I can put up with a sweaty back but drinking warm water is really unpleasant and I find I don't drink at the same rate on longer rides as on shorter ones when using water bottles. So I want a new pack that's big enough for longer rides and will carry 2 litres of water and spare clothing and food but most importantly will actually sit off my back on a suspended mesh panel. Another nice feature would be pockets that are accessible while wearing the pack. I'd seen a review of an Osprey pack which seemed ideal but a look at their website earlier suggests they may have dropped it. I know I'm not actually going to be able to keep water cool but any improvement would be welcome. My current pack is Karrimor Rush 20 which has a ventilation channel but with a soft back it really doesn't do a lot of good.

Insulated pack like this: http://camelbak.com/sports-recreation/hydration-packs/Stoaway-70-oz.aspx

and put ice cubes in / freeze the night before?

Thanks geoffj that could be an option.

Remember the water in the hose heats up fast so if you're only sipping you'll get really nasty warm water all the time, even if the reservoir's cool. Not saying that's neccesarily the case here mind but it could be.

There are some packs where the water bladder pocket is on the side or front rather than the back. Try one of the OMM range.

Either camelbaks NV system packs or ergons clever parks do the trick.

I use a Salomon Raid Revo 20 sack with a Platypus 2l bladder and have never really had a problem with warm water, apart from the bit in the tube, but with the Platypus I've never had bad tasting water. Even on long rides. (I've even used it when the water's been sat in there for a couple of weeks, and it was still fine).

It doesn't have a suspended back, but there is some decent padding between it the water any your back. Also, two very handy pockets on the sides of the waist strap. And a handy loop of the chest strap for the hose. And a whistle 😉

buy a space blanket (the silver foil one) from Tescos, and place it between the bladder, and the side of the bag that touches your back.

You still get warm fluid in the pipe though

After drinking, blow the water in the hose back in to the bladder and lock the mouthpiece, the water in the bladder will struggle to heat up in comparison to the rate at which it will do so in the hose

Aye Osprey seem to have dropped the mesh panel on its talon series, but otherwise Vaude, and deuter do smallish packs with that system. Used 3 so far vaude – deuter – vaude and won't be going back to 'normal' packs. Can't recommend one over the other as both brands are very well made, and I've only replaced them due to my own incomptence, choose one that you believe to be big enough for your needs

the other option is the wingnut packs, I was tempted but they are quite pricey

My experience is that it's only the water in the tube that's drinkable as that has actually cooled compared to what follows from the bladder.

I'll have a look at druidh and sharki's suggestions.

If nothing else works I think I'll just start putting tea bags in the bladder.

I'd never have bought one as I honestly didn't expect it to work, but I was given a Camelback thermal cover for the pipe a few years ago and it really does make a difference. It's still overpriced, but definitely worth a go.

"My experience is that it's only the water in the tube that's drinkable as that has actually cooled compared to what follows from the bladder."

That's just plain weird tbh. You're not some sort of robot disguised as a human by any chance?

I've got a Vaude Splash 20+5 pack with the suspended back, and it is very good. I use it pretty much all the time – the only issue I've had with the pack is the lack of compression straps, but the unused belt that came with my Endura Humvee's works very well as a compression strap when wrapped around the bag (through the red tabs on the back adjuster), and if you don't have those a bit of elastic shock cord as used in tent poles works just as well. With that it means I can compress it down small enough to be useable for short rides as well as longer ones.

Similar to above I've never had an issue with the water in the reservoir heating up. But running ice cubes in there is probably a cheaper option than buying a new pack 🙂

Second what the others have said about the water in the tube heating up rather than the bladder, and Osprey have some new hydration packs coming out next year.

I think the reason they don't normally have the mesh backs is the extra weight of whatever's keeping it stiff and the advantages of having the weight as close as possible to your back.

Yeh I know it sounds weird but the first water out is ok and then it gets warmer. Maybe the back panel and foam on the Karrimor are just very good heat conductors rather than insulators. I'll look at the Vaude and Deuter options as well. I'll be looking at something a bit smaller than the Karrimor which will still get used for the commute so I don't mind spending the money on a new pack.

I'll second the "water in the bladder getting warm" option. This is even more noticeable in winter as the bladder will stay liquid while the drinking tube freezes up.

I'm using a Camlebak Mule NV over here in Brisbane. It's been excellent at keeping the water cool, even on long rides out.