.php?p=149323#149323

I know some people will condem me for 'ruining' such a fine example of a stock kat, but I want her to become everything she should of been.

 

[Billy Ricks]

Nathan,
Go for it, you won't be sorry. It will look better and handle like a dream.

 

[Anonymous]

My thoughts exactly....

The wheels have arrived and i Go and pick them up from the post office tomorrow!!!!

 

[Anonymous]

Web Page

Web Page

A couple of people said I should put up a web page of the project so here it is:
http://myweb.tiscali.co.uk/unclesatan/katana/Index.htm

 

[Hoomgar]

Awesome! I really enjoy following bike projects. Keep updating it