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Discussion Starter #1
So today I was doing my first oil change since owning my 02 ST4S and thought, what the heck, Ill take a look at the clutch while Im down here. I pulled the cover and to my dismay I found some pretty substantial wear on the basket where the tangs from the 1st friction plate impact the basket. I didnt pull the whole clutch out as it was getting dark but did snap a few shots. Any advice would be greatly appreciated. Ill be pulling the whole thing out later this week to inspect everything. I haven't noticed any performance issues other than it being noisy, but i figured that's the nature of the beast.







 

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Discussion Starter #3 (Edited)
Thanks Bill, I did read that thread earlier and my basket doesnt appear to be as grooved as his is. The previous owner had a new clutch put in I believe 10k ago. The bike has 33k on it. That reminds me, I need to get in touch with him to pick up all of his service records for the bike. I just checked tonight and I do have a 42t rear, although I feel it is still too tall of gearing for my liking. Will dropping to a 14t front cause any issues with the swingarm in the way of clearance? I just mainly wanted to know if this is something I should worry about or if it is ok? Im not used to dry clutches and the basket on my VFR looked pristine even after 68,000 miles.
 

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Thanks Bill, I did read that thread earlier and my basket doesnt appear to be as grooved as his is. The previous owner had a new clutch put in I believe 10k ago. The bike has 33k on it. That reminds me, I need to get in touch with him to pick up all of his service records for the bike. I just checked tonight and I do have a 42t rear, although I feel it is still too tall of gearing for my liking. Will dropping to a 14t front cause any issues with the swingarm in the way of clearance? I just mainly wanted to know if this is something I should worry about or if it is ok? Im not used to dry clutches and the basket on my VFR looked pristine even after 68,000 miles.
There have been reports here of 14T front sprockets causing clearance problems with the swingarm. Mark Turbo has used 43T rear sprockets for most of the 72,000+ miles on his 02-ST4s. You might try one of you feel a 42T rear sprocket is still too tall.

Even though I am not yet riding, my son and I would be happy to pile in the F-150 and meet you for lunch some time. Is the Blue Bird Cafe in Arlington still open?
 

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Discussion Starter #5
There have been reports here of 14T front sprockets causing clearance problems with the swingarm. Mark Turbo has used 43T rear sprockets for most of the 72,000+ miles on his 02-ST4s. You might try one of you feel a 42T rear sprocket is still too tall.

Even though I am not yet riding, my son and I would be happy to pile in the F-150 and meet you for lunch some time. Is the Blue Bird Cafe in Arlington still open?
The Blue Bird down on Olympic.. yeah, at least it was a few months ago, but I dont think any new shops have closed downt town for a while so it should still be there. I'd love to meet up sometime, come Oct 1 however Im going to be a lot less mobile seeing as the License inspectors have inspected my license one to many times and the state decided, after 9 months I might add, to take away my driving privilages for 30 days. Im pretty sore about that one still, its gonna be the last of the decent weather and Im gonna miss it. PM some time and we can arrange a meet up, or perhaps I could swing down to edmonds after work some day, i work in south everett.
 

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From the pics it looks like the first plate's tab isn't exactly flat like # 2 is. The protrusion would hit first causing the wear that you see on the basket. Unless the other tangs also have a raised piece on them the rest of the basket should be more consistent.

At least that's how I see it. Mine were VERY consistent. Consistently worn and loud. New basket and plates took care of that. Not I cannot believe how quiet things are down there.
 

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It’s to be expected.

Every time you engage the clutch, the plates that are driven by the engine through the clutch hub, push against the clutch basket fingers that drive the rear wheel. When eventually a gap develops between the plate tabs and the basket fingers, it results in an impact force between the surfaces that will both deform the plate tabs and notch the basket fingers. The larger the gap, the higher the impact forces - and the higher the impact forces the greater the deformation of the plates and basket.

So they get louder and louder until the plates and basket are replaced. It’s a progressive process, reset only by the replacement of worn-out mushroom-tabbed plates and notched baskets.

The OEM clutch (on most models) has steel plates and a steel basket that initially have a small gap between them. Aftermarket clutch components that are aimed at the performance end of the market, substitute aluminum plates, hubs and baskets to reduce their flywheel effect. Aluminum plate clutch packs are about 1.5 lbs. lighter, but because they rotate half as fast as the flywheel, their effect on performance is minimal at best. The plate-to-finger gaps of these pruducts are often initially smaller than the stock tolerances when installed as a plate-basket package such as the Barnett-Nichols combo. However, aluminum is a softer material, and consequently more suceptible to impact-induced deformation that eventually leads to larger gaps.

There has been some innovation to try to address this durability issue, however.

For example, STM has tried to overcome this problem by increasing the number of tabs on each plate (and the number of basket fingers) from the stock 12 to 48 tabs. The intended result is to distribute the impact loads over a larger tab-basket contact area (lower psi) to reduce notching to the clutch basket fingers and mushrooming of the plate tabs.

Nichols Manufacturing designed their CNC-machined aluminum basket with wider basket fingers that results in larger finger contact area and consequently lower impact stresses, particularly when combined with their Barnett clutch pack where extra care has been taken to initially minimize gaps.

All the comparisons that I've read say that Ducati OEM steel plate friction material tends to outlast the aftermarket plates. In one case, 25,000mi vs. 16,000mi (Barnett). So, at roughly the same price, the stock plates seem to be the better deal.

Finally, keep in mind that when you mix steel and aluminum, the softer metal deforms preferentially and clearance gaps suffer, more than for steel-to-steel. So if you have a steel basket, stick with steel plates.
 

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The ware you see is normal. The only thing is that there should be groved on all plates
 

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From the pics it looks like the first plate's tab isn't exactly flat like # 2 is. The protrusion would hit first causing the wear that you see on the basket. Unless the other tangs also have a raised piece on them the rest of the basket should be more consistent.

At least that's how I see it. Mine were VERY consistent. Consistently worn and loud. New basket and plates took care of that. Not I cannot believe how quiet things are down there.
I agree with this observation , wonder why that 1st plate is formed different.
Was it modified and should be at the bottom of the stack and got put back wrongly ?
 

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And looking at the minimal wear on the rest of the basket and other friction tabs, you would be close if not over the 0.6mm clearance for service limit. Mine is the same and has been since new so it makes me think that Ducati tolerances were not that small to start with.

Maybe they want you to hear the rattle from new......................
 

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doesn't look that bad... my personal "ear" enjoys the rattle...keep a normal inspection interval going.
 
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