What does the spring do in the clutch pack? Changing them will result in?

[kneeslider]

Just trying to understand my scooter better.

[BettinANDlosing]

The large spring, or the three "clutch springs"? The large spring is called the torque spring or contra spring and it effects the tension on the variator, tighter spring holds higher rpm longer. The three springs control when the clutch engages, tighter springs act like dumping the clutch later at a higher rpm. Again, not sure which one your talking about!

[zombie]

Yeah! What he said!

[kneeslider]

Thanks, I didn't realize there was another larger single spring other than the 3 small ones.

[zombie]

This video shows why the larger "contra" spring should also be changed.


For changing the "fly" springs.


The Contra spring.
Chinese scooter compression spring change 50 cc

It's all ball park mechanics. An impact driver makes it all easier.
If you take the clutch apart be SURE to use either Blue Lok-Tite on the main nuts or replace them w/ New nuts

[kneeslider]

Are our Taiwan scoots built to such low tolerances that we need to individually 'fine tune' them to work?

[BettinANDlosing]

They are fine stock, some people (Zombie and myself included) can't leave anything stock. Half the fun is tuning the variator to see if you can make it "feel" better.

[zombie]

Yeah! What he said!

Actually the bikes are made for 'common" use. Sort of a balance of safe/long life, and zippy enough for tiny little Asian people (yeah I went there). They are not really designed for us monstrous European types.
That's why most of us adjust/swap/mod almost every bolt on the bikes. They are fine for 5 foot something, and 140 lbs. 6 foot something, and 200 lbs is another story.

[BettinANDlosing]

Exactly.... Everything on our bikes is designed for, um, "smaller" people... If you load the scooter with weight, you need lighter rollers and stiffer fly springs. My bike normal revs to 7-7500 rpm uphill, loaded down with camping gear going over mtn pass it lugs to 5-6k rpm.

[kneeslider]

I am 160lbs, so maybe I am not experiencing the need to change anything except the sliders to Dr Pully rollers for a better top speed, and something to improve the front brakes.

[zombie]

Rollers or sliders alone don't really change the top MPH. It's more the RPM at any given speed they effect.
If they are too far out of range they will reduce mph.
Lightening rollers is the norm for gaining rpm, and getting more torque sooner. Same goes for the "fly" springs. More RPM for more torque.
Some variators add a few mPH just by design. They will allow the belt to travel further up the ramp plate, and = more speed. For the most part tho, the cvt simply controls the engine, vs, the engine controlling the cvt.

Bigger carbs/pipes/air box mods can increase power/rpm/mph. The cvt determines how it is delivered.

Think about it like swapping a trans or rear end in a car. You can install a 5.07 rear and pull wheelies but never get over 70mph. or go to a 2.70 rear gear, and crawl like a snail but top out at 120mph.
If you put in 3.83 gears you will go 120 but get there faster.

Install headers, and a carb you get 150mph.

Dial in your cvt to get the best balance of what YOU need.  just lighter rollers will improve the feel of the bike. Better take off but slightly higher cruise rpm. A stiffer contra spring will improve the feel, and maintain the same rpm at cruise.
Adding both give you the most you can get from the CVT.