Slipper clutch options
 

I'm thinking about fitting a slipper clutch when funds allow, it seems like there is a fair bit of choice, anyone got any recomendations on best value/quality for road/odd track day use??

TIA

Oh the choices....

I guess you have at least the following

Bucci road/track
STM 48T
Ducati Corse
JHP/Sigma.... etc etc

Pros/Cons from my point of view

Bucci (Pros) - You can use your existing plates. plenty of spares and easy to maintain. (Cons) - Bearings supposedly need regreasing every 1000 miles (dunno if that is strictly fact or not), due to being a 12 tooth basket that'll wear quicker than the STM.

STM (pros) - Plates should last longer as there are 48 points of contact (Cons) clutch plates are more expensive as specific to the clutch, and you need a specific (expensive) tool to remove the pressure plate, if you were to do a foreign trip, or track day abroad and your clutch went could you find a set of plates?:puzzled:

Ducati Corse (pros) - probably the best action of the lot, I would imagine will take more HP than the others being a full race item (cons) - spares?

JHP/Sigma (pros) - cheaper? but pretty much identical to the standard 12 Tooth baskets etc (cons) - same as above.

have an stm 48t evolutione love it, had no problems with it probably done 4k+ with it so far. recommend.

I'd looked closest at the DPP road item as I wasn't too sure about plates, spares etc and also how long the race clutch would last.

I was pretty much decided that the STM 48T looked a good option. But I appreciate the spares are a possible issue!

As a matter of interest ... as the standard clutch basket seems to have small tabs and large area of basket between them, would the std plates fit the 48T basket in an emergency? Or is that really daft? (I have not seen an STM clutch (in the flesh) so I have no comparison.

[Edited on 19-5-2005 by HW]

12 tooth plates won't fit a 48 tooth basket I'm afraid.

I have the Corse slipper, as do a few others on here. It's a 12 tooth jobbie and very well made, but I *think* that it may be made by Bucci? Mine is a classic 6 ramp and ball bearing design but apparently Corse dropped the ball bearings and two ramps after that so they could put the plugs in to bump start the bikes without the clutch slipping.

I'd only get the 6 ramp and ball bearing version myself because I don't want to be pulling the clutch apart to grease the ramps regularly (lazy sod!).

Out of interest...anyone know how much a set of plates cost for a 48tooth STM slipper?

Clutch plates

http://www.carbonworld.de/shop/index...43_169_206_213

STM plates link
http://a.shirley.users.btopenworld.com/stm/plates.htm

£181

[Edited on 19-5-2005 by HW]

Don't forget the tool also for the STM

That's needed just to change plates is it?

To remove the pressure plate, it was mentioned in a thread earlier in the week

So it was ... sorry. :(

Just found the thread Henry.

http://www.ducatisportingclub.com/xm....php?tid=19539

Oh right .. ta. I thought you were rapping my knuckles because I had not read your reply from this morning on THIS thread properly .. where you mentioned the pressure plate removal!

:)

anyone know how much they are??:o

Nelly sells the STM's so I guess he would be a good place to start

There seems to be a requirement to mess about with the thickness of the STM clutch pack to keep it working correctly. I may be wrong, but that is what I got from it. Also read that on the Sigma site this morning where they describe slipper clutches. I am not sure I would want to be messing about with that at fairly frequent intervals - alright if you use a bike for track use/racing but if you ride on the road and take on holiday it could be an issue. Same with greasing the bearings on the ones that require that.

OK - just been reading on the Sigma site
http://www.sigmaperformance.com/slip...racesetup.html
where it explains about the thickness of the clutch pack and how changing it alters how the clutch behaves. You can either make it so it slips straight away or give yourself some degree of engine breaking so it only slips under extreme circumstances. As the plates wear a bit the total thickness of the pack changes and it can be enough to change the working point of the clutch.

(I think I explained that for myself as much as for anyone else!) :eureka:

Incidentally .. Sigma have a 48T slipper clutch but it uses the std pressure plate and springs so no special took required. SOunds like a viable option - best of both worlds?

[Edited on 19-5-2005 by HW]

no such thing as a maintenance free slipper clutch yet, unless you have a wet clutch.
I probably strip mine down every month while im using the bike and grease all the parts, if you don't do it regularly there wont be much grease on the parts that need it as it gets flung of by the rotation

Fair comment ... point noted!

You also need a heat resistent grease, again someone posted a link to this stuff ages ago, I bought a tube, it isn't cheap to say the least!

not that i know mutch but .. my 2p ... i didnt like the slipper clutch that came with my bike (corse one i believe) was fine for a few thousand miles but then turned into an arse with every start a raceing start or a stall (fine for the track but makes you look a nob in town) and then the plates died after about 6 k (thank god thers an outpost in thurso)

also ive gotten the idea that slipper clutches were primeraly designed for the races comming off 2 stroke onto 4 stroke (could that be you?)

Don't think that's correct if I am honest, slippers have been around for ages, they primary design was for the likes of Dukes etc (twins) that had loads of engine braking, thus the clutch circumvented the locking of the back wheel on a down change, not so apparent on a 4 cylinder machine, although as we have more powerful bikes now, especially GP machines slippers appear more and more.

errm thats kinda what i ment not much engine breaking on a 2 stroke and will survive overreving whereas the 4 stroke would be the oppisite , no ?

Big V twins and singles are worst for engine braking, its usually easy enough to blip throttle as you go down box but on steep downhills it requires a 2 finger brake, blip throttle with other 2 fingers all while keeping weight on your wrists. The quicker you are going and more gears to shift down the worse the back end lock which is why racers use it. I just want it cos my favourite road involves a couple of hard braking 2 -3 gear shifts into downhill corners.

[Edited on 19-5-2005 by Gizmo]

Yes and no.... 4 cylinder 4 strokes don't suffer as much...

I have fitted a Fast By Ferracci slipper in my 749R bought from Pro Twins to replace the standard slipper, it made a vast improvement and has stopped the grinding noise !

I have had the Sigma slipper in one of my previous bikes as did a friend and in my opinion they are crap, the bearings came out of both of them fortunately not causing any damage, plus one of the posts lost its circlip which could have also caused damage.

When i was at the Munich bike show last year there was a company there marketing a new type of slipper that was completely different to anything i have ever seen, the build quality was fantastic and it came with its own tools for fitting etc. I had a leaflet with the details but unfortunately i have misplaced it and cannot remember the name of the clutch, unless anyone else was in Munich and can remember these clutches ?

Another option is the STM 48 tooth "non-slipper" clutch. Nelly does 'em; I've got one and it's very good. Pro's are: you can use your stock pressure plate, springs, etc; they last longer than the stock clutch; they're quieter; there's no fiddly set-up/maintenance like with a slipper.


I'm yet to be convinced that a slipper is necessary/desirable for primarily road use.
Unless you're a riding god, of course.


In which case, I take it all back. ;)


Oh, the "messing about with clutch pack thickness" mentioned upthread. It's no big deal, really. The worse that can happen is you'll put one of your old "plain" plates in the STM pack.

anyone know a good thread /piece of text telling me how to ride abike with without slipper clutch ?

both the 890 and Baby R have Buchi slippers and have never missed a beat.
The 890 has done 8000 miles and the R 3500 miles.
The 890 is stripped at its yearly service and the R hasnt been touched yet.
Both have over 80 lb /ft of torque and the buchi copes with no trouble at all.
Butch

There was this one a little while ago...