V-belts variators and rollers

[701let]

So I know about how variators and rollers affect acceleration and top end but what about v-belts?

It seems as if there is alot of playing around with the roller weights and springs but is there a specific belt that will be best for specific gearing and torque?

I am about to buy a full roller kit and Torque spring and want to know what size and brand of belt to go with.

If it helps I am running a ditech sr50 2002.

Thanks in advance for any help.

[Grenadiers]

Malossi Special works great on the SR50 (Morini motor). Just be aware that whenever you replace a Drive Belt, utl it's "broken in" you will notice a performance drop.

AFTER the break-in period (about 500km ...give or take), you should see a bit of a performance boost...

[Coore0]

I'd like also know what does a shorter belt do compared to a longer one? And what does the widthness do (for example, if I have a 18mm belt, what would a 18,5mm do?)

[701let]

So is there a specific length I will need to look for? Or are they all the same?

[captdan]

Most want to tune their transmissions to get the maximum (take off and top end) performance out of their scooters. It is common to add/adjust/replace/upgrade the rollers, variator, clutch, clutch springs, etc and those adjustments make a world of difference. You will be surprised what a .5g change in rollers weight will make. However, with respect to drive belts, I would suggest sticking with the standard size for your scooter. I believe that the Morini and Piaggio are slightly different sizes. Also, for safety and best performance, stay with the highest quality belt you can get and if you are running a 50cc set-up, refrain from using a Kevlar belt. I will try to provide a link to HGT’s site which goes into extreme detail about transmission tuning.

http://highgaintuning.blogspot.com/ Just scroll down

[701let]

Thanks guys,
So now I believe sticking with a standard size width and length will make it easier to adjust the rollers and contrast springs.

Just really wanted to see if there would be any major differences.

However with regards to the clutches and bells will this help my acceleration if I go for a lighter clutch bell and get heavier clutch springs to engage at a higher RPM?

Captdan that link really helped thanks, I can see now how if you can get the RPM to the 8-8500prm quicker then thats when you will get more usage out of the rollers/sliders and variators. Or thats when they should start working.

[Cool77]

For a better acceleration you want to engage at the powerband rpm. So it's pretty high. That being said, you also want some driveability in town so too high is not cool most of the time.

[captdan]

701let- When you get a chance, build a signature so we can all see what you are working with. Is the scooter de-restricted (ECU flash, variator ring removed, etc)? The clutch, in general relates to rpm engagement. For instance, a LV ZX-R pipe comes with heavier (red) clutch springs (to install in the stock clutch) which allow the engine to rev higher, closer to its optimal power band before the clutch engages. With that said, once the clutch is fully engaged, it is pretty much done doing its job and there is no more speed to be had. It’s not to say that a lighter, vented clutch will not help in any way, because it has its place in the upgrade continuum; I just wouldn’t put replacing the entire clutch/bell at the top of the mod list. Now, the Contrast spring has a different function but I would still consider that a “down the road” transmission tweak. Not something you do right out of the box. Good luck and enjoy.

HGT’s tutorial is amazing and although I have probably gone through it 20 times, I continue to refer back as the whole tranny tuning thing still gets me confused at times.

[701let]

I will have to build a signature, you're right. However I am pretty sure my sr50 is stock as a rock at the moment. I have ordered about a grands worth of parts which I am eagerly waiting for but no mods until next monday.

Although I am not sure if the ECU has been de-restricted or some one has tinkered with it because I seem to be geting 85-90KMH on a flat and holding approx 70KMH uphill.

I bought the "hog" 2nd hand from a scooter dealer with 19,000km on the clock and after riding 4 different brand new bikes, I ended up buying this one as it flogged the pants off the rest.

So i will have a nice signature to update shortly but for now it's a 2002 SR50 Ditech in Matte black with all the Aprilia replica racing stickers on it. (well used to be on it)

The clutch is the last thing I am yet to buy at this stage but I pretty much think I have my head around it all now and what I want and what is rideable.

I am in the process of buying a 2nd SR50 as I love the first one so much. So looking at picking up a 2nd hand 2005 SR50 Ditech. and tuning that to be a 70cc possibly race spec scooter and keeping the other one to get to work ( as that was originally what it was intended for). But then I found forums and tuning shops.

I dont know if there is much of a scooter tuning crowd in Australia so I think i will be cruising it on my own for a while.

Hopefully will start a build thread for the 2002 for now and then the 2005 when I get that one.

[Rosscofat]

Lots of aussies on the boards just spread out

[701let]

Lots of aussies on the boards just spread out

Need to get them on here. Know of any particular forums with more than 2 people on them?

[Rosscofat]

This one.. there is a lot.. they come in waves.. I wish I could remember their names

[701let]

701let- When you get a chance, build a signature so we can all see what you are working with.

Here you go