[Adrian Clark]

RC, Aren,

First off, I'd like to apologize for posting false information. I clearly did not have standard gear alloys in mind when I posted that. To correct myself: a common steel gear would be around 50-60ksi.

I'm always the first one to jump up and quell the assumption that switching to steel from aluminum isn't necessarily a strength gain. The reason being that your average steel gear, say 4140, has a lower yield than 7075 Al. This is because a lot of steel gears are sold in an annealed state.

I was not aware that vex hardens their gears. Now that I know, I'm even more in awe of the quality and value of products company's like vex are selling.

On a side note, to the vex pro squad: under the CIM gear section on your website at the top of the page the steel gears are said to be made from 5150. However, lower down on the page it says they are 4140. Also, I don't believe it's mentioned anywhere that the gears are hardened. I would personally suggest that on the website you include the fact that you harden the gears. For me, the lack of that information would be the deciding factor in whether or not I buy a steel pinon. I mean, they're listed as 5051 (yield of ~50ksi iirc) when in actuality they're twice the strength.

tl;dr, disregard my previous post. I was incorrect that steel pinions were weaker that their 7075 counterpart. At least for vex pro products.

-Adrian

Edit: Wanted to share a little snipit of wisdom I recently leaned regarding cim pinions. Vex sells cim output shafts for VPs. Be mindful when using a cim pinion on a VP, you're putting a significantly higher load on the pinion by running it through a reduction and if not accounted for it could completely ruin your performance at competition.