Tuning / performance mods for Gilera Runner ST200

[logmavin]

Hi all!

 

Surprisingly little discussion on Gilera Runner ST200 tuning options on this forum... Let's change that!

 

I've got a stock 2010 ST200 which is a nice nippy scooter but after all those years, just feel it'd be nice to make some improvements. In particular, I'm looking to increase initial acceleration and to improve throttle response.

 

After reading tons of stuff on the Internet and consulting some mechanics in Sing, here is some stuff that I've learned. Hopefully it'll be useful to others and it'd be great to get more suggestions/discussion from more experienced fellow riders and mechanics!

 

As a good start, here is a great article explaining CVT drive train: http://modernvespa.com/forum/wiki-cvt-principles-how-it-works-how-to-improve-it-

 

This catalogue from SIP has lots of details on Vespa mods and performance improvements: http://www.sip-scootershop.com/files/modernvespa2013/EN/index.html#/93

 

Even more stuff for Vespa forum wiki on mods (couldn't find anything remotely comprehensive for Gilera http://modernvespa.com/forum/wiki-modifications

 

From all my research, here is the summary of what I understand is the cheapest set of mods which actually appear to be the most effective:

 

Malossi performance air filter -- engine runs a little leaner and it improves throttle response too;

 

Dr Pulley sliders with the stock variator -- their shape allows them to push the driving pulley halves slightly closer together than rollers when they've reached the end of the ramp, giving you a higher gear ratio. Also, it's recommended to get them 10% lighter than stock rollers, so that will help gear ratio. According to this (http://beedspeed.com/html-pages/variator-roller-weights-chart.htm), ST200 has 6 rollers 20MM X 17MM, 14Gr... so, does it mean I need to get DrP sliders 20x17x13? Looks like they only have 21x17 size though -- any idea?

 

Install stiffer clutch springs (from Malossi) on your stock clutch -- you'll make the clutch grab at higher revs hence allowing the take-off to be faster.

 

Stiffer torque spring - to improve on belt slippage, throttle response and stiffer acceleration. There is also stuff like Malossi torsion control (see p 111 in SIP catalogue) but not sure if that's any help?

 

Performance clutch bell -- lighter than stock, apparently should help acceleration but you're looking at SGD150+ just for that already.

 

Even more more expensive transmission mods would include a new performance clutch and clutch bell (Malossi/Polini 3G/Dr Pulley HiT) and a new variator (Malossi Multivar/Polini Hi-Speed 9 roller). You're looking at around US$200-250 for each of these parts in Europe (more expensive in Sing obviously).

 

Checking prices here I was quoted SGD1400 for the full Malossi transmission upgrade (multivar, delta clutch with the bell, torque driver, stiffer springs) and a more reasonable SGD700 for Polini variator + 3G clutch and stiffer springs.

 

Exhaust systems are SGD1000+ and need open pod air filter (SGD150) and extra tuning/ECU override and registration with LTA (SGD80). Second hand cans are flying around at SGD500+extra costs. Nice sound but not sure it's bang for the buck in terms of performance.

 

I'm not discussing hardcore mods like changing cylinder heads, pistons etc.

 

Would be great if someone could answer some of my questions above (on Dr Pulley sliders weights for stock ST200 variator) and any other suggestions are most welcome. Any contracts for good shops to perform the works would be appreciated (happy to receive quotes too) Thanks!

Edited March 13, 2015 by logmavin

[logmavin]

OK guys, here is the update you've all been waiting for, judging by the flurry of replies and feedback )

 

Some more interesting links on mods/upgrades:

 

http://totalruckus.com/phpBB3/viewtopic.php?p=1400933#p1400933 -- a very interesting thread on a Ruckus upgrade with performance improvement charts for each new component. Shows what's really important.

 

This guy nails it by suggesting steps for transmission adjustments: get rollers to spin up to the RPM power band of your engine, then adjust the clutch so that it can easily climb to that RPM and only then add a longer contrast spring to eliminate any RPM drop in the process: http://www.apriliaforum.com/forums/showthread.php?207243-contra-torque-springs-red-yellow&p=2561238&viewfull=1#post2561238

 

These two fellas are sharing their Gilera ST200 mods experiences: http://www.scootershack.co.uk/threads/variators-roller-size-and-brands.33659 and http://www.scootershack.co.uk/threads/new-varitor-smaller-sliders-dimensions-but-heavier-weight.34218/ (he's got a Malossi multivar, that's why 11g sliders were too revvy for it, I think) and http://modernvespa.com/forum/post1549863#1549863

 

So what have I done?

- replaced stock air filter with Malossi performance one;

- 11g Dr Pulley sliders (SR2117) - SGD65 from Tai Hin;

- Put in yellow (medium stiffness) Malossi clutch springs;

- Put in Malossi torsion controller. I left the stock contra spring.

 

All parts (except for sliders) and installation were from Scooter Narcotics. I can't recommend Khai enough -- great service, not pushy and very helpful advice and explanations: https://www.facebook.com/ScooterNarcotics

 

Tai Hin's guy straight away was telling me that my gearbox is gone etc trying very hard to make me spend unnecesary cash, so can't recommend him for installations. You can only ger Dr Pulley from his shop in Singapore though.

 

So under SGD200, the performance improvement is pretty impressive, definitely very noticeable. The scooter moves off from about 4.6k revs, goes to 7.2k instantly. The acceleration is noticably better, the power and torque in the 60-100kmh range is fantastic, overtaking is a joy, overall it's a much more fun and enjoyable ride. Top speed is about the same, maybe 5kmh less. I reach around 9k revs at 120kmh. The bike runs very smoothly, no overrevving. Actually think that 10.5g sliders would work too (Dr Pulley guys recommended to install 10.5 or even 10g) but with a longer contra spring probably 11g is good.

 

I would recommend making these changes to anyone with a stock ST200!

 

Will update later about the milage I now get from one tank, it should be lower.

 

Safe riding,

OK

[logmavin]

The mileage from one tank is about 200km now (used to be 210km). Not bad at all, I was expecting a bigger drop.

[kinsly]

Bro can you recommend a reliable workshop for tuning my scooter ?

Thanks.