Stock variator performance

[Pbowen]

Does anyone have information on when the stock variator on a 2023 PCX160 starts to…variate? In other words, at what engine rpm do the rollers start to move and at what rpm have they reached the limit of their movement. And is the movement linear with regard to rpm. I’ve drawn a blank on Google and my local Honda shop. Documented technical data preferred.

[waspmike]

A couple of years ago I did make a spreadsheet of the effective weight of the weights at different rpm with the intention to try and ascertain what weights to install to get max torque during acceleration.
My PC is currently down waiting for a part so can't access at present.So I am pecking away on a phone while looking at palm trees and sunshine.
The movement may be linear but the effect will not as the distance from the centre will vary and the ramp in the varistor is not linear.

May I ask why you wish to know. Fitting a cheap tach/hour meter will give you some base rpm data. But the clutch springs etc. will compromise the lower end of the data.

[Pbowen]

Curiosity more than anything else. I had thought about a cheap tach, and may pursue that avenue if the need to calm my OCD gets too extreme. Anyway, thanks for your reply.

[Conelite]

I run a tach on all my CVT bikes. Best way to properly tune the variator. I spent decades perfecting my CVT tuning skills for speed.

Variator will never "consistently" start to shift at the same rpm. It's much more dependent on more load vs less load, a heavier rider vs a lighter rider or up a steep hill. Too many factors to assume the bike will start to transition to mid/high gear at a specific RPM.

[Pbowen]

I run a tach on all my CVT bikes. Best way to properly tune the variator. I spent decades perfecting my CVT tuning skills for speed.

Variator will never "consistently" start to shift at the same rpm. It's much more dependent on more load vs less load, a heavier rider vs a lighter rider or up a steep hill. Too many factors to assume the bike will start to transition to mid/high gear at a specific RPM.

Interesting. I was assuming a couple of things in trying to understand variators;

(1) That there was a linear relationship between the engine RPM and how far the rollers (sliders) moved and that their movement would not be affected by applied load, other than taking longer or shorter to move based on a heavier or lighter load. This seemed reasonable just from a physics point of view.

(2) The pulley belt did not slip, since slip would increase heat and wear and seemed less than optimal.

(3) The clutch also did not slip once engaged for the same reason, excessive heat and wear.

It seemed to me that if all these assumptions held then you had a fixed system from the engine through the variator and clutch, then the differential gears, to the rear wheel, with the only variable being the variator ratio from drive pulley to driven pulley, and a directly proportional relationship between engine and RPM and speed.

But from what you said it would seem that at least one of the three assumptions is inaccurate. From your years of experience can you tell me where I'm making my logical error.

Thanks for your replies!

[waspmike]

How far the weights move is not simply rpm dependent. They have to force the pulley halves together to alter the gearing. To do this they have to overcome the force of the counter spring. Then there is the torque tube
which reacts to the amount of torque applied to the pulleys and will essentially try to force the pulleys into a lower gear like auto kickdown.
OCD not withstanding it is a rabbit hole. For practical purposes best tackled empirically based on what results you want. As everyone seems to want differing results some of which have geographic factors.
Yamaha have gone electric. Their new Nmax/Aerox has an electrically activated front
pulley with thumb controls on the left. One setting maintains 7000rpm for climbing hills and passing. Another setting is for engine braking going downhill.

[Pbowen]

Torque tube?? Where is that located?

[Conelite]

But from what you said it would seem that at least one of the three assumptions is inaccurate. From your years of experience can you tell me where I'm making my logical error.

Thanks for your replies!

I think you are forgetting the Contra Spring. The contra spring/torque spring is another factor. The stiffer the contra it is, the more resistant to shifting the variator is going to be. OEM springs & variator weights are usually spec'ed to optimize MPG and smoothness. Keep RPMs low and calm.

Heavier Spring is like going lighter on the weights in the variator to allow high RPM throughout the acceleration range. Typically, if you live in a hilly area, you want the RPMs to hold higher in the "Powerband" for as long as possible to carry you up steep hills. Its a fine balance. Y

IMO: Stock back no internals (ie. Headwork, BBK, Tuner) all you really need is a tach, aftermarket variator and some lighter weights. That should be a night and day difference when it comes to performance.