lighter rollers

[polecat]

i'm thinking of putting 9g rollers in the variator as opposed to 11.2 i sumise that's whats in now will this perk up the accelleration without loosing top end
thanks polecat

[poldark]

Don't just get lighter rollers, the best option is moving to Dr Pulley sliders (10-15% below standard weight).

http://www.drpulley.info/shop/index.php

[bolerus]

When you change the rollers, do you need to change the sliding part ( as on their website) as well, or is that a bit of a, dont need but they suggest deal?

[polecat]

i just changed the rollers and pick up was much better with the loss of 2-3mph top end
polecat

[polecat]

this was on the 250 ie not the x7 125cc i'm building now
polecat

[bolerus]

mine is a xevo 400

I have ordered a set of 17g (im told stock is 18.6)  so hopefully it will improve acceleration a bit

top speed is supposed to be 96mph. so dont need to improve that, as long as it is happy to sit at 70-75 and have a little acceleration left, in case i need to overtake or get out of trouble, I will be happy

[roadster]

The advantage of the D. Pulley shape is that lighter weights do not lower the top speed because they use the extra movement to close the pulley halves a bit further when weights are fully thrown outwards. So you get the benefit of better acceleration but in most cases you also get a sort of overdrive so that the top speed is not restricted by the rev. limiter cutting engine output. Not all variator geometries and tolerances allow this so if your scooter doesn't hit the rev limiter, even when in favourable conditions, the overdrive characteristic won't be of benefit.

[bolerus]

Do they tend to have any effect on fuel consumption?

I cant imagine i'd ever want to go more than 96 miles an hour on a scooter to be honest, so not really too concerned about the top speed, as long as motorway / dual carriage way cruising speeds arnt effected ( like i said above, as long as it is still comfortable cruising at 75ish without screaming, ill be happy....)

Acceleration is what i am looking to improve, my 400 is definitely sluggish and vibrationy for those first couple of feet, but the smoothes out and is fine.
(I am going to change the belt at the same time as the rollers as well - its done 24k miles and who knows when the previous owner changed it.

[roadster]

Fuel consumption won't necessarily be affected. If you cruise at high speed, on motorways for example, engine rpm might be a bit lower so there could be a saving. But its more likely that if you use the performance gains during acceleration the fuel consumption will be worse. Incidentally don't expect different rollers to make the take off any better. During the initial phase the variator pulley halves will be wide open so the gear ratio won't change. Cleaning out the dust will probably help get rid of any vibration during the clutch lock up phase.

[bolerus]

really?

I thought that was the point of them, so is it only acceleration whilst moving that is effected (or is it affected - always forget which is which) so when trying to overtake etc?

[Dave Milnes]

From my experience on the 500, both 6 roller type and 8 roller type, just changing the rollers or 'sliders' as DrPulley call them made a big difference in general launch and acceleration, and also the intermediate lift in revs when whacking the throttle open for an overtake.
Top speed was not noticeably changed nor was fuel consumption as higher speed cruising revs were slightly lower.
Another benefit is less vibration generally from the transmission. I kept the original 3 or 4 slider shoes that the ramp plate slides through, in fact I have never changed them since new.

[roadster]

really?

I thought that was the point of them, so is it only acceleration whilst moving that is effected (or is it affected - always forget which is which) so when trying to overtake etc?

I was trying to make a distinction between the initial take off, i.e. when the pulley halves are as far apart as they can go and the weights haven't started to fling out at all, and the rate at which the effective front pulley diameter starts to increase as the weights press the halves together. Its not quite as simple as just the rotational speed because the belt tension is always trying to force the pulleys apart and the belt tension is greater when there is more engine torque. On the models I have owned there was always a short period on initial take of where the clutch is locked but the engine rpm is not high enough for maximum acceleration. Its only a second or two but its that phase where having the throttle fully open doesn't necessarily give the best pick up. On the 400 engines the Dr. Pulleys helped with overtaking in the 30 to 65 mph range but above that speed the pulley halves were fully closed up and road speed was then directly proportional to engine speed.

It is possible to use what some call the "fuzzy washer" between the pulley halves so that the gearing gives higher rpm in this condition and hence better performance at 70 mph and above but I never tried this myself.

[bolerus]

I bought a set of dr pulley sliders from http://www.mrpulley.info/.

They came Friday,  and they dont quite look like any I have seen on line.

First off,  on the side of each one it says tech pulley on the side and has these little wings.   

Did I' buy the wrong these,  are these going to fit my xevo 400,  and do they do the same thing?

[bolerus]

just noticed the http://www.drpulley.info/shop/index.php (that poldark posted here) actually goes to MrPulleys.  have i just been scammed?

[Mike H]

If you click on 'Our Shop' on the first one it goes to drpulley, same page

[bolerus]

yeah but if you look, after the landing page says Dr pulleys, the other pages say Mr Pulleys.  the tech pulley is not the say as dr pulley

[Dave Milnes]

DrPulley has always been difficult to keep tabs on, they keep changing their authorised distributors especially in Europe. They did sell direct originally but then stopped. Maybe someone has 'hijacked' their old URL?
SIP scooter shop in Germany was the last place I bought from but on Ebay.
https://drpulley.co/product-category/sliding-roller-weight/ seem to be the on-line shop
https://drpulley.co/ lists country based distributors and as per usual, still nothing in the UK.

[bolerus]

so, have I waisted my money? (was just short of 50 quid) if they have spoofed the drPulley website address, they are not going to refund based on "I thought you were drpulley"

[Dave Milnes]

The web address on the box my rollers came in is www.unionmaterial.com. From there if you click on the contact link then on DrPulley right at the bottom of the page it takes you to the same pages you ordered from so I think you are fine. Maybe they have changed the design of the smaller engine rollers and it looks like as a company they have diversified into a lot more cycle parts. The labels on the pictures of the larger rollers is the same as my label and has www.unionmaterial.com on it too. I'd fit them anyway and see.

[bolerus]

Well I finally got around to putting the sliders in.  Also changed the belt.  The old belt wasn't very worn but it was very loose, as though it was too big

Took it out for a ride,. And wow it really is a different bike now.  Take off is instant and acceleration is massively improved.

[Dave Milnes]

Good, worth the hassle. Sounds like it had the wrong belt as well as even a worn belt should still have good tension.