Clutch lever arm distance hot vs cold

[Air4Life]

Referencing: "...distance measured from the center of the barrel in the fork of the transmission-located lever, to the forward transmission casting, should be 201 mm to 203 mm" [emphasis]

http://bmwmotorcycletech.info/clutch.htm


Does anyone know if the following measurement was taken hot if it would be shorter or longer?  I believe the answer is shorter.

[Bob_Roller]

No mention of hot or cold when checking this dimension .

It's not a micrometer precise measurement .

[Air4Life]

Correction, he states "cool" not cold.

"Do this adjustment with the engine COOL"

Okay, thanks.

[Barry]

Does anyone know if the following measurement was taken hot if it would be shorter or longer?I believe the answer is shorter.
Back to top       
 

I think you are probably right but I've never measured it hot.

There's no particular magic to this precise measurement. It just happens to be the figure that results in the clutch operating arm being parallel to the gearbox cover when the handlebar lever is at half travel. The object is to achieve maximum mechanical advantage in just the same way we used to set drum brake operating arms to be 90 deg to the cable pull when the brake shoes had made contact with the drum.

[Air4Life]

I see.  Make sense.  Thanks.  

Well, I discovered if I turn my bar full left it shortens the distance - and vice versa.  I'd estimate that there's a difference of 3-4 mm between extremes.  

[Bob_Roller]

I'd do a quick check and see if the clutch cable is binding up with handlebar travel .

[montmil]

Roger Bob Roller's comment. You have a cable routing issue rather than a major clutch cable adjustment concern.

Beware PO's cable routing as it ain't always necessarily correct. The clutch cable should be routed so as to create a nice, sweeping curve from the chassis down tube to the clutch arm on the transmission. Zip ties secure the cable along the frame tubes. No tight, weird routing or you'll have... well, you already know. If you have shop manuals, eyeball the photos for proper install.

I just completed correcting the cable from the front brake lever to under-tank master cylinder on my latest acquisition, an R100S. Not only was the cable badly pinched as it was forced through a gusset on the head stock but the cable was also installed wrong with the cable ends at the wrong end. Does that make sense?

[Air4Life]

To me the routing seems acceptable...  thought it looks like I'll be installing a new cable soon.  

In your opinion should it have been tied further up, or is this how they normally age?

[Barry]

Route looks OK as far as I can see.

Up RHS of the down tube. Cable ties should not be too tight.
Passes to the RHS of the headstock
Across rear of the headlamp shell
Then over a bracket in a smoothly line to the clutch lever.

Low bars vs high bars may show some differences. I can imagine high bars having more bends before it gets to the clutch lever and maybe causing more movement in the cable free play lock to lock.

I have low bars and cannot detect any significant variation in free play from center to Left lock. Center to Right lock reduces the free play by approx. 1.5mm. I start with 3mm free play and no way does that all get used up.

Going back to your original question of course the clutch operating arm will still move if some of the free play is used up but it's of no consequence as long as there is some free play left.

I would set the amount of free play at the clutch lever so there is just a touch left when you turn the bars lock to lock.

[tvrla]

I agree with Barry. Don't get hung up on the exact measurement - eyeballing that the lever is parallel mid-stroke has been the way I've always done it and can't tell any difference using the measuring method. Set it up so it's right with the bars straight ahead since that's the orientation 95% of the time when shifting. Hey, it aint rocket science!  

[Bob_Roller]

I've never measured for the adjustment .

I do what I've always done with a mechanical linkage activated clutch .

Adjust so there is a bit of free play at the clutch (3-4 mm) on the R65 and then adjust the pedal, or handlebar end so there is a bit of free play there, (2-3 mm) on the R65 .