dont understand gearing

[t-maxxracer32]

well ive been trying to learn about gearing but it just doesnt make sence to me!! i know the lower on the pinion and higher on spur is more acc right?...
1. well how can i make my truck get cooler?
2.you can undergear and overgear?
3. how do you know if you undergear?
4. if i got a 60t spur and a 35t pinion what would happen? that is a 1.71 ratio
5. if i got a 96t and a 12t pinion itd be a 8 gear ratio what would happen?
7. what does gear it up and gear it lower mean?
8. if im in the desert with soft sand what should i do with my gearing?
9. also what about the track
10. also what about the street for most speed.

thanks for ansering my questions lol....

[BP-Revo]

Yes, overgearing is gearing so high that the motor has to work excessively hard. Undergearing is geairing so low that the motor is always running at an excessively high RPM. Both will generate heat. This require you to find a sweet spot in the motor.

Basically, its best to have a few gears to try out. If the tallest gear ran really hot, and the lowest gear ran rather hot, but the middle gear ran ok, then you know that the middle gear is a good place to start, and you can adjust from there.

As for the 35/60, thats gearing WAY too high. 96/12 sounds very low.

Gear up means lower the ratio or increase pinion size/decrease spur size. Gear odwn means increase ratio or decrease pinion/increase spur size.

In the desert, the sand creates more resistance, so you should gear down 10-15% at least.

On the track, you should probably gear it so it just tops out on the straight (unless your track is excessively small or large, where it causes the motor to run hot if you gear like that, just gear within the confines of the motor).

On the street, gearing is preference. You can gear lower at a hopes you can pull a wheelie or do some nice burnouts, or gear high to do some touring car-like speed runs.

[BrianG]

Originally Posted by t-maxxracer32

well ive been trying to learn about gearing but it just doesnt make sence to me!! i know the lower on the pinion and higher on spur is more acc right?...
1. well how can i make my truck get cooler?
2.you can undergear and overgear?
3. how do you know if you undergear?
4. if i got a 60t spur and a 35t pinion what would happen? that is a 1.71 ratio
5. if i got a 96t and a 12t pinion itd be a 8 gear ratio what would happen?
7. what does gear it up and gear it lower mean?
8. if im in the desert with soft sand what should i do with my gearing?
9. also what about the track
10. also what about the street for most speed.

thanks for ansering my questions lol....

OK, here goes:

Yes, decreasing the pinion and/or increasing the spur gains acceleration but reduces top speed.

1: Depends on what part is hot right now. This thread explains much about what it means when certain parts are hot.

2: Yes, you can undergear or overgear. BL motors like to see a certain amount of load on them. If you undergear, there is too little load and they tend to heat up. Too much load and they are simply trying to work too hard.

3: Again, see this thread.

4: That's a pretty tough question to answer. It's not just a matter of the spur/pinion making up the gear ratio; there's the tranny ratio, diff ratio, tire size, vehicle weight, rolling resistance, etc, etc. You mostly hear people talking about the spur/pinion ratios because those are usually the easiest things to adjust.

5: Comparing an 8:1 ratio with a 1.71:1 ratio is pretty easy. The 8:1 ratio will have more torque, but not go as fast (all other variables being equal of course). Think of a 10-speed bicycle. In first gear, it's really easy to pedal, but you don't go very fast. In tenth gear, you go a lot further on one pedal push, but it is much harder.

6: There was no question. Didn't they teach you 6 comes after 5 in school? :)

7: Gearing up and gearing taller both mean to decrease the gear ratio - like going from 8th gear to 10th gear on the 10 speed. Gearing down means the opposite.

8: In desert or beach sand, there is more resistance, so you'll want to gear down a little so the motor doesn't work as hard. Also, since most deserts are hot, you'll want to watch temps more since cooling effectiveness will be reduced. A motor can only get as cool as the ambient air...

9: Depends on the track. Is is mainly all straights with few turns? Then you'll want a higher gear for more speed. Is it twisty? Then you'll want to gear down a little to give you more oomph out of the corners.

10: On the street, you generally are looking for all-out speed. At the same time, there is the least amount of terrain resistance. So, you can gear up.

It's all about knowing your vehicle. If I may suggest, play around with the various calculators on my site to get a baseline so you know which pinion/spur combo to get. Then, get a few extra different sized pinions and/or spurs for different uses. After a while, all this will seem easy.

There is a science to this, but there are a LOT of variables to take into consideration. Sometimes experience is the best teacher.

[t-maxxracer32]

alright cool!! i leanred alot!! WOOT!! more knowledge for me!

and i think i might ahve found my sweet spot! 20/87 works good for me!!

thanks bp!

[t-maxxracer32]

ya i got a 16-26 kit of pinions for xmas and i have about 4 spur gears and im ordering some more tomorow just to have some kind of difference if needed.

ima heck out thsoe sites you gave me to learn it up!!

and i had a 6 but then realized i knew the answer!! lol forgot to change them all!

i like your bysicle analogy! made good sence!! THANKS alot guys!