roller weights
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- vaderscoot
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roller weights
i just got my new roller weights and wondering which ones to try first i have 13 and 16 gram wieghts anybody have experience running either size?
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In where the belt thingy is at there are little ball bearings type things called roller weights.
Most scooters ship with a mixture considered overall for "best" performance of these roller weights from manufacturer.
I'm trying to go off memory here, if they are heavier roller weights they help your top end speed increase some while being slower off initial throttle twist. If they are lighter in weight it helps your initial speed more but you loose higher end speed. Or reverse. Heavier=faster intial, lighter=faster top end. Can't remember which. Sorry.
How to change them...I'd pay a mechanic.
Most scooters ship with a mixture considered overall for "best" performance of these roller weights from manufacturer.
I'm trying to go off memory here, if they are heavier roller weights they help your top end speed increase some while being slower off initial throttle twist. If they are lighter in weight it helps your initial speed more but you loose higher end speed. Or reverse. Heavier=faster intial, lighter=faster top end. Can't remember which. Sorry.
How to change them...I'd pay a mechanic.
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- ericalm
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Roller weights are an essential part of the Buddy's CVT automatic transmission. Good overviews here and here and here. The following is all based on my limited understanding of this stuff...Leeroy Jenkins wrote:What are roller weights?
Why would I want to change them?
How do I change them?
The roller weights are housed inside the variator and are used to "shift" the scoot into different gears by altering gear ratios—in this case tension on your belt. This demonstrates it pretty well:

In the above, the variator is the part which alters the diameter of the top pulley. On your scooter, this is done through the use of roller weights inside the variator, which spins as your engine revs and moves in and out due to centrifugal force. By altering the weights, you can change the how the variator behaves, allowing the scoot to rev higher before it "changes gears."
Here's a pic of the Buddy transmission from the service manual:

Lighter weights provide more RPMs on the low end, meaning the scoot is quicker off the line and accelerates faster from a stop. Heavier weights allow for more RPMs on the high end, increasing top speed. While I used to frequently read that light rollers also decreased top end, people who have done this say it isn't the case.
A lot of riders over on MV have experimented with rollers and more recommend mixing them up in some way. What's important is total weight, but this is achieved by combining heavy & lighter rollers (and alternating them when placing them in the variator so they stay balanced).
Your rollers will need changing at some point (around 6-7K mi.) because they do wear out. If you go with a performance variator or change the weights from stock, it's also recommended that you upgrade to a sturdier kevlar belt.
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my rollers wore out at 3,400 miles causing bearing failure thats why im trying heavier rollersericalm wrote:
Your rollers will need changing at some point (around 6-7K mi.) because they do wear out. If you go with a performance variator or change the weights from stock, it's also recommended that you upgrade to a sturdier kevlar belt.
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Thats odd, I have heard some folks pushing over 10,000 miles and not heard of a maintenance issue like that, now ya got me worried as I just passed through 3,000 miles today, maybe just to be on the safe side I should replace rollers soon and switch to a kevlar belt as well. did you have any indication or performance issues before the bearing failure?
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Interesting. I have over 11,000 miles on mine without any belt or rollerweight changes. No problems. I suspect, however, that I am experiencing less power and acceleration than I should have. I have had the belt and weights on order for some time (about 2 months) with no results yet, but I'm NOT gonna quit riding...
--Keys
--Keys

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Re: roller weights
13's are stock, purportedly....vaderscoot wrote:i just got my new roller weights and wondering which ones to try first i have 13 and 16 gram wieghts anybody have experience running either size?
almost 13K on my b, and i am just about to replace my rollers with 11's... have 14's also, to put in for long out of town rides, or may end up mixing 11's and 14's....
i replaced the belt at 10k, and, although it worn, it wasn't past serviceable....
- ericalm
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Re: roller weights
The total weight difference between stock 13g rollers and mixing 14g and 11g is quite small. Would there still be a benefit?lou76 wrote:13's are stock, purportedly....vaderscoot wrote:i just got my new roller weights and wondering which ones to try first i have 13 and 16 gram wieghts anybody have experience running either size?
almost 13K on my b, and i am just about to replace my rollers with 11's... have 14's also, to put in for long out of town rides, or may end up mixing 11's and 14's....
i replaced the belt at 10k, and, although it worn, it wasn't past serviceable....
Let us know your impressions once you make the change. Doing the work yourself?
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- vaderscoot
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one possible reason im wearing stuff out quickly might be that i weigh 300 lbs so its kinda like im riding 2up all the time. another might be that i spend a lot of time at wotSCOOTER SOLDIER wrote:Thats odd, I have heard some folks pushing over 10,000 miles and not heard of a maintenance issue like that, now ya got me worried as I just passed through 3,000 miles today, maybe just to be on the safe side I should replace rollers soon and switch to a kevlar belt as well. did you have any indication or performance issues before the bearing failure?
