I'm putting together a conversion and the chain doesn't seem to be fitting the cog right. Its like the teeth of the cog are too big and getting slightly wedged in the chain, causing things to jerk a bit.

The cog is an EAI, size 3/32 and the chain is an SRAM PC-69 9-speed.

Will the two wear to each other? (either the chain stretching and/or the cog wearing down a bit), or will this persist?

I'm contemplating getting a 1/8 size chain, but with a 3/32 cog and chainring, I don't see why I should have to do that.

9-speed chains are narrower than 3/32"

get a 1/5/6/7/8-speed chain.

yep, you need a PC-48/58. you could also go with a PC-1 -- a 1/8th chain, which would technically be bigger than the cog, but that's ok.

It'd be a bit noisier than going with 3/32", especially if chainline is not dead nuts.

9 speed is a 1/128. i think this concept is ridiculous. who's with me!!! when the number is that big why use metric!!! it's ubsurd, or just a pet peeve of mine that they use such a large number

what? last I checked inches were an imperial unit of measure.... you are the one that is 'ubsurd'

possibly drunk as well.

que?

Thanks. I'm going to try out the PC-58 and see if that does it. I'll throw the 69 on a roadie or something.

One last question. Whats the difference between the 48, 58, and 68? Can you really tell?

If you are talking mm of length then not much.
I'm sure she'll try not to laugh.

Enjoy

Width, primarily width from outer edge to outer edge, but there is also a slight difference in the internal width. As you put more cogs on a freewheel in the same space, the chain has to get narrower to fit between them.

Actually, I meant the difference between the different Sram chains. The PC-48, PC-58, and PC-68. They are all 8-speed chains that will fit the cog, but of supposed different "performance" qualities. Stronger pins, etc...but I was hoping someone had experiences with them and could tell me if there is any real point to spending the extra $5-10 dollars to get the nicer ones. A friend claims the PC-68 runs quieter.

Most things I see online recommend the Sram PC-58...so I just wanted to know if there is anything to gain by spending the extra $$$ to get a PC-68. Is there noticeably less chain stretch over time or anything?

they are all 8 spd the difference is material and contruction I dont have the down low on the sales pitch but 68 would be lighter and stronger and hopefully last longer the same would apply with the diff between 49 59 and 69 or deore lx xt you understand now