So after last weekend in the black mountains, I got home to realise my 20+ year old sleeping bag has a big hole in it and the insulation isn’t up to much anymore!
So started shopping but can’t get past looking at packed sizes and weights. I know down bags pack small and don’t weigh as much as synthetic bags. But being the flakey vegan guy I don’t want down. So is it possible to get small ish packed and light with synthetic?
So far I think the best I may have seen is probably marmot ultra elite 30. I plan to use it down to around 0 degrees so figure with a liner that should work
Any thing I should head towards? Budget is probably up to £200

Mountain Hardware Lamina bags tend to be a common suggestion over on Bearbones. There’s a range of bags rated to different temps so just pick what you want. I’ve no personal experience of them, prefer down myself.

Snugpak?
Travelpak2 is good to -2 they reckon. I have the 25 year old equivalent of the Travelpak 1 which is still going strong but having camped in the Autumn may not be good to 0 Celsius

You can get thermal liners that add a few C to the ratings:
https://muldale.com/thermolite-reactor-sleeping-bag-camping-liner-from-sea-to-summit.html

Then look at an insulated mat:

Cheaper version: https://www.decathlon.co.uk/p/insulating-trekking-foam-folding-mattress-trek-100-grey/_/R-p-306340?mc=8543045&c=TURQUOISE_BLUE

Then use a quilt instead of a bag. Not a lot of synthetic quilts out there.
I thought this Alpkit hammock quilt might be a good option:
https://alpkit.com/products/mora-hammock-underquilt
Hard to tell the thermal rating but I think it works out at being ok down to 3c or so. Should be ok with the other stuff and wearing some warm pyjamas!

or this one maybe?
https://www.outdoorgear.co.uk/Therm-A-Rest-Therm-a-Rest-Stellar-Blanket-sku52626701.asp

I’ve got a sea to summit reactor liner which is very cosy. Been using an alpkit numo mat, just inflatable so probably as insulating as a chocolate bar wrapper! Never thought of a quilt, a whole new thing to research 😂
I’m getting quite hung up on packed size after everyone told me they only use a 20 litre bag overnight and I filled a 40 litre taking minimum stuff!

The Alpkit Numo is basically a Lilo! Might be comfy but has diddly squit insulation properties. But yeah, a good insulating mat will go a long way to improving the sleep you get with any bag/quilt.

Remember that bag/quilt ratings assume you are wearing a thin thermal layer or pyjamas.

My summer to early/mid autumn kit is:

Exped Hyperlite Synmat (the long wide version)
Cumulus 150 down quilt
Sea to Summit pillow

Then either Borah Gear bivy and Trekkertent DCF tarp or my half of a Big Agnes Copper Spur UL2 tent.

The main issue with synthetic bags is that they really, really don’t like being compressed repeatedly, the fibres that trap the air get broken and so the material doesn’t insulate as well. Probably too early to tell about the latest generation of products.

What’s “minimum stuff” and for what activity?

As above, Lamina bags work really, really well if you are after synthetic. Just pick whichever rating you reckon will suit you.

An insulated mat is essential.

So inside the bag was:
Alpkit numo
20 year old sleeping bag, packed- 20cmx15cm
Sea to summit reactor liner
Msr pocket rocket
Primus kettle
200ml gas canister
3mx3m tarp
Paracord
10 tent pegs
1.5 litres water
Beanie
Montane prism jacket
2 hydrated meals
Mug
2 litre bladder in pack
It was only hiking so carrying it all wasn’t too hard. Thinking of getting a jetboil to save a little space not packing the kettle. There was no immediately available water source where we camped so had to carry extra water.
It all fitted but if I a new sleeping bag took up more space it would be tight! Just don’t think I can morally buy a down bag. Arguments against synthetics aside!

Your list doesn’t look too bad but as ever the devil’s in the details.

An Alpkit 600ml mug will hold a small gas canister and stove like the pocket rocket, that can save quite a bit of space. A lot less space than a Jetboil.

Are you carrying the items like the tarp and bag in their own stuff sacks? If so then that wastes space, just stuff everything in while trying to keep “wet” and “dry” items apart – you may need a dry bag for this.

Decant the dehydrated meals into “Pour and Store” bags – they won’t go off in the day or two you are away. The packaging is designed to give them a long shelf life in store with people handling them, you don’t need that.

Here’s a shot of my bike setup for an overnighter in the Dales:

The front bag is 8L, the rear is 5L. They’ve got all the bivy kit, spare clothing, cooking stuff and food in there. I’m carrying a Camelbak Lobo because things have been a bit dry in the Dales and needed to ensure we’d enough water, I think the only item other than water in there was a lightweight waterproof.

Have a read of this https://www.bearbonesbikepacking.co.uk/tls-the-revolutionary-packing-system/ and see if you can adjust things. I know when I started bikepacking I really struggled to get all my stuff, or what I thought I needed, packed on the bike without needing to take a rucksack as well. Now I know what I can get away with (and have over time replaced worn out kit with lighter, more compact stuff) it’s not a problem.

Getting a bit off-topic here!

Something I just remembered, it’s back on-topic as well. The shell material that a bag/quilt is made of can have a big effect on how compact it packs down. Most of the ultra-light stuff uses 10D material or even 7D in some cases but you have to treat those with a little care.

That costs because those lightweight materials are tricky to work with which is why the mid-range and cheaper bags use 15D or 20D fabrics which also just don’t pack as well.