Modern Vespa

Sorry for starting a new thread as there is one going on here:

Polini Variator 9 Rollers model



but I felt I had to. I must have installed every single variator (apart from the Malossi) so I feel I have some experience to comment.... (I love tinkering and projects and this is kind of an experiment).

JCosta - Great on a Master 400cc or 500c engined scoot, not so great on a GTS, because of that crappy centre bushing. Lovely feel but not long lasting.

Polini 6 Roller - Nice but makes the engine revvy and engages the clutch a lot higher, so not nice for town. Oh and not very reliable according to others on here. (Cannonball Run failure to be precise, I believe...)

Dr Pulley - Lovely. Smooth. But much more revvy. Oh and Cheeky Thomas is correct. Belt wears a groove in the crankcase. EDIT No it doesn't - on closer inspection there is no belt wear in the case. There is evidence of contact, but no significant wear. I previously thought that mine was OK but I didn't inspect closely when I looked two weeks ago. Installing the Polini 9 today I saw the damage (which wasn't too bad tbh).

Now for the big one. Who knows what it is going to do inside. I compared measurements very carefully with the standard variator and it matches so I am keepng my fingers very crossed that there will be no rubbing issues. It is nice and easy to fit, despite being sent with the 6 roller instructions. It is installed grease free (hurrah) and has graphite inserts in the contact surfaces with the gudgeon. Like the JC, except that the gold coloured metal seems harder. Edit: Different from the JC however because it has sliding contact surfaces and a backplate which rotates with the crankshaft splines which keeps the variator in alignment with the outer half pulley.

I will be keeping a very close eye on my innards, and will probably inspect in a couple of hundred miles due to my previous experiences of ripped out sump gaskets from the JC and that crankcase wear from the Dr Pulleys.

Now for the improtant bit. How does it feel?

In essence, it is as big an improvement as the JC is on the Master engines.

The GTS standard transmission is smooth, and is smoother still with Dr Ps, but this makes it really buttery. There is no variator rattle at all at idle. When you're coasting to a halt, when the clutch disengages, the standard variator usually lets out a little rattle (just to remind you it's there) - that's all gone now. Just an uncanny silence. The idle is also smoother, although this may be an effect of the noise reduction.

As others have said launch and acceleration are impressive. It feels much stronger off the line than standard. The nice thing is, that when you get to cruising speed and throttle off the revs drop nicely to where they would be with the standard variator. The Dr Ps were always revvy and this increased fuel consumption from 130 miles per tank (standard) to 120 miles per tank. We'll see if the Polini 9 is an improvement in due course. Talking about hitting a 60mph cruise, the response from this speed with WOT is gutsy. Much better than standard. I am not a throttle fully pegged rider, so am unable to comment on top speed, others will have to do that for me. I suspect it will be little changed, as the revs at 60mph seem close to standard.

Another benefit from the Polini 9 is the superior clutch behaviour. It engages nicely (at higher revs than the standard), but it also behaves well at low speeds (it seems to disengage at the same low revs as the standard). One of the problems with the Dr Ps was that for low speed manoeuvres you were always having to slip the clutch and balance against the back brake. The Polini 9 still has the clutch engaged at low speeds so there is less need for the back brake as you can rely on engine breaking for a little bit longer....

It's a nice bit of kit. Benefits are, catapult-like launch, superior clutch behaviour and buttery smoothness. Only time will tell for the reliability angle. I only bought this for an experiment and so far I like. At the moment, I wouldn't go so far as to recommend it, but others on the thread linked above do not seem to have had any problems as yet. I will inspect at very regular intervals, probably as soon as a couple of hundred miles, and as soon as I am sure that no damage is being done to the belt or the crankcase, longer intervals. Watch this space! If you have some money to burn try it!

Incidentally, I tried to order one of these from PM tuning a while back and got some horseshit about it not being available yet, despite others listing it. They tried to sell me their own kit (Polini 6 + Malossi belt + washer to stop belt rubbing). No way Jose...... Purchased at a special offer price from Adrenalin Pedstop. One word of warning, this has its own clutch spring which has a different tension from the normal. I took my clutch down to my dealer and the mechanic fitted it free of charge. Took about five minutes with an impact wrench. Just a heads up.

