48P or 32P How's the ratio/logic?

[MaFoDes]

So i know that a 32p has deeper teeth then a 48p. But i just don't see the logic in gearratio's.
In my G6 and Rubi i run 48p's 16T pinion and 87T spur. However in 32p that would be different numbers. I do not seem the logic in it.

Can somebody explain that to me? Make me see the logic of it. Isn't a tooth a tooth?

 

[Highmark]

So with a 16T pinion and 87T spur your ratio is 87/16 = 5.43:1

Carry that over to a 32t gear and to get the same ratio with a 32p 60 tooth spur gear you'd need a 60/5.43 = 11.04, so you would need 11t 32p pinion for approximately the same ratio. To verify, 60/11.04 = 5.43:1

The difference is that a 32p gear has fewer (larger) teeth in the same gear circumference. I think a 48P gear has something like 1.5 times the amount of teeth as a similar circumference 32p gear. You could could also run a larger spur with a larger pinion, or vice versa and achieve the same ratio.

We actually don't calculate gear ratios with the most accurate method, but for hobby purposes using the number of teeth is efficient and it works out well.

 

[Col_Sanders]

The 32p gears have a larger contact area and are going to be more durable. You can get pretty close to the same gearing that you currently have with 32p. Your current spur/pinion ratio is ~5.4:1. With a 56t you could run a 10t pinion and be at 5.6:1. Or an 11t would put you at ~5.1:1.

I said 56t because it is easy to get and it gives you the most gearing options that you can run with the stock motor mount and spur cover is 56t. I am running 58/11 (or it may be a 12) on one of my rigs and the cover will not fit without some modification.

 

[Eric0424]

Isn't a tooth a tooth?

Actually no, larger teeth are stronger as long as material and width are the same between the different pitch gears. The compromise with the larger teeth of the 32 pitch, MOD 1.0, etc. is that we don't have as many ratio options within a given size (diameter) of these gears. Larger teeth also tend to make a little more noise.