holding power: 2G vs delta

str8dum

Well-Known Member
Hey guys,

does the delta clutch have more holding power than a polini 2G. I need to get a new clutch and want minimum clutch slip at my takeoff at ~7500 rpms. I have a 2G now, but now is the time to switch if the delta is better.

Thanks!
 
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str8dum said:
Hey guys,

does the delta clutch have more holding power than a polini 2G. I need to get a new clutch and want minimum clutch slip at my takeoff at ~7500 rpms. I have a 2G now, but now is the time to switch if the delta is better.

Thanks!


I thing keep the 2G the Malossi clutch is very heavy, and you can't adjust to very high opening RPM, like the 2G or 3G Polini!
 
delta clutch is not that heavy in fact it's just the right weight ''coz if clutch is too light it'll have less thrust to push the lining against the clutch bell & that leads to excessive clutch slippage. use the malossi clutch bells along with the delta clutch they work better as a combination.
 
I think Malossi clutches are crap. They will self-damage if you use hard springs (black, blue).
However I use the delta clutch, have removed the weights and run very soft springs (white) on my racing zip. That gave me some incredible take-offs.
Next clutch I will buy is the polini 3g.
 
roost said:
I think Malossi clutches are crap. They will self-damage if you use hard springs (black, blue).
However I use the delta clutch, have removed the weights and run very soft springs (white) on my racing zip. That gave me some incredible take-offs.
Next clutch I will buy is the polini 3g.

Removed the weights? hmm, if i run white springs then my scooter won't move in the start :p!
 
roost said:
I think Malossi clutches are crap. They will self-damage if you use hard springs (black, blue).
However I use the delta clutch, have removed the weights and run very soft springs (white) on my racing zip. That gave me some incredible take-offs.
Next clutch I will buy is the polini 3g.


Really? How can you use the white spring in your race bike? In which rpm it engages?? I hate the Delta too! I removed the masses from the clutch and use a custom made spring (stiffer than the black Malossi) and it is even very bad to me!
 
tiba_karotsu said:
delta clutch is not that heavy in fact it's just the right weight ''coz if clutch is too light it'll have less thrust to push the lining against the clutch bell & that leads to excessive clutch slippage. use the malossi clutch bells along with the delta clutch they work better as a combination.

maybe you are right but not 100%:)

At 10k or more RPM the light clutch has enough centrifugal force too!!
 
Browni said:
maybe you are right but not 100%:)

At 10k or more RPM the light clutch has enough centrifugal force too!!

only when scooter has gained momentum the lighter clutch will engage properly (roadracing) but at a stand still (dragracing) the light clutch will surely slip excessively & you'll end up with a discolored clutch bell. i have tried the MK 3shoe clutch & clutch bell combo with just a midtuned 90cc acceleration is bad from stand still that i reused the heavy stock clutch & used stiffer clutch springs for it & it worked much better.

for dragracing i set my delta clutch weights to the outermost position where it will give maximum thrust & use blue springs set at the lowest position so the clutch fully engages just before the powerband hits so clutch slip is minimized during takeoff.

for roadracing it's a different ball game you need to set the clutch springs next step higher & replace the stock weight with the lighter ones supplied in the MHR clutch spring kit.

i balance my clutch shoes & weights by hand as an additional measure to make sure it runs very smoothly, i use a tanita digital weight scale & balance all the shoes within .1gram.
 
If the springs are too hard, they will bend the clutch shoes (on a malossi clutch). Once the shoes are bent, it will not make a good take off, no matter if the rpm are correct.
This won't happen on an polini clutch, since they have the springs placed in the middle of the shoe.

The harder are the springs, this does not mean that the higher will be the rpm. In practice you can't exceed the rpm at the take off of the rpm that the variator works. If the springs are too hard, then the variator will have to go in range to spin up the clutch enough to engage. As a result you have a really bad take off.

