Another OLD Noob

[Clank]

So bumpy roads wouldn't cause fuel to come out of the vent?

[FrankenMech]

Nope...

[FrankenMech]

The new longer Gates belt was installed today on nice clean pulleys. I reduced the number of roller weights from 6 to 3 and it made a difference also. I get higher RPMs more up in the power band at 7000RPM when climbing hills and trying to make speed. I was mostly interested in varying my speed and load today.

I am still checking my carb support after each ride. I may have to put a better hose clamp on than the skimpy clamp that came with the filter. I noticed that it seemed to slip a little one time when I hit some real potholes and a 1" plate on the road at night. Winter is pothole time...

I did find some Dorman 'HELP' shock and endlink bushings that may work on the lower front coil-over shocks. HELP #31019. I will have to cut some off the ends of the bushings to make them fit, and press out those solid metal balls used now.

[FrankenMech]

I pulled my rollers out of my variator but left three in. The three that came out weighed 25g so I must have had a 50-51g set of rollers or probably 6 ea 8.5g rollers with flat spots.

So I am running very well with 25g in there now. RPM's run 7500 cruising and 8500 on slight downhill runs. Should I just replace them with a full set that weighs 25-30g?

[Clank]

That would be the best thing to do. Or get a set of sliders approximately 1g lighter per roller.

[FrankenMech]

So sliders slide easier?

I have one of those Prima 1400-1069 16x13mm weight assortments now. I was thinking of going 3 ea 4g and 3 ea 6g for a 30g total. Are those sets just for testing or can they be used for everyday running? I could probably order a full set of something but it would take forever to get here and cost double for shipping.

I went down to HF and bought one of their 1000g scales for $11. I tested it against the Prima rollers and a couple other weights, -it seems to be right on, or at least close enough for my needs.

I am thinking about lubricating the variator with some synthetic brake pin grease.

[190mech]

I use powdered moly disulfide in the roller grooves,thought dry stuff would not slick up the belt too bad..

[FrankenMech]

I ended up using a set of 3g & 5g rollers for a total of 24g with a little synthetic brake parts grease smeared on the rollers and surfaces. It is a special high temp grease that is not supposed to melt and transfer around under high heat. I also noticed the belt would not go all the way to the top of the variator pulley due to the pulleys hitting each other. So I ground about 2mm off the face of aluminum pulley where it met the steel pulley. It was kind of like removing a restriction washer. I don't know if the 16mm rollers will push the variator apart far enough to do anything though. The little drive pins are long enough to keep everything together. I suppose I could grind a couple mm off the center bushing also. The pulleys do not align to a common center line during movement anyway.

The Gates belt looked to be operating perfectly. I could see it was riding higher at times on the contra pulleys than the old belt. That gives me a very slightly lower gear for starts. I can use every bit of help I can get because of the hills here.

If I get time I will do some test riding tomorrow.

If that grease goes everywhere I may have a mess to clean up.

I did start it up and watched the belt move. It would not start with my 18V Dewalt drill. The compression kick even jammed the chuck. The scoot started fine with my old Craftsman AC powered 3/8 drill. At least it used to be a 3/8" but I swapped a 1/2" chuck onto it long ago because of the power it had. I did not notice any grease flying about afterward.

I did not have any Molybdenum disulphide powder. All I have in powder form is graphite. I know that graphite would blow out all over the belt and pulleys the first time it revved up.

[Clank]

From everything I've read the multi pack of rollers is for tuning to find the weight that works but are not intended for everyday use. After you find the weight that works get either good rollers or sliders. If you go with sliders the general consensus is one gram lighter than the roller weight.
They say sliders push the ramp plate out further and give a higher top ends but that's them. They say sliders transition better and again that's manufacture statement.
But in my opinion and experiences sliders are way more durable. Maybe because the flat spots are already pre formed as I've noticed that all the rollers that I have used get flat spots some faster than others. When they get flat spots they tend to stick and rattle at low to high rpm where as sliders only rattle at idle.
I'll look around but I remember there was a formula or calculation to rpm = sliders vs rollers.

[scooterpimp]

Changed over to sliders from rollers & ill never go back. Like Clank stated sliders run 1 gram different 5g roller = 6 g slider

[90GTVert]

I've had some performance gains from sliders, some documented with vids in projects. Like Clank said, one of the huge selling points for me even without any performance increase is the durability of sliders. They will wear over time, but a much longer time than rollers from my experiences.

