Hill Climbing Performance

[beo111]

Thanks all for the advice!

[andsetinn]

First. Some carb and brake cleaners eat plastic, some eat rubber, some have lubricant (that would be some carb cleaners, brake cleaners shouldn't have lubricant ). Other cleaners (almost all these days) are safe for plastic and rubber. Also WD-40 is NOT a lubricant. If you want something to move smoother use oil or grease.

My :2cents: about cvts, springs and rollers.
The (contra)spring tries to keep the scooter in low gear (first gear).
The rollers, or rather the centrifugal powers working on them, try to shift the scooter into high gear. Higher rpm means more force trying to shift to higher gear.
Lighter rollers will let the engine rev higher before shifting up (because there are less/weaker forces trying to shift into higher gear).
Stiffer contraspring will do the same thing (because there are more/stronger forces trying to keep it in lower gear).
Basically you're making the engine run at higher rpm, compared to speed, which will increase fuel consumption under normal circumstances. But most engines will "have more power at higher rpm" so by lightening the roller or stiffening the spring you're "giving the scooter more power".
Lighter rollers and lighter (comparatively) spring will have less force on the belt. Meaning less wear, unless the force on the belt is too small so the belt slips. Higher speeds and heavier rider increase the force on the belt so tuned scooter with heavy riders should always IMO have stiffer springs. Stiffer spring will heat the belt more, increasing wear and slipping belt will also heat up and wear faster.

The clutch springs adjust at what rpm the clutch engages. Stiffer clutch springs mean that the engine is at higher rpm when it engages so the engine will have "more power" when the clutch engages, giving better acceleration. Too stiff springs can cause the clutch to slip which will heat it a lot.

[2strokd]

Pretty good info to some the system up a bit!
To stiff of clutch spring will let the rear pulley,s spin too fast and let the CVT system start to shift before the clutch shoes engage the clutch bell if the rest of the CVT system is not set up proper for the tighter clutch springs or "pill springs".

[stepthrutuner]

Jun 23, 2010 20:14:56 GMT -5 andsetinn said:

First. Some carb and brake cleaners eat plastic, some eat rubber, some have lubricant (that would be some carb cleaners, brake cleaners shouldn't have lubricant ). Other cleaners (almost all these days) are safe for plastic and rubber. Also WD-40 is NOT a lubricant. If you want something to move smoother use oil or grease.

My about cvts, springs and rollers.
The (contra)spring tries to keep the scooter in low gear (first gear).
The rollers, or rather the centrifugal powers working on them, try to shift the scooter into high gear. Higher rpm means more force trying to shift to higher gear.
Lighter rollers will let the engine rev higher before shifting up (because there are less/weaker forces trying to shift into higher gear).
Stiffer contraspring will do the same thing (because there are more/stronger forces trying to keep it in lower gear).
Basically you're making the engine run at higher rpm, compared to speed, which will increase fuel consumption under normal circumstances. But most engines will "have more power at higher rpm" so by lightening the roller or stiffening the spring you're "giving the scooter more power".
Lighter rollers and lighter (comparatively) spring will have less force on the belt. Meaning less wear, unless the force on the belt is too small so the belt slips. Higher speeds and heavier rider increase the force on the belt so tuned scooter with heavy riders should always IMO have stiffer springs. Stiffer spring will heat the belt more, increasing wear and slipping belt will also heat up and wear faster.

The clutch springs adjust at what rpm the clutch engages. Stiffer clutch springs mean that the engine is at higher rpm when it engages so the engine will have "more power" when the clutch engages, giving better acceleration. Too stiff springs can cause the clutch to slip which will heat it a lot.

I really don't think that a stiffer contra spring will create more belt heat or slip. The belt is going to find the position of least resistance naturally. If anything a stiffer contra should cause less slipping and thus less heat.

[stepthrutuner]

Jun 23, 2010 20:14:56 GMT -5 andsetinn said:

Higher speeds and heavier rider increase the force on the belt so tuned scooter with heavy riders should always IMO have stiffer springs.