Nice write up. I didnt use the spring, might wack it in next belt roller change. Its nice having that slingshot advantage crunch time. Then when you just want to cruise it drops the engine revs nice..then throttle on HELLO

Agreed. It does really catapult you off the line. I really don't think it's a placebo effect! My point exactly. It maintains the gentlemanly behaviour of the standard variator but turns into a lairy yob with a flick of the wrist. Nice. What impresses me most though, is the smoothness. Very similar indeed to the JCosta effect in the Master engine in fact! Take it you agree with all of the above then? Although I see yours is on an LX which is slightly different!

Very nice write-up. Thanks much for that.

As an aside, I think the Polini 6-roller gets a bad rap that it doesn't deserve. Bagel's grease seal failed on CB08, but that's the only case of that I can think of. Mine is still holding up well, although I switched to stock recently for different reasons. The only bad thing about the Polini 6-roller is that the weights are soft and develop flat spots rapidly. Here too, though, I think the rap is undeserved, as the Polini still functions quite well even with weights that are very, very worn -- the kind of flat spots that would bring ordinary variators to their knees.

Just wanted to add that.

I'm actually glad to hear all of that. Thanks! I thought the Polini 6 was a well made piece of kit. I just didn't like its behaviour in town riding that us Londoners have to put up with (early clutch disengagement). I think the lack of grease on the Polini 9 is a major advantage. Let's hope the rollers are made of sterner stuff.

When my warranty expires on the GTS I will defitely be going Malossi V4 in spite of the cost. Please keep us updated!

And the question for all the rest of us!

Will it enhance the performance of the 300 engine? Will it benefit from the higher rev?

Probably not. I think this lifts the revs to where the 250 has peak torque. As the 300 achieves this at lower revs, the benefit might not be so noticable. The 300 is listed on the box, so what we need now is a guinea pig!

Yes! But strange that none with the 300 gts has experimented with Polini/Malossi sports variators!

I have had a JC in a 300. Tore out the sump gasket.

Not trying to be a gadfly, Doug, but I don't understand this statement and the others earlier about clutch engagement/disengagement. I've had the Polini 6-roller on my kitted LX (with Dr. Pulley sliders in it) for a few weeks now, and haven't noticed any difference in the rpm at which the clutch engages or the road speed at which it disengages.

Could it be that the engine being held in the lowest gearing longer allows quicker revving, and therefore any little bit of lag in the time it takes the clutch shoes to actually make contact is exaggerated? Can't see how the variator would affect the disengagement at all, as the rate at which the clutch assembly is spinning on deceleration is determined solely by road speed.

My Polini setup seems very tractable in city riding. Will be interesting to open up the tranny in a couple thousand miles to see whether the belt has been riding high, but I don't think so.

I don't know if it is clutch engagement or lag. It just seem to lose engine braking at a faster speed. My stock ET4 has the clutch engaged until almost a standstill and it seems that you can trickle it along, almost at idle with no clutch slip.

I am sure that the Polini on an LX/ET4 is a different animal. If you like the six roller in your LX so much I might get one. Although I believe they're now doing a nine roller!

Well, don't do it on my recommendation until I've had a bit more experience with it! So far, so good, though.

Yeah, they are now doing a 9-roller for the Leader 150, but it's not available from any Stateside source that I've found, and I wanted something the Dr. Pulleys would work with (for the sake of smoothness and wear).

So from a 300 point of view stick to stock, would stick a J Costa in mine but for the issue Doug has already mentioned, same for the Dr Pully sliders.

I was having a discussion elsewhere with Mike Holland and he was telling me that the J Costas issues on quasar engines had been resolved, anyone care to confirm or deny this?

I dunno Smudger, I would almost say that the Polini9 is better than the JC.

Ok. I mentioned in another post that I would report any problems that would arise with the 9 roller. I also said that I wouldnt be surprised but i'm more pissed off because I was really hoping this variator would prove me wrong. One worn flat sided roller after minimal mileage, why did I go in to look? because I was noticing a large amount of rattle coming to a stop and a certain amount of vibration on acceleration (which wasn't noticable when new)

The speed clutch however is holding up quite well and does still give me a nice boost off the line even with the stock variator

Jim, that's interesting. Why would only one roller go flat? What is your mileage?