I use malossi white springs. My scooter is the fastest at take off of all other racing at our national championship. I usually gain 1-2 places at the race start.:)
 
Browni said:
Really? How can you use the white spring in your race bike? In which rpm it engages?? I hate the Delta too! I removed the masses from the clutch and use a custom made spring (stiffer than the black Malossi) and it is even very bad to me!
If you use springs that are too hard, it will engage the clutch at lower (engine)rpm than needed. In fact you will get the highest possible engine rpm at take off by using the right springs. If the springs are too soft or too stiff it will engage at lower rpm!
 
I just get my Delta and BMG bell, it came with white spring and I didn't make any adjustment at this moment...it works great but of course my bike is not a full race or drag race bike.

I will try playing with the adjusters later to see if there is any improvement.

I want to get a Hebo racing and a Polini to see wich is best.
 
roost said:
If you use springs that are too hard, it will engage the clutch at lower (engine)rpm than needed. In fact you will get the highest possible engine rpm at take off by using the right springs. If the springs are too soft or too stiff it will engage at lower rpm!

There is one problem with this! i tried every springs and every positions step by step from white to black, and tried all of the mass positions and hole position!! The start wasn't very good with them, I found out that my custom made stiffer springs and no mass weights give me the best result!

However I really don't understand your theory! Please explain me with math and physics (force-reaction force, rpm, momentum etc or anyrhing) not with "shoe bending" and other things..This is simple centrifugal force, the more the spring force more the RPM when the clutch engages! If you have a high rpm pipe, you can't adjust to 3-4k opening as you said with the white variator springs or with the green, cause there is no power til ~7-8K rpm!

My problem is that Malossi's little brochure said min 8k or more clutch engages (depends from the variator type and roller weights) but I can't adjust it with that clutch!!
 
tiba_karotsu said:
the light clutch will surely slip excessively & you'll end up with a discolored clutch bell. i have tried the MK 3shoe clutch & clutch bell combo with just a midtuned 90cc acceleration is bad from stand still that i reused the heavy stock clutch & used stiffer clutch springs for it & it worked much better.

But the reason is not the weight on that clutch!! Metrakit clutch is same as RMS, Hebo, and etc.. They all of have very poor quality friction material, they will be glassy after few minutes even in a middle tuned bike! If you change the friction material with another you won't have problem with it! Sure the Malossi has the best friction material thats the only reason I use it! Polini is very good too!

And look at the Polini 2G! It's centrifugal force is totally limited, because it has got pusher springs, and after the springs compressed the shoes can't move anymore. That's why you can't adjust to very tight cause in a case the gap deisappears and it can't open properly and you will have slip, this type of clutch isn't very good self self-righting, cause their shoes are totally separate and they can't affect eachother! However I can adjust higher RPM than the Maloss and works better.
 
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Browni:
Of course the harder the spring, the more the clutch rpm to engage. But if the springs are too hard, the variator will have to change the ratio of the transmission so it will spin up the rear pulleys enough to make the clutch engage.
If you have lets say the variator set to work at 13000, will you be able to achive higher engine rpm than that at take off? The answer is no.

Just take off the transmittion cover, hold the brake and give full gas, then watch the belt on the rear pulley; how much it does dive into the rear pulley? It shouldn't dive more than 1-2 mm for best results.

About the bending shoes: The malossi clutches have springs on side of the clutch shoes. So over time with hard springs the shoes themselves will became bent towards the clutch plate. Don't know exactly the dynamics of what is happening when the shoes are bent, but they do worsen the take off. It's obvious that much more energy than needed is consumed into friction losses rather than traction.

However I use white springs and no weight. If there is no weight, then there is a need for softer springs. I didn't want to use the hard springs and weights, because I knew it will ruin the clutch.
 
roost said:
Browni:
Of course the harder the spring, the more the clutch rpm to engage. But if the springs are too hard, the variator will have to change the ratio of the transmission so it will spin up the rear pulleys enough to make the clutch engage.
If you have lets say the variator set to work at 13000, will you be able to achive higher engine rpm than that at take off? The answer is no.

Just take off the transmittion cover, hold the brake and give full gas, then watch the belt on the rear pulley; how much it does dive into the rear pulley? It shouldn't dive more than 1-2 mm for best results.