I don't know of any specific formula for rollers vs sliders conversions. All I've ever heard is a very simplified one : slider weight = roller weight + 1 gram. That said, I know that does not work for all applications, because on the Minarelli two-strokes the sliders and rollers need to be the same weight with the variators I've used. I've never really recorded results to compare with the 139QMB in an adequate sample size. Just looking back at an early Project TaoTao vid I noted that the stock 5g rollers had an average WOT RPM of 7,000RPM across a set distance and the 5g sliders averaged 7,690RPM in the same conditions. Max RPM seen with rollers was 7,650RPM and max with sliders was 8,220RPM. I never tried heavier sliders to see what matched up because my goal was to get the scooter in tune at that point, not really to compare rollers and sliders. I didn't even make a full gram change in weights because a performance pattern emerged before doing so. At 1/2 gram lighter, 4.5g sliders averaged 7,910RPM and maxed at 8,450RPM. Max RPMs are wherever the Trail Tech recorded the revs flashing to on clutch engagement and I don't really think they're what you'd want to compare, but it doesn't hurt to have a little more data.

Using that info, 0.5g lighter sliders raised RPM (avg) by 260RPM. If we assume that another 0.5g would have the same effect, then 1g lighter sliders would raise RPM by 520. I'll also assume that heavier sliders would have an equal but inverse effect, so 1g heavier sliders would lower RPM by 520. This is a lot of assumption, but without the data I don't have a lot of choice.

So if you look at my 5g slider result it was 7,690RPM (avg). Use the above info that would tell us to subtract 520RPM to get an idea of where 6g sliders would let the engine rev and it comes out to 7,170RPM. The 5g rollers for me were at 7,000RPM. That's a fairly close way to guess at slider weight just on this limited info.

Since I have the results for 4.25g from that same setup (farthest I went from 5g) I can check against that and see if it still equals out near where the simple formula produced above would say. Multiply 520 by 0.75 (75%) and I get 390. So if the 520RPM change per gram is correct, my 5g RPM of 7,690RPM would convert to 8,080RPM (7,690+390) for 4.25g weights. The actual observed RPM for 4.25g weights was 8,110RPM. I could do the same to check the 5g weights vs the 4.75g weights. In that case the calculated RPM is 7,820RPM (7,690+[520*0.25]) and the observed RPM was 7,800RPM.

That looks like it provides a reasonable approximation. I'd prefer much more data to come to a better conclusion, but maybe that's of some use for now. This will not be universal for all rollers vs sliders or even the change to expect for sliders vs sliders when sizes change and variator designs change though. The 1g slider to roller change isn't spot on from this, but there's little recorded info used here and also even if it were actually 170RPM off of an exact change using 1g+/-, the average person would call that close enough.

[FrankenMech]

Thanks y'all, that is good info. I am math challenged due to my brain injuries so I am not sure you are all saying the same thing. I may just order another complete variator with 5g sliders in case this one gets trashed by my experiments... My 'test' setup is equivalent to 4g rollers. I don't have a brain, GPS, or even an accurate speedo so my testing abilities are very poor. I don't have any records either. I have one long stretch of city street that I like to open up on but anything I see or feel is different due to weather and traffic on any given day. I am marked for death by the local constabulary so I am sure I will be shot for speeding someday.

The plastic on the weights in the test set does not seem to be the same stuff that my OEM weights had. The test weights look like plain PVC.

All of the 8.5g rollers in my OEM setup had already worn down to 8.3-8.4g each with flat spots and I only have 4500km on the scoot. The OEM Bando belt was fried also.

[FrankenMech]

The grease plus test rollers was not a success. I think the grease was too 'sticky' or it may have coated the belt. I maxed out RPMs at about 7500 on the flat with pitiful road speed. I may get time tomorrow to clean off all the grease and try again. Medication problems are giving me fits with 'work' time availability.

I have not read any of the popular info on sliders and rollers. Do any of the manufacturers use any of the engineering plastics for bearings like Torlon etc?

www.solvayplastics.com/sites/solvayplastics/EN/Solvay%20Plastics%20Literature/DPG_Torlon_Design_Guide_EN.pdf

[90GTVert]

I believe DrPulley has said they use their own special blend. The sliders work well for me and don't wear much at all from what I've seen. I've only used DrPulley's rollers in my over range variator in 19x15.5mm. Those haven't really impressed me. Never tried other rollers though to tell you if it's better or worse than what anything else would do, but if that's the same material than I guess the main way they reduce wear is to use the slider design vs roller.

[FrankenMech]

I found this on YouTube:
www.youtube.com/watch?v=yxcQGmT8EJc

This with Google:
www.unionmaterial.com/rollerweight6.htm


Some of the pictures are bogus though. Particularly the high gear wear advantage.