You just complemented my argument for a stiffer contra benefitting hill-pulling ability.An incline is no different from wind resistance or rider weight under acceleration. It is added force that the variable transmission has to deal with.

[andsetinn]

Jun 23, 2010 21:30:50 GMT -5 stepthrutuner said:

I really don't think that a stiffer contra spring will create more belt heat or slip. The belt is going to find the position of least resistance naturally. If anything a stiffer contra should cause less slipping and thus less heat.

But stiffer spring, with heavier rollers, will compress the belt harder than regular spring and that means more friction, which again means more heat. How much more heat and how much that is offset by less slip of the belt, I can not say. It depends on the tune and weight of scooter and rider .

[lackthereof]

Does anyone know around what RPM the variator finishes closing at, with stock weights and spring?

My scooter's manual (and the Lifan website) lists peak HP of a stock engine at 7500 RPM, and peak torque at 6000 RPM, but just by listening it sure sounds to me like the engine's spinning a LOT slower than either when the CVT reaches it's "top gear".

My stock transmission holds the engine at just about a constant RPM from 12-22MPH, and then it really starts to spin. But if I'm on a hill, it just groans away, stuck somewhere between 15-20 MPH, and the engine never seems to get into the power band. I want to get a cheap inductive tachometer hooked up to see, but it sure sounds to my ears like it's "upshifting" way too early to get any power out of the engine.

Is the 7500 RPM peak listed in the documentation a trustworthy number for these engines? If not, what RPM range do these (stock) engines make the best power in?

[90GTVert]

It's ahrd to say what a stock transmission setup is revving, because they don't all come withthe same weights stock. It does sound like lighter weights might be worth a try for you.

From what I've seen I would say peak is between 7500-8000RPM stock. With an aftermarket cam mine seems to like about 8000-8300RPM. It will rev higher, but it doesn't seem to be making any more or as much power at higher revs.

[Fox]

On a stock scoot I think all the stiffer springs do is to counteract the force of the weights so take off is quicker hence, lighter weights act the same as a stiffer spring IMO. Lighter weights = less force on the variator = more force from the stock clutch spring in a relative way the way I see it. It's when you get into BBK's and increasing torque by exponential values that the stiffer spring is needed to balance everything out even with light weights.

Again, where the hell is the vote button(s) ?

[90GTVert]

I think they must have some default expire time that you can't get past. They work fine for a while.

[lackthereof]

I finally bit the bullet and swapped in some 5g weights this monday, to my otherwise stock scoot.

VASTLY improved. Hills that were previously 22 MPH are now closer to 28, with no noticeable difference in top speed. Acceleration is much smoother, even if I have to stop on a hill. RPMs are now steady from the high teens all the way up to 40MPH.

I've got a tach coming in the mail, so I'll know exactly where it's at, but it sounds much closer to 7k than before.

[grimsby53]

I'm a severe noob and I just finished reading through this thread, and nothing else has come as close to giving me real understanding of the CVT as this. I love this forum. And I just ordered a set of 5g weights.

[lackthereof]

My ears weren't far off, the tach shows a steady 6500 rpm from 15-30mph (according to the bike's speedo). Seems like the variator's closed up as far as it can around 30 mph.

It's amazingly consistent. The engine speed only varies by maybe 100RPM over the entire speed range, although it does have an initial spike to 7k for maybe half a second.

Above 30, rpm climbs steadily until the bike tops out at 40ish, turning at the "official" HP peak of 7500. This seems the exact same as with the stock weights, so I assume it's still closing all the way.

So it seems like I've got another 1000 RPM to play with. I'm tempted to try and find a set of 4.5g weights, or maybe try and drill the stock weights out to 4.5. For day-to-day riding, though, this will do quite nicely, and I'll think of that 1000 RPM as a safety margin.

[90GTVert]

As long as you are happy with it this way, the lower revs might increase your engine life a little.

[grimsby53]

That 1000 rpms can be reserved for downhills.