What size is this Omar's aluminum sprocket? (Dirt tracker 19" Conversion)

[proeliator]

I was hoping someone here would be able to tell if it this is a 530 sprocket so I can order the correct chain and front sprocket to go with it. Thanks.



I bought a Omar's 19" rear wheel Dirt tracker adapter kit from another member a while back, and it came with this aluminum 34 tooth sprocket from Rebel Gears. It doesn't have any markings other than company logos and tooth count, no part numbers on the sprocket or its packaging either. I did some searching on here and looked at Omar's and Rebel Gears web pages but came up empty handed



From all that I have read about chains and sprockets:
520 = 1/4" = 0.250"
525 = 5/16" = 0.3125"
530 = 3/2" = 0.375"

I took some measurements from my sprocket, it does not match any of the above but I am assuming the sprocket I have is a 530 and the difference in thickness is to account for tolerance between the chain and sprocket. I was just hoping one of you can confirm it.

As you can see the teeth have about .350" thickness

The .347" thickness of the teeth tapers down to .225" at the very end of each tooth

 

[FB71]

I thought the measurement was from tooth to tooth, not width of the sprocket?

 

[TwoManyXS1Bs]

I recall coming across narrow 530 sprockets like that long ago. Extra clearance for offroading, so it won't choke on mud and twigs...

 

[proeliator]

I thought the measurement was from tooth to tooth, not width of the sprocket?

The measurement from tooth to tooth (pin to pin) is the chain pitch measurement, which I believe 520,525, and 530 all have the same 5/8" pitch.

The values I posted are for the chain roller width dimension, or the width between the inner plates of the chain.

Since my sprocket (.347") is much larger than the 520 (.250") or 525 (.3125") values
but will fit within a .375" chain I am assuming it is 530.

I recall coming across narrow 530 sprockets like that long ago. Extra clearance for offroading, so it won't choke on mud and twigs...

Makes sense.

I just went out to the garage and measured the stock 530 sprocket on my '80 XS, it was exactly 0.347" same as the Omar's sprocket that came with the kit, so I guess that solves the mystery.

 

[blagave]

If you are not already aware, Omar's conversion kit is his own design and the sprockets are not interchangeable with the stock bolt pattern. You would either need to buy a 530 from Omar's, make one or find the company that makes them for Omar's