holding power: 2G vs delta

[Browni]

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.


Rollers havent much to do with the launch. What spring? Did you mean (clutch)springs?

"Rollers havent much to do with the launch."

Not directly but indirectly->

Cause if the engine opretates the weights have effects, I mean, as you know the weights change the gear ratio, so they can affect to the rear pulley's rpm, before and after the clutch engages! How can your crankshaft turns 9000-10000 and your variator stil doesn't work? What rpm your front variator start to move? 9000 rpm or so? This can't be! The variator works very soon, only if you use unreal roller weights can this happen!

I would like to bring this home to you, if the total variator system includning the clutch is a whole! Everything has an affect! So I can't catch your point! Why do you say "gone away from what I tried to say"!

 

[roost]

Yes, it does move, but that has no meaning. The point is that when you are launching, when you have the full gas, the transmission ratio should be short (belt the lower possible on the variator and high on the rear pulley). Shure the belt does play a lot if you are just revving freely.
I also don't understand how do you need super stiff springs, while my scooter does best with white springs.

Yes we gone away, we are discussing on how the transmission works, while the thread talks on what clutch is best, then I explained why the malossi delta is bad, from my experience.

 

[Browni]

Yes, it does move, but that has no meaning. The point is that when you are launching, when you have the full gas, the transmission ratio should be short (belt the lower possible on the variator and high on the rear pulley). Shure the belt does play a lot if you are just revving freely.
I also don't understand how do you need super stiff springs, while my scooter does best with white springs.

Yes we gone away, we are discussing on how the transmission works, while the thread talks on what clutch is best, then I explained why the malossi delta is bad, from my experience.

I know, I know it should be!! It's not a real explanation if you tell me the same things everytime but for different words, your last explanation is flippant, sorry but this is good for childrens! Please answer to my question, and not avoid it!

However! This theme is tightly connected to the main topic question!

 

[Browni]

Yes, it does move, but that has no meaning. The point is that when you are launching, when you have the full gas, the transmission ratio should be short (belt the lower possible on the variator and high on the rear pulley). Shure the belt does play a lot if you are just revving freely.
I also don't understand how do you need super stiff springs, while my scooter does best with white springs.

Yes we gone away, we are discussing on how the transmission works, while the thread talks on what clutch is best, then I explained why the malossi delta is bad, from my experience.

And ok Delta is crap, but if the shoes bent then they rotate more difficult, this is favorable for the higher opening rpm, and the shoes connect to the bell in a wider band cause the skewness
this is more area on the bell so it is good for the bell!

 

[Folkert@MinaRally]

Very strange, I replied to this topic yesterday and now my post is gone? I replied right after Browni's 1st post.

Anyways, I'd stay away from the 2G (there is no 3G clutch, that's the Speed Control) as possible. Just looking at how it's constructed make you think twice. I've seen them break and it could be "just a couple", but the whole spring-load system all together doesn't look good.

 

[roost]

Browni: I just can't understand what is your question!!!
About the bent shoes that are favourable; yours is childish explanation. When the shoes are bent, the contact area with the bell becomes smaller and the force is not equally divided on the wear surface.
You are just bringing into the debate things that are hipothetical, unreal.

Folkert: yes, there is a 3g clutch from polini, but you have to know what the "g" does mean in italian language. Then you can call them 2g or 3g.

 

[Browni]

Browni: I just can't understand what is your question!!!
About the bent shoes that are favourable; yours is childish explanation. When the shoes are bent, the contact area with the bell becomes smaller and the force is not equally divided on the wear surface.
You are just bringing into the debate things that are hipothetical, unreal.

Folkert: yes, there is a 3g clutch from polini, but you have to know what the "g" does mean in italian language. Then you can call them 2g or 3g.

The surface isn't smaller! Did you ever see rectangle? It'S diagonal is longer than the sides!

But you didn't answerd my question yet!

You say when the clutch engages the variator most be in the lower gear position, but how can it be?! Let's see for example ther is a bike with very narrow power curve. The variator starts to work about 3000-4000 rpm, so you sholud adjust it in this range your clutch to this rpm (as your theory said)you will have a very bad accelration, cause the bike has for example 4 hores power. Even the lower gear can't compensate this low performance at the bottom. But if the clutch engages at higher rpm like 8000 rpm (crankshaft speed) the bike will have much more power, so it has better start even the variator was a longer position).

Another but totally different example! (I know this is not the right example! BUt maybe you understand my problem) I use a turbocharged car for a long time. If it is in the first gear, I can start the car at 1000-1200 rpm, this is good for a town or for a simple start, but if I want better accelration I have to turn up the motor to 3000 rpm (where the car has much more power) and then engage the clutch. And now here is another important think, if I start from the second gear but at 3000-3500 rpm I even have better accelration then from the 1st gear and lower rpm! So I don't know your low gear and low rpm theory!

