Roller weights, how low can you go?

Leeroy Jenkins · Post by **Leeroy Jenkins** » Tue May 13, 2008 1:14 pm

What is the lightest rollers yall have put in?

What kinda of results did you get.

Looking to get more from the bottom end for mountain riding 40mph tops.

right now my buddy tops out at 80mph indicated. w/ 11g doc pulleys.

KRUSTYburger · Post by **KRUSTYburger** » Tue May 13, 2008 4:24 pm

HOLY CRUD! On a 125 your top is 80mph? Is there something you're not telling us?

Kurzer · Post by **Kurzer** » Tue May 13, 2008 4:27 pm

I think I'm running 19's now, I'll have to try 11's

Anything else done to yours? I top out at 70 on a flat run and low/mid is pretty good, hills slow me down to 40/45mph, much better than the 25/30mph stock

jfrost2 · Post by **jfrost2** » Tue May 13, 2008 4:32 pm

How do you install roller weights? I remember reading you get faster acceleration, but less topend, or more top end, but less acceleration. How does yours work?

Smellybumlove · Post by **Smellybumlove** » Tue May 13, 2008 4:38 pm

roller weights just change the engines max rpm speed and it all depends on the weight of you, the bike and its state of tune.

the lighter the weights the higher the rpm, works the other way with heavy weights.

if you go too light you can over rev and miss all the power, if you go to low it might not quite hit peak power, you just need to keep changing weights until your happy.

also note that when you change the varitor and spring it will need to be changed again, best to do it all at once.

Post by **ericalm** » Tue May 13, 2008 5:03 pm

jfrost2 wrote:How do you install roller weights? I remember reading you get faster acceleration, but less topend, or more top end, but less acceleration. How does yours work?

Overly simplified and I'm sure slightly inaccurate description:
The rollers are inside the variator. This is essentially a bell-shaped cylinder which moves in and out, altering the radius of the loop made by your drive belt. This is effectively like changing gears, though it happens continuously (sort of). The motion of the variator is controlled by the rollers, spinning bearings inside the bell. As RPMs increase, their spin and centrifugal force pushes the rollers outwards, altering the shape of the bell and radius of the belt.

SO, lighter weights allow for faster acceleration because it requires higher RPMs to push them outwards enough for the scoot to "change gears," i.e. more RPMs at lower speeds. Whether this sacrifices top end has actually been refuted in many places. in my experience, it does not.

The weights Leeroy is using are sliding pulley weights, which I believe are a metal core with a nylon exterior. These don't roll, so supposedly last longer and work smoother due to less friction and less wear on your variator.

Stock Buddy 125 rollers are 18x14mm, 11.5g. Usually, a few grams difference is noticeable. (The important number is total weight or all the rollers. For instance, I use a mix of 9.5 and 14g weights in my Vespa for a total of 70.5g.) Leeroy's aren't that much lighter than stock, but the sliding weights probably make a difference.

With regards to how low you can go, there's probably a point of diminishing returns with these, where anything lower than, say 9.5g (or whatever) has little to no effect on performance. But much of this is limited by availability—at least in the U.S., the stock rollers are only available in 11.5 and 14g at this time. If someone came ot with a performance variator, I'm sure other weights would be available.

Leeroy Jenkins · Post by **Leeroy Jenkins** » Tue May 13, 2008 6:30 pm

"But much of this is limited by availability—at least in the U.S., the stock rollers are only available in 11.5 and 14g at this time."

Scooter works has rollers from 7.5g to 16g.
http://www.scooterworks.com/Roller_Set_ ... 40C290.cfm

what do think a set of 7.5s will do?

as for my ride.
mine is stock 06 125, except 11g doc pulleys. 210 lbs rider, tight tuck, flat ground 80mph indicated.

Post by **ericalm** » Tue May 13, 2008 6:53 pm

Leeroy Jenkins wrote:"But much of this is limited by availability—at least in the U.S., the stock rollers are only available in 11.5 and 14g at this time."

