what are the better clutch plates to buy for 850

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comnoz said:
Has anyone out there run these plates yet.

http://www.ebay.com/itm/261304189675?_t ... EBIDX%3AIT
Click to expand...
what are the better clutch plates to buy for 850


Is it just me, or does it appear that a rather large amount of facing material has been eliminated from these plates? If so, that would seem to be contrary to getting a good grip from the clutch. You could argue higher contact pressure due to the smaller surface area, but it's the surface area that counts (for a given material). 'Not my idea of a good thing...

Of course, if someone is using them and loves them, I'm all ears!

Nathan
 
there is more to it than JUST surface area. actually it is a good thing. you have moved the effective radius farther out. it is like adding a cheater pipe on a ratchet so it takes less torque to turn the center but in our case it takes more torque to make it slip

Nater_Potater said:
but it's the surface area that counts (for a given material).

Nathan
Click to expand...
 
bill said:
there is more to it than JUST surface area. actually it is a good thing. you have moved the effective radius farther out. it is like adding a cheater pipe on a ratchet so it takes less torque to turn the center but in our case it takes more torque to make it slip
Click to expand...

+1 and you can turn down the inner circle of the steel plates and loose two thirds of their weight. On the other hand if you use Barnett plates the total clutch stack weighs even less!
 
I like the idea of less surface area at a larger diameter. I used something like these in my racebike with a custom drum. They were KTM clutch plates with a narrow bronze lining and they worked excellent.

I could never stop the original bronze plates from slipping with a performance motor.

Anyway I ordered a set as my Barnetts have 40,000 miles and the teeth are getting a bit thin . I will be increasing the ID of the steel plates and lightening the lined plates before I install them. I guess I will find out how they work. Jim
 
Do you think there might be a problem with heat build up on those narrow steel plates? Less steel, less heat sink?
 
Deets55 said:
Do you think there might be a problem with heat build up on those narrow steel plates? Less steel, less heat sink?
Click to expand...

I never had heat problems with the KTM plates and they were narrow and considerably thinner. Plus I was abusing them on a racebike.
Time will tell. Jim
 
bill said:
there is more to it than JUST surface area. actually it is a good thing. you have moved the effective radius farther out. it is like adding a cheater pipe on a ratchet so it takes less torque to turn the center but in our case it takes more torque to make it slip

Nater_Potater said:
but it's the surface area that counts (for a given material).

Nathan
Click to expand...
Click to expand...

Yes, but up to a point. I agree wholly with you about moving the friction point further out (think "bigger brake rotor"), but we're constrained by the clutch basket for how big we can go, and I believe the stock and Barnett plates already run pretty much clear out to the edge.
what are the better clutch plates to buy for 850

what are the better clutch plates to buy for 850

In that light, the plates in question have removed some of the available material, so I stand by my earlier statement. I think the confusion is that the image makes it look like the contact point is moved out further, but that can't happen in the stock clutch hub.

Nathan
 
Nater_Potater said:
bill said:
there is more to it than JUST surface area. actually it is a good thing. you have moved the effective radius farther out. it is like adding a cheater pipe on a ratchet so it takes less torque to turn the center but in our case it takes more torque to make it slip

Nater_Potater said:
but it's the surface area that counts (for a given material).

Nathan
Click to expand...
Click to expand...

Yes, but up to a point. I agree wholly with you about moving the friction point further out (think "bigger brake rotor"), but we're constrained by the clutch basket for how big we can go, and I believe the stock and Barnett plates already run pretty much clear out to the edge.
what are the better clutch plates to buy for 850


what are the better clutch plates to buy for 850

In that light, the plates in question have removed some of the available material, so I stand by my earlier statement. I think the confusion is that the image makes it look like the contact point is moved out further, but that can't happen in the stock clutch hub.

Nathan
Click to expand...

Nate, it does work, it moves out the centre line of the contact patch, effectively increasing the average swept area diameter. This is why modern sports bikes have large discs with very narrow pads.

P.S. I should point out that I'm talking 'in theory' here and from having used similar plates in Weslake racers, but I haven't used these plates.
 
Apart from the crap work carried out by a previous owners mechanics [ using a copper washer under the clutch hub nut, and not loctiting the start end main shaft nut ] I don't have any probs any more. I don't even experience the gear oil prob in the clutch even though my g/box is slightly overfill with 90 oil. [ next job is to lower that level though as a result of the comments made on this forum.] Most of my riding is high speed as all the towns round here you can get through in 1-2 minutes.
Thanks for all the comment guys. I am still to make a decision on which ones to buy
 
Eddie is right, the center of the friction material is the diameter that counts.

With a little lightening done the complete clutch pack is 20 grams heavier than the Barnett setup I was running before.
If it doesn't squeal, slip or wear out as fast as the Barnetts I will call this a good change. Jim

what are the better clutch plates to buy for 850
 
That looks good, Jim. You could use the aluminum Barnett plates and do your same lightening holes along with cutting off some of the friction material.

I run ATF in my Barnett set up and it does not squeal. I always add just a bit more than the 200cc that it calls for. Dan.
 
The Barnetts have squealed in my bike through the last two sets. I run a dry primary. I am tired of hearing it.

I weighed my clutch packs again. I missed a plate.

The new pack comes out 116 grams less than the old setup with the Barnetts. Jim
 
My 750 which has done just over 13,000 miles, still has the original fibre plates and they still look like new. Those ones just shown above look badly wasted. Why?
Dereck
 
Wow,
I did some digging to see how long the last set of Barnetts had been in my bike. Less than I thought -about 24,000 miles but they looked a lot better than that. Jim

Are you running a lightened crank?
 
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