Lighter rollers?

[Stig / Major Tom]

Did you notice you're running at higher RPM's now per your road speed?
Stig

[Stig / Major Tom]

Looks like another way to have more RPM (and more power) at lower speeds would be to install shims between the variator bush, and outer half of the variator pulley. Complete sets of different size variator shims are available for other model scooters, maybe complete sets of shims will be available for these models as well ?


By using shimms at the Variator, the slightly wider variator pulley actualy allows the belt to be at a lower position - and allows the belt to be in a  higher position at the clutch pulley during take off. This obviously will cause more RPM, and more power during take off.


The only downfall though - aparently top end speed seem to be lower after a modification like this.
Care must also be taken that not too many shimms are used - when the pulley becomes too wide, the belt will start getting in contact with the center bush, and the belt will start slipping.

I think  modifications like this might work quite well, but special care must be taken not to use too many shimms. The reason being - when the belt starts getting worn, (thinner) the pulley might be too wide, the belt will start rubbing against the  bush, and the belt will start slipping.

No expert here on 50cc scoots, and derestricting of same, but I think I've read that yes,  these scoots are often 35mph speed restricted from the factory by use of a shim in the front pulley.
To derestrict this shim is removed to increase top speed a bit. Not sure what that would do to the 'grunt' of a 50 trying to get away from a light in traffic?
Stig

[Stig / Major Tom]

And not sure that manufacturers are always working that hard to stay out front. With rollers or sliders. Honda doesn't even publish HP ratings most often - and to my knowledge has never been known to be the performance leader of the Big 4 from Japan. They do quite well selling bullet-proof - not boy-racer.
Most companies had to be forcefully dragged into releasing bikes and scooters with ABS - long after it was standard on automobiles. The same with EFI, disc brakes, better lights, etc.
My lowly 7 year old Toyota product came with 4 Denso Iridium spark plugs - but yet to see them in a bike.

Sliders give the owner a quick and simple method of slightly changing the way his scooter behaves. Nothing to get angry about - they're not expensive & they do outlast rollers and those who sell them have printed guides for taking some of the mystery out of what to expect from them.

Sliders  very likely have more of an impact on 4-stroke scooter performance than any after market pipe.....yet few get exercised about these pricey, louder,  generic cans.

Stig

[Nireen]

Wow 168 kmh. Geeez how you do that!  I was getting about 135kmh only and of course loss about 10 kmh recently.

[KymcoRockr]

No expert here on 50cc scoots, and derestricting of same, but I think I've read that yes,  these scoots are often 35mph speed restricted from the factory by use of a shim in the front pulley.
To derestrict this shim is removed to increase top speed a bit. Not sure what that would do to the 'grunt' of a 50 trying to get away from a light in traffic?
Stig

It's a spacer, like a ring around the bushing or boss, that is used to keep the pulleys from closing all the way. Kymco uses a boss, or bushing that has the restriction machined into it. You can't just pull something out, you have to replace something on their scooters.
If you use shims to make the variator boss or bushing wider (which is what they do when they try to tune it that way), you do lose top speed because the belt will be lower at the same rpm, once  you max out. If you use enough of them, you can't get the nut on all the way, and we all know that never turns out well.

[mrbios]

I went with 1gm lighter Dr P sliders in my 163cc LIKE...



Stig

Great photo with the truck in the background.

[mrbios]

It's not necessarilllyyy that simple - if he goes a bit lighter, t...

In my GV250 I changed to Dr Pulley 19x23mm 19g flat weights, and sliders (3) at 10K miles and now I have 28K and they are still running great.  If I want more hp/torque I twist the throttle.  Was never interested in changing the weight to make the motor rev higher than it normally does on the highway which is between 8-9K RPMs.

[KymcoRockr]

my 2 stroke SH50

Now you're talking. We never got it in the US.

[boksaman]

Just want to make sure is roller dimensions are correct:

20mm outer diameter
12mm width
OEM weight is 15,5 gr

and then we play around with lower weights to get more acceleration from zero and at lower speeds ?

thanks

[pa-outdoorsman]

Con. Then it will be wound up tighter at cruise, tighter than a gnat stretched over a banjo!

Guys, I am far from the scooter tuning expert, but here's a link to a thread with some actual data from various variator/roller weight configurations on a Honda ADV 150. The model being discussed here isn't important so much as the numbers. As you can see, with an aftermarket variator, paired with rollers of varying weights, you can fine-tune how the power from your engine is delivered through the CVT. And interestingly, while most of these "experimental" setups resulted in a MODEST INCREASE in RPMs at lower speed/acceleration, they actually slightly INCREASED TOP SPEED while slightly DECREASING RPMs at top speed.

https://www.hondapcx.org/viewtopic.php?f=45&t=11524

Of course, I am taking the poster at his/her word here. But to me, this looks promising enough to at least consider an aftermarket variator/roller combo at some point in the future. I can get a Yuminasi variator and roller set for my scoot for less than $150, which isn't a huge investment by any means. And, as others have already said, if for whatever reason I decide I don't like it, it's an easy job to simply re-install the stock components.

[Iahawk]

I'll just add that I recently changed my Kymco OEM rollers for a set of Dr Pulley sliders in 13 gram (1 gram lighter than stock). Now, granted, I changed a few other things as well (new belt, cleaned and regreased driven pulley, new contra spring) but my scoot now leaves stop lights like a bat out of h*ll!

It was always fairly quick off the line but I can now smoke most of the cars. I keep waiting for my front tire to come off the ground! My top speed didn't decrease any, either. In fact, it seems to be up a bit but that could be due to the other items I changed.

As far as rpm while riding at a similar speed? Who knows...I don't have a tach and I ride with ear plugs and bluetooth music playing in my helmet...but it doesn't feel like it's spinning any faster.

[Ruffus]

Maybe my 2 cents.. I did some testing in this subject
https://www.kymcoforum.com/index.php?topic=30655.msg215843#msg215843

[agilebda]

I've had pretty good results with the Tech Pulley flying rollers 14 gr.