KymcoForum.com
General => Technical | How To => Topic started by: GBBBiker on May 17, 2014, 05:12:45 PM
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What are sliders and what do they do for a scooter? :-\ What other tricks sre there?
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I assume you are talking about the alternative to rollers.
Sliders
(https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcRabttgYSoRrCSDIXoDkF2tKYAEvKfV--NJUX0EzEXzndxpE-txjw)
Rollers
(https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSFmcT6j_WhsHmQiqk_Ie7CTkYLAGJyxAqpT5LyGfIwZeXbt5e7mg)
Both do the same job in the CVT (http://en.wikipedia.org/wiki/CVT_gearbox (http://en.wikipedia.org/wiki/CVT_gearbox))
The manufacturer of the slider alternative claim better acceleration and top speed over conventional round rollers. Experience differs, but many report improved performance provided they find the right weight for their scooter.
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Sort of similar to a cam lobe. There is an engineered "lift" in the variator that changes the performance.
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I like them won't use rollers again except for tuning rollers then in go the sliders, better take off smoother shift and no flat spots to jam the rollers but that's just my 2 cents.
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What are sliders and what do they do for a scooter? :-\ What other tricks sre there?
Read up on Dr Pulley sliders....see the youtubes as well. See what you think.
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Dr. Pulley sliders are the S%*& unless you install them wrong!!! The cheap copies of Dr. Pulley (AKA Ninja or other crap brands) SUCK and will flip in the variator. I tried ninja sliders once on a gy6 and almost on a dime every few days boom, they would flip and performance sucked until re-installing them. I have never had Dr. Pulley flip in the variator.
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I wont use plain rollers in a four stroke anymore. Dr. Pulley.
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+1!!!! Best cheep-o upgrade out there
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FWIW, I've always found that round weights get flat spots when used in powerful scoots like BigBore 2-strokes. In hard acceleration, the weights get slammed outward. With flat spots, the variator doesn't variate properly. It gets clunky. The so-called "sliders" last much longer before getting clunky.
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Most people don't realize that the tapered shape of the Dr. Pulley slider allows the variator to compress a bit narrower, which makes the pulley "vee" wider off the line. This lets the belt fits in a bit more onto a smaller circumference, effectively LOWERING you gearing from a standstill. It makes a HUGE difference. 8)
Just changing to Dr. Pulleys made my 2009 Tmax quicker than a 2014 BMW C600 Sport. For less than $100. And my mileage actually increased, as I'm running more efficiently at my torque peak. ;D
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Most people don't realize that the tapered shape of the Dr. Pulley slider allows the variator to compress a bit narrower, which makes the pulley "vee" wider off the line. This lets the belt fits in a bit more onto a smaller circumference, effectively LOWERING you gearing from a standstill. It makes a HUGE difference. 8)
Just changing to Dr. Pulleys made my 2009 Tmax quicker than a 2014 BMW C600 Sport. For less than $100. And my mileage actually increased, as I'm running more efficiently at my torque peak. ;D
I measured all that on mine, and found the initial opening was the same but it opened to a larger circumference sooner or at lower RPM. Approx 500 RPM that would have been wasted as over rev on rollers.
Every bike has it's sweet spot. Sliders do work differently. Figure it out... I'm a slider in 4 strokes, and roller on 2 strokes. @t's don't last as long for SURE!
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I like them won't use rollers again except for tuning rollers then in go the sliders, better take off smoother shift and no flat spots to jam the rollers but that's just my 2 cents.
Just curious how you do this economically …most sliders I see online are around $25 a set after shipping. Are you ordering a cheap multipack somewhere or something?
I hear a lot about 5.5 rollers being a good weight for a stock Agility. Would that also be a good weight for a stock Agility using sliders or is there some conversion needed when going from rollers to sliders?
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Sliders ACT lighter so a 5.5 DR Pulley will ACT like a 3.5 roller. That may be too light. I would suggest going up at least one gram when ordering Dr. Pulley sliders. I think 6 gram is OEM rollers so a 7 gram Dr. Pulley set will keep your RPM's the same, and boost low end performance. I have 7's, and a Malossi Red contra spring, and it rocks.
There is no way to avoid buying piles of useless rollers/sliders unless you get lucky on the first go. We all have piles of useless rollers/sliders.
Buying a roller tuning kit heps but that is also useless after you find what you need.
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Video from Dr Pulley showing how they might work in your scooter.
Hills, rider weight, riding style, quicker & smoother takes offs, slower take offs but higher top speeds, higher RPMs or lower RPM's at various road speeds, better or worse MPG's etc., etc. are all mentioned in the discussions of slider vs roller weights. "You just have to experiment!","20% better performance!" "Sliders are smoother!" "They wear better but performance wise are the same."
(20% of what ,smoother than an already smooth take-off?, better than what?")
I read that: you want to go one gram lighter with Dr Pulleys.
I also read that: you want to go at least one gram heavier (maybe 2) with Dr Pulleys.
(have found both opinions on this forum)
These contradictory remarks muddy the water something fierce for some one approaching this product!
About the only constant statement I can find - is that they wear better than a roller weight.
There seem to be very few charts out there which clearly show how the same scoot reacts to rollers and sliders of various weights compared to the stock rollers.
So far I have used 2 sets, and am considering only trying one more for my 163cc LIKE (13, {stock 14} & 15 next)
It is amazing how little information there is out there which would actually lead one to an informed and clear choice!
Stig
Dr Pulley Sliding Roller vs Round Roller in variator (http://www.youtube.com/watch?v=yxcQGmT8EJc#)
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I saw that vid before. That is why I measured. The variator can only physically move from a to b. The two (rollers/sliders) can only move it from a to b. No where else.
