LCGB Forums

After coming back from Skegness rally,I've decided to put a GP 200 gearbox in my s2 li mugello 186,reasons for this are wind against slight incline and pulled like a wet fart at full throttle getting about 45mph,set up is 26mm delly filterd, taffspeed replica li 150 gearing,what's your thoughts on this or have you got any better set ups,I'm not after a speed Machine just something that will pull easier with thrashing it,cheers.

All depends what box you have in at the moment and what sprockets. If it's an Italian LI box with 15/46 sprockets you will already gave the same gear ratio as a st'd GP200 box on 18/47 which is 5.22. If you have a 16 or even a 17 front sprocket then that would explain the problem up hills and into the wind and you would need to come back down on the front sprocket and I think that would make a difference. Simply changing to a st'd GP 200 box wouldn't help imo.

Rich'

Cheers rich ,will try that at the weekend

Im using an early Mugello kit with a Jetex through the airbox and a cut and altered Indian 40mm clubman. LI150 15/46 standard gearing and its lovely to ride, it sounds like you need to have a look at your front sprocket as Rich says.

I have one on my GP 125, and I use the GP 200 sprockets. I was running a 42 mm clubman and 26 mm through the airbox, and it also wouldn't go much over 50 into the wind, uphill. I have changed to a 30 mm, no filter, and a bigger Avanti Clubman, and it will now sit 10 mph higher than before! It's my favourite bike to ride! So might not just be a gearbox change!

Simon

Changing the exhaust may be a better option but how often do you ride up hills with headwinds ? The setup you've got may be ok for 90% of your riding so is it worth changing ?

A clubman type exhaust will give you a better spread of power but you will sacrifice some top end speed, likewise by shortening the gearing you may pull better but you will be reving more when cruising at higher speeds (well, at all speeds to be honest).

I have 2 Avanti's, both with GP200 g/boxes. One has a Franspeed Race exhaust and a 4.8 final drive, the one has a Ron Moss clubman with a 4.6 final drive. The Franspeed race is fantastic on motorways, accelerating with ease in the 60mph zone and sits comfortably at 60+, the RM Clubman is completely different, not quite as fast and notably slower on acceleration, but you hardly need to change gear as it will pull in 4th from 25mph, it's ideal for hills and bends as very little gear change is required, compared to the Franspeed which would be constantly trying to find the power band. Altogether 2 different machines and each "perfect" , but for different applications.

Probably your exhaust causing that mate. I've got a taffy copy, cast iron 225, 28mm open mouth dellorto, italian GP200 gearbox & I can't get over 50 up a decent hill in a headwind. But I don't have to change down either as there's a good load of low end grunt. My mates GT186 Li150 box & standard sprockets with BGM Clubman pisses past me.