ive built the frame for my locost chain drive and spun it up with a big airgun to around 2500 rpm ,what road speed does that relate to with 165/70/10 tyres?
wish i had paid attention at school now
Rescued attachment chain drive 004.jpg

roughly 185 mph, buy my very ruff calculations. anyone wanna check this?

About 140 by my quick and unchecked calcs. Liam

according to

http://gs.tolan-hoechst.com/tirecalc.htm

a 165/70/10 travels about 60 inches with every revolution.

multiply by 2500 and divide by 12, gives you 12500 feet traveled. or about 2.4 miles per minute.

or about 142mph or about 230kph


I think.

dave

Differing answers so I'll give my answer with workings

Diameter of wheel = 10"

Profile size = 70% of 165mm = 115.5mm = 4.55"

Rolling radius = 1/2 wheel diameter + profile = 5" + 4.55" = 9.55"

Rolling circumference = 2 x pi x rolling radius = 2 x 3.142 x 9.55 = 60"

Times by rpm = 60 x 2500 = 150000" per minute

1 mile = 1760 yards = 5280' = 63360"

Speed = 150000 / 63360 = 2.37 miles/minute = 142mph

looks like it will be be ok then its only geared for 100 mph at 10k in top so looking good

Do you have a free diff? If yes, then you need to consider the average speed of bothwheels; i.e. divide by 2.