hambogger

Hi all! I have been thinking about buying a fixie. I asked a guy at the LBS how long the rear cog should last, and he said about 2000 miles. I know there are many factors to consider like riding style, chain condition, etc. Does 2000 miles sound about average? And how much does it cost to replace the cog on the back? Thanks in advance for any replies!

fietsbob

Ah another pre worrying post. it happens a lot.

get the bike or dont, I never fitted a bike computer to count miles ..

how about a 3 speed instead.. their cogs are cheap. im still using a 15t for 3 years ..

bonsai171

Hard to say how long the rear cog will last as there are 3/32 and 1/8 versions. The 1/8 track cogs are beefier and you will probably get more mileage out of them. Got 800 mi on my fixed cog now (1/8) and it barely looks worn at all. Cogs are pretty cheap too, you can get a Dura Ace one for $30 bucks, or a nice EAI one for $35. Can't imagine your LBS would charge much to install one. It is very similar to a cassette install, but there is a lockring that holds on the cog.

Dave

hambogger

I understand your point! I ride about 150 miles per week, and don't have alot of cash for tools/parts.

79pmooney

If your fix gear has 1/8" chain and you start with new chain, chainring and cog, that cog will last far longer than 2000 miles! It does depend on how you define the usable life. That life will be much shorter if you need the cog to always be compatible with a new chain like might be expected of a cog for a velodrome raced bike. But on the street, you can run the cog with the same chain and chainring a long, long ways. Street grit, cleanliness and lubrication will make a real difference. Still with no special treatment at all, I'd expect 7-10,000 miles on a cog if it is OK that chain and ring will have to be replaced at the same time. A new chain in the first 3000 miles will stretch that mileage further.

Ben

fietsbob

China is good at bike parts, Taiwan is where most bikes are made now, & they have learned to do it well,

Get brakes on that bike , both wheels .. & get a Really Good Lock your stolen bike will sell fast on the black market..

clean freshly oiled chains are the key ..

ThermionicScott 

It depends a lot on how big the cog is, too. A 14T cog won't last nearly as long as a 20T, all else being equal.

seau grateau

If you ride a 16t, I've got some good news for you: https://www.retro-gression.com/colle...ts/2-dolla-cog

79pmooney

+1 I was speaking from my experience riding 16 and 17 tooth cogs with 42 through 44 teeth up front. So my experience with mileage can be adjusted accordingly.

Ben

hambogger

Wow! Thanks for all the info everybody! I'm gonna have to look into that $2.00 cog mentioned.

wphamilton

2,000 miles? Mine has 5,000 so far and I think it's still in pretty good shape. I think you're worrying needlessly.

Fugazi Dave

China ≠ Taiwan but both have damned good manufacturing.

fietsbob

Republic of China, Taiwan, is a separate country after the Chinese revolution, but the PRC still considers it theirs.

you don't know history apparently..

Fugazi Dave

Or maybe I lived in both Taiwan (Kaohsiung) and China (Shanghai) and yeah, I know the difference. Taiwan ≠ China.

fietsbob

temporarily according to Beijing, Hong Kong used to be British, you know, now its not..

but I, reluctantly, pay taxes, funding the Navy, Pacific Fleet to keep the US Warships in the sea between the Island & the Mainland.








....

Fugazi Dave

And your point is what? Different currencies, military, passports, etc. Just because Beijing says it owns Taiwan doesn't make it so. Might as well argue that American slaveholders had legitimate ownership on other humans.

And an ellipsis has three dots, btw.

Scottybigs 

Cog wear life is something I think about often, but could never really offer a definitive answer as to what the average is. Over the last few cogs I've had (all Surly), I'd say that I average 1500 - 2500 km's per cog. I know this because I ride my Wabi almost exclusively on long rides that I track with Strava.

When my chains get to between 75-100% wear, I replace them. When I can feel the chain shifting between the cog's teeth while riding (ie. not a snug fit and the wear has increased the gap between teeth), I'll replace the cog along with the chain.

My approach is overly conservative though, and as others have mentioned, you can stretch the lifespan of the cog further. Just be mindful of chain and chainring wear, though.

the sci guy 

i ride a single speed freewheel, not a fixed cog, but the principle is stil the same - they are disposable parts and aren't expensive. When it wears out, you just plop down the $20 to get another.

ThermionicScott 

1500-2500km per cog makes me curious -- how long are the chains lasting? What cog size?

seau grateau

I think this has a lot to do with how anal one is about their bikes. If you don't care about some drivetrain noise and rarely bother to look at your bike unless something becomes practically problematic or fails (raises hand), then you can get a ****load of miles out of your cogs.

fixedweasel

I have an 1/8" Dura Ace that has at least 10k miles on it ridden through salt/snow/slush/rain.*




*and all with no maintenance on that same rear cog

Scottybigs 

Chains I'm getting about 1000 - 1500km from, which is much less than my geared bikes. Cog is 18T. Wear gauge is the Filzer gauge and not Park Tool's more accurate one, should probably buy that. As Sean ^ alluded to, I'm more anal than I need to be. My commuter bike's chain will practically be disintegrating before I replace it, so it depends on the bike for me.

I recently moved from Nova Scotia, where the riding was super hilly. Since moving to Toronto (totally flat), cog life is increasing a bit because there's no aggressive hills to climb.

Kind of missing the hills.

Scrodzilla

Some people like to overthink their bikes way more than actually riding them.

wphamilton

That's interesting to me, because my chain has also lasted over 5000 miles (8000km). Are you replacing at 1/8" stretch?

Maybe I just baby mine a lot, but it's amazing to me that one person sees 5 to 8 times longer life of his chains than another person does.