- KidDynomite
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I'm WOT if I'm not stopped. I'm serious. I ride hard!!vaderscoot wrote:one possible reason im wearing stuff out quickly might be that i weigh 300 lbs so its kinda like im riding 2up all the time. another might be that i spend a lot of time at wot
I weigh 180 and I'm sitting on 9,400 miles right now. I can still hit 75 indicated at push 80 at times, but I certainly don't have the mid-range like I once did. I'll be making the repair soon.
I have already ordered and possess a Kevlar belt, but I was waiting to figure my next more before installing it.
I thought 11.5 was the stock roller weight on the B125. I was going to go with 10 grams. I ride alot of country roads, but losing 3mph on the top end at the price of better pick-up is what I think I'll be doing.
You don't wanna get mixed up with a guy like me. I'm a loner Dottie, a REBEL.
- ScooterTrash
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The stock wieght is 11.5, I switched to 11 and didnt feel much difference. I'm trying 10's next, I did all the work myselfKidDynomite wrote:I'm WOT if I'm not stopped. I'm serious. I ride hard!!vaderscoot wrote:one possible reason im wearing stuff out quickly might be that i weigh 300 lbs so its kinda like im riding 2up all the time. another might be that i spend a lot of time at wot
I weigh 180 and I'm sitting on 9,400 miles right now. I can still hit 75 indicated at push 80 at times, but I certainly don't have the mid-range like I once did. I'll be making the repair soon.
I have already ordered and possess a Kevlar belt, but I was waiting to figure my next more before installing it.
I thought 11.5 was the stock roller weight on the B125. I was going to go with 10 grams. I ride alot of country roads, but losing 3mph on the top end at the price of better pick-up is what I think I'll be doing.
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yeah, i was basing the 13 being stock on scootover's weigh and the prima weights blurb on the scooterworks site... i believe that they say 11 is stock for the 50's, and 13 is stock for the 125's....Keys wrote:The mechanic at my dealer, Scoot Over in Tucson, has weighed several sets of rollerweights that came out of Buddy 125's and they all weighed in at 13 grams...NOT 11.5 as advertised.
--Keys
i'm putting in the 11's myself, but that requires a free afternoon, which are hard to come by....
- KidDynomite
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Wow, I'd love to hear more feedback.
Scooterworks advertises the B125 to have 11.5G roller weights.
Now we have one or two other sources saying it's actually 13G.
I am going to be ordering some rollers this week and putting them in. I'd like to know ahead of time so I can make sure I get the change I'm expecting.
Scooterworks advertises the B125 to have 11.5G roller weights.
Now we have one or two other sources saying it's actually 13G.
I am going to be ordering some rollers this week and putting them in. I'd like to know ahead of time so I can make sure I get the change I'm expecting.
You don't wanna get mixed up with a guy like me. I'm a loner Dottie, a REBEL.
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i am disconcerted.... when i bought weights a couple of weeks ago, the scooterworks page that now says b125=11.5, blur=14, i read and re-read it to make sure i got what i wanted... and i am fairly certaing that it said the buddy125 was 13 stock.... don't know how my brain could have tricked me... anyone noticed discrepancies?KidDynomite wrote:Scooterworks advertises the B125 to have 11.5G roller weights.
Now we have one or two other sources saying it's actually 13G.
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No, but I think this is worth an email to Genuine. Anyone?lou76 wrote:i am disconcerted.... when i bought weights a couple of weeks ago, the scooterworks page that now says b125=11.5, blur=14, i read and re-read it to make sure i got what i wanted... and i am fairly certaing that it said the buddy125 was 13 stock.... don't know how my brain could have tricked me... anyone noticed discrepancies?KidDynomite wrote:Scooterworks advertises the B125 to have 11.5G roller weights.
Now we have one or two other sources saying it's actually 13G.
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Are the bearings not labeled with their weight? If they're supposed to be 11g, then I understand 10.8. If they're supposed to be 11.5 or 13, then something's not right.
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Oof! Thanks for the correction! I was going off the images in the Service Manual which are rather poorly labeled & identified. Whew.BlueMark wrote:
Ahem ... that is the clutch being labeled 'Buddy Variator' (actually it is the clutch variator), but you want to pull off the round thingy on the left to get to your roller bearings, that is the Engine Variator.
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- bikebuda
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way off
13 and 16 grams that will drop the opperating rpms to about 3400 to 3000
the stock rollers are 11.5g at this weight the cvt will operate at 6800rpms .........you are going to lug the engine to death ....
the stock rollers are 11.5g at this weight the cvt will operate at 6800rpms .........you are going to lug the engine to death ....
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ok to clear up the confusion
weigh all the weights together than divide them by 6 that is how you get the exact roller weight ... but you can get your belts through Scooterworks Chcago, POC or Scootertronics
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My boyfriend put a new pipe on his Zuma and it came with new rollers and springs. I'm thinking this is great as we can experiment on his scooter before mine! (smile). His engine looks the same as the buddy's so my question is how do you get the engine variator cover and the clutch cover off? It seems to need specialized tools or or something to at least keep the engine variator thingy from turning as one tries to take it off. Am I making sense or am I missing something. Thanks for any help you can give me.
