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i ended up ordering about 35 bucks worth of spur gears that are useless because the darn motor hits the case before the teeth on my pinion are even close to the spur.... i never even thought about the size when ordering, i just calculated my ideal ratio against a spur that seemed to be the best.

hindsight is sure 20/20...

i'm using a b2/b3 slipper on a normal stealth btw.

I think 78 is the low end. Stupid 17.5 rule...

13.5 solves so many issues with "stock" brushless...

Keep in mind the track in CT is super tight compared to most off-road tracks, gearing up might not really be a concern. You've seen the video, right?

templeofspeed wrote:Keep in mind the track in CT is super tight compared to most off-road tracks, gearing up might not really be a concern. You've seen the video, right?

That is what I was thinking and I don't even race.

Robinson does a 72 in 48p spurs, and if you really want the flexibility of gear selection, PRS makes down to a 76-tooth 64p spur. At some point (like when the motor hits the tranny), you start to need those pizza cutter pinions, that go up to 65t in 64p from PRS.

i think i'll just replicate marks setup from the vid. i shoulda just done that in the first place, now i got a bunch of 70t spurs...

i actually dont mind using the 17.5 motor. i think it'll be more than fast enough for me and i can most definitely re-use them in crawler builds.

what is this video your talkin about?

badhoopty wrote:i think i'll just replicate marks setup from the vid. i shoulda just done that in the first place, now i got a bunch of 70t spurs...

i actually dont mind using the 17.5 motor. i think it'll be more than fast enough for me and i can most definitely re-use them in crawler builds.

are you just trying to get the spur/pinion(or spur/spur) ratio right for the 17.5 gearing??

if so I have quite a few oval motor plates that you can use for an outrageous gear combo
like the 68spur/60pinion(64p) combo we use with 13.5

if you are using a 2.25 stealth here is what i have done on some dirt oval trannys along with an extended slot oval motor plate. since some cases are warped/distorted slightly i have seen some with extra material or un-even halves where the case is closest to the motor. i have some cases that were ground down almost an 1/8 inch due to a heavy lip around it. i simply mount up a motor with no gears attached and slide it until it touches the case and mark it so i can dremel it down for clearance. i put everything together loosly so i can tear it all down quickly so i can keep checking the inside of the case so i dont grind too far or else it's daylight or the case will not seal up. you will be surprised how much closer you can get a motor when the case is contored around it.

i managed to dig thru my stealth box last night and found an 81t spur to just test the gearing with. final ratio is around 6.25:1

i only managed to scoot around the house on unglued tires, but it seems like there is plenty of scoot in the motor, and i'm sure using the waaay lighter lipo helps out as well.

Well, with a 17.5 (81/28) in my 15 year old RC10 Team Car, my fastest lap has been a 16.6 second.

The fastest 2wd buggy laptime on the track with a current Kyosho RB5 and a 8.5 motor is a 16.3 second.

Just for a bit of off-road racing trivia, most racers change the size of the pinion to change gear ratio's, and change the size of the spur gear to move the weight of the motor forward or back to change the handling of the car. Using a large 81 spur and a large 28 tooth pinion, positions the motor futher back over the rear axles for more traction. A small 72 spur and a 25 tooth pinion achieve the same transmission output ratio, but move the motor forward more over the rear axles for more steering. I did use the 81 tooth on purpose, Just something to think about.

thanks for the advice, moving the motor for traction never crossed my mind.

i'm so gonna get slaughtered.

badhoopty wrote:i'm so gonna get slaughtered.

There are going to be lots of us in that boat.... slide over!

n33no wrote:what is this video your talkin about?

Sorry....it's in the VNats thread:

http://www.youtube.com/watch?v=qPmuohuUBQQ

templeofspeed wrote:

n33no wrote:what is this video your talkin about?

Sorry....it's in the VNats thread:

http://www.youtube.com/watch?v=qPmuohuUBQQ

who's car is that? that was a sweet race. i'm curious to how his car is set up.

littleVETTE wrote:

templeofspeed wrote:

n33no wrote:what is this video your talkin about?

Sorry....it's in the VNats thread:

http://www.youtube.com/watch?v=qPmuohuUBQQ

who's car is that? that was a sweet race. i'm curious to how his car is set up.

Mark listed his car's set up here: http://www.rc10talk.com/viewtopic.php?f=4&t=6600