Dry Clutches for Motorcycles
Dry Clutches for Motorcycles
(OP)
Hi,
What ever happened to dry clutches for motorcycles? I raced and maintained CZ motocross bikes which had dry clutches for years and never saw a worn clutch. Also had a Triumph with a dry clutch, worked great. Although they are a tad heavier and for sure more expensive, they can be just as compact and durable as a wet clutch. Some major roadrace machines also used them. Anyone use them now?
What ever happened to dry clutches for motorcycles? I raced and maintained CZ motocross bikes which had dry clutches for years and never saw a worn clutch. Also had a Triumph with a dry clutch, worked great. Although they are a tad heavier and for sure more expensive, they can be just as compact and durable as a wet clutch. Some major roadrace machines also used them. Anyone use them now?
RE: Dry Clutches for Motorcycles
RE: Dry Clutches for Motorcycles
Cheers
RE: Dry Clutches for Motorcycles
RE: Dry Clutches for Motorcycles
Although wear was not really a problem, there was notching of the clutch basket and mashing the edges of the drive plate tangs. Both seemed to be from rotational hammering.
As I recall, the friction plates were a somewhat heavy bronze plated steel with impregnated lube. This left a very thin steel section to engage the basket. This, and perhaps the fact that it was a 2-stroke, seemed to be a bigger source of problems over that of lubrication.
They can't be too bad if thundair is running 3 of them!
Thanks for the replies.
RE: Dry Clutches for Motorcycles
RE: Dry Clutches for Motorcycles
RE: Dry Clutches for Motorcycles
RE: Dry Clutches for Motorcycles
Well that raises other questions. My Honda CR500 (60hp dirtbike) uses a wet clutch and 85wt gear oil. The clutch never slips or anything. BTW, it uses aluminum drive plates with friction material added. Pretty much bullet proof. Never was aware of special or different oils but then again maybe all the MC trans lubes have it.
RE: Dry Clutches for Motorcycles
RE: Dry Clutches for Motorcycles
Regarding the use of ATF, you can't do that in a motorcycle engine as the crankcase and gearbox share the same oil.
RE: Dry Clutches for Motorcycles
Now that you mention it, non-FM ATF might work pretty well even for the shared sump on a 4-stroke combined box motocross bike since these typically have about a 4-hr change interval.
RE: Dry Clutches for Motorcycles
I race a CR250 and use Atf for the gearbox, ( not the F/mod one of course !)
Its good for ONE ,,MAX two races and gives a nice(r) clutch feeling ,
The 06 /07 bikes have a lighter clutch ( unless the display model didnt have any internals!!!~)
I am in the middle of modding my bike to get a reduced lever feeling ( these modern tracks are hard without a light clutch)
Stephen
RE: Dry Clutches for Motorcycles
ATF works. People have been using it in dirt bikes since the 70's.
I don't recall who makes it, but there is a gizmo on the market the goes on the clutch cable that reduces pull effort (and the throw). There are also some hydraulic clutch conversions.
Converting to a Hinson basket sure helped on my CR500.
RE: Dry Clutches for Motorcycles
My bike is a 91 Cr with Highly modded everything ! I have been trying to find out the difference between the 06 clutch and mine , and I cant see any ( yet ) have ordered 06 clutch springs to see if they are a different rate
Wonder why the hindson basket helped .....
Stephen
Sorry to steer slihtly from the topic of dry clutch
RE: Dry Clutches for Motorcycles
RE: Dry Clutches for Motorcycles
Below is a picture of the Easy-Pull in-cable unit, about $40.
RE: Dry Clutches for Motorcycles
Clutches and brakes (both wet and dry) share a lot of technology. Wet brakes are used on tractors where they control the distribution of power from side to side by continuously slipping. Tractors don't operate at speed, so slipping a dry brake would quickly lead to overheating.