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The Beta Clutch Fix

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  • You bet!

  • markparrish
    markparrish

    Having only recently embarked on my trials experience I have been so pleased to have found the great advice and support on this forum. I thought you might be interested to see my clutch mod based on s

  • dan williams
    dan williams

    Your oil is roughly the same as 15wt motor oil according to the charts I can find so nothing odd there. It sounds to me as if your clutch is operating properly but you could try adjusting the set scre

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Thanks Dan, my neighbours are all a darker shade of green now!

Just to add to this, it's very important to pay careful attention to the free play in the clutch lever. Adjusting it to the minimum slack you can get away with, means more separation of the clutch plates when it is pulled in.

Its a pity Beta leave us with this to sort out as it takes a fair bit of time to do this and you would need to be confident in your mechanical abillity!!! Surely they could get better cluch plates for little extra cost.

I think this is where the GasGas build quality shows as they seem to concentrate on the bike performing but the rest of the bits and pieces like the airbox etc can suffer a bit.

Its a pity Beta leave us with this to sort out as it takes a fair bit of time to do this and you would need to be confident in your mechanical abillity!!! Surely they could get better cluch plates for little extra cost.

I think this is where the GasGas build quality shows as they seem to concentrate on the bike performing but the rest of the bits and pieces like the airbox etc can suffer a bit.

I have a 2010 evo and the clutch works fine as did my 09, maybe I'm lucky but I haven't heard of many complaints about the evo clutch as compared to the rev 3.

chewy, Could you post the specs on those 80% clutch springs. I'd like to give them a go. Do you notice any slipage, Is there a noticable difference at the lever, and do you think you could go lighter?

  • Author
Its a pity Beta leave us with this to sort out as it takes a fair bit of time to do this and you would need to be confident in your mechanical ability!!! Surely they could get better cluch plates for little extra cost.

I think this is where the GasGas build quality shows as they seem to concentrate on the bike performing but the rest of the bits and pieces like the airbox etc can suffer a bit.

It's possible Beta just never understood this to be an issue. Remember we're dealing with a small manufacturer with limited resources. Also remember ALL the bikes have some foibles from Beta stators to GasGas transmissions and starters to Sherco shocks to Montesa wheels. As far as quality goes at this point they're all about the same. These are after all purebred racing machines from small companies that are struggling to survive. The fact that the bikes are as good as they are at this point is frankly amazing. It wasn't long ago a trials bike was a modified trail bike and before that a modified street bike. You get to ride the two-wheeled equivalent of a Lamborghini Countach with all of these machines. How cool is that. As I've said before the difference between a full on factory bike and the everyday bike you can buy from the dealer is 90% preparation and 10% fancy parts. Just consider this part of the 90% prep that makes your bike that much better than the next guys.

"It's better to light a single candle than to curse the darkness."

I'd rather this didn't turn into a whine and moan thread. As an engineer I see a need to fix something and get satisfaction from the exercise of analysis, design and testing necessary to solve a problem. There are engineers at each manufacturer who do the same. I'd rather help them then pick on them. I'm sure Beta isn't pleased with this thread even though in the long run it will be beneficial to them. Maybe now understanding the problem they will go back to the supplier and give them a, "What's it to ya?"

I'll have to talk to my spring supplier for exact details physically of course they are same dia & length ..I just took my std ones in and asked for c.80% rated springs. They do lighten the finger pressure rqt if you're sensitive and the clutch feels less snatchy. however Dan's fix although a lot of fiddling/ time & effort makes a really noticeable difference even from cold. Next move is to sort out the lube I hear that PJ1 is best option dont know spec of that either! Will get back to you with spring force rating etc. You could of course put em on the bathroom scales and get an approximation of standard springs..(force = Mass x acceleration acceleration is gravity 9.81m/s/s) so mass is your unknown in F=ma..so if my maths is any good (which is aint!) Force (in newtons.. ...1 newton =1kg x gravity)= however many kilos it takes to compress it x gravity 9.81)) Then you can be sure(by sods law)that the spring people will want to know the pressure exerted Pressure = force per unit area.... I 've had enough of this theory stuff..my edumacation ended over 40 years ago... I'll ask and get back to you.

I'll have to talk to my spring supplier for exact details physically of course they are same dia & length ..I just took my std ones in and asked for c.80% rated springs. They do lighten the finger pressure rqt if you're sensitive and the clutch feels less snatchy. however Dan's fix although a lot of fiddling/ time & effort makes a really noticeable difference even from cold. Next move is to sort out the lube I hear that PJ1 is best option dont know spec of that either! Will get back to you with spring force rating etc. You could of course put em on the bathroom scales and get an approximation of standard springs..(force = Mass x acceleration acceleration is gravity 9.81m/s/s) so mass is your unknown in F=ma..so if my maths is any good (which is aint!) Force (in newtons.. ...1 newton =1kg x gravity)= however many kilos it takes to compress it x gravity 9.81)) Then you can be sure(by sods law)that the spring people will want to know the pressure exerted Pressure = force per unit area.... I 've had enough of this theory stuff..my edumacation ended over 40 years ago... I'll ask and get back to you.

what he said :xmas:B):)

I'll have to talk to my spring supplier for exact details physically of course they are same dia & length ..I just took my std ones in and asked for c.80% rated springs. They do lighten the finger pressure rqt if you're sensitive and the clutch feels less snatchy. however Dan's fix although a lot of fiddling/ time & effort makes a really noticeable difference even from cold. Next move is to sort out the lube I hear that PJ1 is best option dont know spec of that either! Will get back to you with spring force rating etc. You could of course put em on the bathroom scales and get an approximation of standard springs..(force = Mass x acceleration acceleration is gravity 9.81m/s/s) so mass is your unknown in F=ma..so if my maths is any good (which is aint!) Force (in newtons.. ...1 newton =1kg x gravity)= however many kilos it takes to compress it x gravity 9.81)) Then you can be sure(by sods law)that the spring people will want to know the pressure exerted Pressure = force per unit area.... I 've had enough of this theory stuff..my edumacation ended over 40 years ago... I'll ask and get back to you.

Chewy, what you need is the spring constant in N/mm. You're nearly there, if you put 1 kg on top of the spring and it moves 1mm, the spring constant is 9.81N/mm. So 80% of that is 7.8 N/mm, which is what you need to ask them to make!

Just finished my son`s bike. What a difference, the best ever mod I can think of doing for free. Wished I`d had this back when I got my first `89 Beta. Can`t believe how many points it would of saved through the years. I cheated and used a dremel for the whole thing. Thanks Dan for the great advice!!

  • Author

Glad it's working for you.

Now if I can get Andy to pin my ignition epiphany post/document from last year I'll only be one away from a hat trick!

Glad it's working for you.

Now if I can get Andy to pin my ignition epiphany post/document from last year I'll only be one away from a hat trick!

Thought you said your stator was going anyway?

Lineaway did it with the dremel, on another thought, one of them vibrating multi tools with the diamond cutter disc might just knock the edges right off?

  • Author
Thought you said your stator was going anyway?

Not my bike. Friend's '01 that had been absolutely hammered. I won't go into that horror story.

I still think the ground wire mod is absolutely essential to the longevity of the Beta ignition system.

Chewy, what you need is the spring constant in N/mm. You're nearly there, if you put 1 kg on top of the spring and it moves 1mm, the spring constant is 9.81N/mm. So 80% of that is 7.8 N/mm, which is what you need to ask them to make!

bought 100 yesterday ..going like hot cakes just coincidentally dan the spring pressure is specified at 9.95 Newton/mm

Dan,

what is the ground wire mod, any idea where the link is :)

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