Bigger chainring or smaller cog?
 

So whats the difference/benefit/advantage of going to a smaller cog vs a larger chain ring? To my understanding 14x42 and 15x44 are similar if not identical.(?)

So what i would like to know, is there any performance difference or mechanical benefit to going with either combination.

Rear cogs are cheaper! Other than that I don't know.

with a bigger chainring the drivetrain will wear slower because the load will be distributed over more teeth.

More teeth in the drivetrain means more teeth to spread wear on (good), it also means increased friction (bad). I also maintain that the low angular separation between teeth and the larger ring and cog circumference means that it takes more chain slack to throw the chain, but that's just my pet theory.

Same theory here, sorry 'bout stealing your pet.

Another point is that, the crank will be up for more chainring changes than the hub will be for cog changes (bolts vs threads), if you like to fiddle with your gearing a lot.

The smaller you keep everything, the lighter your bike.

weight weenie.

Yes, go with the smaller cog. The weight difference between a 15T and a 14T is actually phenomenal. This decrease in rotating mass will allow you to increase your top speed by AT LEAST 8mph on level ground. Your acceleration will get better, and you will be able to get up hills like a pro. If you were to increase your chainring size by two (!) teeth, oh man, why would you bother adding that much weight? You might as well have someone riding on your handlebars!

:D
In all seriousness, if you can find cheap chainrings in your BCD, I would swap chainrings. I haven't even done that much swapping, but just in theory I agree with a lot of the above, especially considering the difficulty and wear of swapping a cog vs. a chainring. You have to get that lockring off, and then the cog, which is probably quite sunk in there by now. You either need to use a chainwhip and all that jazz or get creative with the wheel mounted on the bike, versus spending a couple minutes with an allen wrench and a screwdriver.

I went with the 14t cog. So far so good, no complaints, just a slightly tougher ride, but that was expected.

going to the velo swap next week, ill see if they have anything there! (re 144 pattern chainring from other post)

Thanks for everyones two cents!

Using a chainwhip is not difficult. I think changing a cog is at least as easy as changing a chainring...
just my 2 cents...




In all seriousness, if you can find cheap chainrings in your BCD, I would swap chainrings. I haven't even done that much swapping, but just in theory I agree with a lot of the above, especially considering the difficulty and wear of swapping a cog vs. a chainring. You have to get that lockring off, and then the cog, which is probably quite sunk in there by now. You either need to use a chainwhip and all that jazz or get creative with the wheel mounted on the bike, versus spending a couple minutes with an allen wrench and a screwdriver.[/QUOTE]

For someone who doesn't own one (myself), its another thing to have to consider though.

Yes.

I believe the advantage might go to the chain ring change because you will impact more gears. If you have a 9 cog cassette and can use 7 cogs for each front ring then a ring change affects 7 gears. If you change a rear cog and it's useable by 2 front rings then you only affect 2 gears. If your desire is to only affect a low or top end gear then the weight advantage goes to changing the rear cog. Cog wear I suppose is a consideration but unless you're a one cog rider I believe that's secondary.

Which is all sort of moot when we're talking about fixed gear.

You mean a triple fixt gear right?

Um... ?

And the Matt Gaunt Award for roadie/MTB'er who is obviously lost goes to ...........................................

BOYZE!

for those who don't remember Mr. Gaunt:

http://www.bikeforums.net/showthread.php?t=72174

there's lost, and then there's lost.

Go for a bigger chainring. Think of it this way... with 14 teeth on the rear cog you're only getting maybe 5-6 teeth to contact the chain at any one time. That's only 5-6 teeth taking all the force of a skid, or even just normal riding. the more you can distribute the load the better (at least as far as I'm concerned). Something to keep in mind tho... smaller cog you can just take out chain links, a bigger ring and you might have to add links or buy a new chain.

Which brings me to a question: when I changed my chainring and then brought my bike into the LBS the owner nicely yelled at me for putting the ring on wrong! Something about lining up the right holes from the ring to the right holes on the crank. What's up with that? What did I do wrong?

And the J. M. Brevity award for most succinct answer to a query in Bike Forums goes to kurremkarm.

The back side of a ring has slightly recessed holes that will hold the back side of the stack bolts. I'm not sure why it really matters. I suppose in that configuration there may be less play. On the other hand, if you have your ring installed right, there should be no play. I know I have one of my chainrings backwards. I've been too lazy to switch it around.