| #3  11-Aug-2004, 16:55 | ||||
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| Decisions, Decisions ... 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.  The price of the Ducati original equipment manufacturer (OEM) parts varies from dealer to dealer, so shop around. Also, the 999 comes with an aluminum basket that works on the older bikes. It retails for less money than an alloy aftermarket part. Aftermarket Clutches After market clutch components are marketed as performance items with unique features that are intended to address design defficiencies 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 drivetrain 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 buy. 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. Only STM makes a 48-tab clutch pack, however. 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. 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, stick with steel plates. [Edited on 8-11-2004 by Shazaam!]  |
| #4 11-Aug-2004, 17:42 | |||
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| cool thanx for the info I've always been tempted by nichols mnf's dual spark cyclinder head  I'll give ducati coventry a ring, see if they have the clutch parts I need. Is there any UK based online suppliers for ducati stock bits so I can compare prices? |
| #5 11-Aug-2004, 17:46 | ||||
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| #6 11-Aug-2004, 18:30 | ||||
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| Ducati have their dealers on the same price list so JHP won't be any cheaper than anywhere else. You may get a "deal" if you show 'em your DSC memebrship card.........if you have one? If not, it could be worth joining  |
| #8 11-Aug-2004, 21:05 | ||||
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Shazaam!
...and I fancy the trackday discounts 
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