I am not terribly worried about flat rollers anyway, more about transmission case damager. Edit: I see you are over 3000km, which can't be bad, still strange that only one roller is flat.

Would Dr. Pulley Rollers, not sliders, fit in the Polini? They might last longer due to the outer material being the same as used in the sliders.


Dave

I thought it might be worth splitting this off into a different thread as it might get more answers...

Why would one roller have flat spots and not the others???

It strikes me as being very strange that one roller would wear and the others not. They normally all wear equally. Manufacturing defect perhaps?

I gave my best answer in the other thread, but had a question about the Polini 9 rollers. Do you know the size and weight? I know they must be a good bit smaller, but if they are a standard size, you can experiment with aftermarket rollers of different materials to see how it affects wear.

It took a bit of searching but it looks like the Polini 9 roller variator takes 20X12 rollers. I'm not sure of the weight....

Here's a link to the SIP page.

Dave

Here's a link to the Polini catalogue

http://www.polini.com/en/page_33.html

and indeed it is 20 x 12

Never thought to click on the catalog button when I was at that site

Thanks.


Dave

I'd like to be the "pig", and thought I would be today, but a broken piston ring is holding up the whole show. Not one to be had in the Seattle area

Thought I would drop in and give a progress report on my 9 roller.

Firstly, after approx 9,000km this variator is holding up quite well. I have changed the rollers out twice in that mileage, although only 2 or 3 rollers where flat sided at the time, I could have easily have left them in. Performance is still gunshot quick off the line and smooth as silk right through till top end..unlike other variators Ive tried which are great to begin with and then play up giving worse performance than stock.

Whilst ordering rollers through SIP They had the incorrect roller size (20x12) listed for the 125/150 Leader. The actual size of the roller is (19x12) and the weight 5.5grams

Hmm. Not convinced. Rollers in the GTS were flatting after 1000 miles. So much so that they were rattling really badly from about 20mph in decelleration. The inside of the original variator made by TGB has smooth roller surfaces and sides. The Polini one has rough cast surfaces. Not a very good design. I agree the performance is great, but longevity of the rollers stink. The picture you posted looks the same as mine.

The Dr Pulley sliders are far better and achieve similar results in the bigger engined scoots. For the 250 I would recommend 12g despite others recommending less. What I perceived to be case wear from the belt in my first post was not... that was my mistake.

10g DP weights give 8500 rpm WOT from a standstill (=far too revvy -10mpg)
12g DP weights give 7200 rpm WOT from a standstill (normalish mpg if not thrashed and behave nicely)

Use the 21 diameter ones and not the 20.9

211712 are what I'd recommend.

Don't get me wrong I like the Polini, I just don't like its durability.

I would rather a worn roller or two instead of a hole in my sump.

I've just re-evaluated the Dr Pulleys and re-edited my first post. There is no significant wear in the case/sump from the DPs. The J Costa I believe has now also been modified to use a stronger bushing.

I am not criticising your choice. And we are also talking about 2 different machines. I am also running a 9 roller in my kitted ET4. I do less mileage on that so it isn't a big problem; I like the way it performs.

No worries. It would frustrate me however not being 100% confident to go on the freeway and not know if that belt is chewing into the sump.
For anyone that rides only in town and does an occasional freeway jaunt I'm sure that the sliders are perfect.

Ive noticed the sliders are flat sided already, how do you know when they are worn out.
I mean, they are flat to begin with, how would one guage this (spooky)

Lots of people are using the sliders with no ill effects. They are cheap from SIP but very expensive purchased direct from the manufacturer. (SIP charge £20 and Dr P charge £40 direct on Ebay UK - what a rip-off!!! Dr Pulley, I hope you are reading this and are suitably embarassed).

They tend NOT to wear as they are supposed to be made of a very durable plastic. There are a lot of you tube videos of wear testing (posted by the manufacturer). Rollers wear so badly because they really do NOT roll but slide, so wear out really quickly because of the small contact are. Sliders are designed to slide and have a larger contact area....

