Why the big ring is smoother
 

Interesting post about why the big ring might feel "smoother". Not sure if it's true but sounds reasonable.

http://chasingwheels.blogspot.com/20...-smoother.html

plus its dura-ace...+1

I feel it on my bike. Small ring is really clinky.(I have a triple)

I think it has to do with how a lot of people's pedal strokes tend to smooth out while mashing as opposed to spinning as well.

Conspiracy theory, but if it makes you go faster, so be it.

Hmm on my compact small ring has always been smoother...

Some related stuff on Berner pulley rings. Can't believe this has been slowing me down for so long.

http://djconnel.blogspot.com/2010/08...y-upgrade.html

When Shimano came out with the 12T cog (or maybe it was the 11T), they had one engineer working solely on optimizing the shape of the cog. Since a smaller count cog will be less round (imagine a "1T cog"), you lose roundness as the tooth count drops. Below 14 or 15T it gets pretty significant, i.e. pulley wheel size.

But between chainrings.

This is why you rarely see 10T cogs (like on the folding small wheel Moulton bikes) on regular road bikes. You could use smaller rings with the 10T, saving weight, but it's less efficient.

It's also why Shimano went to the 1 cm drive (10mm) versus the slightly longer but standard 1/2" drive. This refers to the distance between chain pins. 10mm is slightly less than the 12.2mm of the 1/2" drive, and it was enough to significantly reduce the size of the cogs without losing roundness. Shimano could make much smaller cogs, a smaller chain, and save weight overall. Since they didn't do anything with shifting (lateral loads on chain etc) this was made just for track bike use. The System 10 is still a sought after drivetrain for trackies and collectors.

OMG. Sad world when someone has to write some gibberish about what is obvious. This internet thing is getting stupider by the minute.

Well if Andy Schleck used it last year it must work...he never has chain issues.....

It is sort of an interesting theory though and would be easy enough to quantify. Find a ratio that you can be in while either in the big ring or small and measure the torque required to achieve a certain wheel speed (on rollers or trainer).

Really? Being on the big ring is about vanity?

Sounds bogus to me. You could have tons of friction and still feel "smooth".

For a given cadence and power output, the chain will be moving faster in the big ring, and the tension in the chain will be less. Both would seem to increase felt smoothness.

IMO, a lack of smoothness (where you get a vibration from each link of the chain engaging) comes from a worn drivetrain, probably chain and cogs/chainrings worn to different pitches...