For the sake of argument let's assume you don't have the relevant kit or have some cheap and nasty item and having caught the bikepacking bug you are looking to replace it with something decent. Items are for UK late spring to autumn use, say mid-April to October. Once you get into winter then you start needing much more specialist kit (and more kit!) Starred options are the ones used in the final summary.
Sleeping Bag
Use a quilt rather than a sleeping bag. The main reasoning behind a quilt is that the insulation under you gets compressed and therefore doesn't work as intended so remove it. Removing the back of the "bag" also means removing the hood so more weight saving. Which bag/quilt you go for does depend on how warm/cold you sleep so a couple of options. The best "bang for buck" quilts are probably Cumulus, Alpkit are the sleeping bag representative. (I had a look at PHD and also ultralightoutdoorgear and while those bags are lighter than the Alpkit equivalent they are very much more expensive)
Warm sleeper so comfort rating around 4C - 7C:
Alpkit Pipedream 200 weighs 545g and costs £146
*Cumulus 150 quilt weighs 375g and costs £141
So 170g weight saving and £5 cheaper!
Cold sleeper, comfort rating -4C
Alpkit SkyHigh 500 weighs 970g and costs £159
Cumulus 350 quilt weighs 585g and costs £181
So 385g weight saving for an extra cost of £22
This is almost a no-brainer!
Providing you get on with a quilt, not everyone does, then you are either saving weight and money or saving weight for very little extra cost.Sleeping mat
Unlike a sleeping bag which has a range of temperatures in which it's comfortable a sleeping mat just has a lower recommended temperature so a mat that's good enough for winter is also fine in summer but the opposite isn't necessarily true. The usual suspects are those from Exped and the Thermarest NeoAir range. The easiest way to save weight is to reduce size (length) but there's also the option of reducing the insulation.
Full length NeoAir XLite is 460g and £155
Short length NeoAir Xlite is 207g and £110
*Klymit Inertia XFrame is 175g and £65
Another no-brainer! Not only are we saving weight but also significant cash. Win-win! Either a saving of 250g and £45 or 285g and £90. The Klymit is meant to be used with a sleeping bag to fill in the "holes" but I've had no problems in summer when using it with a quilt.
Tarp/tent.
This is where cuben fibre comes in!
Alpkit smallest tarp is 300g and £55
Trekkertent equivalent sized cuben fibre tarp is 125g and £140
So to save 175g would cost an extra £85. Not worth it unless you've done everything else and want to treat yourself.
Stove
A gas stove like the Pocket Rocket and its clones weigh 44g upwards and cost from £24 up.
*A meths stove such as the BB 8g weighs, well 8g, and costs £22. If you make your own from a couple of pop/beer cans then the weight is 10g and a cost of zero.
Weight saving of 35g+ and a cost saving of 100% plus a warm inner glow from recycling what would be waste.
The real difference though is in the fuel - meths isn't as energy dense so you need more of it but then gas requires a sturdy container to hold it. For short trips meths is the clear winner as 100ml is enough for an overnighter or possibly two nights. The cost of camping gas cylinders is exhorbitant and for the same price you could buy enough meths to last the best part of a year.
Taking the winners from the above, going for the lighter options (starred) saves you a total of 490g and is £120 cheaper. If you then decided to get the cuben fibre tarp you'd end up with figures of 665g lighter and £30 cheaper.
The above surprised me somewhat as I thought that the cost of the lighter kit would be much higher than the "heavy" alternatives. I've sort of gone with what I know rather than items I know to be very light/heavy or cheap/expensive. Obviously the costings would be different if you already had decent kit - I've a PHD summer bag that cost £170 and weighs 470g(?) so the quilt would be a cost of £141 to save 100g.
Plus the bike has to actually cope with what you want to do. My best man is a serious weight weenie and will buy very light road bikes (he doesn't go mountain biking) and the frames will invariably crack, sometimes it's the wheels. The bikes are just too light for his weight, he's about the same as me, but he won't accept that a bike that's maybe 1Kg heavier will actually be better and not really slow him down.
)
. I do so like a nice cold hard bit of steel between my legs - all 11.6kg of it. Sorry I mean 25.5lbs.
and the actual shipping from US was £6 so total cost of £43 coming in about £20 cheaper than UK.
... I can actually see the point of having the choice of a 3" difference (although the original claimed 'advantage' that they "roll over obstacles so much better" was a big turn off for me - where's the fun in that was my reaction), but That Stupid Diameter other one is a giant con trick. 3/4" radius difference? I can fit a 26" TYRE that could give that if one so desired without being scammed another sales ploy needing a whole new damn bike. Harrumph!
