Using hardened steel R.R. spur on 5mm 32 pitch pinions

[crazyjr]

I'm running the Robinson plastic 66 and 72 tooth spurs and have no problems. The 66 is in the G2R with a mambamax and a 9XL, the 72 is on my G2 Gmaxx with a 4400 hv brushless currently.

[BrianG]

Common consensus from many here states that you shouldn't run hardened pinions with hardened spurs. And don't even think about running regular steel pinions with the hardened spurs. There was a fairly lengthy discussion posted here. All the advice says to use plastic spur with the regular steel pinion.

I want to try using both hardened gears in my buggy and see what happens, but I'm half expecting there to be issues from what everyone is saying.

I really never understood the advantages of Mod1 over 32p. Mod1 teeth are bigger, but there are fewer of them meshed at any one time. Conversely, 32p teeth are smaller, but there are more of them meshed at any one time. There is a user here (can't remember who) who uses 32p spur/pinion on his BL Revo conversion with success.

[zeropointbug]

Just to make sure everyone knows what im doing, im not running it through a tranny. I will have the spur connected directly up to the diffs from CVD's of course... i don't know if you knew that?

Im a little stuck for gearing though, im thinking 14 or 16 tooth pinion with a 66 T Spur directly to the diffs with 7XL on 5s2p A123 pack.

Well, way back when i had my stock emaxx, i bought the R.R. Racing spur and ran it, WOW, filings everywhere, it was noisy too. And seemed to be slower.

Exactly, i don't see an advantage running Mod1, 32 pitch in my opinion is big enough, and would be more efficient and quieter.

BrianG, what gear ratio do you think i need, 14 or 16 tooth, thats running RD Logics Spikes tires, i have some 20, and 22 tooth for 1/8 tire running also.

[BrianG]

Yeah, the shape of the teeth from a normal steel pinion and a hardened steel spur are different and bind quite a bit. You can even tell that by trying to spin the pinion on the spur by hard. The binding was probably what made it go slower and is definitely where the filings came from!

I'm not really sure what tooth pinion you'd need. I would use this page to figure out what pinion you need. First, enter all the values from a stock emaxx except leave the top speed blank. Write down the top speed and overall gear ratio. Then, clear the form and enter the total gear ratio and top speed calculated from before and the rest of the values, but leave the pinion blank this time. The calculator will figure out the pinion to use to get the same overall gear ratio and top speed.

[zeropointbug]

Oh, okay cool. I was dead on, i had 45mph for a 14 T, and 52mph for a 16 T pinion.

[starscream]

I haven't experienced any performance difference between 32P and Mod1. As long as you use a metal pinion and plastic spur, you should be good.
Its more a matter of finding the appropriate setup that will accomodate the gear ratio you need. Its really up to you which route you take. I made the switch to Mod1 because I wanted to use the Revo slipper so I invested in some Mod1 pinions (They didn't have the tmaxx .8 metric spurs at the time). I then needed a larger spur so I got the Strobe slipper from Mike and used the 51T Mod1 spur.
The price between the two types of the gears are practically the same. I would recommend choosing the pitch that gives you the most options for now and future use. If you think your future applications will never use Mod1, then 32P should be fine. If you ever see yourself doing any 1/8th scale conversions or using 1/8th scale center diffs, go with Mod1.