General Lee minibike.

#21
Sorry if I missed this, but have you weighed the 2 weights to see if they are equal?

Here is my Polar



As you can see it is significantly wider than regular Tav plus needs a reinforcing stand.
I measure 7-1/4” from the face of the engine to the end of the crank bolt.
 
#22
Interesting to note is that instead of the rounded corners of the stock sliding bushing on the outer sheave, the Polar uses a square drive.

1559766353748.jpeg

The difference is the juniors are inspected every week, so this is not a low maintanence item
 
#23
Sorry if I missed this, but have you weighed the 2 weights to see if they are equal?

Here is my Polar



As you can see it is significantly wider than regular Tav plus needs a reinforcing stand.
I measure 7-1/4” from the face of the engine to the end of the crank bolt.
That really is wider!
A square bar will also function as a slider, but I'm planning to re use the stock hub.
Thanks.
 

delray

Well-Known Member
#24
Yes, It's a lot bigger I think. And more expensive. But I do like how it's designed. With the ramps, rollers, etc. And not the weights that are supposed to be held in place by garter springs.

Design of improved TAV2-30 series driver clutch is in progress.
Goal is to come up with something that eliminates vibrations, caused by unevenly moving weights, to nearly zero.
With the use of:
Stock sheaves; stationary and movable.
Stock splined driver hub. (maybe slightly modified)
Stock pilot washer and bolt.
The stock weights and the garter springs can be thrown away...
Some kind of "bolt-on" performance piece...

It will take some trial and error, but would be nice to get it to function.
This is what I have come up with so far.

It's not complete yet, as the other parts need to be figured out.
also note using a 30 series design may not be the best for your performance application. personally don't like using a flat side belt and the front side V angle just makes less material hold on to the pulleys and more to slip. now on a 20 series both sides are V and from my experience i have less slippage under full load when drag racing my bike. belt palace does make a good aftermarket belt that helps with this problem for the 30 series. never really a big fan of the 20 and 30 series stock steel pulleys. they never spin true and are heavy over aluminum setups.
what kind i ideals do you have in mind to make the the pulley travel. you think you might have to incoporate a outer shell so the moving parts can push up against or try to make everything travel with in the center section.
 
#25
also note using a 30 series design may not be the best for your performance application. personally don't like using a flat side belt and the front side V angle just makes less material hold on to the pulleys and more to slip. now on a 20 series both sides are V and from my experience i have less slippage under full load when drag racing my bike. belt palace does make a good aftermarket belt that helps with this problem for the 30 series. never really a big fan of the 20 and 30 series stock steel pulleys. they never spin true and are heavy over aluminum setups.
what kind i ideals do you have in mind to make the the pulley travel. you think you might have to incoporate a outer shell so the moving parts can push up against or try to make everything travel with in the center section.
My bike is no performance bike. The tav2 should hold it.
I was thinking to put levers/arms on the center section pushing against the movable sheave.
 
#26
Just another day at my office...
A lot of text, so I took a cup of coffee to start with.


This is where I am at with the design of an improved TAV2-30 series driver clutch.

The picture shows the driver clutch at WOT position, but also (less clear) at the idle position.
The blue part will be a steel plate, welded to the movable sheave. This is where the arms/levers will push against, to make it move.

This is just a provisional design. It might change as I need to figure the shape of arms and the weights of arms needed.
And it all has to work with springs available that are capable of stretching enough and have the right force in idle position and at stretched position. At this time I haven't found any proper springs for it.
Also I don't know how much force is needed when there is belt tension to the movable sheave, to make it move.
The total weight of the new center section (including arms, dowel pins and blue steel plate), which will replace the stock weights, garter springs and drum is 312 grams. This is almost the same weight as just the stock weights in a driver clutch. I can say it will not be heavier.

But as this design needs a lot of thinking through regarding springs and shape and weight of arms, it will take time to figure it out. So it's a bit of "on hold".
It is "fairly" easy to create it with a proper engagement rpm, but what will it do at WOT? Will it create enough force to push against the belt tension or to much? Example: On WOT it might desire other springs or arms then on idle. While I need the same springs and arms on both positions and in between.

Yesterday I put the movable sheave in the lathe and made it true again. After that I mounted the primary clutch again. After I mounted it I put a dial indicator up against the drum and tried to make that true also and I ran the bike.
The vibrations were still there as soon as the driver clutch started to function. The vibration were less, but still there. With bot sheaves made true, I think that it's caused with play of the movable sheave on the splined driver hub, this might cause the movable sheave to be nonparallel to the drum side.

As a lot of people here on oldminibikes mention that a genuine Comet is superior to a Chinese (you get what you pay for), I might buy a genuine Comet clutch and see if it doesn't create vibrations. Their price is almost the same as a complete Chinese TAV-2 kit, so I'll have to think about it.
If it doesn't create vibrations; I will keep running it.
If it does create vibrations; I will go further with my design "made in the Netherlands".

Does a genuine Comet clutch create vibrations?
 
