BMW R100/7 New Owner, New to BMWs so a few questions

Hello All,
I'm new to the BMW Motorcycle world and obviously new to the Forum.
I used to have Honda's back in the 80's when I went to school in Austin, Texas but when I moved back to Dallas, there weren't many bikes around so the commuting was scary, so I sold the bike. This summer I've had the itch for a classic bike so I've been watching BMWs, Ducati's, Moto Guzzi's, etc.
I found a restored 1980 R100/7 for sale in Tulsa, not too far away, so I pulled the trigger. I really like the bike and have earned compliments and smiles from other folks.
Naturally, I've been over the bike quite a bit checking adjustments, fluids, etc. The bike has about 51K miles on it.

A few questions which I couldn't readily find in the archives:
I hear a buzzing noise on the left hand side of the bike, at speeds greater than 20 mph. Obviously, noises are hard to diagnose if you haven't heard it, but it most closely resembles the sound a cicada makes in the summer.

The shifting into gear isn't always exact. If I'm at a long traffic light, I'll put the bike in neutral. But it doesn't always engage first gear on the first try. Sometimes, it takes 5 or 6 tries to get the gear in. It will help if I let the clutch out just a bit. In addition, sometimes the change from 2-3 or 3-4 doesn't happen and it leaves the bike in between gears. I've examined the gear shifter assembly and there seems to be some wiggle on the pivot shaft but other than that looks appropriate. Is there an additive for the case to help shifting? Does it sound like it needs adjusting on the shifter linkage?

Many Thanks, Charles Rahm, Dallas, Texas

Charles -

Welcome to the forum and you have a nice bike there. First, some reference info...check out this link to many other resources for your Airhead:

http://forums.bmwmoa.org/showthread.php?t=47142

You may or many not know about the front wheel recall on these bikes. It appears from your picture that you have the older wheel that needs to be recalled. Snowbum and Rob Frankham describe the situation (see link above). Here's Rob's website on the wheel.

http://robfrankham.co.uk/bike/dreaded_bmw_front_wheel_recall.htm

Living in South Texas, I know what those cicadas sound like...LOUD! That's quite unusual unless it's the valve noise that you're not used to. Not only do you have to set the valves to a proper clearance, but there is an up-down float that needs to be adjusted. When the head bolts are torqued, or rather just before they are torqued to the recommended 25 ft-lbs, the pillow blocks that support the rocker arms need to be squeezed together. Open back up the valve cover and move the rocker arms up and down. If you get clicking or reasonable movement, then this is likely the problem. If adjusted correctly, you should only see enough movement to cause the oil film to change.

As for the clutch/shifting, these bikes are serious clunkers, especially 1, 2, and 3rd. They're a bit smoother going to 4th and 5th. Some searching on the forum will bring up many discussions about this. Bottom line is, "preload" the shifter and keep up pressure on the shift lever while you let the clutch handle out. This should go a long way to eliminating the false neutrals.

You may need to adjust the clutch cable. Again, search the forum for "clutch cable adjustment". There are several posts which describe a method that is factory approved. You'll need a new BMW tool...it's a piece of wire that's 201mm long. Tom Cutter has provided the adjustment technique and has been posted before. Also, the link to Snowbum's website has the same technique.

Hope that helps. Welcome to the fold!!

Welcome aboard Bud. You snagged you a really nice lookin machine there........

The "buzzing" could be who knows what; but by chance it isn't the clutch lever vibrating a bit and making noise?........There is a spring washer that often gets omitted that allows the lever to move a bit and it does make noise.......

The shifting is just the nature of the beast............LOLOL.......I like to think of who designed that series of transmission...........The same guys who back just a few years earlier were designing and manufacturing breach mechanisms for heavy duty howitzers and anti-aircraft cannons. They needed to be slammed into place with zero finese................NO, I am not saying to slam it into gear but some folks will put a bit of pressure with their toe before and after clutch engagement as they shift into 2nd or 3rd..........The neutral procedure is just what YOU are doing.........just slip the clutch a bit...barely............

