Modern Vespa

Based on comments I read on the forum I believe I should buy 9.5g rollers since I'm keeping the original variator and only swapping the rollers and sliders, but DougL on this ancient post What a difference a new OEM variator makes.... Leader engine went with 7.5g which is throwing me off.

Not much price difference, Malossi, Polini, Dr. Pulley, J.Costa, V Parts, Naraku and PM Tuning where the ones I've found so far, but the Malossi belt seems to last less then OEM so wondering which make is best?

If it helps, I ride mostly short trips of 5 miles, at 20 to 40 mph, sometimes with a pillion, so if there's any upside my priorities would be better mpg, then low end acceleration from red lights.

Cheers

You need 19mm x 17mm 9g weights for stock performance or what you desire.

The manufacturer is immaterial except J Costa which are a different shape and wont fit a stock variator.

https://modernvespa.com/forum/wiki-standard-roller-weights

i guess if you wish to use 9.5 that is up to you.

And Malossi belts are essentially competition spec and designed to be thrown away fairly often, not used for prolonged commutes.

You will not notice any performance increase, just a shorter life.

So go original on the belt, or keep an eye on the Malossi.

Thanks mate, if the stock rollers weight 8.7g, do you know if 8g would already make a difference or would I have to go down to 7.5g to see if there's any gain in acceleration and how much this will impact mpg?

Thinking more about how I ride, I'm actually willing to sacrifice some mpg in favour of low end acceleration. I mentioned their belts in case their rollers were designed to last as long as the belt, so I can avoid them as I'm going with the original belt, so looking for rollers that would last longer than OEM.

I've found 8g Piaggio rollers, so I might try those, they cost twice as the others though.

Don't get sucked into lighter this, heavier that to gain on either launch or top speed.

One roller weight and one roller weight alone gives you both at the same time and is probably the weight you have now.

I recently serviced my Xmax and wasn't convinced the weight advertised by local bike shop was correct for my scooter.
So popped one out and simply weighed it to confirm.

I'll pop a video below which explains roller weights really well.

Are you guys positive the OEM weight in the wiki is correct? I just spoke with a vendor that is saying Piaggio doesn't specify the weight and they have never weighted it, so they don't know, and another vendor has it at 9.5 grams.

The wiki has it at 8.7

I can't help you with that, but worst comes to worst, get a set of both and see which performs best.

Takes about an hour to test a couple of sets.

I was wrong and DO NOT want to spread mis-information

That's not correct.

Any scooter has maximum power at a certain RPM.

The idea is to have the variator variate at that RPM.

That will give you maximum acceleration and maximum top speed in the same hit.

You DO NOT pick rollers to try and gain one or the other......it's a myth, and if you see a substantial improvement you had the wrong rollers in the first place.

Good to know. Thanks for the correction!

It's cool mate and massively common misconception.

Glad the word is spreading

I heard j costa make a big difference

but you could do dr pulley sliders if you at a budget


but you could try 8.5g if I was you if stock is 8.7

but if you want longer lasting slider/rollers get dr pulley they do last a lot longer and work better so if you go for dr pulley get 8.5 you could get 8g but then you going to rev the crap out of the engine and then fail faster

Concerning roller weights you will read many different opinions.

My 2004 ET 4 125 (before the 187 kit upgrade), had original weights. I thought the motor had to rev up too much before the scooter moved.

From previous excellent experience on another Vespa, I mounted the 8g. Dr. Pulleys. My opinion, just excellent. I'm 190 lbs.

This choice allowed the scooter to roll off nicely, without revving too high initially. Also, the acceleration was a bit better. No difference in top speed, which was 105 km/h shown on the speedo (with flyscreen mounted).

After the 187 kit, I added the longer Polini primary drive, but kept the 8g. Dr. Pulleys. A Malossi belt was added, just this is somewhat wider then original belt, which was not a good choice.

Dr. Pulley 8g, with OEM belt, was the best choice for my scooter.

Even after more than 20,000 km, the Pulley sliders are in great condition.

I tried 9g. Dr. Pulleys, not so good.

I wouldn't recommend a variator change, not really necessary at normal power ranges. Spending lots of money for things not really necessary is for me a waste of time and resources.

Want a big kick, get a 187 kit and a longer primary drive. Quicker acceleration, more top speed, lots of fun, especially with a friend on board.