Originally Posted by
hacker
how do I work out the FDR with the fast gear set 35t spur, I don't know the internal g/box ratio....
and what is a good FDR to start off with 21.5 blinky?
I'm running pinion 25t as that is the biggest it will fit at the moment without any dremeling yet, car seems slow compared to the tamiya's that I have seen, although have not had a side by side comparison on track yet, but that's my observations so far.
Something like this should help (paste it into a spreadsheet to get the columns to line up):
Diameter in mm 62.00
Diameter inInches 2.44
Spur 35 35 35 35 35 35 35 35 35 35
Pinion 22 23 24 25 26 27 28 29 30 31
Rollout in mm 45.16 47.21 49.26 51.31 53.37 55.42 57.47 59.52 61.58 63.63
Rollout in Inches 1.78 1.86 1.94 2.02 2.10 2.18 2.26 2.34 2.42 2.51
Internal Gear Ratio 2.71
FDR 4.31 4.12 3.95 3.79 3.65 3.51 3.39 3.27 3.16 3.06