Looking at a new set of risers & notice that nearly all are oversized so will have to buy a stem too. What are the advantages then and does anyone seek out and prefer the old 25.4 ones?

I wanted some wider bars for my Inbred – the stem is a ‘standard’ size and it did limit choice a bit, but there’s still plenty out there. I didn’t want to fork out for a new stem as well, seeing as the RF Deus is still perfectly good.
Ended up getting a Sunline V3 bar for <£30.

I think unless you are really hammering it, you’ll not gain much benefit from oversize over standard – reckon it’s more of a fashion thing.

some argue a std. is actually better/stronger

probably worth making the switch now as std stems are not as numerous and it will only get worse.

I was after some 25.4 bars for my Soul – can’t bear to put fat bars on a skinny steel bike!

Got some Easton Carbons from Jenson USA, they were ridiculously cheap because they’re the less sort-after diameter.

I can’t tell any difference in performance between either – I have a mixture between several bikes…

Definitely stiffer IME.

Oops, misread title.

There are some bargains around in 25.4mm, (50% off RRP 2010 flat EC70s for example.)

I think a major advantage in oversize is choice. It’s very tricky to find exactly the stem rise and length you’re after in 25.4mm, unless it is a generic size. You can get just about anything in 31.8mm.

I didn’t notice that much of a stiffness increase in size, but I really noticed a difference going from a noodly Giant stem to a chunkier RaceFace stem, on a old Giant AC a few years ago.