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Discussion Starter #1
I've tried the search function but didn't find anything.

I'm looking for a 7-plate clutch kit for a 1970 Bonneville
650, from a vendor in the US.

Does anyone have a source/link for this kit?

If not in the US, other vendors will be considered.

Thanks!
 

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HM, I guess its implicit in the question that you're having trouble with the 6 plate set up. Whilst I have no experience with the 7 plate kits, I'd be interested in why you're considering a change. RR
 

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If you've got a spare steel plate,you can do with standard plates for about $10.
Do it the same way Triumph did on the later models;glue some friction material into the clutch basket with contact adhesive.
If you want good friction,use 1/16 thick cork sheet (gasket material).This stuff has about 3 times as much grip as the normal linings,and I've never worn one out.

The total stack-height of the plates is increased,so you need to bend 4 tangs on the outer steel plate inward at 45 degrees.Otherwise,the outer steel plate can drop down when the clutch is disengaged.

You then have 6-1/2 effective plates ,compared to the original 5-1/2 effective plates(18 % improvement).
 

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I can't see why anyone wants a 7 plate clutch,I would rather spend the money on something else. There is nothing wrong with a standard Triumph clutch as long as it is set up properly with no deviation on the pressure plate. This can take up to 1/2 hour to get exactly right.
 

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There is nothing wrong with a standard Triumph clutch as long as it is set up properly with no deviation on the pressure plate.
Triumph clutches are marginal,at best,and have been ever since Bonnevilles were invented.If you want to use full hosepower they are hardly,and often not,up to the job.
I gather that Plewsy recently fitted a 4-spring cush-drive to overcome the problem.

At times I've got sick of washing every last trace of oil off plates with solvent,maybe every few weeks;just to get 2% more grip than I need,instead of 5% less than I need.The plates obviously weren't worn,they just didn't grip.Some people sandblast the steel plates and claim it helps,for a while.
How do you go when you're making 5,10 or even 20 bhp more than a standard engine?
 

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Triumph clutches are marginal,at best,and have been ever since Bonnevilles were invented.If you want to use full hosepower they are hardly,and often not,up to the job.
I gather that Plewsy recently fitted a 4-spring cush-drive to overcome the problem.

At times I've got sick of washing every last trace of oil off plates with solvent,maybe every few weeks;just to get 2% more grip than I need,instead of 5% less than I need.The plates obviously weren't worn,they just didn't grip.Some people sandblast the steel plates and claim it helps,for a while.
How do you go when you're making 5,10 or even 20 bhp more than a standard engine?
Pete,

You are right you know. Like the cylinder heads, the clutches on the Bonnevilles are marginal. You're suggestion of a 5 & a 1/2 plate clutch sounds just right to me. RR
 

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I BOUGHT MINE FROM WALRIDGE IN ONTARIO CANADA, I FIGURED BECAUSE THE CLUTCHES WERE WEAK FOR A 650 THEN THE 750 MORGO KIT ON MINE WOULD NEED SOME HELP, IT WORKS FINE,
WWW.WALRIDGE.COM
I HAVE A 72 TIGER AND THINK THE KIT WAS $143
 

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I have never had a Triumph clutch slip. Always use new plates and have the plain plates grit blasted, then there is nothing wrong with them at all. I drag raced my Bonneville for a season and it never slipped.
 

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I have never had a Triumph clutch slip. Always use new plates and have the plain plates grit blasted, then there is nothing wrong with them at all. I drag raced my Bonneville for a season and it never slipped.
Hi TBS,

Good to hear someone is supporting ET's clutch design.

To be strictly fair to dear old ET, I rode a '64 T120 in '66 (with no great mileage on it) and I never had any clutch problems with that bike.

Your experience may be the exception rather than the rule, as I see many complainants about the Trumpy clutch, and the 7-plate upgrade is touted by many to be "the end of your clutch problems". What problems you say?, slipping and/or dragging would be the response from a vast multitude.

Whatever you're doing with the clutch set up TBS, don't change it!!

My '72 has been completely rebuilt from scratch, and using Triumph's recommended spring tension, it will let go from time to time, and this is in 5th. I have this past week-end applied additional spring tension in the hope this will be a cure. The springs are new and are now tensioned much tighter than recommended.

It is not rocket science to set up a Triumph clutch, though one must understand several nuances associated with the thing.

With a shared engine/primary, oil does come into it, but in my case I've retro modified the primary and so I use ATF type "F" in lieu of engine oil to eliminate this as a cause of these problems.

Whilst I'd like to say the real cause of the slipping is the 200 bhp the old tart produces, this would be a fib, and we must not tell fibs.

My experiences lead me to the belief, along with Pete, that the whole clutch design is marginal. This does not exclude the possibility of reliable, serviceable clutches (as you seem to have), but it does explain all the problems many others do have. It also explains the present booming business being done by the manufacturers of the 7-plate upgrade.

Pete's suggestion makes a lot of sense to me and I'd be trying that (should the need arise) long before throwing good money at 7-plate setup. RR
 

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I have a 7 plate clutch from Norman Hyde. If a clutch needs complete replacement, as mine did, I think it's a good upgrade. The friction plates are different and you get good grip with no slippage and very little sticking. Also you can use less spring pressure or lighter springs to give a lighter pull on the lever and if you also change the lever to one with a 7/8" fulcrum point it makes a world of difference.
Just my two pennyworth.
John
 

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I'm very pleased with the 7 plate conversion on my TR5T. No need to free off before starting, no clunking into gear. Dont remember it costing much and cant remember where I bought it but IMO well worth it.
Chris
(Lewes England)
 

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Well, there you go HM. I think the ayes have it.

All the boys are happy and no doubt you will be too. I'm saving my money and settling for the 5.5 plater, should the need arise. Best of luck. RR
 
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