The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: 79beem on December 24, 2010, 07:29:44 AM
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Just got my bike, 79 R65 See "My special Lady" in general announcements, runs beautifully,plenty of grunt,excellent handleing on the twisty mountain i live on,
First issue -
With very Little pressure on the clutch lever the clutch is disengaged, max lever travel 5-10 mm to disengaged. Is this normal ?
Makes it a bit tricky for me on hill starts with little room for error or control.
I've wound cable adjuster right in ( tightest ) resulting in no change. Slacken completely off results in not being able to disengage clutch.
Was going to try and wind out adjuster bolt on clutch release lever as far as possible. Any suggestions?
Second Issue -
Front brake lever loose in resting position, but is solid once pulled and immediateley activates brake. Its either on or off. Pads are close to minimum thickness and are so close to disc no gap visible or movement detectable when activated, but not binding on disc. I have the rectangular reservoir not the original circular one. fluid is clean.
Any suggestions greatly appreciated
Regards Ian
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The clutch cable adjustment is done at the transmission, there is an adjustment bolt at the arm .
There's a procedure to 'correctly' adjust the clutch, but I don't follow it, I just make sure there is free play between the clutch push rod and adjustment bolt, so the clutch isn't being partially disengaged .
The adjuster at the clutch lever is for the free play at the lever, about 2-3 mm, eighth inch or so .
Your brake lever may be worn, where the lever contacts the piston rod of the master cylinder, or possibly the piston itself, isn't returning all the way .
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Slacken off the adjustment at the clutch lever; loosen up the cable as much as the adjuster will allow.
Under the bike, check free play at the clutch actuation arm. As the arm is relatively long, you may have to keep a good eye on the adjustment bolt-to-clutch push rod distance. What you're seeking is just a wee bit of free play which will eliminate partial clutch disengagement.
After you're all happy and satisfied with the lower adjustment, go back upstairs and set the lever free play adjustment using the knurled deal-y. Confirm the pivot bolt is secured with the required nut. A simple clean n' lube of the pivot would be nice, too.
There's an adjustment measurement in the Haynes and Clymer manuals. Most Airhead owners use a piece of coat hanger wire, cut to the proper length, to gauge correct cable adjustment at the transmission end of the cable. If you have not yet secured a manual, getcha one. Big help. Lottsa answers.
Your clutch cable probably has a nylon inner lining. Don't pour cable oil down into the cable.
And... your brake calipers may need some love. As in disassembly, cleaning, inspection and fresh fluid... after you have cleaned out what may be a nasty brake fluid reservoir.
Post up some real-life pics now that your baby is home.
Monte
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With very Little pressure on the clutch lever the clutch is disengaged, max lever travel 5-10 mm to disengaged. Is this normal ?
Makes it a bit tricky for me on hill starts with little room for error or control.
Correct clutch adjustment aside this is sort of normal. An airhead clutch will seem a bit abrupt if you are used to wet multiplate clutches particularly if the bike has been stood for some time. When you have been riding it for a while the clutch will get more progressive as any corrosion gets cleaned off and you will get used to the the relatively narrow engagement band. A good airhead clutch is very smooth and progressive but the engagement band is narrow.
As far as adjustment goes any book method you read is designed to achieve 2 things :-
2 or 3 mm free play at the handle bar lever
and
with the handle bar lever at half travel the clutch operating arm should be parallel with the back of the gearbox to give max. mechanical advantage.
As Bob said though as long as you have free play at the handle bar lever it's not hyper critical and it's best not to keep changing the adjustment or you won't get used to it.
Front brake lever loose in resting position, but is solid once pulled and immediateley activates brake. Its either on or off.
If the lever is a bit floppy then you may be missing the wavy washer from the pivot screw which helps to minimise free play.
Properly bled the front brake should have a very firm feel due to the relatively low ratio of master cylinder area to caliper piston area. If that's what you mean by on or off it's normal on the other hand you might want to check what master cylinder bore was used when the change to rectangular reservoir was made.
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Be aware that the clutch lever in particular is prone to wearing the pivot hole oval and then pulling the cable off line.
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Cheers everyone for the responses,
Im going to have to pull calipers apart as i didnt block pads off when i took wheel off ( lower allen fork screw leak ) and then mindlessly pulled lever, pistons wont push back in. Swear words......
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Hi Ian.
The is a spec distance between the end of the clutch arm on the back of the tranny and the flange on the forward part of the tranny that the clutch cable goes through. It's 203mm. Cut you a piece of coat hanger wire this length and fit it in Use the adjustment nut on the handle bar to change this distance until the coat hanger wire just fits between the forward flange and the end of the clutch arm where the cable attaches. Tighten down the lock nut on the handle bar.
To adjust the freeplay at the handle bar you then change the adjustment on the BACK OF THE TRANNY! This is completely backwards from what you would think to do. I have mine set at 2mm. Whatever works for you.
If the clutch doesn't release or engage properly after this adjustment then you have another problem.... :-[