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95 K75S ABS - Confirmation of Tire Size

drneo66

Active member
The date codes on my tires are so old that Prince was still singing about 1999... so it's time for some new skins.

I have been searching on several forums but have yet to find a definitive answer about my K75S as it seems the "S" model is often just a bit different. I have seen where people talk about their K75s (as in they own several), but before I go and spend several hundred dollars, I wanted to ask you friendly folks.

I've had very good luck with a Metzeler Lasertech front tire and an 880 rear. On my last bike, a Honda Gl500 Silverwing, I had a pair last 18,000mi before cords were showing. I mostly ride solo for longer distances at reasonable speeds, so I want something that will last a long time.

It seems the original sizes for my 3 spoke rims are:
Front - 100/90 - 18
Back - 130/90 - 17

I'm looking at installing:
Front - 100/90 - 18
Back - 140/80 - 17 (since Metz. doesn't make an 880 in the correct size)

Both will be bias ply since that's what the bike was designed for. Am I on the right track?

~Thom
 
One of the K100RS's (about 1988 I think) came with 110/80-18 front and a 140/80-17 rear. I have used a 140/80-17 on the rear of my 86 K100RS and there was a spacer (BMW part) that went between the wheel and the hub to give a bit more space to the monolever. It can get pretty close for clearance depending on the tire (not all 140's are the same) and my experience was that after riding a few hundred miles the tire widened out a bit and got very close to the monolever. It did work and I used the tire for it's full life but I found that there was no performance advantage that I could see so I went back to the 130.
 
I have run at least a half dozen 880s in size 140/80-17 instead of 130/90-17 with no noticed ill effects whatsoever. This is on a K75S, K75 standard, and K75RTP. The K1100LT bikes had an identical rear wheel to the K75S and came with the 140/80-17 size stock.

For reference: The drum brake K75C and K75T bikes had an 18 inch rear wheel
All disk brake K75 standard, K75/3, K75RT and K75S bikes had a 17 inch rear wheel.
 
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