Also, does the R90/6 seem harder to keep straight up when go very , very slow?

[topoutat76]

Sorry for the inane questions, but I'm just trying to get it going again. Perfect forum for asking experienced air head riders, especially R90 riders.

I've had a new Metzler 33 in the front and I believe a new 99 in the back. They stick a lot better than the former Conti's, of this I am absolutely sure.

But when following other bikes, when I'm going very slow, almost at a stop, it feels like tipping/falling over if I'm not exactly balanced straight up.
Ok, the other, newer bikes have big, fat wider tires, so I reason they shud feel more stable. But, how about the old R90 with it's narrower tires? Is this normal?

However, what a joy in the canyon - it is very easy to fliop side to side.

[pmdave]

Remember, it's countersteering, not fat tires, that hold a bike up. Yes, the newer BMWs handle better, but that's mostly because of clever front end geometry. On your airhead, if you want to go right, push the grips more toward the right. If the bike is falling over to the right and you want to go straight, push the grips toward the left. If the bike is falling over to the left, push both grips toward the right until it rebalances.

At slower speeds, the front wheel is rotating slowly, and the effect of countersteering is much slower. So, at slower speeds, it's necessary to use more dramatic handlebar input. Just turn the bars farther and more quickly (toward the direction you want to go).

It also helps at slower speeds to keep your boots on the pegs, and to put more weight on the pegs than on the saddle. By rising slightly off the saddle, you can more quickly lean the bike under you to make small balance corrections.

I'll risk being very commercial here, and suggest that you read the book "Proficient Motorcycling", which covers this in greater detail. Cheapest source: www.amazon.com

pmdave

[bprigge]

topoutat76,

There are a couple of other things that will make your R90 feel unstable at very slow speeds. One is worn or 'notchy' steering stem bearings. Put your
bike up an the centerstand and rotate the handle bars back and forth. If you
feel what feels like a detent when the bars are passing through the center
or 'straight ahead' position you have worn steering stem bearings and a source of funky very low speed handling.

Also, my R75/6 has a steering damper on it that is either on or off. I assume your R90 has the same damper. When I run with my damper in the 'on' position the bike steers weird when going very slow, just like you describe.
I run mine in the off position and have no stability issues at any speed.
The numbers on the damper control knob don't relate to the way the
damper works. My knob is numbered 0 through 3 but the only positions that
have any meaning are 0 and 1. 1 is on and 0 is off I think. In fact you can't
get the knob to go to positions 2 or 3 unless you pull the shaft and knob out of the steering stem and re-insert it rotated 180 degrees. Good luck with your R90, i've always wanted one of those. These days I would be happy to
have just the cylinders and pistons from an R90. :)
Bruce

[dlearl476]

>There are a couple of other things that will make your R90 feel unstable at very slow speeds. One is worn or 'notchy' steering stem bearings.

Another is simply out of adjustment SHBs. Check by putting the bike on the centerstand, stand in front and see if you can rock the front wheel back and forth. (fore and aft) If there is ANY play there, you should re-torque the bearings.

For that matter, if you're getting this bike back on the road you should probably do a little PM and take the bearings out, clean, re-grease, THEN re-torque them.

[amiles]

Your question opens up many possibilities. The prior responders gave some great possibilities. Perhaps the easiest test is to see if it is "You" or "the machine". Compare & contrast yours with a similar bike. You and the other bikes owner should be able to put your heads together to figure out that first question.

As far as the machine goes The head bearings are a great place to start, in addition to the notchy problem previously mentioned they can be too loose or too tight. IMHO the bearings being too tight would have more negative effect at low speed than if being too loose. Too tight head bearings make the bike feel as though you are fighting a "giant hand" at low speed.

Checking & lubing all other bearings: wheel & swingarm, Checking the attachment points of major structures: engine mounts, subframe connections, even the handlebar mountings.

Today it seems to me that many riders overinflate their tires, Several pounds over the original specification is pretty good for me, Maximum rating most likely will act a bit more sensitive and I don't think is good overall.

Andy '76 R90/6