What kind of radials do you like?

[Cassius086]

swapping over to gsxr or katana rims, I do believe, are required. Maybe some of the other, more wisened fellows here know otherwise

EDIT: Meant to include that gsxr/katana forks are neccessary, too. duh....

[80GS1000]

What kind of mods do you have to perform to run Radials on the older GSes?

I'm part way through the radial conversion on my GS1000.

In order to run radials on a GS1000, you need to do some front and rear end mods.

On the rear:

Swap out the rim, swingarm, rear brake assembly, and do a 530 chain conversion.

I'm using a 2003 Katana 600 4.5x17" rim on which I can mount a 150 or 160 radial tire.

The GS1000 swingarm appears to be too narrow to accomodate the wider tire and rim, so a GS1100E swingarm will be used.

The rear brake is being changed to a Katana 600 brake to accommodate the smaller rear brake rotor so a bracket needs to be welded onto the underside of the swingarm to hold the brake torque arm.

You also need to convert to a 530 chain so that the chain doesn't rub against the tire and frame, and because the Katana rear sprocket is set up for a 530 chain. An offset 530 front sprocket is required for the front as the Katana rear hub and sprocket sticks out further than the stock GS rear hub and sprocket, and to prevent the chain from rubbing. The Katana rear sprocket is 47 tooth, so the new 530 offset front sprocket will be 17 tooth to keep the gearing ratio close to stock at 2.8.

On the front:

Because you shouldn't mix radials and bias ply tires on the same bike for safety reasons, you also need to swap out your front end to one that is designed for radials. By doing this, you also get far better front brakes and adjustable suspension.

A common swap is for the '90-95(please correct these years if incorrect) GSXR 1100 front end. The steering head bearings on this bike are identical to the GS1000 bearings, so it's a straight swap, no fuss or muss.

Another option is to use a more modern GSXR front end. I'm in the process of installing a 2004 GSXR 1000 front end on my bike right now. The tricky part about this swap is that the bearings are different - the GS and Gixxer have the same size steering stem bearings on the bottom (30x55x17), but the top bearings are different, so you have to figure out a way to get the Gixxer steering stem to mate with the GS steering head. The easiest way is to find a bearing that has the same inner diameter of the new steering stem, and the outer race diameter of the steering head on the bike, with the same height as the stock bearing. Problem is that nobody, and I mean NOOOOBODY makes a 30x47x15 tapered bearing. After several weeks of research, I found a guy that custom makes bearings for fork swaps so we're set.

You'll also need to figure out the speedometer situation as your stock speedo set up for a 19" wheel won't work on the new 17" wheel. Bicycle speedometers or the rather nice aftermarket gauges from Electrosport are a couple of options.

Here's a pic of a trick looking GS1000 with the front end from a 2003 Gixxer 1000. The guy reports that his bike handles much better than stock with excellent braking and no ground clearance issues.

[devildog0]

Thanks for all the info.