I am currently using a 20t cog and was looking to "downsize"
I was wondering what a good quality and cheap cog would cost me

I have an Eighth Inch cog, which is available on eBay for $24.50 + free shipping.

If you are looking for something 13-16t, I have heard good things about Dura Ace cogs.

You could always have your LBS order you a SingleWorks cog (same as EighthInch but without the fancy finish and about half the cost).

Soma cogs are also cheap... the matte black phosphate finished one...~$20

dura ace. They are around the ~$25 price point.

I have been using dura ace for my last 3 cogs. I run a 16t

how long has your last 3 cogs lasted?

One dura ace cog has been running for about 1.5 years.
I have another one running for 6 months.
The third one was bought used off craigslist and is being used for my next project. But under 5 months of riding.

I trust dura ace for cogs. Reliable and yes, they last a long time.

wow that is pretty freakin long

Right now I'm using an EAI Superstar on my Leader and I'm looking forward to seeing how long it lasts.

What would a good 17t cog be? Dura Ace doesn't make those as far as I know

Soma or EAI.... soma being the cheaper one.... get the cheapest ones they sell.

As far as a cog goes; aside from it failing via cracking in half and falling off, which is very unlikely, you are theoretically paying for durability. But the durability of a cog has many variables such as chain tension.... so yeah, it doesn't hurt to go cheap.

The last couple of cogs I've used are Dura Ace, Soma and the one I am using is Origin8. All of them have been extremely well, silent, reasonable wear-time, cheap.

I recently scored two Suntour cogs, 15t and 14t, both with Suntour NJS lockring for a grand total of $25. I have not used them yet as they are way too high for my application.

haha yeah my friend just bought a FG off craigslist and it had 14t cog on it...it's been really brutal on him especially since it's his first FG

i bought a 14t cog...and iw as coming from a 17t, that was rough...i had to switch back...couldnt get up hills anymore...

I keep telling myself that I will use it (them) when I go to the track.

Of course, it won't happen for a while.

On ebay?

I would totally like to score one myself; they'll go quite nicely along with my superbe hubs.

Bike co-op.

I think it came from an actual track rider.

EAI Deluxe seems like the best bang for your buck. Plus u get more of a variety in terms of t count.

aha nice; wish I had a co op near me...

Finding nice parts at our local co-ops is rare... a lot of parts are from old road bikes and the likes. I was lucky enough to snag up some nice Race Face risers.

If you're building up a beater, though, the co-op is a great place to find parts.

I agree.

Co-ops are thrift stores for bikes. I wouldn't expect to find anything nice. It literally is the stuff that no one wants but they won't throw in the trash. There are gems, but few and far between. Craigslist is a better source of good/great used gear for cheap. Plus you can browse CL from your couch or smart phone.

Just as yummy says, if you want to build a beater, then you can do it at a co-op for sure.

haha youll be surprised what comes through a bike co-op.

awhile back some just rolled in and dropped off a vintage pinarello traviso XP

Yeah, I know stuff like that happens. But, that's one of the rare cases I'm talking about. Stuff like that is a bonus, not normal. There are just as many stories about attentive craigslist or ebay searchers finding stuff. Bonuses, all of them.