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-   -   Motor gearing (https://www.rctech.net/forum/electric-road/226090-motor-gearing.html)

katfish317 06-09-2008 03:58 PM

Motor gearing
 
Can someone explain how to get the proper gearing for a brushed stock motor(27T). I hate having to ask someone everytime before I race what they are running.
I am running all different tracks and different configurations. Most of them we will run twice so I already know them but I would reallylike to get some feedback on this.
Thank you for any information.
Info:
Asphalt tracks or concrete, rubber tires

TeckLancer 06-09-2008 04:07 PM

try like 6.20 to 6.30 that works for me

Team Ash 06-09-2008 07:56 PM

Gearing
 
The best way is to do as you said and ask others what their rollout is. Once you have that you can set yours the same then fine tune to suit yourself. Otherwise you will have to get some lap times from the relevant websites for the club organise some track time and play with different gearing until you get close.
Terry

oldschoolracer 06-09-2008 08:03 PM

A good and still valid old-school "rule of thumb" to
follow and easy to do on your own ~ gear the car
so that it reaches full song, tops out, somewhere
between 1/2 & 3/4 down primary straightaway.
That should do it, or at least get you close.
From there you should be no more than a tooth or two away. ;)

F. Mendoza 06-09-2008 08:49 PM


Originally Posted by Team Ash (Post 4523828)
The best way is to do as you said and ask others what their rollout is. Once you have that you can set yours the same then fine tune to suit yourself. Otherwise you will have to get some lap times from the relevant websites for the club organise some track time and play with different gearing until you get close.
Terry

I could be wrong but I don't go too much by rollout because the rollout is pretty close on all rubber tires. Rollout basicly matters for foam tires where the the tire size is changing almost every pack. Please clarify if I'm wrong as I have never raced foams.


Originally Posted by oldschoolracer (Post 4523856)
A good and still valid old-school "rule of thumb" to
follow and easy to do on your own ~ gear the car
so that it reaches full song, tops out, somewhere
between 1/2 & 3/4 down primary straightaway.
That should do it, or at least get you close.
From there you should be no more than a tooth or two away. ;)

Great advise, we usally go close to 2/3 to 3/4 but 1/2 will get him close.

majicman 06-09-2008 09:49 PM

I have wondered this as well. Top level stock racers show up to big races and look at a track and say I should start at XX FDR. If looking for top speed at 1/2 - 3/4 is the starting point, how do we determine based on length of the straight where the gearing shoould start?

Is there a understood formula that says: length of straight per foot = XX amount of gear, or is there a general safe gear (say 6.5) that most start with and adapt from there?

oldschoolracer 06-09-2008 09:54 PM


Originally Posted by Stratus Racer (Post 4524030)
Great advise, we usally go close to 2/3 to 3/4 but 1/2 will get him close.

Well, that's why I said "between 1/2 & 3/4" (and I'd rather a newbie be undergeared than overgeared).
I continue to hear guys try to make it more complicated, which makes it all the worse for newbies, but the simple "old school" rule of thumb still holds true to this day.

Thanks

bowl806 06-09-2008 10:27 PM

hey there oldschool racer--All I can say is Great minds think alike!

decibels 06-09-2008 11:45 PM

i beleive its up to your motor build and track layout!! sometimes there is a long straight but you need good power on the infield. so you need to look at that first. in other words where you would like to have best power. It also depends on grip level and car setup! if you car is a rocket around the corner for corner speed then you can run high gearing for extra speed as you dont need to accelerate much! but if your car bogs down or is taily then you are going to work your motor to hard accelerating in which case you will go very soft in the last minute. Biggest thing to look at is motor heat! if to hot then gear down if cold then gear up!! But brushless is different to sometimes you can run to hot if your undergeared! but you will be way to slow if you are undergeared in a brushless!! thats my thoughts!

katfish317 06-10-2008 04:54 AM

Thank you everyone for all of the information, I really appreciate it alot!
Tim


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