Sprockets & Speed

just thought id let ppl know that if your in adelaide racing at pooraka its good to run a 6-74 or close 2 that as we have a small track and it has alot of turns so therefore u need acceleration


p.s 200th post

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49cc cag
#14 "SHREK"
mods:

• full alloy pullstart
• genuine Zocchi exhaust
• Carbon Fibre reeds
• Zhongya slicks (2 front tyres one on the rear)
• full alloy brake levers
• 2 piece head kit
• Heck of alot of compression

Here's one for you . if you know what top speed you want to achieve (within reason ) use this formular


S = RPM x T / G

RPM is obviously revs per minute
T is the Circumference of your back tyre in meters
(SAVA tyres are diferent to chinese tyers)
G is your gear ratio (eg 6to54 = 9)
S is speed in meters per minute (60km/h = 1000 meters per minute)

if you don't have a dyno but know that if your mum chases you in the car and you are doing a top speed of 60 klicks your max RPM can be found by

RPM = S / T x G

once you know your max RPM and you know what speed you want use this to get your gearing

G = RPM x T / S

now my head hurts . make sure you use the right units .I'm going for a lie down.

ive got my polini {5.2hp} up to 90km/h {scary!} it just show how fast little bike can be.......

Good gearing chart, very helpful - one of the guys over a pocketbikeplanet.com just linked to this thread .....

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"The Rat":No fairings, period.Volkswagon gas filter.DuPont spraycan muffler.Altoids box air cleaner. Dremel wrench killswitch cover.Check it out here: http://www.pocket-bike-racing.com.au...html#post92825

Here's the one I put together:

It doesn't have speeds but if you need to go up or down in ratio it shows the options available if you estimate the final drive ratio.