These things don't go "snick snick" as they shift............they go KLUNK with a heavy Germanish accent.................God bless........Dennis

Nice Bike

The 1st gear not engaging is the nature of the beast. I find that if I roll the bike forward a little bit I am able to engage 1st gear easily.

Noise - Check speedo could be cable driving speedo.

There is a reason for some of the shifting difficulties (assuming a tranny in good nick), and knowledge of them should make it easier to understand/compensate/detect real problems.

1. BMWs have dry, single-plate clutches, just like most cars. Most other modern motorcycles (Japanese in particular) have wet (oil bath) multi-plate clutches.

2. These transmissions are (for the most part) not shifted by sliding *gears* sideways along the tranny shafts, but by sliding smaller engagement wheels sideways *between* adjacent gears. The sliding wheels have projections ("dogs" -- small "nubs" that stick out from the side of the wheel). When the sliding wheel is moved sideways along a shaft toward a gear in order to shift the tranny into that gear, the dogs are supposed to enter corresponding slots in the side of the gear, thereby locking the previously free-wheeling gear to the tranny shaft (the sliding wheel is splined to the shaft), and off you go. (for the purists, yes, the gear may be splined and the wheel free-wheeling, but I'm trying to keep it simple here!)

3. If, when you move the shift lever (whose motion is transferred to an internal "fork" that causes the sliding wheel to slide toward the selected gear), the dogs on the sliding wheel and the slots in the side of the gear are not aligned with one another, then the tranny will not "go into gear."

4. When a wet multi-plate clutch bike is sitting in neutral at a stop, the tranny input shaft is constantly rotating (the clutch is connected to the crankshaft, so it is constantly rotating) -- and even when disengaged (as when getting ready to shift into 1st gear), the oil between the plates still transfers enough of what I'll call microscopic motion to cause the input shaft to be "jiggled" a bit. This constant motion helps maintain relative motion between the sliding wheels and the gears, so that the dogs always nearly instantly engage the gear slots.

5. With a single dry clutch, when the clutch is disengaged (as when you are shifting into 1st) there is no contact whatsoever between the crankshaft and the tranny input shaft. With no motion at the input shaft, and no motion at the output shaft (the rear wheel and driveshaft aren't turning), there's no relative motion between the dogs and slots, and the bike won't go into gear.

6. The solution? Let the clutch out just far enough to "jiggle" the tranny input shaft -- in other words, create the missing relative motion to get the dogs to align with the slots so the sliding wheel can fully engage the gear. Alternatively, you can roll the bike a foot or so, causing the rear whel to rotate the driveshaft (and thereby rotate the tranny output shaft) to create the desired relative motion for the dogs to engage.

HTH!

p.s. On the between-gear shifting, *slightly* pre-load the shift lever with your toe as your prepare to shift, and then move the shift lever deliberately up -- note I didn't say "hard" (although you can't be "woosie-toed" either). These rtannies do not take extraordinary effort to shift. Deliberately means taking your time to consciously move the lever through its travel (and ensure that you are moving the lever *all* of the way through its travel before releasing pressure). These trannies reward relatively slow, deliberate shifts; they are not lightning-quick Huyabusa-type shifters. That said, *after* you get some experience with the tranny, you'll find you can actually get some good, quick shifts out of them (quick enough to muck with the minds of unsuspecting crotch rocket riders at a track day ) -- but that won't happen until you have practiced enough doing the shifts slow to know how to precisely balance clutch and toe and throttle movement.

p.p.s Pretty bike

If no luck going into 1st from neutral at a stop, release the clutch lever and grab it again. On my bike, it works every time.

Dude, new wheels! You're bike is like Cracker Jacks.

Mark mentioned the splines that the clutch mechanism rides on. Another thing that may be necessary is to pull back the transmission to clean and lube the splines. It's possible some of the shifting problems is associated with the clutch pack not sliding completely clear of the spinning flywheel which can create problems with shifting.

