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R75/6 Commute

175781

Bill Lumberg
After only short weekend rides, I finally got around to swapping the RT for the R75 for a days commute. Every imperfection in the pavement resulted in notable tracking of the front tire, which made for a very intense 76-85mph commute. Missed the comfort and jet-like feel of the R1150RT, but the old school R75 still turns heads.
 
What was you steering damper set to? With the bad roads around here, my front end will wander unless set to "2", especially on the rain grooves.
 
R75/6

Couple of things to consider. Are the steering head bearings in good shape, greased and adjusted correctly? What brand tire are you using and how old is it?
Just saying.
 
Also, those vintage style tires popular for older bikes, like the type with multiple constant grooves around the tire parallel to the path of travel, are MUCH more reactive to anything like a groove in the pavement. Modern tire styles with almost NO circumferential grooves do a LOT to reduce that "hunting/tracking" effect of the old style tires.

Note that none of the current tire styles feature constant, unbroken, circumferential grooving. Many in fact have solid rubber down the center, with angled grooves with large solid sections between the angled grooves. Fewer grooves, larger solid block sections also mean less tire squirm reaction.
 
I have a fairing, which I believe was not tuned correctly. I think this contributed greatly to the death-wobble that seemed just below the surface. Never been that bad. Next time I do a bombing run on the R75 and leave the fighter jet at the house, I'm going to do it sans fairing and see how that feels. I'll keep the other suggestions in mind too. Particularly about the steering damper. I don't even know how that works or what a "normal" setting is.
 
R75/6

I have a fairing, which I believe was not tuned correctly. I think this contributed greatly to the death-wobble that seemed just below the surface. Never been that bad. Next time I do a bombing run on the R75 and leave the fighter jet at the house, I'm going to do it sans fairing and see how that feels. I'll keep the other suggestions in mind too. Particularly about the steering damper. I don't even know how that works or what a "normal" setting is.

The steering dampner on your /6 has a knob at the top with three positions. 0 is off with positions 2 and 3 pushing the end of the shock farther from the pivot point of the steering stem.
It really isn't all that effective IMHO.
The biggest concern with the steering head is that the bearings are lubed, not nothced, and adjusted correctly! If not, then the dampner won't do anything, or even mask a bearing problem.:banghead
 
FWIW, I took the steering damper off my /6's and I don't have a problem cruising at 80mph all day long. I have Metzeler ME tires and (I think) a properly adjusted steering bearing setup.. and no fairing.
 
I have a fairing, which I believe was not tuned correctly.

huh?

whatever it is you mean by that... it ain't the fairing. its either the front tire (see Andy's post), or possibly steering head bearings. my vote is tire, especially if you have something like the old RB2 from Conti. could be suspension too- please tell us you are not still on the 35+ yo original shocks....
 
Let's not forget the swingarm bearings, just as important as the steering head bearings in regards to high speed stability. I would go in this order to resolution:
1. Tire tread style: old style/vintage tires like the Conti RB2 will "hunt" on every crack/feature parallel to the path of travel.
2. Old/aged tires, simply not a good/safe idea, upgrade to modern rubber.
3. Chassis alignment, make sure nothing is tweaked/busted/broken welds.
4. Steering head bearings, setting, proper grease, preload.
5. Swingarm bearings, same as steering head bearings.
6. Steering head damper, unless the previous five items are addressed and right, all a steering head damper really does is mask the real issues.

The older chassis do flex a lot more than the rigid chassis we have come to love/expect since the early 90s. I recall a frightening high speed wobble on my 76 R100RS at 110mph, oscillating left to right about five feet wide. I very slowly backed off the throttle until it stabilized again at 105 and then backed down to the speed limit. Change of shorts at the next stop. That year I bought my current 94 R1100RS.
 
Au contraire - the damper adjustment at postition 2 is quite effective on gravel, slippery surfaces and rain grooves - just sayin'...
 
Yes, it was the fairing, which wasn't tuned properly. The fairing I have on this bike is removeable, fork/handlebar mounted, and was thrown on at 5am just before departure. When the fairing is off, the mounts stay on, but when they're not bearing the fairing, they can shift position and alignment. This resulted in a fairing that wasn't pointing perfectly straight forward. This caused unequal pressure and created an effect far worse than that you'd expect from this sort of fairing. The bike runs fine without the fairing, and it runs fairly well with the fairing back in adjustment.
huh?

whatever it is you mean by that... it ain't the fairing. its either the front tire (see Andy's post), or possibly steering head bearings. my vote is tire, especially if you have something like the old RB2 from Conti. could be suspension too- please tell us you are not still on the 35+ yo original shocks....
 
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