Folding Bikes - Tire Circumference?

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Uberneot
04-26-05, 07:25 PM
I bought a bike computer for my Dahon Mariner D7 today and I don't have a tape measure. Does anyone know the circumference for the Kenda 20" x 1.5" tires it comes with? The instruction booklet only has the codes for 26" and 700cc tires. Thanks!

meb
05-07-05, 02:22 AM
I bought a bike computer for my Dahon Mariner D7 today and I don't have a tape measure. Does anyone know the circumference for the Kenda 20" x 1.5" tires it comes with? The instruction booklet only has the codes for 26" and 700cc tires. Thanks!

An approximation on diameter is to take the bead diameter + 2 times the tire width.
Multiplying the diameter times pi will give you circumference.
1.5" is about 38mm.

Not sure if that tire is a 406 or 451, but a majority of 20X 1.5 tires have an ISO 406mm bead diameter.
Diameter = 406mm + 2x38mm =484mm.
Circumference= 484mm* 3.14=1520mm
MisterJ
05-07-05, 07:30 AM
Its too easy just to measure, put the valve stem down on a sidewalk crack roll the bike forward until the valve stem is down again, mark it and get out your tape measure.

gybatman2004
05-07-05, 07:47 AM
good god man....do you have the cure for cancer formula too?