What does happen is you get a better profile or slower response from sliders in the variator. They will hold a lower gear longer, and transition smoothly into top range. That is why I recommend going with heavier than OEM or what ever you have that is providing the correct RPM. Going too light w/ sliders does make the bike rev higher, and hold a lower ratio for too long.
I have proved this out dozens of times vs those that have only used them in one bike one time. Sometimes you do NEED more rpm, and staying at the same weight or lighter is the key but not too often do you run into this.
They also hold the gear up much longer on de acceleration. That does provide for less engine braking but certainly a better feel for what the engine is doing.
I went thru 3 sets at 17.00 a pop till I figured them out., and unlike common rollers they have a proprietary size for the core weight. They will not swap out like roller cores do.
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Ahhh yes but you can always get heavy and grind down!!
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I've tried that with little luck. Usually the core will start spinning inside the roller shell.
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Dremel tool and a gram scale.
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I'll spend that hour... entertaining. ;)
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I've tried that with little luck. Usually the core will start spinning inside the roller shell.
Wrong tool. If you use a Dremel with a narrow rasp bit, you can adjust the weights quickly & quite accurately. Use a pocket electronic scale (about $8 on eBay). This is much cheaper than buying a lot of weights because you can recycle surplus weights. You only need to go through the exercise once because it's real obvious when your weights are too light.
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Yes, sliders *will* act lighter than the equivalently weighted rollers. So for smaller scooters, go 1 gram heavier. For mid-range scooters, go 2 grams. For bigger scooters, 3 grams.
On mine, the heaviest Dr. Pulley manufactured were 16 gram sliders, but the OEM rollers were 17.5 grams. So the sliders put me into the rev limiter WAY too easily.
I used Liquid Metal to fill in the centers of the sliders, which increased their weight to 18 grams (actually, 18.03 grams, 18.05 grams, 18.05 grams, 18.05 grams, 18.06 grams and 18.06 grams), and now they feel equivalent to the rollers. I'll lathe up a set of heavier weights some time in the future, as it's still too easy to hit that rev limiter.
One trick for sliders... use extra fine (FF) emery cloth to polish the variator tracks where the sliders slide, then get some very thick, very high-temperature grease (I use a synthetic grease that guaranteed on the package that it wouldn't run up to 600 F) and put a very thin coat on the outward facing edges of the sliders, and in the variator tracks where the slider slides. Buttery smooth action out of the variator when you do that, and it appears to make the sliders act more like a similarly weighted roller.
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Oh snap bringing it back old school, all the old Hondas have the variator FILLED with grease, huge sinking mess lol. Not sure who at Honda decided it would be a good idea to literally full the variator with grease. I've never had to go 3 grams heavier with Dr pulley sliders tho that's crazy.
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Well, that's assuming you want it to upshift a bit more quickly. I was trying to get it to go to the highest gear ratio at as low an engine RPM as possible (like my old scooter did), for a lower engine speed under around-town cruising conditions.
Not quite there yet, it starts variating at about 5000 right now if I'm light on the throttle. About 7000 if I'm heavy on the throttle. Coming home from work, right out of the parking garage, there's a long stretch of road that's got a 25 MPH speed limit. I set the RPMs to 5000, and if I hold it there, it'll creep up to about 35 MPH. From 5000 to 6000 RPM, it goes from 35 MPH to 53. I can cruise at 60 MPH at 6500 RPM.
When it hits 7000 RPM, the engine takes on another persona, it seems to come alive a bit, gets a surge of power. WOT from there will launch me up to about 78 MPH if the weather and humidity is just right, but I'm running right at the ragged edge of the rev limiter there. If everything is *just* right, I have to back off to about 3/4 throttle to maintain 8000 RPM, but usually about 7/8 throttle will do it. Typically it'll easily take me to 75 at WOT even if the weather's not just right, but I don't like riding there, as I have to keep looking at my RPMs to be sure I'm not gonna hit the rev limiter.
I think for me, 20 gram sliders and a slightly taller rear gear will work pretty well. But I did a hard break-in of the engine to better seat the rings to get more compression, and I've put the Ceratec in for three oil changes. So it's got excellent compression and more power than gears.
Another thing I wanted to try was a suggestion by MotoRandy... shaving down the variator boss width by a millimeter or so, to try to get a higher gear ratio... not sure if that'd work, so I'll order a new boss, and play around with the old one.
Anyone have any idea where to order new (higher gear ratio) rear gears for a 2010 Kymco Yager GT 200i?
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Gears might be a hard find for that bike without ordering some made for another bike and testing yourself. I've had luck grinding down the boss mm at a time. It didn't always lower the great ratio however. The Dr pulley variator comes with shims to adjust. What I've found with boss length is it will obviously raise the lowest and highest "gears" on the scoot adding a bit of top speed if the motor can pull through the wind resistance but will sometimes suffer off the line. It also changes the characteristic of the variator through its operating range. Tuning my Dr pulley boss length I actually found that less washers (shorter boss) actually made the engine rev HIGHER on normal use, IE: cruising at 20mph then give it wot throttle no spacer constant 8500rpm, with spacer 8000rpm. Note that the Dr pulley spacers are 1mm.
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I ride a 300i downtown, I did not touch the boss, I shaved the inside face of the variator, where they touch, to make the variator narower and that lowered my rpm. 500 to 1000 rpm at differant speeds, to shave it down I used a belt sander it took a few seconds on each side to shave it off measured by the hole of the boss, 1/2 mm off each side of the variator,