Bicycle Mechanics - Handlebar clamp sizes... does it matter?

Can someone tell me why there are different diameter sizes for handlebars? I've seen some with 26mm and 31.8mm. For rigidity?
Is 26mm adequate for commuting and light touring?

31.8 gives you the widest choice of drop and flat bars. I imagine the range of choices in that clamp diameter will only increase in the near future.

25.4 drops are tough to come by. Dunno if any 26.0 flats exist.

26 is just fine for commuting and light touring.

25.4 drops are tough to come by. Dunno if any 26.0 flats exist.

You can always shim out a 25.4 to fit a 26.

Indeed.

As far as rigidity is concerned, I don't find my 31.8 flat bars to be any more rigid than my 25.4 flats or 26 drops (edit: or my old 26.4 drops). Plenty of other variables like tubing thickness that could alter stiffness. I have one pair of 25.4 that seem too rigid, they seem to transfer more shock to my hands than any other bars I have.

26 will be fine, if you are strong and fast to be racing at the highest level,
then the other oversize stuff may matter..
But by then You are paid to ride stuff rather than buying it out of your own pocket.

OTOH, you have a 31.8 stem you can always shim to use the smaller handlebars.

31.8 gives you the widest choice of drop and flat bars. I imagine the range of choices in that clamp diameter will only increase in the near future.

Yes, i try to stick with 31.8mm for just that reason. Almost everything that matters is available in the 31.8mm size. So I stick with it as a way of future-proofing.

future-proofing in the bicycle industry? ha.

I'm sure in a year and half, companies will convince everyone how we all need the 32.1 new standard to be a better cyclist.

25.4 is fine.
26.0 is fine
31.8 is fine.

I cant tell a difference in actual performance. All I know is that my favorite bars and stems are 25.4 or 26.0 so that's what I use.

Deda's pushing 35mm
(http://velonews.competitor.com/2010/09/road/deda-3t-rotor-ritchey-campagnolo-and-prologo-display-components-at-2010-eurobike_138585/attachment/eb2010_components1_22)

@TimeTravel, I realize things change. What I mean though, is that the trend is solidly towards 31.8, at least in the mountain-biking world. There's a wider selection of bars and stems in that size, and some newer products are release *only* in that size. It's an easy size to stay with, at least today, so that's what I do.

On my last MTB build, I went with 31.8 because they didn't cost appreciably more than the 25.4 version of the same make/model. I haven't taken a tally, but it sure seems that 31.8 offers the widest variety in drops/flats/risers. Haven't seen much in the specialty styles like north roads/porteurs/trekking as of yet, however.

26 will be fine, if you are strong and fast to be racing at the highest level,
then the other oversize stuff may matter..
But by then You are paid to ride stuff rather than buying it out of your own pocket.

OTOH, you have a 31.8 stem you can always shim to use the smaller handlebars.

I still race on 26.0 bars. Not exactly at the highest levels though. Maybe that's what's holding me back? ;)

I still race on 26.0 bars. Not exactly at the highest levels though. Maybe that's what's holding me back? ;)

For sure! That is why they put 26.0 bars on children's bikes. Don't want the little gaffers going too fast do we.

Caloso, I see you are from California. That means you have untapped human potential. Get 31.8 carbon fibre bars and release the inner beast!

Reason I am asking is because I came across a Deda 215 which is fairly light @ 215g. It has 26mm clamp size though. At the moment, it will be on my commuting and touring bike. Should I or just skip it?

Deda's pushing 35mm
(http://velonews.competitor.com/2010/09/road/deda-3t-rotor-ritchey-campagnolo-and-prologo-display-components-at-2010-eurobike_138585/attachment/eb2010_components1_22)

That's hilarious, especially since they are making the entire width of the top of the bar 35mm.
Whatever happened to the concept of aerodynamics?

For sure! That is why they put 26.0 bars on children's bikes. Don't want the little gaffers going too fast do we.

Caloso, I see you are from California. That means you have untapped human potential. Get 31.8 carbon fibre bars and release the inner beast!

LOL




Reason I am asking is because I came across a Deda 215 which is fairly light @ 215g. It has 26mm clamp size though. At the moment, it will be on my commuting and touring bike. Should I or just skip it?

If you already have a 26.0 stem, why not?