Boxerworks.com

DanielMc wrote: He asked me if I was some kind of Buddhist...

Chuey wrote:It won't look too silvery. It will look groovy and clean. It will clean up well. You will experience engine aesthetic nirvana. Try to keep your feet on the ground when it hits you.

Chuey

HAHA, thats hella funny.

Finished up the Rub N on the engine today. Turned out pretty good. I'm happy with it.

Before: and After:

A closer pic of my shiny engine.

DanielMc wrote: Chuey - your excellent words remind me of the time I was explaining to a friend why I prefer the challenge of changing gear on my R90S to doing likewise on my much slicker, driveline shock-absorbed R65LS. I explained how I tried to plan ahead so that unnecessary gearchanges were avoided, tried to avoid having to come to complete stops wherever possible and generally treated the gearbox as carefully as I could by matching road speed to gear selection and pre-loading the lever before each change. Downshifts, I advised, need a lot of care, but the rewards when I got it right were worthwhile. I said it's possible that getting a good gearchange on an old airhead is one of the things that adds greatly to rider happiness..

He asked me if I was some kind of Buddhist...

Oh man, my R90S has the transmission from the planet "Clunk". My other bikes shift so smoothly, it makes me wonder what the difference is. I have a lightened flywheel and the trans was rebuilt lavishly by The Beemer Shop. It still clunks. When I first got the bike, my first BMW, I rode it around and marveled that it didn't break, what, with those loud clunks; but how could I help it shift better. I have striven to perfect the technique. The thing I noticed about it was that if I was having a fang in the hills (you guys know I love that word, fang, thanks Ozzies!), it shifted pretty fine indeed. It was as if it was saying "Hey, that's more like it! Come on, let's keep this up. Isn't it more fun anyway?" And that's how I came to learn that the bike appreciates spirited riding.

Chuey

Cheuy,

My R90/6 also with lightened flywheel clunks as well, you can fit the driveshaft damper from a later bike. if you use one from a pre 81 bike you will hardly tell the difference from the outside. It helps not so much with the clunking but with stopping the rear wheel from locking if you are a little clumsy shifting down into 2nd or 1st gear.

What does seem to really help with the 90/6, is to be really careful about adjusting the clutch, using the method for the later bikes.

To briefly describe:
Use the cable adjuster at the handlebar to adjust the position of the clutch arm at the gearbox, so that 203mm is the distance between the rear of the crankcase (where the clutch cable exits) and the front of the lever arm where the cable nipple is. Lock off the handlebar cable adjuster. I use a piece of stiff wire from a coat hanger cut to size as a measure

You then use the adjuster bolt on the gearbox clutch arm to create 2mm free play at the handlebar. The adjustment of the bolt and locknut is quite sensitive and I usually need a couple of goes.

Getting this right does really help.

Charles

chasbmw wrote:Cheuy,

...

To briefly describe:
Use the cable adjuster at the handlebar to adjust the position of the clutch arm at the gearbox, so that 203mm is the distance between the rear of the crankcase (where the clutch cable exits) and the front of the lever arm where the cable nipple is. Lock off the handlebar cable adjuster. I use a piece of stiff wire from a coat hanger cut to size as a measure

You then use the adjuster bolt on the gearbox clutch arm to create 2mm free play at the handlebar. The adjustment of the bolt and locknut is quite sensitive and I usually need a couple of goes.

Getting this right does really help.

Charles

Chas,

Pardon my temerity, but I think you said it backwards. The 203 mm distance should be adjusted with the bolt/locknut on the throwout arm, then 2mm freeplay adjusted at the handlebar lever. N'est ce pas?

I say this because if the bolt/locknut at the transmission is out of whack far enough, one will never achieve the required 203mm distance using only the handlebar adjuster. Or, the range of adjustment at the handlebar will be exhausted at one extreme or the other. I start the adjustment at the transmission with the handlebar adjuster at mid range.

Chuey has it right.

My understanding of the 203mm measurement (actually I thought it was 201-203mm) is that it's just a convenient method of ensuring that the clutch operating arm is parallel with the gearbox end cover when the handlebar lever is at half travel so as to achieve maximum mechanical advantage. I've never found a slight variance from this setting to affect gear change quality - other than in my imagination. As soon as I stop thinking about it any perceived difference disappears.

Barry,

I think that the word accurate might be better description of the measurement method. My experience is that as a result of adopting this method of getting the clutch arm set right, is that the gear change on both light and Heaney flywheel bikes is greatly improved.

I returned from a long trip to Greece last summer and during the trip apart from fiddling with the carbs a couple of times, very little work had been done to the bike (a newly rebuilt R90). When I got home the bike was given a full service and as a result I had a greatly improved gear change. Some of that improvement might have been as a result of everything else being st up better, but I think that most of the improvement was IMHO down to adjusting the clutch.

Charles

Charles

I agree it's accurate and wasn't suggesting it should be done any other way. It's the right and easy way to adjust the clutch no argument. If the clutch adjustment is way out then I can see it's going to produce an improvement. I just don't see it as a precise magic number at which good gear changes can only be made. If it was why would there be the 2mm tolerance. I see it as an easy way of obtaining a 90 Deg pull on the clutch arm at half handlebar lever travel. I've done it both ways and satisfied myself in as far as I could accurately measure that they amount to the same thing. The 201mm method sure is a much easier method to carry out even though at first reading it can seem counter intuitive. In the face of that I found it useful to have a visual image of what I was trying achieve. In fact I always strive to understand the effects of what I'm doing so If it's achieving something other than a parallel operating arm then I'd genuinely like know what that mechanism is.