2 replies [Last post]
Slash2's picture
VBMWMO #9015
Joined: 10/17/2015
Posts: 264

After getting fresh balanced rubber on my 88 R100RS I immediately noticed a very disconcerting wobble in the front end around 40MPH. When decelerating or taking one hand off the bars it was downright scary. I contemplated the possibilities and decided to check the steering head bearings for proper adjustment. While I could feel no discernible play while yanking back and forth on the forks while on the center stand, I found that the adjustment was off by about 1/6th turn. Once back out on the road the problem was completely gone. Just a heads up for anyone experiencing a similar issue.

Ride Safe.


64' R60/2 - 66' R27 - 51' R67 - 68' R69S
88' R100RS - 06' K12R

schrader7032's picture
VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6540
Another thumb-in-the-air

Another thumb-in-the-air check is to see how the forks act when they are nudged from center to one side or the other. With the RS, it's a little difficult if the rubber boots are installed. But the idea is that the forks some gradually move towards full stop once they are persuaded to move. If the forks clang off the stops, then the bearings are too loose. If the forks just stay where you put them, they don't want to move at all, then the bearings are too tight.


Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

RickR90s's picture
Farmington Hills, MI
Joined: 11/28/2016
Posts: 63
Slash 2, Glad you got it

Slash 2, Glad you got it figured out.

Years back I had the issue with my R90s and a buddy of mine from Australia suggested to set the bearing preload with the bike fully weighted (off the centerstand). It seems to work out fine.

I had a '83 RS in my shop last year with the same complaint. And this bike would go into a violent tank slapper at 40mph.

The rear shocks were extremely worn so I replaced with IKON's. It took a few attempts to get the steering bearings set, but it all worked out with the method I described.



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