Sliders vs Rollers?

[Drifter]

I have read alot of posts about changing these so what is the diff or advantage of one or the other?
Some look round others like cam lobes Why?

Lower weight roller/slider gets quicker take offs and heavier slider/roller more MPH right or wrong?

Having both quicker take offs and higher speed would be great. What do i need to do this...im a cheap #$% so keep that in mind. I like cheap easy Mods that actually work!

[Valiant]

You get better acceleration and higher top speed, and they also last longer than rollers.

You should also note however that there seem to be some compatibility issues with coated variators(NCY, Malossi).

Having weights that are too light can raise RPMs at the same speed, which can kill mpg and cause your engine to strain. However, I've never heard of heavier weights actually increasing top speed, as once the belt lifts up to the top of the pulley, the top speed should be the same.

[dasshreddar]

If you have a stock 2013 pcx 150 get the 12g sliders, best bang for the buck. If you have a pcx 125... I don't know.

[Drifter]

Seems like a win win.......why dosen't Honda do this, there must be some downside??

For no more than they cost and energy involved in doing the work seems like a Top 10 mod for sure! Thanks!

[Valiant]

Seems like a win win.......why dosen't Honda do this, there must be some downside??

For no more than they cost and energy involved in doing the work seems like a Top 10 mod for sure! Thanks!

Maybe? I'd call it "copyright infringement", as Dr Pulley Sliders are patented in all likelihood, and Honda pretty much makes everything in-house.

As for the choice of weights, I'd venture a guess to say that Honda designed the PCX for maximum longevity of all parts from the engine down to the belt.

[sendler2112]

Seems like a win win.......why dosen't Honda do this, there must be some downside??

I would hope the DrPulley sliders are patented. They are one of the most simple, ingeneous engineering solutions. Lower low range, higher high range, and last almost forever. I reused mine that had 14,000 miles on them when I replaced my variator and belt with stock parts and still got 74 mph on the stand. The factory weights are way too heavy with an emphasis on fuel economy. 12 gram sliders should get you to a pulling rpm of 8,000. Do this, remove the seat hump, drill the exhaust, remove the air snorkel, and you have my four best bang for buck mods.

[Valiant]

Could you clarify what "pulling" rpm is? Because I was under the impression that both pulleys shift from high to low and vice versa based on rpms, or how fast they're spinning. If they're both "pulling" at 8000 rpms, wouldn't you be stuck in high gear from the start? Are you referring to rpms after the belt is raised all the way up/out? Or should rpms at that point be the same no matter the weight if the belt is locked out all the way?

[Drifter]

2112, that is a great Rush CD......back to sliders. So if i change to 12g sliders my MPG will drop? I ride mostly service streets with speeds of 40-50 MPH i want the best gas mileage at those speeds.

What is gained from snorkel removal? Is there a sound clip of a drilled.. muffler?

Did the hump mod.

[sendler2112]

2112, that is a great Rush CD......back to sliders. So if i change to 12g sliders my MPG will drop? I ride mostly service streets with speeds of 40-50 MPH i want the best gas mileage at those speeds.

What is gained from snorkel removal? Is there a sound clip of a drilled.. muffler?

Did the hump mod.

MPG might drop a couple percent at those speeds if you gun it with the new found acceleration. maybe very little power is gained by the snorkel removal. Drilling the exhaust makes it sound just like the deep bass of an aftermarket exhaust and you get to keep your $250.

[DeaninMilwaukee]

I think part of the reason Honda chose the heavy rollers for the bike is actually noise regulations. Lower average revs = quieter. I think this is the real reason for the airbox snorkel too, just noise reduction.

Valient, regarding pulling rpm you have it partly right, but left out the effect of the contra spring. The weights are trying to push the front pulley halves closer together with rpm, while the contra spring ( in the rear pulley ) is reacting to the torque applied to it by the drive belt, ( throttle setting ) and tries pull the front pulleys apart based on how much torque its receiving through the belt.

At low transmission rpm the contra spring wins, but as rpm climbs the roller weights start to have increasing power and start to overcome the contra spring and close the front pulley halves.

The "pulling rpm " is therefore variable depending on how much throttle you are giving.

If you were cruising say 30 mph at light throttle, the engine would be at a lower rpm, but if you then nailed the throttle, engine torque suddenly jumps, the contra spring is overcome, and allows the front pulleys to spread apart and engine rpm jumps into the " pulling rpm " which is set by and limited by the weight of the rollers.
This interaction, the rollers " fighting " the contra spring allows a properly setup vario to have acceleration rpm be nearly right on the engines best hp rpm at nearly all road speeds when you are at full throttle up to the road speed that locks the weights completely out.
If throttle is reduced at speeds below where the weights are locked all the way out, ( 50ish mph on our pcx's ) the engine rpm will be reduced too.

Dean

[DeaninMilwaukee]

I would hope the DrPulley sliders are patented. They are one of the most simple, ingeneous engineering solutions. Lower low range, higher high range, and last almost forever. .

I think there is one more thing too, and the reason they are such an odd asymmetrical shape. I think the shape is calculated to do a better job holding a small gas engine with its narrow torque rpm band right at a steady rpm than the stock round, ( or any other symmetric shape ) could.

As you said, ingenious!

Dean

[sendler2112]

The shape is so that every surface is optimized in it's radius dimension to do it's job. And to maximize surface contact area to eliminate wear especially at the edge of the ramp plate which digs into a roller creating a cut and starting it's demise.
.
By pulling rpm I always mean at full throttle. The torque slot allows lower rpms om mild acceleration.

[Drifter]

OK, if i go with 12g sliders at a constant speed of say 45 MPH will the RPMs be higher or lower vs stock rollers?

Does the snorkel twist off?

[sendler2112]

What is your rpm now?

[Valiant]

OK, if i go with 12g sliders at a constant speed of say 45 MPH will the RPMs be higher or lower vs stock rollers?

Does the snorkel twist off?

Given that the stock rollers are about 16g IIRC, I'd say RPMs will be MUCH higher.

As for the snorkel, that's actually just stuck into a plastic slot on the airbox cover, you can easily slide it out no problem.

[sendler2112]

My stock rollers were 18gm and I now use 12gm sliders. Surprising, fuel efficiency was unchanged. The rpms are only a little higher versus speed at low throttle openings where you can still put around town at 5,000 rpm.

[Drifter]

I have no tach, dont want one either. Good to know the rpm and gas mileage are about the same....dont understand how but you guys have done the mod i have not....yet!