Clutch cooling

[DeanP]

I'm wondering how cooling the clutch helps with the clutch. I saw Johnny248 cut his up to allow cooling but am wondering how it really helps.
I am noticing after riding a couple hundred miles that my clutch engages sooner than what it was before. Will cooling it help this out?

[scootfast]

I'm wondering how cooling the clutch helps with the clutch. I saw Johnny248 cut his up to allow cooling but am wondering how it really helps.
I am noticing after riding a couple hundred miles that my clutch engages sooner than what it was before. Will cooling it help this out?

Its because it's heating up and xpanding.

[scootfast]

I'm wondering how cooling the clutch helps with the clutch. I saw Johnny248 cut his up to allow cooling but am wondering how it really helps.
I am noticing after riding a couple hundred miles that my clutch engages sooner than what it was before. Will cooling it help this out?

Its because it's heating up and xpanding.

And there is a breaking in period.

[DeanP]

So I guess I'll have to readjust my clutch which means the next set of springs...

[Johnniespeed]

All of the larger Honda Scooters, NH125,CH150,CH250 have clutch/ variator cooling systems factory installed, they have fan fins on the fixed variator half with inlet ducting and outlet ports.
I dont know what you are running, but Honda seemed to think it was inportant enough to include that cooling system on the large scooters, so perhaps some cooling is in order for the modded smaller scooters as well.

[DeanP]

Maybe before I change out my springs, I'll keep the clutch cover off and see what happens.

[Johnniespeed]

On many scooters the clutch cover is bolted and dowelled to add strength to the engine case, I know many guys run without the cover, but I have seem several who have hit potholes and broke the engine case in two.
Word to the wise, if you run without the cover, stay away from curbs, potholes and off roading.


Hope the added cooling helps your scooter.

[curtis966]

I have never seen any thing but a gy6 case brake from not running a cover. And that's the entire cvt cover, not a halfer. And it's made in China

[Johnniespeed]

I agree that the GY6 breaks, but so does the Spree. I have not seen an Aero broken yet.

[johnny248]

On many scooters the clutch cover is bolted and dowelled to add strength to the engine case, I know many guys run without the cover, but I have seem several who have hit potholes and broke the engine case in two.
Word to the wise, if you run without the cover, stay away from curbs, potholes and off roading.


Hope the added cooling helps your scooter.

That clutch cover is bolted down with bolts and rubber grommets. I don't see it adding much strength to the case. If you look at the case, it has a lot of structural webbing casted into it, and it also short which helps in strength.

The clutch gets very hot, and the friction material is basically like a brake pad or shoe. When brakes heat up beyond their heat range,they lose grabbing power , which turns into brake fade. This is why the have racing brake pad formulas, and they generally don't work well until they reach that extreme temperatures. Friction materials have a temperature range they are meant to operate in. They don't act the same when they are too cold, or too hot. When they are in their range they work how they are designed to. These clutches are run MUCH hotter than the original was designed to run. On a stock bike, you don't need all the extra cooling since you are not grabbing at 6000 rpm+ , nor are you running the same power through the transmission or the same RPM's. Once you add power everywhere, the original design doesn't allow for enough cooling for the clutch to be happy.

[Wheelman-111]

Greetings:

Johnny is precisely right. The stock clutches are too small to begin with, and adding mods only stresses them more. It gets downright hot behind the belt case - I've had a cheap Chinese belt delaminate at speed. NOT fun. Take the rear cover off altogether, or artfully carve it to remove most of the material, as we've recently seen. Cover probably won't work at all if you have a bigger ZX rear pulley.

[Johnniespeed]

Johnny 248, I don't know which scooters you are referring too, both the CH 150 and CH 250 are rubber grommeted on and I agree they would not add any structural strength, my comment was directed at smaller scooters whose covers are bolted and dowelled on, by removing those covers the assembly is weakened, which will not be an issue unless a pothole or impact happens.
I am not opposed to additional cooling, nor am I opposed to cover removal, but some covers are part of the structure and avoidance of potholes is important.
I did not take any pictures of the broken GY6 or the broken Spree engines, but have seen several of both, so I am positive the breakage occurs.

[johnny248]

Johnny 248, I don't know which scooters you are referring too, both the CH 150 and CH 250 are rubber grommeted on and I agree they would not add any structural strength, my comment was directed at smaller scooters whose covers are bolted and dowelled on, by removing those covers the assembly is weakened, which will not be an issue unless a pothole or impact happens.
I am not opposed to additional cooling, nor am I opposed to cover removal, but some covers are part of the structure and avoidance of potholes is important.
I did not take any pictures of the broken GY6 or the broken Spree engines, but have seen several of both, so I am positive the breakage occurs.

I can only only speak for the AF05 and AF16 engines. I'm not familiar with the other ones. From what I have sitting here, the clutch cover "may" provide some bracing/strength, but I don't see it being a make it or break it structural part. I can't speak for other scooters. At least on the AF16, I think it would be EXTREMELY difficult to break this case.

[DeanP]

My AF18 motor clutch cover is only bolted on with no dowels. I'll try taking it off later next week to try the cooling effect.

[maddog]

If you use cheap springs you will get heat-fade, I use Daytona products= 1 less post!