Rollers weight

[Faber32]

Hi everyone A question for the experts: my Gti 125 requires 18x14 rollers of 13.0 grams weight. I have a set of 18x14 12.0 grams Bando rollers. Do you think I should avoid a different weight or I can go with the 12.0 grams without too many consequences? I was wondering if the engine will rotate at too high rpms when accelerating. Thank you very much for help

[Iahawk]

people will typically drop down a weight or two in a search for better acceleration. Most do this when going to Dr Pulley sliders. I dropped a gram in weight and noticed better acceleration (with no loss of top speed). The theory is lighter weights will give you better acceleration at a possible cost of reduced top speed. Will 1 gram in the rollers make a difference? Who knows, give it a try!

[Faber32]

Thank you. I've just read that usually an engine of that size has rollers in the range 10 to 15 grams. So probably the difference won't be so excessive. Anyway I'll keep the topic posted for future readers

[Ruffus]

@Faber, did some testing on a LIKE 200i, maybe you have a look at this link...

Whether you're happy with your scoots performance depends on several factors as, weight, windshield, out in the flats, urban, temperature, etc.

https://www.kymcoforum.com/index.php?topic=30655.msg214654#msg214654

[Faber32]

Thank you very much I'll read all of it carefully

Update: after reading your interesting topic I think that a difference will be perceptible, so if I'll find enough time I'll try first with 13g. If I'll be in a hurry I'll order the genuine kymco ones (14g) just to avoid problems. I'll keep this posted, thanks again 

[agilebda]

I've had the GTI 125cc in the past. The roller weight is very sensitive. 10g is too light and 11 too heavy. 10.5 is the sweet spot for that scoot.

[Faber32]

Hi and thank you. If I go to the Kymco parts website, it talks about 14g rollers. Probably we have different engines because mine is european?

[Ruffus]

@Faber, since BANDO rollers are inexpensive, just have a try with even 15 grams (gives you a calm middle speed with low revs). Order several weights and put it in, then test ride. Mixed (i.g. 3x12 and 3x15 grams) is possible too. All depends on your personal likings.

[Faber32]

Ok, I'll do some attempts. I'll let you know, thanks

[agilebda]

@Faber, since BANDO rollers are inexpensive, just have a try with even 15 grams (gives you a calm middle speed with low revs). Order several weights and put it in, then test ride. Mixed (i.g. 3x12 and 3x15 grams) is possible too. All depends on your personal likings.

The 125cc has large rollers. 15g are wayy too big for this scoot. Wouldn't have enough horsepower or torque to take off.

[Ruffus]

@agilebda, with all respect I disagree. Takes (admittingly) off slower, but still has enough performance to give a smooth midrange cruising, and saves fuel.

Exemple: just for fun I tried on my GD 150 19.5gr
NON original squares (similar to TechPülley) and the scoot is still driveaable.
Of course takes a while to get 'em galopping, but it's fun to experiment with.

[Tromper]

Hey Faber please let us know what ya come up with and whatcha think.

For what it's worth, here in the U.S. I've generally found going a gram lighter's worth the bit of mpg, but I also live in a pretty hilly area.
It's also of note that you can mix weights a bit so if 12 g is too much one way and 13g too much the other, even number of both evenly spaced would yield the equiv of 12.5g.  Fair warning I ain't done it personally, but more 'n a few folks have on various models.  If you try it and it don't feel right swap it back to what worked before.

If ya want to get all fancy and read a bit check this out http://www.scooterfocus.com/scooter_variator_tuning_roller_weight.html

[Faber32]

@Tromper: for sure I'll let you know. Within a few weeks I'll do it. My People with genuine belt was good, had a decent acceleration. Then 2 years ago I put on a Bando new belt and it lost a little acceleration. It's as if from 30 to 60 km/h it lacks of power and struggles revving high. I hope with 12g rollers it will regain the lost "power". I'll let you know the result

[Stig / Major Tom]

@Tromper: for sure I'll let you know. Within a few weeks I'll do it. My People with genuine belt was good, had a decent acceleration. Then 2 years ago I put on a Bando new belt and it lost a little acceleration. It's as if from 30 to 60 km/h it lacks of power and struggles revving high. I hope with 12g rollers it will regain the lost "power". I'll let you know the result

While you're in there maybe put on a Kymco belt again
?
Stig

[Tromper]

I can't find the spec on the OEM belt vs. what you picked up (don't have that spec either), but the size and other dimensions of the belt do have some impact as well. 
Normally when you change out a belt, even with OEM, you do lose a bit at first since the belt sits higher in the pulleys cuz it's a bit thicker.

When you changed out your belt did you change out your rollers as well, or leave the old ones in place?

@Tromper: for sure I'll let you know. Within a few weeks I'll do it. My People with genuine belt was good, had a decent acceleration. Then 2 years ago I put on a Bando new belt and it lost a little acceleration. It's as if from 30 to 60 km/h it lacks of power and struggles revving high. I hope with 12g rollers it will regain the lost "power". I'll let you know the result