Need help gearing brushless revo

[R00ST]

I am going to hopefully get my 9920 and 7xl from mike (just waiting for the motor to come in stock) and will be running 75% of the time on 14 cell ib3800's and 25% of the time with some older 6 cell gp3300's.

I am at a loss as to how to gear this thing. I am not sure what the ratio of the revo diffs is to the emaxx diffs, so I have no idea where to even start. Another issue is I will be running tires from all ends of the spectrum. I have the 1/8 wheel adaptors (17mm hex), standard maxx sized tires, then also some alrger street tires (40 sized trinity's) and 40 series mashers.

I am a bit low on funds right now, so I think I will have to make the stock slipper/spur setup work. I obviously can then use anything from 66-72t on the spur, but what about pinion sizes? I cant afford to buy all the 5mm sizes mike offers, so if someone (how about you revo-emaxx tranny converters) can give me an idea that would be helfpul.

Hope everyone is having a good thanksgiving weekend!

[rchippie]

What tranny are you using ?. On my EVO i use the emaxx tranny with the strobe slipper, with 51 spur 12t pinion mod 1 gearing on 14 cells. my motor is a 9L with 9920.

[R00ST]

I have the emaxx tranny as well. I cant afford the strobe right now so will just be running the stocker pretty tight (so 32 pitch pinions)

[RC-Monster Mike]

Are you using the stock emaxx tranny? The Revo diffs have the same reduction as maxx diffs, so if the tranny is from an e-maxx, gear it like an e-maxx. :)
I did get 8xl and 9xl motors, as well as a few 1940 and 1930 motors, but still waiting for the 7xls!

[R00ST]

I never ran a REAL brushless in my emaxx (only the HV). so am not really sure how I would go about gearing a 7xl/9920 on 14 cells.

Also, is the mod1 really necessary? I dont usually dial in much slip (hoping with this setup its petty bulletproof, not too woried about the drivetrain, and I also dont do a whole lot of jumping)

It would just be a lot easier for me as I already have a whole slew of stock 32p spurs (66-72)
As of now my bill from you will be pretty hefty!
9920
7xl
motor clamp/heatsink
TF battery trays (hoping they come in!)
along with a few other possible finishing items.

& I still have to buy my new batteries (ouch!)

[rchippie]

I would say the MOD 1 setup is a must when you can afford it super super strong. The stock will work fine, just make sure you have a good mesh with the right amount of play. but the strobe is better. Mike says gear it like a emaxx 66t spur 16-18 pinion.

[R00ST]

really can run that high of gearing? I know with the novak BL series I always had to run at least two pinions sizes down.

I usually prefer to be geared down a little bit, as max speed isnt somthing I really care for (no room to really open the truck up)

So maybe for the 1/8 scale buggy tires I should get probably a 20, then for standard tires run 16-18, then for the larger tires run a 14, or maybe a 12?

[rchippie]

The 7XL has alot of torque so it can pull a big gear.

Mike will have to cominment on gearing for buggy tires.

[squeeforever]

you might want to also consider that a brushless motor will get hot when undergeared like a brushed motor when overgeared.

-corey