Need 2 one for me and my son, max I want to spend is £100 for the two.

Cheers.

Define warm and where/when you will use them.

Here in Scotland, last weekend DofE camp was -3.

I suspect that the south downs were warmer.

I’m in northern Ireland, will be mostly bike packing in the Mourne mountain area

I’m guessing if you want to stay warm, you may well have to up your budget..

http://m.gooutdoors.co.uk/vango-ultralite-600-sleeping-bag-p196171

We have one, great bag for the money. With some fleece clothes, my son has used it a few times around freezing, including last weekend’s DofE.

For £50, second hand would be worth thinking about.

Spotted a vango nitestar 450 for £49, any user reviews would be appreciated.

any user reviews would be appreciated

I’m not a user but looking at the specs it’s big old thing to lug about!

Mountain equipment lamina 35

You could get a couple of duck down bags for £60 each on sale. Should pack down smaller for bikepacking than any synthetic bag of equivalent warmth.

http://www.blacks.co.uk/equipment/133692-eurohike-down-500-mummy-sleeping-bag.html#reviews

Millets were selling the eurohike 500 down for £54

Warm, compact, cheap: pick two.

You don’t say what time of year you intend to use the bag, a big difference in the UK between summer and winter, for the price you mention I’ll assume summer pushing in to spring and autumn but not the cooler months of those seasons.

For the best warmth to weight ratio go for a down bag, the downside (sic) is that for a decent quality bag you will pay more. Also for a given weight/warmth down is less bulky when packed than synthetic filling. A good quality down bag will last a lot longer than a synthetic bag, a poor bag can lose up to 20% of its warmth per year depending on use.

Another option is a quilt, not everyone gets on with them but they are lighter and a bit cheaper than an equivalently rated sleeping bag as they don’t have down on the section underneath you. You do need a reasonable sleeping mat to use with them though.

My current system is a 2 season down sleeping bag (rated to 5C) which is suitable for quite a chunk of the year as I’m a warm sleeper. I augment that with a similarly rated quilt during the cooler months, the system is good to around -5C at least (I haven’t had chance to test it in anything cooler yet) and is much more flexible than a -5C rated bag would be. It does cost though.

With a budget of £100 I’d look at second hand as I think you’ll struggle to get anything that isn’t massively compromised, one range that might be worth a look is Blacks – they do DofE kit but it can be quite bulky which you’ll notice when packing on a bike.

Blacks/Eurohike down 500 compresses down nicely in it’s own bag to fit in the wider half of an Airlok Tapered 13l. Clothes in the tapered half. Or easily into a 13l bar bag not compressed as much and plenty space for other stuff.

1200g and about as good as you’ll get for the budget.

Think I’ll go for the vango ultralight 600 slighlty over budget but ticks all the boxes.