Friends, I managed to get my new motorcycle lift, tools, and such to start working on the bike. I was able to get the carbs balanced enough to take the bike out for her maiden voyage (to get inspected and registered). The only issue I had was the front break has noticeable pulsing and some bar shake when you apply the lever. This happens at any speed but especially when downshifting and slowing to a stop. With 36,000 miles on the bike I didnt think the rotors were warped but I checked anyway. After inspecting them carefully with a high-quality precision straight edge I can find absolutely zero warping. The front break pads look like they are almost new with plenty of pad left. Front rim spins with a slight touch of the pads....exactly as I would expect.
Any thoughts on what to diagnose next? Anyone have a similar problem? I'm thinking maybe the wheel balancers are not properly applied as the tires are brand new and maybe they didnt balance them appropriately...but then again that would typically show up in constant riding conditions...no?
Your thoughts and advice please,
Matthew
1982 R100RT
IMHO you'll need a dial indicator to detect warped rotors, which your issue certainly sounds like. Tire balance is more of an "at speed" issue, with or without brakes applied. You don't need "high mileage" to encounter a warped rotor because that has more to do with the "normalization" of the rotor metal before the disk assembly is even made.
The only suggestion I can offer is to change the fork oil. Otherwise, borrow a dial indicator and indicator mount.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Thank you sir, I plan to replace the fork oil anyway along with ALL the other fluids, plugs, air filter, etc. Then take the bike out and ride it for a few months to shake it out.
Cheers,
M
1982 R100RT
Scott, thank you for the reply. The bike is "new" to me as a Christmas present from my wife. She saw me admiring it on-line and got it as a surprise. Not the first time she's bought me a BMW bike. At any rate, the bike is a one-owner all original from Maine with 36,000 miles. She got it from Max BMW where it sat for a bit because they had it priced to high. Unfortunately, it seems the original owner who took very good care of her passed and I dont have the bike's records. Ugh.
I plan to try new pads, bleed the breaks, replace fork oil before attacking the rotors.
Cheers,
M
1982 R100RT
By all means try Scot's suggestions first. If for no other reason than that brake rotors, even third party, are NOT cheap !
If it does come to rotor replacement I can tell you that the floating versions from EBC are highly desirable over the stock BMW units, and probably a good bit cheaper.
One final suggestion. The tire air pressures suggested in your manual are no good for tires made within the last 15 years. I've found that with modern name brand tires something closer to 35psi front/ 33psi rear works much better.
Hope this helps.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
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