[T McCall]

May have the rotor you need for gsxr wheel, what size?

[Wild-Bill]

Ummm... I've got a 5.5" GSXR rear rim. I think it's a 91 but Ron Ayers says the same rotor was used 88-92. It's got a 5-bolt pattern spaced about 67mm apart. (center to center) The Metalgear look-up says the rotor should be 240mm OD, 0 offset and (going from memory here) 5.5mm thick.

[Bart]

I would tend to think that this would cause the speedo to read low, unless yours already has the notorious sportbike problem of reading 10+% high.

[Wild-Bill]

1. the speedo reads off the front wheel. We're talking about the back wheel right now. Gotta keep up!
2. The speedo error is induced by a difference in the circumference of the front wheel from OEM design. Any tire other than the originals will have some speedo error. Under or over-inflated original tires will have some speedo error. It's not a big deal. That's why cops will generally give you some slack as long as you're pretty close to the speed limit.
3. Stock tire on an 1100 Kat is 120/80-16. That should make the sidewall height 96mm high. Add that (twice) to the 16" (406mm) rim and you've got the tread at a 598mm diameter. (In truth, that's the diameter of the sidewall. There's too many variables that affect the curve of the tread-and its' rise above the sidewall height-so I'm really just ballparking here.) OK, so let's say you go with a 120/70-17 tire on a Pre-750 rim. 84mm sidewall, 432mm rim gives a 600mm diameter. That's a .3% difference in diameter which, since circumference is pi x diameter translates to a .3% difference in circumference, also and therefore the same .3% difference in speedo readings. As I mentioned, the curve of the tread varies. In general, the wider the tire the flatter the curve. A 120/70 tire will crown out at about the same height from the sidewall as a 110/80. So if I'm reading 100mph on my speedo with 17" rims I may actually be doing 100.3mph. Bummer...
4. It might be an interesting experiment to take a GPS speed reading before and again after doing a wheel swap.

[T McCall]

Ummm... I've got a 5.5" GSXR rear rim. I think it's a 91 but Ron Ayers says the same rotor was used 88-92. It's got a 5-bolt pattern spaced about 67mm apart. (center to center) The Metalgear look-up says the rotor should be 240mm OD, 0 offset and (going from memory here) 5.5mm thick.

No not have that rotor, have a couple of the smaller ones.
Try bikes2nv.Should have what you need.

[Wild-Bill]

...Try bikes2nv.Should have what you need.

Try what at bikes2nv? Judging from their website they sell chrome wheels and seat inserts. Nothing at all about anything like brake rotors. I hate websites that throw a bunch of flashy graphics at you instead of information!

[T McCall]

Have bought rotors and wheels there before, seems to be good bunch of guys.Yes , their specialty is chrome exchange now.
You have to actually ask them if they have what you need, like the good old days.
I was just trying to help you out.

[Wild-Bill]

Hey, not picking on you. I appreciate the input. If you want to talk real good-ol-days then let's talk walking into a shop or parts yard to talk to folks face-to-face. As soon as I get back in country there's a couple parts yards in Jersey I need to check out. Found them on Flea Bay and turns out they're not far from McGuire.

[T McCall]

Most certainly agree.Too easy to hind behind a computer screen it seems.Swore i would never own one or a cell phone but knee deep in in now= $$$$