Scooter works has rollers from 7.5g to 16g.
http://www.scooterworks.com/Roller_Set_ ... 40C290.cfm

what do think a set of 7.5s will do?

as for my ride.
mine is stock 06 125, except 11g doc pulleys. 210 lbs rider, tight tuck, flat ground 80mph indicated.

Ah, I didn't check the menu for all the weights they offer.

You may want to call Scooterworks. I suspect the lighter weights are offered for mixing with heavier ones. Running straight 7.5s may actually be bad for your variator or at least cause the rollers to wear much faster. But I dunno...

nissanman · Post by **nissanman** » Wed May 14, 2008 1:53 am

Scooter Revolution seems to have a great selection of weights on their website...

trevo_man · Post by **trevo_man** » Fri May 23, 2008 1:31 am

So I really have no idea how to change the roller weights. How much do you think a dealer would charge to swap them out for me?

Do the weights have to be 18x14 or can you put like 15x12, 19x17 in there?

jfrost2 · Post by **jfrost2** » Fri May 23, 2008 1:36 am

They gotta be 18x14. You gotta open up the variator to change the weights, the prima ones look pretty easy to change since they're all the same size and shape in a pack.

MikieTaps · Post by **MikieTaps** » Fri May 23, 2008 1:48 am

this is definitely something i am going to do... along with a Prima Pipe and new jets... Who needs a warranty?

nissanman · Post by **nissanman** » Fri May 23, 2008 1:50 am

Changing the weights is easy. Figuring out what weight to go with is the tough part.

trevo_man · Post by **trevo_man** » Fri May 23, 2008 2:09 am

I am so not motorcycle/scooter mechanically inclined... I don't even know how to get to the variator. This would be a great photo step by step tutorial *hint hint*

This really is something I want to do to my buddy though. I have been riding for a year on stock everything, it is time to "trick it out."

MikieTaps · Post by **MikieTaps** » Fri May 23, 2008 2:18 am

When I do it I will take plenty of photos... Im not sure if I will try it on my own, or work on it with my mechanic... thoughts?

MPA · Post by **MPA** » Fri May 23, 2008 2:22 am

Here's a video that shows how to change the weights. It's not a Buddy scooter, but it's basically the same

http://www.youtube.com/watch?v=hyb9NyR-Sjs

MikieTaps · Post by **MikieTaps** » Fri May 23, 2008 2:31 am

that is a great video! it makes it look so easy!

trevo_man · Post by **trevo_man** » Fri May 23, 2008 2:44 am

So let me get this straight.

The lower your weight (without going too low) the higher your RPMs at lower speeds (resulting in faster acceleration, and possibly lower top speed.)

The higher your weight (without going too high) the lower your RPMs at lower speeds (resulting in slower acceleration, but increased top speed.)

Also, Leeroy where did you get those Dr. Pulleys... they sound awesome

jfrost2 · Post by **jfrost2** » Fri May 23, 2008 2:57 am

I'm looking at the Prima roller weights, the video seems real simple, and the guy did it in less than ten minutes.

My only concern is will the prima rollers wear any faster than the stock rollers? When would these usually need to be replaced?

Post by **ericalm** » Fri May 23, 2008 4:12 am

trevo_man wrote:So let me get this straight.

The lower your weight (without going too low) the higher your RPMs at lower speeds (resulting in faster acceleration, and possibly lower top speed.)

The higher your weight (without going too high) the lower your RPMs at lower speeds (resulting in slower acceleration, but increased top speed.)

That's somewhat correct. There's some doubt about whether lighter weights actually lower top speed.
With heavier weights, you lose off the line acceleration, but may gain some in the mid-or-high ranges.

There are a lot of factors that effect this, though, including your weight, what kind of riding you do, etc. I know a lot of the more seasoned MV members have experimented with this quite a bit until they found what the preferred.

