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Varietor Roller Help

Mexicano

Mexicano
How to know I'm runing the right rollers for my engine?, I mean, is there a rule of thumb for this?

If using too light rollers= more r.p.m's but sacrifice top speed?
If using too heavy rollers= top speed very quick but low r.p.m.'s at start?

Thanks for your advise!!
 
Mexicano,
I have found this formula works very well for roller set-up. Use rollers that let you see 25-30 mph @ 8,200 rpm. This works great for street set-ups.

scootertrog
 
mexicano


its depen on your engine setup.
 
Aloha Mexicano. I judge them by:

1: In city I can go a bit heavier
2: In hilly driving, I need a bit lighter
3: Find the power range of your setup.
4: For example if it is 8000-10000, with most power at 9000;
a) then for city driving have your rollers "hit" at slightly under 9000 rpm (8500) when you WOT at 10-40 mph
b) In hilly driving have your rollers hit at slightly over 9000 rpm. (9500)

A proper variator must hold an exact rpm from say 10mph to full speed, when the engine starts to overrev because you run out of pully.

5: I also modify the grooves in the rear pully to make the rear pulley open and close with more length. I modify the variator and outer variator 1/2 and shave off 1-3mm to make the pully close tighter and belt ride higher. (that is why I can hit 120kph on stock gearing.
6: Use a slightly shorter belt for more top speed (so rear pulley is opened more in comparison to front pully ie: gear ratio), slightly longer for more bottom end.

frank
 
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there is only one optimal roller weight !!
theres a nice easy way to check
you should remove your vario and then draw a line on it face with a marker then when you drive you can see precisely how highi up the belt is coming by how much of the marker has been rubbed out,
if it alll goes away keep trying lighter rolls until the line just starts to disappear
if the line does not disappear fully then you should use heavier roll's
 
adas said:
6: Use a slightly shorter belt for more top speed (so rear pulley is opened more in comparison to front pully ie: gear ratio), slightly longer for more bottom end.

frank
Click to expand...

I have wanted to try different belt lengths to experiment with exactly this. I had theorized that a slightly longer belt would have allowed a higher top speed (assuming it would pull the rear pulley apart to the same amount.) due to the fact it would allow a higher belt position at the same rpm. You have brought up a very important variable in questioning the rear pulley /belt ratio.

Once again this is another variable in addition to rear pulley spring and roller weight to acheive higher top speeds.
 
Aloha, and on my wish list is to have different belt widths. A wider belt would allow a "taller" gear on the Variator when the halves are fully closed. I like the stock gearing for bottom end power around town, but cannot WOT for a long duration as my engine will overrev like the Energizer Bunny. I don't know why different belts widths are not offered.

Using the shorter belt works for me because there is a bit more travel on the rear pulley vs the Variator. And my belt starts off slightly compressing the rear pulley at standstill, and is riding lower on the rear pulley when the variator is fully opened thus taller gear.

frank
 

But how high should the belt go? All the way up?
 
Aloha, Well with my setup PGO, I need to use a Polini overdrive for Honda Dio and yamaha overdrive front halve and Honda weights. Since I cut 2mm off each face of the variator halves, the varitor closes 4mm tighter and the belt rides 1/3 off the variator when fully closed (top speed). With stock gearing, I start to overrev at about 110kpm.

But normally the belt should go to the top of the pulley caused by the fullest extent of the roller travel.

The lighter rollers/lower speed situation is not as noticable. I think in highly tuned scooters that can overrev. Mostly noticable in stock and "Sport" piped ones that stop revving before the lighter rollers can fully extend. If you are a little light on a tuned scooter with a proper pipe, then when you build up more overrevs the rollers will extend fully out and you will not notice any less top speed.
frank
 
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a wider belt will only work if both vario & rear pulley are designed for it, if you use wide belt for a rear pulley designed for narrow belt then it won't go up all the way on the vario, that's why OR kits come as a package they are built to operate as a matched combination.

everything that you have thought about transmission mods we have done so a long time ago, been there, done that.
 
Aloha, yes all this is old stuff. Just trying to trade and share ideas.
Grinding the slot longer on the rear pulley will allow it to accept a
wider belt. frank
 
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You might have done all of this a long time ago but unless you are sharing the knowledge you have it is useless.

You said one thing that is key: MATCHED. It is the little things that make big power combined and NOT one major mod on it's own. A lot of people on this forum seem to be searching for big power but seem to lose the point in that small things need to work together just like a transmission. I see post after post going for huge carbs, big ports, massive compression, maximum advance timing.... big and extreme all of the time.
 

the reason i'm not sharing or not open to talk about it is b'coz it's one of my secrets, just giving someone ideas is reason enough to start trying it & if they persist they will hit the right combo, i still have my old 2000 MHR OR kit & it took a lot of thinking on my part before i got it to work & i'm not about to share stuff like that freely.
 
adas said:
Aloha, yes all this is old stuff. Just trying to trade and share ideas.
Grinding the slot longer on the rear pulley will allow it to accept a
wider belt. frank
Click to expand...

yes but you need to do a bit more than elongating the slot on the rear pulley before it can accept a wider belt.
 

Fair enough. I guess some people need to keep our experiences secret but that begs me to ask the question why are you here if you aren't here to share?

When I was racing we all shared our "ideas and secrets". We shared spare parts with our competitors even if an hour later we were doing our best to beat them. I even had the guy who I was leading in the championship lend me a whole bike when my motor blew and he crashed and was unable to continue one weekend.
 
Aloha Ex racer. This MUST be kept secret. Do you not know what could happen if this information leaks out? I am in Hawaii and probably 1/2 a world away from "the Secret", do you not understand the havoc that will be sustained if I got a hold of "the Secret"? Happy fathers day whoever and wherever this applies. Frank

Disclaimer: For all using babelfish to translate this from english to your language, my post here is an attempt to be Silly, absolutely nothing else intended, ....just a little humor on Fathers Day.
 
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Aloha, All. I tend to agree with the above. I stated to elongate, but that is only a part of the equasion or solution. You have to take the idea of wider belt, front and rear pully opening and closing more and experiment how to do it. It is impossible to describe it here as different variators, rear pulleys are all different. (Most times the manufacturers of the pullys don't give you a lot of room to modify, sometimes they do). You have to play it by ear. Elongate, one way for the rear pulley to close more and/or open more and then you have to grind a bit on the faces....but not too much because you will ruin the seal or strength of the rear pully half. Then to let the belt come all the way down on the variator without having to lengthen the boss, you may want to "bury the rollers" (the small air belt sander works great for this).

So as Tiba says "just giving someone ideas is reason enough to start trying it & if they persist they will hit the right combo" is so true. frank
 
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