Chainring/cog size question
 

My new bike came with a 3/32" chainring and cog (it's the 2005 Pista) and when I bought it I had the bike shop install a 17 teeth rear cog. They put in a 1/8" cog on there and when I asked them if they had a 3/32" they said not to worry about it.

So is it OK? I don't want to be riding and have the chain pop off and kill me or anything like that.

I also don't like how the chainring is screwed in behind the crankarms, there's almost no clearance between the chainring and the chainstays. Am I worrying about it for nothing?

Everything else about the bike is great, it's much stiffer than my Fuji track was, but it still feels more comfortable than my Langster. Plus the 48x17 gearing is much better than what I had before (48x15).

Does it have a 1/8" chain? Otherwise that person is an idiot.

did they install a 1/8" chain too? a mismatched drive chain is just a bit more audible in my experience. two of my three fixies have 3/32" chainrings and 1/8" chain and cogs.

I would assume it's a 3/32" chain, since it's the stock chain... but it fits the cog. Anyway, I haven't ridden it much yet, maybe just 5 miles.

I guess your answer is "Yes it's a problem"

I don't care about the noise (it is more audible, like a grinding), and it didn't affect my cadence or anything when I was taking it for it's first spin in Central Park.

I'm just worried about the chain coming off and throwing me off the bike or something. If that's not a worry then I'll keep it the way it is.

mismatched in that way is bad news as it is being forced onto the cog, stretching the chain.

If it's really a 1/8" cog and a 3/32" chain, it's no good. I'm surprised the chain even fully seats in the teeth. I certainly wouldn't ride it like that. I would take it back and tell them to trade you for a 3/32" cog as you asked, refund your money, or give you/sell you (at your discretion) a 1/8" chain.

Thanks for the answers, I'm going to have to order a new 3/32" cog. I still have the stock cog that came with the bike, but I'm prolly gonna get a Surly 18t cog instead. The bike shop will put the old cog back for me, I just have to wait until Saturday.

Huh? When I first set up my fixed gear the LBS put on a 1/8" cog and chain (had done other stuff myself, but when I buy things from them they put them on at no charge so what the heck?). Not realizing this a few months later I put on a new 3/32 chain which practically wedged onto the 1/8" cog. I could ride it, but with difficulty and noise. I suppose if you don't have any of those aggrevations it doesn't matter, but I could not have ridden on it. I put on a 3/32 cog so I could use "regular" chains.
FWIW,
Raymond

Ultra-G -

I have the same bike - it comes stock with 3/32 all round. I recently picked up Sugino 75's with the 1/8 chainring so I switched the chain out but kept the 16T cog. You can run 1/8 chain on 3/32 parts (with noise) but 3/32 chain on 1/8 parts is bad news.

I'm eventually switching the cog out so I can be noise-free and to general keep things in order.

Hi, How much did the Sugino 75's cost?

I'm kind of annoyed now that the bike shop told me that there wouldn't be any problem with the 1/8" cog on the bike.

Sugino 75's can be had for anywhere from about $175 to $220 depending on where you look, and with or without a chainring. I was fortunate to get a good deal on Craigslist locally which is why I put 'em on.

Airbomb has em for about $175: http://store.airbomb.com/ItemDesc.asp?IC=CR1011

BikeWorks, $198: http://www.bikecult.com/works/parts.html#bb

Business Cycles: $194 http://www.businesscycles.com/trcomp.htm

track king on ebay had 75s for 140 a while back...

I got a killer deal that I could not pass on for the Sugino 75's. $150 with a Sugino 49t chainring, and a Salsa 42t chainring. The only reason I got the great deal was because I placed an order for some cranks which turned out to be on backorder for about a month... They must have felt sorry for the delay and offered me the deal.

still does (w/out chainrings)

http://cgi.ebay.com/ws/eBayISAPI.dll...tem=7126376292

I recommend this place.

Hey, didn't your friend buy my restored Trek? How's he liking it?

bikeusa.com (a.k.a. mud, sweat, and gears) based in good ol' oklahoma has the best deal on the 75s that i've seen. $157, which includes a 49t ring.

do it up.

http://www.bikeusa.com/MERCHANT2/mer...ct_Code=CR1011

sweet find habitus!

aebike.com also has it for $157.
http://aebike.com/site/page.cfm?PageID=30&SKU=CR1011

your predicament is exactly why i don't let anyone touch my bikes or cars with a wrench.

that auction picture is hilarious. it just needs dingle balls and a few lines of coke.

Henry right? Yeah my buddy bought the Trek from you a few weeks back. He's still getting used to it, it's his first fixie. I'm in the process of building my IRO, just waiting on all the parts to arrive. Know of any good LBS?
Thanks,

I had found the cranks for $157 when I was shopping, but they are all 165mm, if this matters to anyone. The best deal in 170mm length was from airbomb.com, $173 w/ a 49T chainring - I like my length, and wasn't willing to compromise for a difference of less than $20.
They should be arriving today - I can hardly wait!

ryan, bikeusa.com also has the 170s for $157. they are "all up ons"!

http://www.bikeusa.com/MERCHANT2/mer...ct_Code=CR1012

ARGH, you shouldn't have told me
;)
I guess I should start checking that site!