Is It Possible: An Ultra Slim Moto Clutch Pack?

[nicholastanguma]

Track riders always lighter weight and less mass and more lean angle. On the right (alternator/stator) side of the engine this has traditionally been accomplished by simply eliminating the alternator/stator altogether.

Or, in the case of endurance race bikes that need illumination for night racing, by custom fabricating an impossibly super slim stator that just barely keeps the lights bright at the sustained rpm of track speeds.

But the left (clutch) side, that remains fat; all the discs in a clutch pack simply require space, duh.

So is it possible to somehow create an uber slim moto clutch, something with the width of only two or three discs in the clutch pack? Perhaps create a moto clutch only one or two or three discs wide? Imagine a parallel twin with the narrowness of a single, or an inline four with the narrowness of a triple!

[Rick!]

Calculate the total friction area of all the current "fibers."
Throw away however many fibers you want to get rid of.
How much friction area do you have left?
Now, figure out what the dynamic to static friction values you now need to allow driveaway and hold the engine power in top gear.
It'll probably the inverse of how much fiber area you threw away, i.e. a reduction in 50% of the fiber area may need a 200% increase in friction coefficient.
At this point, evaluate the GOOD, CHEAP, FAST triangle and figure out which two of those you can accept. As a rule, you only get two of the three in real life.
Now evaluate the effect of a high zoot friction material in the engine will affect engine longevity. Carbon soot in diesel engines are really small particles but carbon fibers shedding from an overworked clutch pack will be larger and my not be friendly to other engine/transmission bits.
Now, do you have asphalt scrapes in the clutch cover now? If not, then I'd re-evaluate the value of reducing the width of an engine by 1/2" or less. YMMV.

[miniv8]

Kawasaki put the clutchpack up high in the case.
When dragracing, the Kawasaki has to cool the clutch between rounds to prevent overheating. The other brands of bikes keep going. I guess it has less oil cooling up there.

[Momus]

Using a single plate 5.25" Tilton or AP racing carbon/carbon car clutch plates run dry with an appropriate hub and pressure plate is one way to do it.

I'm planing to do this on a 700cc B50 BSA I'm building.

[nicholastanguma]

Using a single plate 5.25" Tilton or AP racing carbon/carbon car clutch plates run dry with an appropriate hub and pressure plate is one way to do it.

I'm planing to do this on a 700cc B50 BSA I'm building.

Thanks for the info. Wow, one plate!

Um, how tractable would this setup be? Racing only, or at all streetable, too...

[Momus]

Using a single plate 5.25" Tilton or AP racing carbon/carbon car clutch plates run dry with an appropriate hub and pressure plate is one way to do it.

I'm planing to do this on a 700cc B50 BSA I'm building.

Thanks for the info. Wow, one plate!

Um, how tractable would this setup be? Racing only, or at all streetable, too...

It would be streetable, no problems.