Has anyone any recommendations for a day sack good for UK mountain biking?
I use bottles so don’t need it to have a bladder pocket.
I was thinking big enough for food for a day, water proofs, down jackets, spares first aid kit. Ideally close to water proof and with Some external pockets (? these could be mesh)

Whatever size osprey suits, if it comes with a bladder, sell it on here.

They are really well designed and thought out packs.

Osprey user here & the bladder is top notch.

+ 1 for the Osprey Escapist

I have an Osprey, which is good, I don’t disagree. But I prefer a Deuter of about the same size as it just works better for me.

Osprey here too. Good build quality and well thought out.

Better than the previous Deuter bag that got returned (zips pulling away at seams).

Couple of ospreys here. One is biking specific and one more general. Both extremely comfortable but I think I prefer the non biking one.

Osprey, or if you’re made of money the Epoc packs are good. I have one for snowboarding, but couldn’t justify the expense for my bimbling MTB skills.

Son has a Vaude Path (older version), and I have an *ancient* Vaude Tour. Both are brilliant bags – comfy, stable, a few features but not too many. His has more – including a zip to double the size on big days. Mine is now 20 years old and is just starting to show its age some… Underrated IMO.

Youngest son has a Salomon Trail 10-15 running pack, again it is simple, light and stable, with similar expander zip to the Vaude. It is well made, but a bit too light and I expect it to not last as long.

Avoid the cheap Karrimors – I have one, and while it works, it says a lot that I keep choosing the Vaude…

I used a kid size Deuter.

OMM 35lt made for the mountains. Stable on the bike. Pockets, lightweight. Made by people who know and tested in mountain marathons.

Did 7 days Sarn Helen route north to South Wales. Brilliant pack, rugged and well designed