Lighter Weights =(?) Heavier Ctr. Coil: Theory and Practice

[Wheelman-111]

Greetings:

So I've been turning this one over ('scuse the pun )in my head for a while now:

I've tried to conceive of the Variator pulley/Belt/clutch pulley as an
Assembly. Obviously the prime motivator for the Assembly is the engine, but the wheel/axle also exerts some effect, "backdriving" the Assembly when off-throttle. (KMcC's term, and I like it.)

The belt spec per Honda-san is 2.4:1 at 0 RPM. At max. RPM the ratio becomes 0.8:1, or an Overdrive of 5 to 4 before the transmission factor.

If you put in lighter weights, the belt upshifts at a higher RPM for a given center spring stiffness. Easy to imagine. A stiffer spring will have the same effect if the weights stay the same. Easy to figure in Theory.

Q1: In Practice, is making either change exactly the same as making the other one? How does it feel if you put in a heavier spring compared with putting in lighter rollers? Is there any difference at all?

I appreciate any advice available.

[Wheelman-111]

Greetings:

Don't all chime in at once...

[evilone]

I was thinking the same thing the other day! But i don't have your answer. I plan on replacing both for the acceleration and top speed (stiffer spring with heavier weights).

[scooterwerx]

its basically the same. in my experience, i only changed the contra spring if the rollers were getting outrageous. we were down to 3.5g on my bros zuma, it was barely anything but the plastic! so we changed to a heavier contra to bring up the necessary amount of weight in the variator. with the 2000 spring from daywot, it now runs 7.5g rollers.

[Wheelman-111]

Greetings:

Thanks, Werx! My theoretical mind reached the same conclusion, but nothing beats Practical experience. I can come down a long way from current 9g rollers before I need to think about a spring stronger than my +1000 from DayWOT.

In another thread you said it sounded like a Variator issue, and that's exactly how it feels. The tranny "shifts" into high before the speed potential of the power that's there is reached. The engine lugs, can't overcome wind drag and I'm stuck @ 42.

With more RPM, I'm confident it can push through and reach that elusive 50. It did, once AND held speed with the help of a little downhill. The revs were still not real high. Temperature stayed below 300. Now that I know my carb isn't about to suck air, (tapped for 1/4" bolts...) I can go WOT with confidence.

[noiseguy]

Both should do the same thing. There's probably some governing equations somewhere that would tell you the rate of change of each alteration... Oh here we go. Probably also buried in some engineering text elsewhere:

http://www.springerlink.com/content/0n2138416r56626p/

I think it's more a practical issue. It sounds like you're running into the minimum mass you can run on the rollers without needing to change your spring. As the rollers get lighter, don't they start wearing out faster?

[Wheelman-111]

Greetings:

Thanks for that input, NoiseGuy. I should have specified that my rollers are 9g EACH, or 54g in total. Not sure about roller weight/wear. They undergo the same stresses only at different RPMs. I can see how a stronger contra spring could accelerate wear however.

[scooterwerx]

the only problems with wear were from running cheap-o aftermarket rollers, switched to drilled out oem rollers and havent had a problem since. i pulled out the rollers that came with the leo vince, they look fine so far...i see how a heavier contra spring would make them have to push harder, effectively, to over come the force of the spring.

[Wheelman-111]

Greetings:

At 2900 miles the stock Honda Rollers had a pretty good flat "bite" out of their moon shapes. LeoVinci didn't include any in my pipe package, curses. I got the 9-ish ones with the Keli from DayWOT. At 300 or so miles, they were still pretty round.

We'll see what kind of material composition the Taiwanese rollers have. Thanks for the warning.

[scooterwerx]

no lube either, i used to spray dry moly grease lightly on the rollers, but i was thinking about it, and they are suposed to roll, not slide, lubrication makes things slide, dry makes them roll. if only there were some some of friction modifier you could add to grease, like LSD oil, we would be set! and i dont mean hallucinogenics!

[Wheelman-111]

Greetings:

I'll clean up the BoeShield T-9 Teflon spray I had applied if you think it's a good idea. Despite their round shape, the "rollers" are trapped between two inclined planes. Their location within the triangle so formed determines the pulley position, counteracted by the Contra spring actiing through the belt thickness. If they roll up one plane, they have to slide on the other. Maybe put dry lube only on the steel backing plate ramps, letting the rollers "grip" the rougher aluminum variator ramps?

[scooterwerx]

the aluminum and steel will have different coefficients of friction, ive been running mine dry for a while with out incident...

[scooterwerx]

also, have you seen the Dr. Pulley "slider" weights? they are already triangular and slide on both surfaces! it looks like a good system...i think it requires to use their special variator though...

[Wheelman-111]

Greetings:

No clue from triangular Dr. pulley Slider Weight Thingies. Do tel!

[scooterwerx]

check this out!


http://www.unionmaterial.com/rollerweight6.htm