ROLLER COMP WEIGHT

[mamo]

Please tell.
I am going to change it for Dr.Pully, is ROLLER COMP WEIGHT(22121-LEA7-E00) of Downtown300i where is in a normal state several grams per one?

[de dee]

  standard gram Wt. is 15.5 per roller,.  from kymco,   I bought Dr. pulley sliders 20/12   15 gram Wt.   some people like 14 gram Wt. for better pick up, you can buy 15 gram and grind them down to what ever Wt. you like,   use your dremal grinder tool to do that,   
   
    I have a 2011 300i downtown with 57,000 km. on it , 

[windwheeler]

My factual acceleration tests 1:1 back to back same stretch of road have shown that you need to go (at least) 2 grams lower than original roller weights to see better acceleration/performance data.  That does not mean that 14g or 15g does any harm, they just don't give you the acceleration benefits described above. 

ALL slider weights also lower top speed rpm, thus from about 70-75 mph on the rpm are lower when compared to roller weights, or can permit a slightly higher top speed, depending on various factors. 

I would recommend 13g and you should see a remarkable difference.

[Goodrich]

I have 12g rollers and it has great acceleration 

[mamo]

Hello! Thank you for all communication.
I thank for de dee, windwheeler, Goodrich.

The mother that there is not an effect when I do not lower it more than 2 grams.
That I take 12 grams or 13 grams of whichever is a place to be troubled with.

[mamo]

I hesitate about 12 g or 13 g or choice.
How much will the engine revolution per minute at the time of the start become when I make 12 g?

[Goodrich]

I just had to get a new tire, my last one was a bit shorter than stock.  The new tire is stock size and now I'm noticing that it'll show 90+mph indicated.  I've never been able to do this.  My belt has almost 14K miles on it maybe it's reduced weight from having so many miles on it is making a difference.  The fastest I've been able to get prior to this is about 86mph indicated.  I used to do 70mph at 7K RPM but now it's showing about 6K rpm.  I've had the 12g rollers for about 6K miles. The rollers are cheap just get the 12g and if you don't like it go to 13g and be done.  12g rollers make the DT pretty zippy.

[agilebda]

Please tell.
I am going to change it for Dr.Pully, is ROLLER COMP WEIGHT(22121-LEA7-E00) of Downtown300i where is in a normal state several grams per one?

MAMO,

Here's some useful general "rule of thumb" information for DR Pulley sliders.
https://www.buggypartsnw.com/index.php/250cc-cvt-performance-package-level-1.html
Personally I prefer the yellow spring with 15g dr pulley's and a variator. Excellent combination.

[mamo]

agilebda,

Thank you very much for your advice.

I thank for information of agilebda. I want to examine it.

[windwheeler]

I hesitate about 12 g or 13 g or choice.
How much will the engine revolution per minute at the time of the start become when I make 12 g?

With 13g you FOR SURE will have no problem, with 12g  a bit higher starting rpm that will settle down quickly.  If you go heavier than 13g you start loosing some of the benefits of Dr. Pulley and can just stay with the standard weights. My personal opinion and factual observation.

[ktienation]

I cant agree with that. I have 14 gr and the increase in performance was noticable. I have the 2010 model with lea7 variator 33hp engine. According to the spec, maximum torque is achived by this engine at 6500 RPM and thats exactly where the 14 gr rollers put the scooter at WOT.

As far as i know, if the revs will settle in a higher level, and therefore torque will be lower it will not improve accelerations. Correct me if i am wrong, but thats all the purpose and one of few benefits of CVT transmissions - the engine is able at request to constantly operate in its most effective rev range.

Kind regargs.
Peter

[windwheeler]

I cant agree with that. I have 14 gr and the increase in performance was noticable. I have the 2010 model with lea7 variator 33hp engine. According to the spec, maximum torque is achived by this engine at 6500 RPM and thats exactly where the 14 gr rollers put the scooter at WOT.

There is no right or wrong answer, it depends "what the/your set goal is". 

I have done many "on the road bench-mark tests", so -to-speak "real life tests", meaning certain stretches of roads, often with inclines were measured with time and speed.  THIS is a very objective measurement, not a "theoretical"  Dyno-chart, and also not a seat of the pants "feeling", where just a change in characteristics can trick the mind.  This to explain where I come from with the following.

My roller/slider changes and measurements were done on two different displacement and different brand scooters  (PS: my original "feeling" was also proven wrong...):

Performance-wise the heavier Dr. Pulley weights (same weight as OEM, or even 1-2 grams  heavier) tend to not improve actual performance compared to OEM roller weights, rather drop rpm early; they can improve fuel efficiency. A higher top speed can be (under certain circumstances) achieved, but the measured acceleration 0-50 mph, 0-60, 0-70 was not better, most of the time worse than OEM.

The lighter Dr. Pulley's, "best rule of thumb choice" is IMO around 2-3 grams lighter, will knock off seconds in acceleration, and can also improve top speed, as at higher speeds it settles the engine at lower rpm. However, the fuel economy can suffer if driving the scooter a lot at lower speeds (city), because there in average higher rpm is used compared to the roller weights.

As I said above, "IT IS YOUR PERSONAL PREFERENCE", what is important to you, the individual. There are certain trade-offs or gains either way.

[ktienation]

windwheeler, you misunderstood me. I changed only the rollers - the lea7 is stock variator (or i massed something up) - anyway the variator is stock. I do not say you are any wrong. I just mentionned how it should work in teory.

1 question - what are your rpms at WOT with 13gr or even 12gr! sliders? I assume 7.5k+ ? I wouldnt like to stress the engine that much (just my personal opinion - i do not criticize anybody).

Peter

[windwheeler]

Peter, I did not understand it as critisism, no worry.

I have no bench-mark comparison data on the DownTown, but under WOT acceleration the rpm hangs around 7500 rpm with the lighter weights, it jumps very quickly there; if one likes the benefit of faster acceleration. 

If you are happy with that you have with the 14g sliders then I would not give it more thought.  As I said, different weights, different characteristics, different personal preferences.

PS: As long as the engine is not in the red-line rpm, no reason to worry.  Many Motorcycle engines turn way over 10,000 rpm today, the Kymco engine is by far  not compromised at even 8,000+ rpm

[AMAC1680]

Worth reading.
http://www.advrider.com/forums/showthread.php?t=780204&page=2

Be Big,
AMAC