juddering clutch

[Red3446]

Hy guys

I have a problem with my bike's clutch: is juddering when hot.
As I have a spare new engine I tried first to replace discs and springs (genuine)....with no results. Then I tried to replace center and outer clutch comp....no results.

On the web I read that maybe the genuine clutch doesn't like very much actual syntetic engine oils and an aftermarket clutch can solve the problem.

This is right? Could you sugget me a good aftermarket cluch brand?

Thank you!

[Watty]

Get rid of Synthetic oil!!

[alanfjones1411]

Get rid of Synthetic oil!!

+1 wot he said

[tony.mon]

Fully synth will only cause slip, not judder.
Semi synth is what you need but it won't sort the clutch grab problem.
I tried for years, and couldn't find a way, captive washers for springs, new anti judder seat and spring, heavy duty plates etc, all failed to fix it.
Filing baskets, different spacings for friction and fibre pack depth, nothing worked.
It stopped me from getting into the tens on the run what you brung drag strip.
All you can do is live with it. Use the torque, luke, and get the clutch home early and surf the torque to the redline.

However, when racing these bikes back in the day it was sorted by making (at high cost) dome spring outers.
It would double the cost of your bike.
But sadly not its value.

[Red3446]

It dosen't slip continuously, like a worn clutch, but it slips in a rough way, only starting from low rpms at full throttle, causing vibrations. It disappeares after 4000 rmps...more or less. During winter no problems....
So...If I unterstand well.....it's a common problem, isn't it? No different disks or harder springs can solve it?

[Wicky]

Try not lugging it at low rpm - use the gears a bit more to give a few more revs and change the oil to semi-synth

[fabiostar]

a lot of us have had the same problem. but after awhile you learn to ride round it and use the engines stump instead of the clutch...

[ste3800]

i also have the problem. is there really nothing we can do but... live with it?

[tony.mon]

It dosen't slip continuously, like a worn clutch, but it slips in a rough way, only starting from low rpms at full throttle, causing vibrations. It disappeares after 4000 rmps...more or less. During winter no problems....
So...If I unterstand well.....it's a common problem, isn't it? No different disks or harder springs can solve it?

No.
I tried Kevlar plates, uprated springs, even had titanium spring holders but nothing worked.

[Red3446]

It's a very strange behaviour....and I'm a little bit disappointed that I cannot use low rpms with the V-Twin.
.....I've to invent something, I cannot accept this problem, I've to solve it!

[fabiostar]

mmmmmmm normally its a problem with high revs when moving of? as in trying to get of the line fast...

[Red3446]

Maybe I've found the solution.

Two months ago I installed a new cutch discs set with reinforced springs (+ 15%) from EBC. Oil is Castrol Power One racing 10W-40.

Yesterday, after an intense raceway session I noticed no problem under stress.

For a final answer I must wait for summer....when temperature will rise....but now I'm satisfied!!

[AMCQ46]

was it both EBC clutch plates and EBC springs? and was it just new friction material?

I think I need a new clutch now as mine has started slipping as the bike hits 7000revs .... just to add to my list of issues that need fixed

[fabiostar]

was it both EBC clutch plates and EBC springs? and was it just new friction material?

I think I need a new clutch now as mine has started slipping as the bike hits 7000revs .... just to add to my list of issues that need fixed

Al i put an EBC plate set and heavy duty springs from them into my yellow one. job done. great clutch now.

i done the same on the blue one and it was sh1t and ended up buying toni's kevlar set up. also job done..

i dont think the blue ones sh1t clutch was caused by the ebc parts but more the basket...

[AMCQ46]

good to know, I will order the EBC kit & springs