Variator doesn't return to low "gear"

Still having issues with the CVT on my aerox. Now the problem is as following:

If i start the bike after it's been off for a while everything is fine, as in it will start moving when getting near the power band and even tho the rollers seem to be a little too heavy as it reduces its rpm below the powerband after the launch, its decent.

The problem is: when I get to the higher ratio, if I lose speed or go up a hill or whatever, it stays in the same ratio and ofc loses most of it's power as it's running at really low rpms. Even weirded, even i I completely stop the bike and try to take off again it takes off still in a quite high ratio, making it really difficult to actually start moving.
I removed the cvt cover to confirm and indeed the v belt was at about half of each pulley. If i stop the engine for a few minutes and try to move again it will be in the lowest ratio and take off nicely again, the problem repeats itself as soon as I loose speed.

I think the problem is that the torque spring is too soft (even tho it's a new aftermarket spring, the softest in the 3 I bought), but what really bugs me is that if it was I believe it should still get to lowest ratio when the clutch disengages, aka I stop moving... So I'm thinking maybe the rear pulley is damaged somehow?

Thanks in advance (sorry, I keep writing these goddamn walls of text)

 

No one?

 

Strip out both front and rear pulleys. You could be right about the contra spring, but there could also be dirt built up in the sliding shaft of the clutch pulley. Need to separate and clean, regrease, reassemble. Clean front pulley channels where the rollers sit, they could also not be returning to their "home" position.

 

and check for major flats on the rollers whilst the front pulley is off. Any flat spots, replace rollers.

 

The front pulley and rollers are fine as I replaced the rollers like one month ago and made sure to clean everything. I didn't take appart the rear pulley tho, that's why I considered it to be the problem. Let's hope it's really just dirt buildup or so... The big issue is that I can't always be assembling and disassembling the rear pulley since I don't have a big enough wrench lol, hence why I asked before touching anything

EDIT: I now remembered that the rollers have these weird marks to them, please wait around while i find the pictures and upload them here again? thanks

 

Pictures of said marks in the rollers http://imgur.com/a/AU3BO#6 You can also check the rest of the pictures of the front pulley, I've been said it's fine...

These marks appeared after just a few days of using the rollers, but i believe it was because I was running with only 2 of those plastic sliders that sit between the roller housing and the back cover lol that's fixed tho, no sure if the rollers having these little spots is a problem?

 

What the hells gone on with those??? Looks like they have got really hot and started to stick to something, peeling little pieces off them.

on those shiny spots on the variator plate, are they deep worn indentations?

 

About the rollers, that's what I asked
About the variator plate, they're just visually shiny, you can't feel any outlining

 

Never seen rollers go like that.
Little trick you can try with the clutch pulley, take the belt off and see if it snaps back and forth with a slight twisting motion. If it is strong enough to take your fingers off then the spring is good enough. Should move freely, nothing rough. If not, off it comes.

 

I seriously can't understand what's happening. Today I disassembled the driven pulley and replaced the contra spring with the strongest I had. The whole pulley seems to be working fine, but when "test driving" the bike could get past the 70km/h mark, so I assumed the spring was just too strong for the stock engine. Changed to a medium strenght one, inicial acceleration is fine, but it still doesnt go over 75km/h (and cuts because of the restricted cdi) when it was previously doing 85.


ButThe major problem is that, even tho it's not as bad, the problem that it doesn't return to it's lower ratio is still there. Most specific, if you stop so the clutch disengages it then works fine, but if you brake to about 30-50 km/h there's no change in the ratio, leading to too low RPM. Any ideas what could be still causing this?

 

Aah, you have one of those problems................there is a technical name for this.........................what was it now.......................oh yes,....................BASTARD!!!!

seriously though, sounds like the rollers are too light and staying out when they should be dropping back at mid range. Or the belt is not running down the face of the variator plate, sticking to it, if you like.

 

If i use heavier rollers it upshifts too early and still doesn't downshift (I've tried before).. also, how can rollers too light stay out?

 

engine speed and centrifugal force. If the engine is spinning fast then the rollers cannot/will not drop down.
By the same token, if the rollers are too light they will take less centrifugal force to keep them up, not physically being able to drop due to lack of weight. Vice versa for heavier rollers.

What weight rollers do you have in at the moment and what weights have you tried?

 

Have you changed the belt lately?

 

But don't heavier rollers shot out easier than lighter rollers? If so, shouldn't they also require less centrifugal force to stay out, when compared to lighter rollers? I'm missing something here, but I'm tired, that could be it

Anyway, i currently have 4.5g and have tried 5g, and even tho it's such a small difference it seems to do a lot when changing the rpms at which the vario works. I've changed the belt about, hm, 2 or 3 months ago I think

 

The problem you describe is exactly the same as the one I´m having at the moment.
I´ve changed my belt, the old one was obviously worn and there was tonnes of dust in the casing. I changed my rollers with brand new one´s , the stock weight is 6.5g and I fitted 6.0g because I was told that slightly lighter weights would give me better acceleration and give me a bit extra going up hills.
At the moment I´m getting better acceleration off and on and I´m still suffering up any kind of mild slope to proper hill. It feels as though a couple of gears are missing. I was also told that I might have to do 100 miles or so, to break the new belt in, I´ve exceeded this milage and the problem hasn´t changed.
Did you get any wiser about this issue?
Cheers,
Jools

 

Some rollers need to be lubricated, others don't, it depends on the make and model.

I would recommend that you buy a can of PTFE dry lubricant and spray the variator shaft and the inside of the variator, so that there's not a lot of friction to stop the rollers returning as the revs drop and that the pulley slides back smoothly. Using oil to lubricate things can cause all sorts of pain, as dirt and belt dust will stick to the oil and make the rollers stick.

Make sure you don't get any on the variator pulley surfacess though, as it might cause the belt to slip.

 

Hi Merlin, thanks for the sound advice, much appreciated .

 

Will try that in the next few days, thanks. Altho I believe i found the cause. Trying to slide the variator on the boss, it seems to get stuck in some points instead of sliding freely. This would make sense of the big rise in RPMs I have before the variator seems to actually "work" when I take off, and then the rpms drop quite a bit (since the variator is stuck it needs extra force to move, hence higher rpm, then that extra force makes the variator travel too much hence getting in a too high gear?)

Can anyone confirm this theory makes sense?

 

Yes, it does. Constant speed running can wear grooves in the variator boss. Your best bet is to get a new one, as trying to polish out the grooves by hand may put the boss out of balance.