 

[roost]

No, my theory doesn't say that. And it's not a theory. You got it wrong. My clutch with white springs it does not engage at low rpm. I said I removed the weights, so it engages at higher rpm.
When I hit the gas at the start, my engine revs up to the same rpm as when the clutch is locked and the variator does its work. I got full powerband rpm right from the start. And if I take off the cover and watch the belt and give full gas and hold the rear brake, the belt does dive only about 1-2mm into the rear pulley. This means that the clutch setup is perfect, so it will lock at low bike speed and leave the work to the variator, since a slipping clutch removes lots of power.
I don't want to argue anymore about how I understand the transmission is working. I know I got it right. In fact I burn all the competition at race start.

 

[butch-182]

Very strange, I replied to this topic yesterday and now my post is gone? I replied right after Browni's 1st post.

Anyways, I'd stay away from the 2G (there is no 3G clutch, that's the Speed Control) as possible. Just looking at how it's constructed make you think twice. I've seen them break and it could be "just a couple", but the whole spring-load system all together doesn't look good.

Youve seen them break? Id love to see a picture of one broken, sorry but i dont believe that.. Yes there is a 3g, and no its not speed control, thats a variator....

I think im going with the polini 2/3g, Whats the best for a fully tuned setup guys?

 

[Browni]

No, my theory doesn't say that. And it's not a theory. You got it wrong. My clutch with white springs it does not engage at low rpm. I said I removed the weights, so it engages at higher rpm.
When I hit the gas at the start, my engine revs up to the same rpm as when the clutch is locked and the variator does its work. I got full powerband rpm right from the start. And if I take off the cover and watch the belt and give full gas and hold the rear brake, the belt does dive only about 1-2mm into the rear pulley. This means that the clutch setup is perfect, so it will lock at low bike speed and leave the work to the variator, since a slipping clutch removes lots of power.
I don't want to argue anymore about how I understand the transmission is working. I know I got it right. In fact I burn all the competition at race start.

I haven't got weight's too, and if I use the white spring my bike can't start and all of the other racing bikes too!! You never answered my question, that how can it be that your variator stay at the low gear at high rpm (only if you use the variator without the roller weights)!! I think you can't answer it!

 

[roost]

I haven't got weight's too, and if I use the white spring my bike can't start and all of the other racing bikes too!! You never answered my question, that how can it be that your variator stay at the low gear at high rpm (only if you use the variator without the roller weights)!! I think you can't answer it!

???
It does stay at low gear becouse of it's own principle of work! That is how the variator works; it tries to keep the engine in the rpm for which the rollers are set.
If you ride on a flat, then incounter a hill, the variator will scale down the transmission ratio to keep the engine rpm in powerband.
But you know that.

At the start, the clutch does hold the variator down.
If the clutch springs are too soft, engine rpm will go under powerband. (because the variator can't anymore lower the ratio)
If the clutch springs are too strong, the variator will go in range to spin up the clutch fast enough to make it engage. But then the clutch will slip until the bell achieves the same speed as the clutch. And becouse of that, the clutch will work for more time, which is bad. The rpm may also fluctuate up and down.

If the clutch setting is good, the engine rpm will be in powerband, and the variator will be on it's lower gear. This makes the best start.

 

[roost]

And also if the springs are too hard, the clutch will unlock before the variator has reached it's lowest ratio when you are braking. That is bad bad in slow corners.

 

[50cczip racer]

the polini 2g does fail regularly
the backplate bends badly and also the mounting location for the spring and bolt set up ive had 3 fail
despite them breaking i found them to be a very good clutch very easy to adjust and obtain the correct engagement rpm and it doesnt suffer the problem of some other clutches in that when it engages you get lots of slip this clutch engages with very strong bite probably due to large surface area and heavy shoes, i race 6 hour 50cc endurance and got through a clutch a race so it was too expensive to continue running them
i need to set my clutch to engage at 9500 to get the scooter moving so i set the 2g with a lot of spring tension on the heavy springs this may not be the case on a 70cc motor and if set up to engage earlier then it may last longer
i may consider using one again but carry out some strengthening to the back plate i think a triangular gussett plate which joins the back plate to the spring post would cure it.
the malossi clutch for 50 cc i find too heavy and no matter what i do or try even black springs and no weights i cannot get it to engage above 8500 rpm which is below my power band so i no longer use it
the polini speed clutch works ok but the strongest springs needed to get good start rpm 9000+ tend to snap after around 5 hours use for higher rpm bite then doppler do a heavier spring that is also more reliable
the metrakit,doppler,hebo type clutchesfor my set up(50cc) work well they are light and give a high rpm engagement and have proved reliable having done about 30 hours use now without problem ,the clutch bite doesnt seem as strong as the 2g and feel there is a little slip on take off but its good for road racing as it delivers the power gradually which is especially good in a wet race. i have a friend who ripped the linings straight off his hebo clutch when used on his 70 cc but i dont know if this was a one off or its common
the new tjt clutch looks fairly good id be interested in what they work like

