1974 R90/6 Clutch Adjustment

[dgarber]

I am trying to adjust my clutch cable for the first time. I have searched and read as many threads as I can on this site and many others. I made the 201mm tool. I have unscrewed the knob at the TOP as described in the Tom Cutter procedure...but I can only get me clutch arm to a measurement of about 210mm. The TOP knob is showing almost all of it's threads and the clutch arm is past the right angle...it's actually pointed slightly forward. I am putting my 201mm tool flat against the back side of the Transmission mounting flange. The bike has 18,000 miles and shifts ok. I have to let the clutch lever out almost all the way before I get any action. Can someone help a new BMW owner?
Thanks.
Doug

[mneblett]

You have things slightly backwards.

1. Loosen the locknut and adjusting bolt in the center of the tranny lever to give yourself a fair amount of freeplay.

2. From where you have the upper adjuster now, rotate the upper adjuster in until you are down to 201 mm between the tranny flnage and the front edge of the cable cylinder at the tranny lever (i.e., use the UPPER adjuster to adjust the distance at the LOWER end of the cable).

3. Screw the tranny lever adjusting bolt in until you have zero freeplay at the lever, then back it back out until you have 4-5 mm of freeplay at the hand lever (i.e., adjust the LOWER bolt to obtain the desired UPPER freeplay).

4. Lock down the adjusting bolt locknut and the upper adjuster's knurled ring.

Also, while it sounds obvious, make sure the ends of the cable sheath are *fully* seated in their respective bores.

[dgarber]

Thanks for the reply. So with the clutch arm adjusted to 201mm, how will it look...slightly forward...backward...or parallel to the transmission housing?
Thanks.
Doug

[r90r100r]

Tilts backward. Make sure it doesn't touch the swingarm.

Mike H
76 R90/6
93 R100R Legend

[20774]

Yes, backwards. The reason will be that when you pull the hand lever in about 50% of the way, the lever at the back of the tranny will be nearly parallel with the back face of the tranny. This is where you have the most mechanical advantage when you need it most during actuation.

[dgarber]

I will check again when i get home tonight...but my measurement from the back side of the trans mounting flange to the clutch arm, with the arm parallel to the trans, is about 210-215mm. I was using the top knob to draw that in but there was no way I was going pull up that much slack. Does the entire clutch arm move forward and backward when you loosen the lock nut? If not, what would cause my arm to be back so far back? Maybe it will make more sense when I'm looking at it.
Thanks again.
Doug

[dgarber]

Also...does it matter where the adjuster on the handlebar lever starts at? Should it be screwed all the way in or out to start?
Thanks.
Doug

[RoboRider]

Mine was similar, where the upper clutch adjusting screw is WAY out to get 201mm. I know the fische shows a longer and a shorter cable, so perhaps your cable is too long. You can if you are handy shorten your cable but it requires nickle solder etc. to do it right. But, It does sound like your cable is too long or stretched.

[mneblett]

Also...does it matter where the adjuster on the handlebar lever starts at? Should it be screwed all the way in or out to start?
Thanks.
Doug

It does not matter where the top adjuster starts, as you adjust it as necessary to achieve the desired 201 mm distance. The critical thing is to have the clutch arm adjustment bolt fully backed out so it doesn't interfere with the motion of the lever as you adjust the 201 mm distance.

The lever is mounted at one end on a pivot pin, so that the large range of motion at the cable end with a relatively small hand force generates a small, high force motion at th eclutch pushrod end of the lever. As the lever cable end is drawn forward, the lever pushes the pushrod forward (toward the engine) to push the clutch pressure plate away from the clutch plate to disengage the cltuch.

[dgarber]

The part I don't understand...unless my 201mm tool is the wrong length after making 3 different ones...is how can the current measurement be 211-215mm with the clutch arm parallel to the transmission. If the end result is to have the arm facing slightly rearward, then it seems the pivot point needs to be pulled forward towards the transmission in order to achieve the 201mm measurement, regardless of the cable length. Does anyone else see it this way?
Thanks.
Dogu

[mneblett]

Double-checking --

When you say:

I am putting my 201mm tool flat against the back side of the Transmission mounting flange.

Do you mean you are placing the front of the tool against the rear face of the tranny projection which holds the lower end of the cable sheath?

[mneblett]

BTW, you may want to put your location in your user profile -- there may be a fellow airhead near by who could pop over to eyeball your bike.

[dgarber]

Like this....

[dgarber]

I will also update my profile tonight...right after I double check my tool and measuring capabilities.

[20774]

Something doesn't make sense here. You keep saying that the distance you're getting is something like 210-215mm and the arm is parallel to the back of the tranny, like you show in your last picture. That just doesn't seem correct. I adjustment my clutch cable not that long ago and 201 puts the lever arm quite a bit more to the rear...regardless of what has happened at the handlebar. I'd certainly like to have confirmed the tool dimensions!!