Clutch Master Cylinder Alternatives

[trialswarrior]

Has anyone tried a different (non Beta) clutch master cylinder to help with clutch drag ? I wonder if a cylinder that pushes more fluid through when the lever is actuated would get the clutch plates to separate more reducing drag.

[zerorev3rev4]

have you looked at beta clutch fix on here personally i have not experienced drag on my rev3

[trialswarrior]

Yes, I did the clutch fix.

The clutch dragged since day one. It is now tolerable, but I'd like to make it better. This is on a 2010 250 EVO.

[lineaway]

I have had Beta`s since the `89 TR34. Usually problems with the clutch hydraulics are the rider trying to get every last little bit out of the adjustment. Which usually just screws the whole thing up. The piston has to move the correct distance to work. ( This happens to all brands) This was actually the problem Gas Gas riders had when the Pro came out. They always tried larger master cylinders. It never really worked. It is possible you had a bad M/C. Did you ever try a rebuild kit?

[dan williams]

You could try less oil with thinner viscosity. Overfilling the box can cause drag and Billy Traynor did a nice bit on different oils.

[0007]

There is a shim involved as well

The clutch only slightly disengages, it does not push the plates apart by even 1mm per surface

I think it's roughly .040 thou

So if your clutch shim is too thin then maybe you are simply not getting full stroke on the pressure plate

[lineaway]

With all the info on the net any more. The only shim I`ve ever saw was from Wise Motorsports in Japan. And they seemed to know what they were talking about. (In Japanese) 007 might know otherwise. I could probably find the link . It would cost dearly for a .60 cent part

[0007]

I can't see a selection of shims not and I wonder if maybe it was on my Rev 3

Here is a description from the manual.......good luck with it

And I Quote, I wish I could attach the graphic but I can't do it with my iPad

Note:

The device you pressure plate must have a play between 0.4 mm and 0.6 mm. There- fore, proceed as follows when replacing disks:

•Reassemble the clutch without the outer

cover

•Send the control rod to end of travel by

pushing the pressure plate and measure

distance F

•Operate the clutch lever until the control

rod activates the pressure plate. Measure distance G and check that there is difference of approximately 0.4-0.6mm.

[copemech]

I can't see a selection of shims not and I wonder if maybe it was on my Rev 3

Here is a description from the manual.......good luck with it

And I Quote, I wish I could attach the graphic but I can't do it with my iPad

Note:

The device you pressure plate must have a play between 0.4 mm and 0.6 mm. There- fore, proceed as follows when replacing disks:

•Reassemble the clutch without the outer

cover

•Send the control rod to end of travel by

pushing the pressure plate and measure

distance F

•Operate the clutch lever until the control

rod activates the pressure plate. Measure distance G and check that there is difference of approximately 0.4-0.6mm.

I seen that at some point. Never quite figured it out because the thing is self adjusting. It may limit the furthest inward travel of the actuator against the pressure plate as a stop, but it is not going to normally make things separate further as it still only pushes so far.

I do see Beta is using some different plates now in the later bikes, one thick plate and such, possibly an upgrade ?

Anal Japs?

Edited March 15, 2014 by copemech

[lineaway]

http://www.microsofttranslator.com/BV.aspx?ref=IE8Activity&a=http%3A%2F%2Fwise-motosports.ocnk.net%2Fproduct%2F248 takes a little while to load

[lineaway]

There was a whole DIY video tied to these shims. Took me forever to hunt then down.

[dan williams]

0.4mm to 0.6mm is a pretty small range. Sounds more like just making sure the actuator pulls back enough to disengage but not too much. As Cope pointed out the thingus is supposed to be self adjusting so the effect of the shims without some range limiting mechanism is kind of meaningless.

[0007]

Cope is right about the self adjusting aspect

But all it takes is a bit of a sticky seal and the seal pulls the piston back to the same place regardless as to clutch pack thickness and wear

That is difficult thing to account for as it's not factory spec and could vary between bikes

So if the total stroke of the slave is like 3 mm (Guess) and you are 1 mm off then you have lost 30% of your stroke

Anyway, if the glue removal doesn't deal with drag then this measurement should be checked