MOPED ARMY

learther ist gear. Cork second gear

personally i like asbestos, try 'em both and see what you like.

To

Graham; what sort of asbestos you using? Find strips somewhere?

The McMC stuff definitely is intruiging;

For the sake of bench racing here, what you want in clutch material is a high coefficient of friction, high max operating temp and pressure correct? So the Hugh friction molded sheets seem best...

I'm currently using NAPA rubberized cork. Exact thickness and easy to work with and bond. What exactly do the various materials do, ie: last longer, grip harder, slip then grip, lower RPM engage, higher RPM engage...? Just curious before I start experimenting further. With the NAPA rubberized cork, first and second clutches, one diagonal groove on second, first engages with a slight slip and holds hard to 7K+ and I blip for shift. I realize a lot is the springs (stock), but just curious what other material does...

put an a3 first gear clutch on the a35 clutch hub:

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and i suck at the internet...

one more time...

I have found some thicker .090 rubber material that is made for clutches. Lets hope I get some and reline a set. It may not slip enough insteaad inst-grap.

My fuck Graham that sounds tasty, which variety or the friction material are you using? Care to share what you are personally bonding it with?

Meh, roll O cork always worked for me

Dee heck is it? Imported from mars by the looks if it.

kevlar?

Oh yeah, I've used the rubberized cork gasket material, which I actually really like in terms of performance, but it doesn't last very long.

ha, neat! pic.

I think I am having ss 17-7 spring made for the clutches.

What pipe you running. The one leather clutches that I did slip nice tho you can't tell cause of the bighitter pipe.

This was the last thing I tried, carbon fiber:

This is the semi-metallic brake and clutch lining:

This stuff works pretty well on first gear, doesn't work at all on second gear. The second gear clutch needs to be able to slip quite a bit, you don't want it to just grab, and that's what this stuff does. It doesn't slip at all, so you get a ton of shudder in the engine. Also, it comes in 3/16" (~5mm) thickness, which is about 2x what you need, and there's no easy way of cutting it. I bonded the material to the clutches and then turned it down on a lathe. Also, I think it's a fiber glass base material because the fibers it created when cutting it itched like fuck.

The carbon fiber didn't work so well only because it's woven more like wool than like the nice silky material you see in carbon fiber body panels and stuff. The nap of the material creates too much friction and you end up shifting into second at 10mph. The same thing happened with that big role of kevlar. Both of those materials are just too thick and nappy, and since they're fabrics there's no (easy) way to thin them. The little role of kevlar is not only thinner in width it's also much thinner in thickness, so I think it has a better chance of working.

If you search for "friction material" on McMaster you'll find all these things. The "brake and clutch lining molded sheets" stuff would probably be ideal, and come's in 1/8" thickness which would work well, but since it comes in huge 15" x 15" sheets it's really expensive. The stuff that comes in strips is way cheaper, but it's 3/16" thick and 1" inch wide. That's the "asbestos" nonmetallic molded strip that Graham is referring to, and the semi-metallic woven strip that is in my second photo.

Another problem with super high friction materials is that in order for them to work the way you want you need to clutch to engage much later than stock clutches do, which means cutting your springs. Also, since the Tomos clutch hubs and pins are steel and the shoes are aluminum cutting your springs and putting on high friction material that grabs really hard is going to lead to bad things (granted, this happens to Tomos clutches in kitted engines regardless of messing around with clutch linings):