I am running mixed weights with a performance variator in my Vespa now, and while I like the increased top end and smoother acceleration curve, I miss the off the line speed and will be going lighter in the future.

jfrost2 · Post by **jfrost2** » Fri May 23, 2008 4:39 am

Leroy said he doesnt notice any change at all using 11g rollers, but those arent much lighter than what is stock on the buddy. He's getting 80mph indicated (probably 70-75mph real speed). I'd like to see if it really does effect the bottom end or not.

trevo_man · Post by **trevo_man** » Sat May 24, 2008 12:44 am

How does he get that fast? He said that was the only mod he had done. I can't get past 65 mph indicated.

jfrost2 · Post by **jfrost2** » Sat May 24, 2008 1:09 am

You can hit higher rpm's if you change the roller weights/sliders. Higher rpm, higher speed.

trevo_man · Post by **trevo_man** » Sat May 24, 2008 1:41 am

So would you guys suggest the dr. pulley 11g weights? In hopes to break the 80 mph barrier?

jfrost2 · Post by **jfrost2** » Sat May 24, 2008 1:46 am

Depends on how you weigh, I'm only 100 pounds so I'd probably have max results for bottom and top end. People who are 200 and over still notice a change and can hit those speeds. But I wonder what 10g sliders would do?

Leeroy Jenkins · Post by **Leeroy Jenkins** » Sat May 24, 2008 2:13 am

"In hopes to break the 80 mph barrier"

I bury the needle @ 80 indecated on my bud down hill. I dont think the speedo goes any farther. It feel like accelerate even after the needle sticks.

trevo_man · Post by **trevo_man** » Sun May 25, 2008 12:45 am

Yea I guess that came out wrong. What I meant is I would love to be able to hit that 80 mph marker. I weight about 160, should I get those 11g dr. pulleys?

trevo_man · Post by **trevo_man** » Sun May 25, 2008 4:16 pm

"when you change the varitor and spring it will need to be changed again, best to do it all at once."

Are you saying I need to change a spring as well? I think I am going to order those dr. pulley sliders. If leroy can get to 80 mph with stock everything but those and weighs 200 lbs hopefully I can get there too!

fsantapau · Post by **fsantapau** » Sat Aug 28, 2010 2:24 pm

for any body interested in changing roller weights on a piaggio fly 50
the fly 50 was 19x15.5 6.5grams i changed mine to 5.3 grams ny bike was slow like a turtule now i love it very fast take off and did not lose any top end speed so if you or thinking of changing weight i recommend 1gram up for top end or 1 gram down for take off speed

rick71454 · Post by **rick71454** » Tue Apr 23, 2013 8:23 pm

Hello BuddyLand:

Does anyone know how much difference in RPMs it might make to have a set of roller weights be one gram heavier than the next?

I mean......would a set of six 12grams slow down the RPMs as compared to a set of six 11grams, due to the extra 6 grams total?

The stock set in a Buddy 125 is six 11.5grams. Do you all think if you used like a set of 6 14grams or set of 6 17 grams, it would slow down RPMs?

Thanks
Rick71454

JettaKnight · Post by **JettaKnight** » Fri Apr 26, 2013 7:59 pm

rick71454 wrote:Hello BuddyLand:

Does anyone know how much difference in RPMs it might make to have a set of roller weights be one gram heavier than the next?

I mean......would a set of six 12grams slow down the RPMs as compared to a set of six 11grams, due to the extra 6 grams total?

The stock set in a Buddy 125 is six 11.5grams. Do you all think if you used like a set of 6 14grams or set of 6 17 grams, it would slow down RPMs?

Thanks
Rick71454

What do you mean by "slow down the RPM"? I'll assume you mean do what a multispeed transmission does - allow the engine to operate at a slower or faster speed than the input.

Perhaps your question should be worded, "What is the engine speed while cruising at 45 MPH with 11 g rollers versus 12 g rollers?"

The answer will be a percentage, but that percentage is not the same over the full range of road speeds - it's not linearly proportional.

Since I don't have a tachometer, I can't give you an answer. Maybe if you look up some of Rusty Shackleford's post you can find something.