About the bending shoes: The malossi clutches have springs on side of the clutch shoes. So over time with hard springs the shoes themselves will became bent towards the clutch plate. Don't know exactly the dynamics of what is happening when the shoes are bent, but they do worsen the take off. It's obvious that much more energy than needed is consumed into friction losses rather than traction.

However I use white springs and no weight. If there is no weight, then there is a need for softer springs. I didn't want to use the hard springs and weights, because I knew it will ruin the clutch.


Ok, Ok!! I know what you would like to say! You talk about the variator changes to longer gear ratio so the rear pulley has enough rpm for the clutch opening (in my case, if I use stiffer springs). Sure you are right, but look at the other side, if I use the white springs my variator don't need to change the gear ratio to open the clutch, and maybe my variator is in it's standard position in this case but this can be possible only at little rpm, so I am here again!! For example my crank has a very low rpm where the variator stil keep the gear ratio at low position, so this cause the same problem, I have only few rpms and my clutch opens very soon cause I use a soft spring. If a bike has the correct weights you have a concrete point where the variator starts to change gears this can be very soon or later (it depends from setup), but I won't change my roller weights to keep the variator in standard position for a longer time! The roller weights are not for adjusting the clutch. Sure with very light rollers the vario changes the gear later in this case you theory works great, you can use soft springs, without any problem but this can't work every case! So the advatage is my adjustment, that I have more rpm, so the rotating parts have more kynetic energy, when my bike stars, I know I have longer gears in this time, and when the clutch engages the gears go down to lower gear ratio again! But when you use your method you haven't got rpms energy, only lower gear but this lower gears can't compensate that very little crank rpms. Sorry I can't word it well! :)

My other question, what do you think why Malossi makes these very stiff springs (blues, black)? I will be very happy if I can use the white ones, but this can't work to me!
 
Well, there are many approaches.
In my case, it is not that the clutch engages at low engine rpm. But it does in full powerband rpm! At the start of the race my bike is at full engine rpm while the others are slugging with the clutch working and the engine at rpm under the powerband.

At launch the transmission(the belt-pulleys system) should be at the shortest ratio possible, this way the clutch will finish it's work ass soon as possible (the clutch consumes lots of energy at the launch). The clutch will slipp until the bell reaches the same rpm as the clutch.
The most of the point of the ovverrange transmission kits is to reduce the ammount of clutch work needed.
 
roost said:
Well, there are many approaches.
In my case, it is not that the clutch engages at low engine rpm. But it does in full powerband rpm! At the start of the race my bike is at full engine rpm while the others are slugging with the clutch working and the engine at rpm under the powerband.

At launch the transmission(the belt-pulleys system) should be at the shortest ratio possible, this way the clutch will finish it's work ass soon as possible (the clutch consumes lots of energy at the launch). The clutch will slipp until the bell reaches the same rpm as the clutch.
The most of the point of the ovverrange transmission kits is to reduce the ammount of clutch work needed.


You can't understand what I mean! My bike isn't under the power band when the clutch opens!

"The clutch will slipp until the bell reaches the same rpm as the clutch."

Really I never thought this:):):) I "didn't know" the role of the clutch:):):):)

A really don't know how can your bike start with your spring, do you use 0,1 gr roller weights, cause than I understand why you have full rpm and your variator is stil in the base postion (lowest gear)! isn't your bike undergeared cause the to light roller weights? How much is your top speed and accelration (0-100) with this setup?

Once again, why Malossi makes very stiff springs, if a race bike can use the white one, the black is for crazy people like me :p
 
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Yeah, we have gone away from what I tried to say. What I tried to say was:
Malossi clutch is crap. When the shoes became bent, it won't make a good launch, even if the engine is at powerband rpm. And they will bend if strong springs are used.

A really don't know how can your bike start with your spring, do you use 0,1 gr roller weights, cause than I understand why you have full rpm and your variator is stil in the base postion!
Rollers havent much to do with the launch. What spring? Did you mean (clutch)springs?
 
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