#30
any up dates on your new torque converter?
No updates untill now. But I haven't put the idea in the fridge. Currently busy with work and other things.
I might have to change the design as I can't find any matching springs; regarding length and strength. They are to long or not strong enough. If I would redesign the fingers a bit, I might find some matching springs. I want to use some easy available springs and not custom made ones.

I also purchased 3 more used GX160 engines and had cleaned up the workshop a bit, as it was necessary after building 2 minibikes.
In the meantime I took my first minibike and mounted a GX140 on it and have put it for sale, just to see if there is any interest.
 
#32
I wonder how a variator style CVT would work (If you're building one). I like the idea that they use roller weights to move the belt.
With variator style you mean like a bully clutch? Because that's what I am planning to do.
The arms with the weights on them will keep the weights, reasonably centered.
 
#34
If you get a chance, look up through Google Honda varistor. Should come up with some pics
That looks like loose roller weights in there. Like Comet 44 clutch?
I'm not sure if DAF trucks are known in usa, but it's a Dutch brand nowadays part of Paccar. 60 years ago they made cars with cvt transmission in it. They even made a cvt transmission for a F1 car, but it was not allowed by Fia.
Here is a link. It's Dutch, but it has pictures, too.
CVT transmission in racecar picture.
Their driver clutch has arms/levers with weights on them. It also has a membrame in it, vaccuum created by the engine will contribute to the "kick down" effect.
I don't need the vaccuum stuff, but like the principal that the movement of the weights is "controlled" by arms.
 

delray

Well-Known Member
#35
If you get a chance, look up through Google Honda varistor. Should come up with some pics
cvt unit is a interesting piece. I also see they come in different sizes depending what kind of scooter you have. if a guy could find one that use the same width belt as a 20 series so the travel spacing is correct and pulley size. if not i'm sure the travel spacing could be modified and then you would want to fab the centers of the cvt unit to fit over the 3/4 crank. that's if there is material to machine or weld too and you want to reverse the mount or I should say flip around so the weights are on the outside and the fix pully is on the inside. then it could work with a rear driven 20 series 6inch or 7inch unit. nice thing if it did work it would balance out 10x times better then a steel comet unit that is stock or even been modified. also looks like it would not take up a lot of spacing. I see they make some aftermarket parts too ,Teflon coated unit,different rollers...etc...
 
#36
cvt unit is a interesting piece. I also see they come in different sizes depending what kind of scooter you have. if a guy could find one that use the same width belt as a 20 series so the travel spacing is correct and pulley size. if not i'm sure the travel spacing could be modified and then you would want to fab the centers of the cvt unit to fit over the 3/4 crank. that's if there is material to machine or weld too and you want to reverse the mount or I should say flip around so the weights are on the outside and the fix pully is on the inside. then it could work with a rear driven 20 series 6inch or 7inch unit. nice thing if it did work it would balance out 10x times better then a steel comet unit that is stock or even been modified. also looks like it would not take up a lot of spacing. I see they make some aftermarket parts too ,Teflon coated unit,different rollers...etc...
After reading this thread, I just remembered that those units are readily available, highly modifiable, and run smooth. I had it on a Honda Helix that I had. If one could be modified to work with a mini bike it just might be way cool. I don't know, just a thought.
 

delray

Well-Known Member
#37
After reading this thread, I just remembered that those units are readily available, highly modifiable, and run smooth. I had it on a Honda Helix that I had. If one could be modified to work with a mini bike it just might be way cool. I don't know, just a thought.
yes mrpat,one thing that I was trying to figure out is where the most impact would be on that type of clutch and from the looks of it doesn't really have a impact point like a comet or others do. just opens and closes and the type of rollers dictates opening and closing and no flying parts mounted on the outside of the unit.. it appears the back steel plate the rollers ride on would be lock to the crank,so that part would have to have a tig welded on keyway coller or something. most of it looks to be aluminum and machine out pieces. so it would spin very true and should be balance good too. if it did work it would be perfect for billet flywheel engines. still a lot of if's
only if a guy had a lathe....lol
 
#38
A Comet 40 series works about the same with it's rollers, I would say.
The Honda variators, or aftermarket ones, are being sold for the same money or more as a genuine comet 30 series clutch. And like Delray said a lot of if's. It would require a lot of modifications to make it fit (if possible) and to make it work (again; if possible). They use symmetrical belts; my knockoff 30 series doesn't.
If someone wants to try it, you have my blessing.
I will stick with my plan, to make parts for- and modify a stock, aftermarket, cheap 30 series clutch. I know it already fits and I hope it will work...
 
#39
A Comet 40 series works about the same with it's rollers, I would say.
The Honda variators, or aftermarket ones, are being sold for the same money or more as a genuine comet 30 series clutch. And like Delray said a lot of if's. It would require a lot of modifications to make it fit (if possible) and to make it work (again; if possible). They use symmetrical belts; my knockoff 30 series doesn't.
If someone wants to try it, you have my blessing.
I will stick with my plan, to make parts for- and modify a stock, aftermarket, cheap 30 series clutch. I know it already fits and I hope it will work...
I just thought it was an option to look at is all. Trying to think outside the "normal" box.
 

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