Question for mathematical geniuses.

[LoserShoes]

Hey, you can always just take a piece of chain with the same number of links as the sprocket, put a connector link in it and lay it out in a circle and measure it.

Steve

[canned_heat]

Originally posted by skids

R2-R1 = {301(16mm)-300(16mm)}/{pi(2)}
R2-R2 = 2.5mm

I guess it does boil down to a constant:

R2-R1 = (T2-T1)16/(pi x 2)
R2-R1 = (T2 - T1) x 2.55

Originally posted by pggg
Rn = (2 * Rft * tan( 2 * PI / 28)) / ( tan( 2 * PI /(2 * n)) - yeah...aaahhh...ummm...wellll... O.K! I believe it!

I revised my calculus, and the correct formula is :

Rn = (2 * Rft * sin ( 2 * PI / 28)) / ( sin( 2 * PI /(2 * n))

which, simplyfied comes to:

Rn = Rt * Sin (1 / t) / Sin ( 1 / n )

This formula is exact values.

If we use the first terminus of Laplace's function, we get to the proportionality at the begginig, which is a fairly good aproximation for most purposes.

v´ssssss

[gaffer77]

There is an internet site that can do the calculations of this cant remember it off hand but you maybe able to search it

my friend used it for racing mini moto and converting a rear axle to chain drive for a trike

(robin reliant 3 wheel fibreglass car we have )
just bolt the sprocket straight on which was $80.00 from a supplier ready to fit
incase of anyquestions that is !!!

[gaffer77]

Gear Ratios - Motorcycle Front/Rear Sprocket Combinations

.....14.....15.....16...17..18..19

49 3.50 3.27 3.06 2.88 2.72 2.58

48 3.43 3.20 3.00 2.82 2.67 2.53

47 3.36 3.13 2.94 2.76 2.61 2.47

46 3.29 3.07 2.88 2.71 2.56 2.42

45 3.21 3.00 2.81 2.65 2.50 2.37

44 3.14 2.93 2.75 2.59 2.44 2.32

43 3.07 2.87 2.69 2.53 2.39 2.26

42 3.00 2.80 2.63 2.47 2.33 2.21

41 2.93 2.73 2.56 2.41 2.28 2.16

40 2.86 2.67 2.50 2.35 2.22 2.11

I know the thread wasnt about ratio but heres a quick guide i found on that if anybody needs it