R100GS swingarm touching tire. What's the correct clearance?

[tourists]

Recently picked up a 1989 R100GS in San Francisco. I've enjoyed almost every second of GS ownership so far, it's a major step up from my 71 R75/5.

History: the bike was low-sided by the PO. It was explained to me that the crash bars and luggage took the hit. When I test rode it that story checked out the bike rides beautifully, 65mph+no hands, no problem. I was hesitant to buy a salvage bike but... you know the story .

Anyway, I rode it back to Los Angeles and immediately noticed blue on the lip of the right rear tire. The swingarm was definitely touching the tire and now maybe you could fit a sheets of paper between the two. The bike has an Wilber shock and Avon Gripster 130/80-17.

Between talking to the PO and searching around I've come up with the following:

1. Send the wheel off to Woody's Wheel Works to add some clearance by adjusting the spokes and re-truing. This is the PO's advice. It feels like 2 wrongs to make the bike right to me.
2. Frame straightening Seems like it will cost at least 1k to even figure out if there's a problem? I was planning on visiting Dr John's in Anaheim if I go that route.
3. K bike spacer? Searching around I saw someone with a clearance issue talking about a spacer. Couple guys I talked to didn't think it would work.

I'd appreciate any thoughts or info on what the correct spacing should be.
Thanks!
Josh

 

[20774]

The 130/80-17 seems to be the right tire. Not all tires measure the same width, though.

Hmmm...what do they say, when you hear hoof beats, don't think zebras? It was in a crash...I'd want to be real sure that all aspects of the bike are correct, especially the frame. Doesn't make sense to start spacing things out, relacing, etc., until you knew you were at the proper starting point. If the frame is bent, there are bigger problems ahead.

 

[guenner]

Josh,

I have an Avon Distanzia 130/80-17 on the rear. I just put bricks on either side of he tire to measure the true overall width: 140mm.

I have a clearance of ca. 2mm between the tire and the closest part of the swing arm. I put some plastic pieces with different thickness in between to find that out.

I heard that the Heidenau K60 130/80-17 for example do touch the swing arm.

This may give you food for thoughts.

/Guenther

 

[jnclem]

Josh,

I have an Avon Distanzia 130/80-17 on the rear. I just put bricks on either side of he tire to measure the true overall width: 140mm.

I have a clearance of ca. 2mm between the tire and the closest part of the swing arm. I put some plastic pieces with different thickness in between to find that out.

I heard that the Heidenau K60 130/80-17 for example do touch the swing arm.

This may give you food for thoughts.

/Guenther

I have an '89 R100 GS here with K60 Scouts. I have >5mm clearance. This is my third set, and none of them have ever touched, or even come close.

 

[guenner]

ERRATA: K60 touched the shock and not the rim

jnclem,

I went back to read the email from my R100GS friend. In his case it rubbed the shock spring. I THINK he has an aftermarket shock.

So I have to correct that it touched the swing arm.

/Guenther

 

[NavyCWO]

Had the same problem. Avons widths vary apparently.
I was told via one of the forums to place a "K-bike" spacer
btwn the inside of the wheel hub and the drive hub and this
sets it off slightly and stops the rubbing.

 

[20774]

Is it this K-bike spacer, #2 that is 2mm in thickness:

http://www.realoem.com/bmw/showparts.do?model=0555&mospid=51717&btnr=36_0180&hg=36&fg=31

 

[tourists]

Perfect–just the info I was looking for.
My tires is also 140mm wide so something is off. I may try the 2mm spacer temporarily to get it to the guy. Thanks!

 

[NavyCWO]

Is it this K-bike spacer, #2 that is 2mm in thickness:

http://www.realoem.com/bmw/showparts.do?model=0555&mospid=51717&btnr=36_0180&hg=36&fg=31

I can't recall the part number but this looks like it. Mine is still on and works just fine!