Charles welcome to the airhead world. It takes three or four years to teach yourself the little nuances. Be patient. Start checking into the local airhead community. There must be a bunch in Dallas. One of the most pleasurable aspects of airheadism is hanging out at the garage during a "tech session" at some other airhead's house. Consider the Airhead Beemer Club to discover more. You've got a real beaut there. Enjoy.

Welcome to the Forum. Very nice bike. Once you get used to owning an older, simpler bike, you will love it.

My recommendation, find another airhead and let them teach you the finer things of owning one of these bikes. Enjoy.

What the others said. and of course, nice bike.

One thing that escapes a lot of new owners of these big twins is that they are happy to rev. The sulk below 3000, are in good stride at 4000 and busy, but happy at 5000.

Have fun and keep us posted.

Putting a bike in neutral at lights was important when clutches were feeble. These days, I would leave it in gear. I have had reason to split in a hurry when an approaching car driver was inattentive.

criminaldesign said:

If no luck going into 1st from neutral at a stop, release the clutch lever and grab it again. On my bike, it works every time.

Dude, new wheels! You're bike is like Cracker Jacks.

Click to expand...

I was having trouble getting neutral at stop lights and going to first before taking off and an Airhead expert showed me that my clutch lever needed to be adjusted correctly. A coupleof fiddleswith the adjustment bolt and I have a perfectly shofting tranny!

Look up an Airhead Beemer Club member in your area and get him to g over you bike with you to do a baseline set-up and to show you how it's done.

Thread Leader Responds and Another Question

Thanks all for the welcome and the suggestions.
I did adjust the valves as some of my early attention.
My front wheel is an 8 spoke, but has webbing on the spokes, although not as large of webbing as it appears on the 10 spoke replacement wheel. I tried to read the manufacturing date and I couldn't really read it. But, I visually examined for cracks and saw none.

I have the Clymer book so I'll review the clutch cable adjustment situation. The quick grab of the clutch takes getting used to and I see some guys have put a ratio change modification in - interesting.
Dang good suggestion of being ready to get out of the way while sitting at a light.

New question - the center stand doesn't return to the underside home position on the frame by itself. You have to lift it with your foot. Surely that is a weak spring and not how the bike was designed?

I checked are there are two BMW riders clubs in North Texas/DFW area.

Many thanks, Charles Rahm, Dallas, TX

DFW has a very active BMW motorcycle club scene and your best bet is to get onboard. Yahoo! also has a Texas Airheads forum. Includes real, live engineeers that can't get enough working on these bikes.

Orders of magnitude better than attempting to learn about/fix BMWs via Internet advice. (Except this advice, of course!)

http://bmwdfw.org/

Hey Charles,
Beautiful machine. My 1980 R100 has the same issue with the center stand. when I am sitting on the bike and 'bounce off', the stand needs me to hook it with a toe and lift it up. Not sure if that is normal, but is just one of those things we get used to.
Oh, and mine also has that tough to find 1st gear. These old bikes need a firm toe on the shifting operation. I replaced my adjustable shift linkage with 2 pieces of thin steel. All in all, my shift lever has a lot less sideways play than before which translates into a more positive feel.
Enjoy your fine steed....

Center Stand

Your bike is, as the others have said, stunningly beautiful. That is a rare find.

As far as your center stand, remember that despite its looks, this bike is old, and from the looks of it, has spent most of its life on the center stand, meaning the springs have been stretched out for years. Springs are like anything else, They will lose some of their strength over the years, particularly if that time is spent with them being stretched out. Check to make sure the tabs on the frame are not bent, the stand bushings are lubed, and last, replace the return springs.

crahm said:

New question - the center stand doesn't return to the underside home position on the frame by itself. You have to lift it with your foot. Surely that is a weak spring and not how the bike was designed?

Click to expand...

Duh, so does mine, I thought it was because the spring had not crossed center yet, thus spring tension is holding it down. My current bike is a 78, but on newer airheads (my now sold 1988 and 1995) they had a different center stands that would raise when moved off. Maybe a new set of springs are in store for me too.