But then there the argument lyes, a normal roller effectively wears itself into a slider, would you agree..no.
So now have the best of both worlds a roller to begin with and a slider within a few thousand miles..win win.

T'would be nice if that were the way things actually worked, but the reality is a bit different. The sliders have the wear advantage of the large contact patch from the git-go, and full effective diameter. By the time rollers acquire a flat spot of equivalent size, their effective diameter is a millimeter or so less.

I've been using Dr. Pulley sliders in my Polini 6-roller for about 6000 miles, including 4000 miles at relatively high speeds on my trip to Colorado and back. They were making no noise whatever and still performing very well, but I opened up the tranny a couple of weeks ago just to check on them and to make sure my belt hadn't been rubbing (it hadn't). Four of the sliders had almost no visible wear, one had a bit more, and the sixth was totally knackered (worn very unevenly as though it had somehow gotten cocked at an angle in the ramp). That one slider was just beginning to show the brass core insert at the worst-worn part of the flat spot.

Still, good performance in a Polini for 6000 miles is nothing to sneeze at. I'm sticking with them.

Ok to many variables here. One minute their to revvy. Then they wear a groove in the tranny casing..hang on now its not? There is damage but it doesn't seem to bad (any damage even minor is bad) Now I'm using a different weight which seems to work. How does "cocked at an angle in the ramp" sound anywhere near normal??
Your scaring people away from this product.
I'm sure Polini or Malossi would have tried and tested something similar they have plenty of time RD but chose to stick with the round roller keep it simple

..Why try and reinvent the wheel.

Your Polini would be too if you used too light weights. Yes that is what I said. They do NOT wear a groove in the tranny casing. The groove is already there, made by Piaggio. The belt has made some contact with the transmission case, polishing it. No damage to belt or case. On the contrary, it would appear that the Dr Pulley sliders are more popular than the Polini 9 roller. Cost seems to be a big factor, as does reliablity.

PS I would suggest you return to an OEM belt as that Polini belt is the one thing in your set up that is most likely to let you down if reports of non-OEM belts on here are anything to go by.

I have the Dr Pulleys running at 10.5g for 3500km now. That's a mix of 10&11g SR2117, in a stock variator with stock belt. Results are very good- pulls about 8000rpm wot, but backs off nicely at part throttle. In bang-for-your-buck terms it's totally awesome.

Some things I've noticed though:
-The clutch does seem to disengage earlier and there's less engine braking, as noted above
-They are smooth underway, but rattly at idle when cold, though this is mainly when they're new. Not so bad now, they seem to have a run-in period.
-In my previous setup of 11g, one of the sliders rotated at some point, and came out with wear on the wrong side. I think this actually caused revs to drop a bit, maybe at the expense of smoothness
-I've had no issues with rubbing on the case, with OEM belt.

I do believe the Malossi belt has a taller profile than OEM, this could give a bit of a rub. Does anyone know if that's also the case with the Polini belt? I've also heard stories of unusual wear on the variator from Dr Pulleys, I guess i'll find out about that soon enough. Hopefully not too soon!

What is the maintenance interval like with the Polini? How long between openings of the case would you be prepared to leave it?

...says the guy with the long list of aftermarket mods!

Gotta love performance goodies. This is like a performance thread

Very interesting

I got today my polini 9 roller 241.665 for the 300 and it looks like this:-(

http://www.polini.com/catalogo/en/risultato.php?op=po&id=157866

Are there 2 Types of the 241.665 or why i got the version with double grease seal for the bush/steel pin?

DougL, i am very intersted in hearing more about your findings. I understand that it can be fustrating reporting to people that preech oem, but im a man of power in need of more power!!! Haha.. i am thinking of getting the polini 9/12 but with heavier weights 13-15. And if you have the resources to test i would love the info. And if you get a chance can you test the longivity of the dr.pulley. much apperciated!

That is my understanding. Here I wish to add that the J Costa "bell" rotates with the crankshaft. It is clamped between the shoulder on the crankshaft and the steel bushing. That is why torquing the nut to the correct torque is important when fitting J Costa.