Lighter clutch

[stu109]

Looking to lighten the clutch on my Evo 300 4T.

Was thinking of taking out two springs as suggested on this forum.

Looking at the clutch the springs have a fair amount of pre-load. I was thinking that some slightly longer bolts (say 2-3 mm) would take some of the tension off and might produce the desired result.

Has anyone tried this, or got any thoughts?

[stu109]

I have the top hat type washers.  They have the "hat brim" outwards so that the washers fit within the spring.

Regarding clearance the current bolts, when tightened, fit flush with the clutch plate.  There looked to be at least 5mm between the clutch plate and the casing.  Also the OEM bolts have quite a deep head.

Slightly longer bolts , particularly with a shallower head may well still clear the outer casing.

The easier solution is to run on just four springs but not sure if this will result in slipping.

[carlos]

I took out one of the thicker fiber clutch plate's (3mm) and replaced it with one of the thinner 2.7mm ones. Big difference, very easy to pull now. Haven't cooked a clutch yet and i can be hard with it in 3rd gear at times.

It's mentioned in the Beta Clutch fix at the top of the index page.

[markparrish]

As the bolts don't bottom out (they tighten down in their threaded holes in the basket until the spring retaining washer is held tight and the spring is compressed below applying pressure to the plates) I don't think their length makes any difference. What you need to do is change the amount the springs are compressed by using a "top hat" washer as mentioned above or introducing a spacer washer. The problem with a spacer is that the resulting height of the top of the bolt is increased and may therefore interfere with the inside of the casing. I made some top hat types and used countersunk screws on my 2T - this gave me approx 3mm less compression with no increase in overall height and the clutch seems lighter but doesn't slip (for me anyway!). I think the standard top hats that some models have give about the same change on compression length, so we are not talking about too much height change. You might get away with a simple spacer but there isn't much room in there!

[pauls320]

Have you looked at going with a different of modified lever with a shorter distance between pivot and plunger pin? You will get a little less overall throw but will make lever pull easier...might not notice but will make clutch action bit quicker too. 

[reggie]

Clake One Light Clutch  may work for you.

 

[lineaway]

Best way is to find lighter springs. And no I did not do all the work for you. My `16 Beta 250 I used Gas Gas 160 springs, no slip and the lightest clutch feel on the planet. No lie, everyone that tries it cannot believe it. I had too as I cut the tendon off in my clutch finger last year.

[stu109]

Thanks for all your helpful comments.  I can now see how my thinking on longer bolts was completely flawed.

In summary my options look to be:

• Remove 2 springs.
• Replace one of the 4T's thicker plates with a thinner one from a 2T.
• Put small washers under the "top hat" washers.
• Fabricate new "top hat" washers with a deeper "hat".
• Fit lighter springs.
• Try different lever set up.

I'm going to start with the washers under the top hats as this is simple and keeps all 6 springs.  Will let you know the outcome.

lineaway, at the risk of sounding dumb, when you say Gas Gas 160 springs, is this the weight of the springs or the springs off a GG 160?

 

[lineaway]

Off a 160 gas gas, but I did have to shorten the springs. Spring companies do make springs to order, but tend to be cheaper in lots of 100. Years ago the bike shop that I worked at had a spring tester. That would be handy now.

[chesticle]

OK, here is what I did, and it works great. I am on a 200 Evo 2T and I weigh 115 pounds, so every bike/rider combo is going to be different as to whether softening the clutch will make slip or not. I had to play around with some different combos...

1. Put one thick friction plate at the back of your clutch pack, and one at the front. The other four in the middle should be the thinner plates (these come stock on the 2Ts).

2. Remove all springs.

3. Purchase a set of the Beta top hat washers.

4. You will now replace 4 of the springs (2 each on the opposing sides so the clutch is still balanced) and place the top hat washers with the small end facing away from the engine. This puts more preload on the springs, which is what you want since you now only have four).

 

[lineaway]

 Taking two springs out always comes with slippage. If you only ride around in first and second gear all is good for the most part. If you ride hard or any kind of loop it is worthless. The first time you hit something steep and the clutch lets loose, I hope the results are not too bad (Just like hitting nuetral). The factory puts in a full compliment of springs for a reason.

Edited March 8, 2018 by lineaway