Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 998 / 996 / 916 / 748 > Techi clutch question.

[Red-leader]

Due to various reason I am now on my third clutch assembley. None have been changed due to the clutch actualy slipping, so could you please help me out here.

What is the best combination of outer baskets and plates. So far I have had the standard set up, the outer basket and plates wore and both needed replacing.
Then lightweight outer basket and steel sintered plates, again both have worn and now need replacing.
And now Iam trying Ali plates and lightweight outer basket.

Is it right that the tabs on the plates should wear, all the changed plates have had loads of life left in them if only the tabs would not wear so bad.

So what say you ?

Thanks K

[Edited on 8-3-2005 by Red-leader]

ha ha ha ....... try changing gear less ....... or baby oil the tabs .......


or buy a H O N D A

x

[NBs996]

I got through a set of plates and basket on very few miles.
Changed to a 48 tooth assembly - in theory the contact is spread over 4 times the area so the tabs should take much less of a beating.

What sort of miles are you talking about from the 3 sets you've got through kev?

c29000 miles .. the tight git ....... joke

[Red-leader]

I guess the last set up did 10k. Its not the fact that the plates go that gives me the arse. I would happily change plates every 10k miles. Its that you have to change the whole bloody lot. Surley the plates are a cosumable, we all realise that. But the whole clutch assembley, I dont think that is realy on.
Now I know the usual coments about buying the Duke, and Iam still very happy with it and enjoy owning it. It just seems wrong some how.
K

[NBs996]

Just keep filing the groves out of the basket until they break off!

p.s. i didn't mean it!

[nelly]

As Nick mentioned, the 48T setup will give longer life. It may be coincidence but 4 times the longevity seems to be the rule of thumb.
If using standard parts is your favoured route then probably ST4S clutch plates with either a steel or alloy basket will give the best results.
The ST4 plates are alloy but have a broadened contact face on the tangs.
A steel basket will mean the plates take the wear, and whilst maybe accelerated over an alloy basket, will at least mean you only need change the plates when they are worn.
To be honest, 10k isn't bad for a clutch set. I know what you mean about the life span compared with "other makes" but a dry clutch will always wear quicker than a wet one and the V motors do give them a hammering, even without too much help from a hefty right hand
It's not very often a set of plates wear away the friction material before the tangs are mullered. You will be surprised how bad they can get though and still work OK. They rattle like buggery but still do the job...........ask Old Yella

[Shazaam!]

If you’ve not worn-out your clutch pack friction material, but only the plate tabs are hammered, there’s really no need to replace the plates.

Also, just because your your clutch basket fingers have been notched by the plates, that’s no reason to replace them either.

You’ll just have a noisy clutch.

The first time that the plate friction material wears out you’ve got a decision to make. Do you replace them with stock parts, or do you take this as an opportunity to install an aftermarket clutch, or for significantly more money, do you install a slipper clutch.

So, what should you know before you decide?


Ducati Clutches

The Ducati dry clutch on most models use steel plates, hub and basket. It’s noisy and it’s heavy, compared to aftermarket units, but it’s pretty durable and the friction material lasts at least as long as aftermarket plates. The reason that they’re noisy is that each time you shift, the edges of the plates hammer the fingers of the basket, causing each to deform, causing the gap between them to get larger, causing higher impact forces, and causing more rattling noise when the clutch is disengaged. So they get louder and louder until the plates and basket are replaced.

You’ll need to replace the plates when the thickness of the friction material gets too thin to prevent slipping. You’ll notice a little slippage first when starting-off in first gear, but when it starts to slip in top gear it’s time for a new clutch pack.

Depending on the mileage and the depth of notching, you will probably will want to replace the basket at the same time. A notched basket will be louder, but I’m not convinced that it makes it any more difficult to for the plates to separate when disengaging the clutch. But replacing just the plate stack, which then has to engage the basket notch pattern worn-in by the previous plates, will possibly affect your ability to shift smoothly.




Aftermarket Clutches

Aftermarket clutch components are marketed as performance items with unique features that are intended to address design deficiencies in the OEM clutches. Foremost is lighter weight.

Aluminum drive and friction plates, basket, hub and pressure plates combine to reduce rotating mass as well as overall bike weight. Less rotating mass in the engine allows it to change rpm more quickly and less overall bike weight improves acceleration, braking and handling.

However, the reduced mass offered by an aftermarket clutch alone is not very significant because the clutch turns once for every four revolutions of the flywheel. Consequently, it is accelerated one quarter as quickly as the flywheel, so rotational weight reduction at the flywheel, gram-for-gram, will give you four times the effect as weight reduction at the clutch. Reducing the flywheel and clutch weight often will adversely affect drive-train smoothness (so unlike lighter wheels, for example) this is not necessarily an overall improvement for the street.

The weight savings from an aluminum clutch basket and plates is about 3.5 pounds, less than 1% of the overall bike-plus-rider, so any improvement in performance is not really of major importance in deciding to change to an aftermarket unit.

Clutch durability is another area where aftermarket clutches are marketed as an improvement over stock clutches. Clutch life varies widely from rider to rider but all direct comparisons suggest that the Ducati OEM clutch plate friction material has outlasted the clutch plates from aftermarket manufacturers. In one case 25K vs. 16K miles. So, at roughly the same price, the OEM plates seem to be the better deal.

There has been some innovation to try to address the durability issue associated with the plates impacting and notching the basket.

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. STM also changes the angle of the tooth and the angle on inner steel drive plate teeth which gives length to the tooth as well to increase the loaded area.

Only STM makes a 48-tab clutch pack, however, so you’re locked-in to using their plates next time.

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 aluminum clutch pack where extra care has been taken to initially minimize gaps.

Another option is a Barnett aluminum basket with stainless steel inserts to protect the basket fingers.

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, ALWAYS stick with steel plates.

Don’t mix materials.

[Red-leader]

Thankyou very much for your information, very helpful.
I have the new clutch to fit so lets see how it performs.
K

[adam]

did you go for the slipper clutch?