Trials Australia Forums

Currently riding a 2013 gg280 pro. I really like everything about the bike except the clutch. I think the current matter cylinder on the bike is an AJP?? Is it possible to swap for a braktec?

The reason I want to change is I find the take up of the current one is very progressive but the main part of the friction point is at the end of the stroke.
Will changing to a braktec move the friction point?

I ride the same bike - If you've adjusted the lever so that there is about 10mm of play at the lever end and bite point is still at the end of the lever travel it sounds like your clutch pack is worn and new clutch pack is an easier option than a master cylinder change. Call Paul Arnott at the Hell Team - he'll help you out.

cheers Paul Mac

Firstly the Braktec and AJP master cylinders are absolutely identically internally. Swapping from one to the other will make no difference if your AJP seals are good, and there is nothing else wrong with it.
The Gas Gas clutch is really really adjustable. Changing the stack height of the plates will make it really progressive, or like a switch.
It is definitely the bench mark clutch out there, and with some tweaking should be able to custom build it to however suits your style.

Plate height
Lower grouped plate height - progressive
Higher - faster response and take up

There is also different plate materials available.
Standard - quite progressive
S3 / Hoerbiger - More aggressive.
XiU Engineering Kevlar plates - Very aggressive

There is two spring thicknesses
1.5mm Standard and softer feel, less effort on lever
1.7mm Stronger more aggressive take up. Harder pull on lever

The you can also modify the spring preload plate.

And the type of transmission oil will also make quite a difference.
Preferred oils for quicker take up are thin tranny oils like GRO Extreme 75w specifically designed for this bike.


Give me a call if you would like to discuss further, or send me your complete clutch pack and I can build it to your requirements.

regards

Awesome info Paul. I'll have a dig around and try to find some info on plate height. I'm comparing my clutch to a gg 280fr of the same year.
I'm currently using mtx 80w. My clutch is great for slippery corners and finding traction. Just lacks a bit of grab through the middle when I want faster power.

When I got my Beta EVO it had been fitted with 2 thicker clutch plates in order to give it a much more aggressive take up. After putting in 2 normal plates back into the stack this really helped with clutch feel.

A Beta clutch is a completely different beast to a Gas Gas clutch.
Changing plate thickness on the two types ends in quite different results.
Beta, Sherco, Scorpa and Montesa are all traditional type spring stack clutches. Gas Gas, Ossa and JGas clutches are more modern diaphragm style clutches. Very very different to each other. Apples and oranges!
Diaphragm clutches have much greater range of "tunability", and broader range of adjustment, and are a lot slimmer packaging wise than traditional type clutch arrangements.
New Vertigo and TRS will both be diaphragm type, and there is a $2000 conversion available for the Sherco to switch it to diaphragm from BDI for those with the $'s.
Manufacturer movement is away from the traditional style clutch release system towards the GG type since it's introduction on the TXTPro in 2002.

I would suggest checking stack height on the Gasser clutch and possibly going a tad higher. But make sure the m/c is set up corectly, and the seals are all good in the master and slave first.
You can do this quite simply. You do not need to remove oil or coolant. Lay the bike on it's left side, bars turned hard to the right. Remove the 3 bolts holding the water pump on, and pull it out of the way so you have clear access to the side case. (a dutifully bent coathanger, or large cable tie works well for this).
Remove kickstart lever.
Remove all remaining side case bolts. (good trick is grab a bit of thick-ish cardboard, draw a mud map of the side case on it, then poke the bolts through in the correct positions, you'll easily keep track of them, and get the correct lengths back in the correct holes on assembly)
Remove side case straight off. Be careful there is a shim washer that lives on the kickstart shaft, but sometimes it will stick to the side case and drop off onto the garage floor when you least expect it. Locate it and put it back on the shaft.
You can now check the plate height.
This can be checked by measuring from the top of the diaphragm fingers to the deck height (see attached drawing), or by removing the clutch (centre bolt) and actuallly measuring the height of the 5 individual plates stacked together.
Don't hesitiate to call if you need some help.
cheers

Hi Paul

Did ya ever hear of anyone fitting a diaphragm clutch to their EVO? Is it a lot of money to buy a complete GG diaphragm clutch, say from a Raga? Then I could get on the lathe and make my gears fit the GG clutch, mess around for hours perhaps.

John (Lawton) would have kittens if he knew I fitted GG parts to my EVO but if you don't tell I won't!

Cheers ... Mark

:mooning: I am deevil!