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Regardless of what is printed ANYWHERE, here is the deal;
The OEM roller weights in a Buddy 125 weigh 11 Grams each (10.9333 Grams as determined by Wx6/6
The most frequently requested aftermarket roller weights are the 10 Gram Prima weights. Those weights actually weigh 9.95 Grams each.
Tune the weights to your riding situation. If you are constantly riding on hills, you will want a lighter weight. If you are a lightweight person riding on flats most of the time you will want a heavier weight. If you weigh between 170-200 lbs, you will need to go lighter. The weights dictate how fast the bike "shifts" into higher gear. This is important when you start out from a stop as you want the bike to rev up to its power band (the rpm range that the motor produces optimal power) before it starts to "shift" or vary the transmission. If it shifts too soon, the bike will not perform well.
Heavier weights tend to "shift" earlier, their weight is thrust outward at a lower rpm.
This is a conundrum tho' because if you think "well, I'll just put the lightest weights I can get in there" it won't have enough mass to push the variators all the way together to give you an accurate "top gear". So, a little experimentation is needed to get the right mix.
I'm 210 lbs in gear...I've put the Prima Pipe, Prima Clutch Spring and 10 Gram weights in my Buddy 125 and I still think I need to go with lighter weights.
The OEM roller weights in a Buddy 125 weigh 11 Grams each (10.9333 Grams as determined by Wx6/6
The most frequently requested aftermarket roller weights are the 10 Gram Prima weights. Those weights actually weigh 9.95 Grams each.
Tune the weights to your riding situation. If you are constantly riding on hills, you will want a lighter weight. If you are a lightweight person riding on flats most of the time you will want a heavier weight. If you weigh between 170-200 lbs, you will need to go lighter. The weights dictate how fast the bike "shifts" into higher gear. This is important when you start out from a stop as you want the bike to rev up to its power band (the rpm range that the motor produces optimal power) before it starts to "shift" or vary the transmission. If it shifts too soon, the bike will not perform well.
Heavier weights tend to "shift" earlier, their weight is thrust outward at a lower rpm.
This is a conundrum tho' because if you think "well, I'll just put the lightest weights I can get in there" it won't have enough mass to push the variators all the way together to give you an accurate "top gear". So, a little experimentation is needed to get the right mix.
I'm 210 lbs in gear...I've put the Prima Pipe, Prima Clutch Spring and 10 Gram weights in my Buddy 125 and I still think I need to go with lighter weights.
Phil Waters
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- KidDynomite
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I'm not familiar with the Prima Clutch Spring. Where did you find this? How can I search for such things myself? I'm about to change my belt and rollers and I'm guessing I should do the spring at the same time.pocphil wrote:I've put the Prima Pipe, Prima Clutch Spring and 10 Gram weights in my Buddy 125 and I still think I need to go with lighter weights.
You don't wanna get mixed up with a guy like me. I'm a loner Dottie, a REBEL.
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I was under the impression from the shop that changed out the roller weights in my kymco that you need to find a proper balance between stock weights and not having enough weight. When mine were changed out, my goal was to get the engine to rev a little higher to improve the midrange acceleration (20-45 MPH) without losing any top end. I would think this would be anyones goal when changing them out. That is what happened when my (6) stock 14+/- gram weights were changed out with (3) 10 gram weights and (3) stock 14 gram weights. I think it is false to assume that using heavier weights would increase your top speed, you can reach the top speed using your stock weights. Besides, the belt is only going to ride so high on the pulley no matter how much weight you have added.
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I changed the weights on the Rattler tonight. HUGE difference!
I logged my results on the Black Cat forum.
-K
I logged my results on the Black Cat forum.
-K
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He rides: crappy 35 year-old Vespa (and 70cc Rattler)
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- Kevin K
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Here's another useful site that details the workings of the CVT:
http://www.apriliaforum.com/forums/show ... php?t=8960
I'll most likely be playing around with the variator some more. I'll try to remember to grab my camera.
-K
http://www.apriliaforum.com/forums/show ... php?t=8960
I'll most likely be playing around with the variator some more. I'll try to remember to grab my camera.
-K
She rides: nothing yet
He rides: crappy 35 year-old Vespa (and 70cc Rattler)
Minnesota Motorcyle Monthly
My SmugMug
He rides: crappy 35 year-old Vespa (and 70cc Rattler)
Minnesota Motorcyle Monthly
My SmugMug
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- ericalm
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Awesome thread—great step-by-step tutorial. Anyone want to take their Buddy transmission apart and take photos of each step?Kevin K wrote:Here's another useful site that details the workings of the CVT:
http://www.apriliaforum.com/forums/show ... php?t=8960
I'll most likely be playing around with the variator some more. I'll try to remember to grab my camera.
-K

I hope to change the rollers on my Vespa soon, but not the Buddy. (The point is to get the Vespa as fast as the Bud off the line—or closer to it!)
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