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Let the R100 Deluge begin

timburn

New member
OK, I did some searches to try not to ask too many newbie questions that have been done to death. These bikes are so long lasting that the variety out there on the road is dizzying. New to me 1980 R100. Rear brake sucks. Adjusted tight as I dare. Thought I would buy new shoes and disassemble. Anything obvious I should check first. I should say that the bike came from a small independent shop that does not seem familiar with airheads. They assured me it was "fully serviced and did not need a thing". I beg to differ. First thing (except for brake) was idle stuck high after riding and high with handle bars over to right. Pulled tank and re-routed cables. Better but still there. Lubricated cables (before I found Snowbum saying not to) which fixed high idle. Now I can not get any slack in casing on left. Both cable feel slightly slack with left adjuster all the way down. Able to get nice idle (with just a bit of de-acceleration burble) using Snowbum's shorting method. Will fix up manometer eventually and retune. Cleaned and adjusted points. Dwell 100. 4 times 8cyl setting correct? the right cable has a bit of slack. Is there an upper and lower when putting back into the hand grip? Lastly: for now. What recommendations do people have for parts without all the dealer gouge. Have a new Brown side stand coming from Max, but could not find brakes or bans for side covers on site. Thanks for the spelling correct on this site. Thanks in advance for the advice.
Tim
 
Airheads.org... it's a great support group and can help you sort out your airhead or get you together with shops that provide the service you need.
 
another thought. You're close to Tom Cutter of Rubberchickenracinggarage.com in Yardley, PA. It would be hard to find someone more knowledgable about airheads.
 
Rear brake sucks. Adjusted tight as I dare.

"tight as I dare" - what does this mean? Will the brake lock-up the rear wheel? If not, you may have a "glazed" drum - burnished from using oily brake shoes for example. MAXBMW has brakes shoes on their site.

How many miles are on the odometer?

+2 on Tom Cutter. Not being familiar with the marque, if you want to be sure what you have is "right", and more importantly be informed about what isn't, he'd be the guy to give it a once-over.
 
"tight as I dare" - what does this mean? Will the brake lock-up the rear wheel? If not, you may have a "glazed" drum - burnished from using oily brake shoes for example. MAXBMW has brakes shoes on their site.

How many miles are on the odometer?

+2 on Tom Cutter. Not being familiar with the marque, if you want to be sure what you have is "right", and more importantly be informed about what isn't, he'd be the guy to give it a once-over.

+2K on all of this............Gotta bite my tongue on the advice side of this; but can't really recollect anything about setting timing and points with a dwell meter.......Most use just a standard old fashioned feeler gauge of the appropriate size, some use a light/ohm meter to set the timing statically, and others use a timing light...........Good luck.....get some help...........God bless........Dennis
 
Pick up either a Haynes or Clymer manual. Or, buy both as there are some differences in each. Just spitballing here, but regarding your cables, there were two different types of handlebar sold on the R100S. The low or European style, and the higher US style. It is fairly common for the bars to have been changed out by a previous owner. Cables must also be changed if bars are changed. Could this be your issue?

Regarding replacement part sourcing, there are various sites to check. The IBMWR and ADV sites have alternatives. Boxerworks and Airheads are both very good sites for information. Do your searches first though to avoid asking the repetitive and obvious questions. Lots of Youtube videos as well. Good luck!
 
Tim -

Be sure and check the resources and links through the clickable link in my signature block.
 
Tom Cutter is the man. The rear brake should would reasonably well if there's nothing in there lubricating the surfaces. I would clean everything with rubbing alcohol and if that doesn't work, new shoes. The front brake on those is pretty good; I used to leave the rear brake on my '84 loose to avoid using it too hard in a corner.

Any knowledgeable BMW dealer charges premium prices for parts. You pay for the knowledge that comes with the parts (same with mechanics as anyone can turn a wrench). Your closest dealers are Bob's in MD and Hermy's in Port Clinton, near Hawk Mountain. Both are pricey and excellent. Cutter is in Yardley, so that's your best option. I expect he's pricey too, but I've never taken any work to him. The advice he's given me has been invaluable (I know him through friends and because he's a control rider for the club I do track days with; I wouldn't expect anything from him on a cold call or email).

And routing the throttle cables correctly is a problem unless you have a manual that specifies how to do it.
 
Late to this, but endorse advice to spend some money/time to jump start your learning curve with Tom Cutter, especially given your proximity. These bikes are fundamental, mostly logical and predictable with many strengths and a few known weaknesses with documented updates,fixes. You should, and will need to, go thru the bike from stem to stern, starting with a diagnostic of engine and tranny/spline health, forks, wheel/steering head bearings etc. you can not assume condition or trust what you have been told without verification. You will no doubt find surprises along the way but will end up ultimately with a bike you won't hesitate to take cross country
 
OK, . Rear brake sucks. Adjusted tight as I dare. Thought I would buy new shoes and disassemble.

Lubricated cables (before I found Snowbum saying not to) which fixed high idle.

Just an opinion, but I do not buy the argument that is used NOT to lube cables. Their reasoning is that the cables are lined with some sort of plastic, and oil based lube would hurt plastic. I don't buy this argument - I think it was a factory "sales" pitch used to get people to think that the bikes were more "maintenance-free")!! It is true that certain types of lube COULD do that, but that would be determined by the type of plastic. Having spent some years in a R & D department of a large well-known-product factory where the product used plastic gearing, etc. we tested LOTS of various greases and oils to see what was compatible with various plastics and what was not. Most combinations were just fine. As a side, inside my factory BMW speedometer are plastic gears that are lubricated with grease from the factory.

I would disconnect both ends of cables and manually work inner cable by hand in and out to see how freely it moves. It should be free. If not, work it with Marvel Mystery Oil to "clean" it out (keep one end very low so oil flows and takes "garbage" with it), until it moves freely. I like Marvel for this because it is very thin, and also very detergent. It has the remarkable ability to "solve" the clogged previous grease and clear it out.

As for rear brake. I am assuming that you are describing drum brake with shoes. It could be saturated with some grease/oil from the spline or rear drive. If so, clean it out thoroughly. In the end, I use lacquer thinner on the brake shoe surface and on the inside of the drum. Then I lightly use some wet or dry paper to try to remove any glazing that may have occurred in the drum liner. Clean again, and re-assemble.

No matter what, the drum rear brakes weren't that good (by today's standards) but just OK. My rear ('78 R100/7) isn't that good but does work.
 
The new cables are Teflon lined, no lubrication required.

Right!! Except teflon wears and lube helps it NOT to wear!! And f done with a good oil (like Mystery Marvel) will wear better, be slipperier and will not clog.

Yes, we also tested gears, etc. made of teflon!
 
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