 

[Browni]

???
It does stay at low gear becouse of it's own principle of work! That is how the variator works; it tries to keep the engine in the rpm for which the rollers are set.
If you ride on a flat, then incounter a hill, the variator will scale down the transmission ratio to keep the engine rpm in powerband.
But you know that.

At the start, the clutch does hold the variator down.
If the clutch springs are too soft, engine rpm will go under powerband. (because the variator can't anymore lower the ratio)
If the clutch springs are too strong, the variator will go in range to spin up the clutch fast enough to make it engage. But then the clutch will slip until the bell achieves the same speed as the clutch. And becouse of that, the clutch will work for more time, which is bad. The rpm may also fluctuate up and down.

If the clutch setting is good, the engine rpm will be in powerband, and the variator will be on it's lower gear. This makes the best start.

I know you understand what I mean, but you purposely say another things! And most of them aren't true!!

My front variator starts to move at ~6500 rpm, so (if you are right) I have to adjust my clutch 6500 or less (<6500), but at 6500 or less rpm the bike hasn't got enough power for the start!! I really don't know why you don't understand this! Look at 50cczip racer's post, he needs the 8-9000 rpm too as I or any high-end setups, for the best accelration!
Don't say me your bike has enough power at 5000 rpm for a right start, maybe with a Giannelli Shot but this isn't a high-end pipe!!

 

[Wille]

I know you understand what I mean, but you purposely say another things! And most of them aren't true!!

My front variator starts to move at ~6500 rpm, so (if you are right) I have to adjust my clutch 6500 or less (<6500), but at 6500 or less rpm the bike hasn't got enough power for the start!! I really don't know why you don't understand this! Look at 50cczip racer's post, he needs the 8-9000 rpm too as I or any high-end setups, for the best accelration!
Don't say me your bike has enough power at 5000 rpm for a right start, maybe with a Giannelli Shot but this isn't a high-end pipe!!

If you have a high end setup and your variator starts to move on 6500 rpm then it isn't possible that your transmission is adjusted correct.

 

[roost]

My variator begins to moove even sooner. But when the clutch begins to engage, the variator goes back to the lowest ratio possible. If I keep the brake and give full gas, my engine is screaming at 13000rpm! And the belt stays on the lowest ratio possible.

If I use much stronger springs, then the belt does not stay at its lowest ratio. It does increase the ratio to spin up the clutch enough to make it engage. But this means that the clutch will have to work for more time.This is the same as if I used smaller pulleys.

At launch, when the clutch is doing it's work, the variator-belt should be in the lowest gear ratio possible. It should be if you want to make a good start. Now answer to me if this isn't true!

Of course I purposely say other things. I just don't find much reality in your affirmations and examples.

 

[Browni]

If you have a high end setup and your variator starts to move on 6500 rpm then it isn't possible that your transmission is adjusted correct.

Hey guy!! This was an example! I wrote a lot of others but maybe they aren't evident and I would like to say him an extreme example look at the post, I say him this is only possible with a low-middel rpm pipe!! Belive me my setup is good!

But I think you don't know what we are talking about, you talk about the constant rpm at accelration this is much more higher, but we talk about the first movement of the variator they are totally differnt things Please read not only write!

 

[Browni]

My variator begins to moove even sooner. But when the clutch begins to engage, the variator goes back to the lowest ratio possible. If I keep the brake and give full gas, my engine is screaming at 13000rpm! And the belt stays on the lowest ratio possible.

If I use much stronger springs, then the belt does not stay at its lowest ratio. It does increase the ratio to spin up the clutch enough to make it engage. But this means that the clutch will have to work for more time.This is the same as if I used smaller pulleys.

At launch, when the clutch is doing it's work, the variator-belt should be in the lowest gear ratio possible. It should be if you want to make a good start. Now answer to me if this isn't true!

Of course I purposely say other things. I just don't find much reality in your affirmations and examples.

You said that after the clutch engages the variator is in the low position, yes thats right but this is evident, my bike do the same!

 

[roost]

Yea, that's great.

 

[Browni]

Yea, that's great.

ok! And peace