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  1. #1
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    gearing down or gearing up? how? why?

    so i am headed to the beaches of Baja for a few days of fun in the sun and SAND! i have Emaxx 3908 with the stock MambaMonster 2200kv motor. currently i am running with the stock gearing but after a few suggestions to change the gearing to accomodate the power transfer to the wheels plowing thru the sand, i am seriously considering switching it up. I will be running the Proline Slingshot sand paddle tires and just got my 7600 mah lipos. my guy at my LHS didnt know much about the gearing as he is a heli guy. can anybody shed some light on this subject for me. how crucial is it to gear down or up? the LHS guy said to go with the stock setup i think cuz he didnt know enough to make an educated suggestion. is changing the gears just a pain or is it fairly easy to do? should i have a specific gearing just for the beach? i am also gonna program my ESC with the Castlelink tomorrow with the help of my LHS dude. he says he's a pro at the link deal.

    any help/quick responses would be awesome as i am leaving thurs early am.


    one of these days i will learn how to upload some pics of my super legit el camino body i painted. it came out pretty fresh for a noob!

  2. #2
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    I would gear DOWN, based on what you're telling us (paddle tires + sand = more work for the motor). Maybe go down 1 or 2 teeth on the pinion. Basically, gearing should be based on your desired performance parameters, taking into account the working temperature of the ESC and motor. The bigger the pinion, the higher you're geared; higher gearing = higher top speed but slower acceleration. Smaller pinions = lower gearing; that means faster acceleration, but slower top speed.

    If you're overheating, you're likely over-gearing (pinion too large). The ESC or motor will be too hot to touch. 180-185 deg. F is the hottest you should really go on a brushless motor. I recommend getting an IR temperature gauge from Radio Shack or Home Depot, or install the temperature telemetry sensor with your Tqi radio and iPhone/iPod Touch. It works great and you get up to the second temps without having to take off the body.

    Whether or not you're over-geared depends on a lot of factors. What's the outside temperature? Are your wheels and tires larger than stock? What surface are you running on? And so forth...

    You can also be UNDER-geared, i.e., having a pinion that's too small. In this case, your RPMs can get high enough to overheat the motor.

    What you're looking for is a happy performance medium and reasonable motor temps.

    Hope this helps...
    Last edited by zippogeek; 03-04-2013 at 05:55 PM.
    Make it idiot-proof and along comes a better idiot

  3. #3
    RC Turnbuckle Jr.
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    You might be good with stock gearing. You running 4s or 6s?

  4. #4
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    Quote Originally Posted by 50togo View Post
    You might be good with stock gearing. You running 4s or 6s?
    im running 4s. what do you think 50togo?

  5. #5
    RC Turnbuckle Jr.
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    You should be good with the 4s. Grab a few smaller pinions to be on the safe side.
    Do have an outerwear for all that sand?

  6. #6
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    Quote Originally Posted by 50togo View Post
    You should be good with the 4s. Grab a few smaller pinions to be on the safe side.
    Do have an outerwear for all that sand?
    roger that 50! i got a dusty motors shroud. w/ zipper! gonna also grab a castle motor fan to help temps too. what size on the pinions?

    Quote Originally Posted by zippogeek View Post
    I would gear DOWN, based on what you're telling us (paddle tires + sand = more work for the motor). Maybe go down 1 or 2 teeth on the pinion. Basically, gearing should be based on your desired performance parameters, taking into account the working temperature of the ESC and motor. The bigger the pinion, the higher you're geared; higher gearing = higher top speed but slower acceleration. Smaller pinions = lower gearing; that means faster acceleration, but slower top speed.

    If you're overheating, you're likely over-gearing (pinion too large). The ESC or motor will be too hot to touch. 180-185 deg. F is the hottest you should really go on a brushless motor. I recommend getting an IR temperature gauge from Radio Shack or Home Depot, or install the temperature telemetry sensor with your Tqi radio and iPhone/iPod Touch. It works great and you get up to the second temps without having to take off the body.

    Whether or not you're over-geared depends on a lot of factors. What's the outside temperature? Are your wheels and tires larger than stock? What surface are you running on? And so forth...

    You can also be UNDER-geared, i.e., having a pinion that's too small. In this case, your RPMs can get high enough to overheat the motor.

    What you're looking for is a happy performance medium and reasonable motor temps.

    Hope this helps...
    thanks a bunch for the great info zippo! i will definitely grab a smaller pinion
    Last edited by cooleocool; 03-05-2013 at 04:49 PM. Reason: post merge

  7. #7
    RC Turnbuckle Jr.
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    Maybe a 15 and a 17 pinion.

  8. #8
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    ok so the beach bash was awesome! i was doing great until the second to last day when i broke the drive shaft yoke. im really thinking about going with the hi-po drive shaft setup. any suggestions. pics will be up soon!

  9. #9
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    Looking forward to those pics !
    Always get a 2nd Opinion!

  10. #10
    RC Turnbuckle Jr.
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    are you taliking the center shafts? traxxas cvds work great

  11. #11
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    Quote Originally Posted by 50togo View Post
    are you taliking the center shafts? traxxas cvds work great
    yea 50 the center drive shaft yoke blew out but i think the traxxas steel CVDs will be the next upgrade.

    MUgs sadly i didnt get any good pics of my rig in the sand in Baja but i will def. put up some pics of the Baja 250 races! super awesome! and im gonna take some beach pics of my rig in Santa Cruz hopefully this weekend.

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