need help gearing my brushless emaxx.
 

i know its best to buy a few sets up pinion/spurs and try it myself but i really dont want to spend money on that sorta stuff just yet so which is why im asking you guys that have the experience already.
i have a 3905 and will be running a mmm, feigao 7xl, trakpower or neu energy 5000 20c. i really wont be doing too much speed runs, mainly bashing. my questin is whats the tallest pinion i can put onto a stock 68t spur to reach the fastest speed, yet not too big so i have to worry about thermal on the motor.
and with this pinion, will i still be able to wheelie on command even though its geared for more topend? i want something in the low 40's. i was gonna gear it 24/68 but someone told me i would only be getting 35mph with that. i can move up to a 26-28 but im not sure itll fit plus i dont want thermal or am i good to go with that size. or will i HAVE to switch out my spur to get the best setup? main thing is, i want the fastest setup without losing th abiltiy to wheelie and not have to worry bout thermalling. just a reminder, i dont do many speed runs so i think that will keep the motor a lit bit cooler than most of how you guys run your trucks.
thanks for the help guys and sorry for the long post. its just because i am going to place my order (not the mmm) first thing tomo and i want to get all the info i can get now, and so that i dont have to do the trial and error thing and end up wasting money on exttra pinions and spurs. yea im a cheapo when it comes to those two things cus i noticed once i have a set spur/pinion, i NEVER change it for some reason...well thats when i had my buggies and stadium trucks and onroad cars.

http://scriptasylum.com/rc_speed/_top_speed.html

That's the top speed calculator which ought to help you. I have found that this seems to be off a little bit but a 22t should put you about where you want speed wise but I would suggest going to an 8xl and gearing higher.

You can copy and paste the information below to post your values into a forum thread:

Differential Ratio: 2.8461538461538462
Transmission Ratio: 1.8333333333333334
Other Ratio: 1
Spur Tooth Count: 68
Pinion Tooth Count: 22
Total Voltage: 14.8
Motor KV: 2382
Tire Diameter (inches): 5.75
Tire Ballooning (inches): 0.5
Motor Current Draw: 0
Motor coil Ω: 0.0056
Spur/Pinion Ratio: 3.09 : 1
Total Ratio: 16.12821 : 1
Tire Circumference (inches): 21.21 inches (538.63 mm)
Total Motor Speed: 35253.6 RPM
Vehicle Speed: 43.89 mph (70.51 km/h)
Effective Speed Rate: 2.97 mph/V (4.76 kmh/V)
Estimated Adjusted Speed: 41 mph (66 km/h) - 6% loss
Effective KV Value: 2382
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

if you are concerned about your temps you got the wrong motor, the 7XL will run hot, I would have gotten a 9XL, How much voltage will you be running?and dont be concerned about not being able to wheelie with a BL truck, you will get tired of that quick, and you will be more concerned about how to get it not to wheelie.

Why not move to a smaller spur? All the Jato spurs fit right on. Or even a 62T for the emaxx. I ran 22/54 setup for awhile with a 10XL on 5S. The thing was crazy fast. Temps were not too bad either. I must concur with azjc as far as keeping temps in check.

i chose 7xl becuase i hear alot of ppl are running 7xl with no problems. i mean they say there motor gets hot, but its fine. but main thing is i KNOW i dont run nearly as hard as any of them either. i rarely do speed runs, i pretty much only full throttle it only for like 3 secs and then i let off. i just like to go up hills and go over terrain. but i jus like the speed of bl so when i do feel the need for speed i can.
oh, ill be running 2 packs 2s. and is there a difference when ppl lower the spur instead of raising the pinion. i know the pinion is more costly but say...if 24t/68spur got me 42mph, and 21t/62spur got me 42mph, how come i always see more ppl lowering the spur and pinion when they could have just changed one thing which is the pinion. does having a lower spur count reduce temps, run smoother, more effieciant or something.

a spur gear with a smaller amount of teeth will make your gearing taller, this will increase your motor temps, increase your top speed and make the throttle less reponsive, and to a certain point keep the trucks nose down, also increasing your pinion size does the same thing

not meaning to tack controle of your thread but about what would be the gearing for a 9XL on 12 NmHi cells in a old e-maxx without 1st gear? i just need to know about what the correct rotio of pinion to spur i would need to start off with so i don't spend a wile trying to gear it correctly.

does anyone know about what i would haft to gear my 9XL in my e-maxx?

18 -22T use brian's calc

see sticky http://www.rc-monster.com/forum/showthread.php?t=2259

ok i knew about that calc, i just couldn't seem to find it. thanks!