Decent sized HS 15t sprocket

So… the entire time I was machining these down I was wishing I could buy them. It would please me to no end if VEX replaced that darn 1" wide 15t sprocket with something like this.

Regards, Bryan

Pictures for your viewing pleasure.

Whenever I’ve needed a thinner tank tread sprocket, I’ve found that a 12 tooth high strength sprocket works well in its place.

This was a matter of needing a 15t high str. sprocket. We looked at the math with 12 and 18 tooth sprockets, but liked 15 more, so we took the tank tread sprocket and made it into a normal sprocket.

These perticular sprockets were specifically lathed down to fit inside a very compact drivetrain origionally designed for regular HS sprockets. However, after reviewing the math, we decided that the gear ratio needed to be slightly reduced for optimal performance. Unfortunatly, without lathing these sprockets down we would have had to jump from 1:3 all the way to 1:2 which would have led to a steep drop in performance.

Having a standard 15t sprocket allows some attractive ratios (especially for drivetrains) such as:

1:1.2 (18:15)
1:1.25 (15:12)
1:1.6 (24:15)
1:2 (30:15)
1:2.5 (15:6)

Without utilizing 15t sprockets, there is only:

1:1.25 (30:24)
1:1.333 (24:18)
1:1.5 (18:12)
1:1.667 (30:18)
1:2 (12:6) (24:12)
1:2.5 (30:12)
1:3 (18:6)
1:4 (24:6)
1:5 (30:6)

Edit: Thanks jumper11: Corrected

A 36-tooth sprocket doesn’t exist so a couple of the ratios you stated wouldn’t actually work. The high strength sprockets only go to 30-tooth.