Pto centering

[doug tenney]

as a side note. I have run g0ld on g0ld RLV since getting back into karting in 2010. I probably run more than most. On a 9t Max torque it will dimple the sleeve until it eventually shears off leaving you stranded. Happened probably 10 times to me. I went back to old chain but that sure didn't work. I'm trying the black and silver now to see if that is a bit different. Either the chain is to large or the 9t is hobbed just a bit to much. I don't have an answer to this problem but when you drive 1200 miles one way to an event and the sprocket shears off on the first lap of the first heat you are not to happy. I know gearbox time. Not.

Yikes, that is really bad news.  Your hobbing theory sounds right.

As I  recall, the way that we use chain on our karts (pitch .375" for #35, 9k or 10k rpm or so, on a 9T sprocket) is COMPLETELY outside the engineering design rules for chain.  For one thing, the design charts I've seen only go down to 10T, and even there, everything has turned to crap (wear rate, noise, uneveness, chain stress, etc). 
Smaller pitch (like #219 @ .306") helps a lot, but it's still not great.
Obviously 9T sprockets at 10k rpm will get you around the track, but I can definitely see why people prefer to run 10T drivers and accept that they're more likely to whack the axle sprocket if one tire goes off the tarmac.

See attached.