My roller weight quandary

[deejais]

I have a stock GY6 50cc that I unpacked from the shipping box myself back in June. Hums along nicely, my only complaint is that it slows wayyyyyy down going uphill, even a slight grade. Not unusual, at least so I read, but it's the only thing I wish I could improve.



Talking to a guy at a scooter shop couple of days ago, and he told me I needed this variator kit with 6g rollers. Exactly this kit:

He told me this was a performance kit, the lighter weights would help me slightly on the hills, and also that the pulley had an upgraded surface that helps the belt move on it. OK, whatever, sounds good. Fifty bucks.



Put the new kit on today and there is definitely no improved performance. In fact, by the seat of my pants feel, it's slightly more sluggish. I wasn't expecting a giant improvement to begin with, but this is in the other direction. Rainy day today, so i couldn't test ride it very long.



Brought the original (stock) variator home to use my precision scale on the rollers, and they are 5g! I actually put on heavier weights today instead of lighter ones. Damn.



So question: did the scooter shop guy mean to sell me HEAVIER weights to help me on uphills, or did he think the stock 50cc rollers were heavier than 6g, and he was bringing my weight down?



I don't want to go faster, I'm cool with the top end speed. I just want help on the hills, and I know the answer is somewhere in the weights, but I could use some help. Thanks.

[aeroxbud]

Most variator will come with a weight close to stock. That variator covers a range of different models. So that might be stock weight on one of them.
There is no one size fits all for variator weight. You can have an educated guess. But for really fine tuning, even 1/4 of a gram can make a difference.
Buying the variator is just the first step in tuning the CVT.
Perhaps buy some 4g rollers. You can mix these with yours. But also add silver foil to them, and experiment to find what weight works best.

[GrumpyUnk]

What he said, plus. I would have taken the shop words with a grain of salt. Or a 1lb of Mortons. A variator will do so much, and a 'performance' variator is limited by physics to doing exactly the same thing as a non-performance variator. Get skinny as the rpms increase, forcing the belt to squeeze down in the clutch end against the torque spring tension trying to keep the belt at its perimeter.
If you add more weight, the variator will tend to squeeze harder, and get into HI gear more quickly.
If you replace with lighter weight, the variator will be less able to squeeze and the belt will stay closer to the crankshaft longer. It is just 'weaker' at upshifting the gear ratio, and cannot pull hard enough until higher rpms against a given torque spring. IOW, it will stay in 'lower gear' longer, and may never get into as 'high' a gear as you may with heavier weights.
You can mix ande match differeing weights as long as you keep them balanced. Three of one, three of another, equally spaced so you don't create an imbalance. ABABAB going around. That sets all the A equally, along with the B weights.
I don't know the colors offhand for the torque springs, nor clutch springs for that matter, but if you have a stronger torque spring, it will resist going to higher gears and will make sure the belt grabs tighter than a weaker torque spring. A weaker spring will more readily allow the variator to pull the belt into towards the center, effectively shifting to a higher gear.
I do not know how or if the variator/torque spring can be induced to 'downshift' to a lower gear ratio when climbing a hill. The only thing that would allow that would be the variator losing its 'squeeze' and the torque spring being allowed to push its pair together, effectively down shifting. That will happen when you come to a stop as the variator will 'let go' and the torque spring recover its original condition.
Get a good running start, and hope for the best... A bit of improvement that is actually noticeable would be to go to a BBK. Someone will be along shortly to tell you you should have bought a more powerful machine. I bumped a OLD Jonway to 63cc, and the effect was noticeable. I doubt that the longevity would be much affected, but the performance certainly was. You can put together a gasket, piston, rings and cylinder for a low budget bbk of your own. Honestly, it actually became fun to ride with just that little improvement. The guy that bought it came from Tennessee to my home to buy it, and was very pleased.
tom