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Gas Gas Clutch


coxy
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The std GG springs in a 250 should be 1.5mm thick. If you stuck a 1.2mm thick belville type in, your clutch will slip under hard acceleration and your acctuation point would change outside the adjustment range. Even a .1mm change in thickness is a big change in spring K (It changes as the cube of the thickness).

Have you seen these? http://www.jackscycles.com/lpse.html

My dad makes them and puts them in alot of bikes - including mine. Ideal in a 250. Makes for a lighter and more progressive clutch feel. Great in wet conditions. The down side is that if your an expert rider and want a quick clutch for doing splatters, then pass.

You can buy Lipse springs to fit your bike and riding style (thicker for aggressive riders, but still a lighter pull than stock) - they are not just a thinner spring, but also have a full thickness inner ring so the accuation point isnt upset. The flatness spec of these springs is the same as the OEM spring. (very tight)

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ive been told that the standard spring size for the belville spring is 1.3mm thick in the 06 gassers.

do you know anyone in the uk who has one of these lipse springs fitted so i could maybe contact them and see or maybe even try the different belville spring and see how it feels?

the reason why i am doing this is because my clutch has become heavy and i am trying to find ways of lightening the clutch without spending masses of money on the bike

cheers coxy

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ive been told that the standard spring size for the belville spring is 1.3mm thick in the 06 gassers.

do you know anyone in the uk who has one of these lipse springs fitted so i could maybe contact them and see or maybe even try the different belville spring and see how it feels?

the reason why i am doing this is because my clutch has become heavy and i am trying to find ways of lightening the clutch without spending masses of money on the bike

cheers coxy

If Your clutch has BECOME more heavy, dont mess with the spring. The cause is much likely clutch fibers swelling. Check clutch hight (you will find descripsion other places in this forum. Dont have time to explain now) and adjust with thinner steel plates or buy new fibres.

-Jan

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If Your clutch has BECOME more heavy, dont mess with the spring. The cause is much likely clutch fibers swelling. Check clutch hight (you will find descripsion other places in this forum. Dont have time to explain now) and adjust with thinner steel plates or buy new fibres.

-Jan

Finally back from work... puhh..

To check your clutch fibres measure the hight from the clutch fingers down to the even surface below. Between 17 and 18 mm is spot on. For each mm lower the clutch get signifantly harder to pull because the lever action angle gets too low.

If you take the entire clutch pack out all the plates should measure 9,75 mm +/- 0,1 mm. For each 0,1 mm thicker the finger higth lowers 2 mm.

You will probably find that the clutch pack is too thick. This could be caused by dirty oil. Clean the plates thorughly and measure again. If still too thick You have some options to get it thinner:

1. Buy a new clutch pack. Easy solution. Be sure that the new clutch pack have the right heigth before you buy.

2. Change the steel plates to thinner ones.

3. Sand the fibres with very fine grain paper on an even surface. Cheap solution, but a bit risky. If fibre plates get uneven the clutch will vibrate.

Be sure the pack doesnt get too thin. If so the cluch will slip as Laser says

-Jan

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ive tried the clutch pack and it is exactly 9.75mm as it should as its a brand new clutch pack so that isn't the problem. tried other things like all new o rings in the clutch also and checked that i have no blockages etc in the pipe and that everything is working perfectly fine.

ive had this problem ever since i had a new gearbox put into the bike but everything rides fine its just the clutch is heavier. ive not done anything to any part of the bike except the new gearbox, clutch packing and new o rings so any ideas why im having this problem??

cheers coxy

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What is the thickness of your clutch spring (Belville washer) - maybe an older (pre 06) spring found its way back into the bike?? They were stiffer. The 06's went to a nominal thickness of 0.060". Anything thicker is old.

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coxy, I am in the UK and am using one of the Lipse spring that Jack Hemmingway manufactures [see laser1 reply] on my 2006 250 pro.

i fitted it as my clutch has always been stiffer than every other GG Pro I have tried, and I have done all the same checks as you.

New Clutch pack - set to correct pack AND finger height as defined by Factory Kev at GGUK - no change

New seals and o-rings in slave cylinder - no change

New master cyl seals - no change

New Fluid [mineral oil obviously] - No change

I even fitted the larger diameter clutch hose [even though I couldnt understand how this would help] - No change

So I got one of Jacks machined down springs, and it made a big change to the lever effort, but it had clutch slip in 4th & 5th [and some times in 3rd if the oil was old].

based on that I got Jack to make one slightly thicker, and that is the one I use today and that only slips in top gear if the ATF oil is getting old.

When I get back home I can check my notes and confirm the thickness of both washers, and you can get Jack to make you one, or if you are interested, I can send you the thinner one I have for you to try for your self.

Send me a PM with your contact details if interested.

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i've got a 1.3mm belville spring in ma bike at the moment which is about 0.050" so it can be that its a thicker spring

Your either measuring one of the steel clutch plates (2A was 1.3mm) or someone turned down a std spring - way too much. GG never made a 1.3mm spring.

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its definitely the belville spring that im measuring at 1.3mm, although it has been in the bike since new so could this of worn?? ive put a 1.4mm belville spring into the bike and it makes the clutch unbearable to the point where after 1 section of riding would give me arm pump and its not like im not bike fit i ride every weekend. yeah maybe it would be a good idea to fit one of the lipse springs and see how it goes once ive got the bike to peices again. yeah ive been told to fit the bigger clutch hose and cylinder but i too cannot see how doing this would make any difference to the bike what so ever. after taking the bike apart and cleaning the clutch this weekend the clutch didnt seem too bad, heavier than afew other bikes i felt but not to the poiunt where i was getting bad arm pump so im going to leave it for a while and see how it goes.

thanks for all your help

coxy

Edited by coxy_gg
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Where did you get a 1.4mm spring?

Just to throw this into the mix, I took a new 06' on up, Belville spring

(#MT280632015) out of the parts box and it measures 1.42mm. This

is reportedly the newer type thinner spring.

Jon

ps. Another thought to add, sometimes the outer post/inside servo clearance is a little tight due to manufacturing tolerances and add swollen o-rings and you have a very heavy clutch pull. I polish the inside of the servo top hat and use DOT-5 fluid and with 7+years of use (2002 280, original o-rings) it is still very light and smooth in operation.

Edited by JSE
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Interesting Jon - Thats a mystery as all of the lighter 06 springs we have measured (20+) have been between 0.058 and 0.060" (1.5mm) The older ones were closer to 1.6mm. My dad was puzzled as well. He called Tim and had him measure what was in stock and measured 1.5mm...strange. If it was anyone else, I would write it off as your measurement error, but your credentials preclude that conclusion...darn!

Im a big fan of the DOT 5 trick as well - I know the new top hats have been honed for a few years now (we used to have the old ones honed), but we dont polish them - what do you use as a substrate/polish? Does it noticably improve the feel over even the honed ones? (I would seem to think the honed surface would help reduce stiction)

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