L.Fairtrace

iTrader: (24)

Same as the Regular JRxs or the XXXS

a_main_attendee

iTrader: (2)

Same as the original jrxs and xxx-s i beleive.

1.83:1

MikeXray

iTrader: (73)

Same as the XXX-s and JRXS pro 1.83, and 1.71 with 41t pulleys.

racingboy14

iTrader: (25)

thanks I edited my post with another question by accient

RedRocketRacing

iTrader: (8)

All your rollout of FDR for foam or rubber tires, just input your gears, tire diameter, and there you go.

www.gearchart.com

RedRocket

MikeXray

iTrader: (73)

With foams you really need to target rollout instead of FDR since tires wear every run. Start around 48-50mm.

racingboy14

iTrader: (25)

is fdr used more with rubber tires? What exactly does rollout do that fdr doesnt?

RCSteve93

iTrader: (11)

FDR takes into account tire circumfrance.

SweepRacingUSA

iTrader: (6)

FDR is mostly used for Rubber tire, Roll out is for foams.

roll out give you actual distance car travle on each revolution of the motoro shaft, since foam tire wear out fast and changing diameter in every run, you do need to check your roll out to stay on same ratio or if you wat to change your gear ratio.

but if you changing rubber tire in diffrent brand and found diffrence on diameter then you have to do rollout as well.

SweepRacingUSA

iTrader: (6)

I thought its 1.78 with 41t on both side.

John Tag

iTrader: (42)

That ratio is more for 13.5 not 17.5... You want to be somewhere in the 3.60 area for 17.5 with 57mm foams....

Mike Haynes

iTrader: (2)

Yes it is 1.786 with 41's.

racingboy14

iTrader: (25)

what spur would you suggest to get it that low? I am running a 118 and I dont think i can get a 3.6 with it no matter the pinion, it wont fit!

SweepRacingUSA

iTrader: (6)

then approximate value should be an 1.79 !

SweepRacingUSA

iTrader: (6)

you need a spur adaptor made by RPS, or PRS? that company to mount a spur either either 108 or 104