31.8 vs 25.4 mm – what are the pros and cons of each?

Are there any..?

31.8 has gota be stronger, surely? And lighter too?
If so, why do people (like me, for the moment) use 25.4?

Hmmmm..

25.4 is the traditional size so most people will have used that at some point. 31.8 does claim to be stiffer for the same weight. I have OS on two bikes but can’t say I have noticed any difference. Then again I am not exactly powerful in the arm department.

its mostly marketing i think !!! i have both on road bike s- cant say i notice a difference.

paul

I noticed a difference, but I was changing bar and stem for a different brand so could be just that the new ones were bettter anyway.

Probably not worth upgrading an existing setup, but i’d not even considder a 25.4mm bar/stem on a new bike build. Unless is was rigid, in which case some extra twangyness in the bars could be a good thing.

Makes me laugh when you see people upgrading to OS bars and stem because its like stiffer man which is better but then they go and fit a carbon bar because it absorbs trail buzz dude

So what people are doing is spending a fortune on something that is at the same time stiffer and more flexible 😕

I’ve just changed from an old 25.4 RF SYSstem and 660mm X-lite Gforce bar, to a Thomson X4 with a 737mm Sunline V1OS bar. Ste stem is signifficantly stiffer, and the combo is lighter than the old set-up, but the longer bar has a noticable deflection when you’re really hauling on the bars.

I’ve gone from QR front hub, weedy fork stantions and 25.4 bars to 20mm thru-axle, humongous stantions and oversize bars. There is definitely a difference, but I doubt I could detect a difference if I’d just changed the bars. 🙂

theres definately a difference in feel between a carbon bar and a thin alu one, the thin bar deflects more, the carbon doesn’t vibrate as much, thats how it felt anyway.

The carbon bar also weighed significantly less than the alu one!

So what people are doing is spending a fortune on something that is at the same time stiffer and more flexible

Not really – stiffness give more control and the bar gives dampening without flex.

OS makes things noticeably stiffer IMO. Not essential but nice, and needn’t be expensive either.