To boost a bag?

[MartinFarrent]

In UL hiking wisdom, you can use a sleeping bag that is too cold for your trip's worst temperatures, boosting it with clothing you will be taking anyway.

Does this also apply to cycling?

Wind chill aside, cycling is generally a warmer activity. So, in true three-season conditions I need less clothes than a hiker. It follows that I either won't have the clothing to boost my bag... or must carry additional clothing for that purpose only. Of course, the possibly lighter alternative is a warmer bag.

Another sleeping bag idea: You see people carrying high fillpower bags for temps they aren't actually expecting - arguing that loss of loft in damp conditions justifies the 'overkill'. I'm wondering whether cheaper, less sensitive down might not be a solution (same overall weight, less expense).

[bmike-vt]

In UL hiking wisdom, you can use a sleeping bag that is too cold for your trip's worst temperatures, boosting it with clothing you will be taking anyway.

Does this also apply to cycling?

why would mode of transport change how well a bag works?

[MartinFarrent]

It doesn't.

What changes is the amount of clothes you need (cycling is generally warmer than hiking).

[fotooutdoors]

You still need warm enough clothes to hang around camp and should be carrying enough clothing that if you need to hike out for a mechanical or injury, you aren't going to freeze.  In short, while the clothing I carry for bikepacking (in my limited experience) is different than what I carry backpacking, it still adds up to about the same maximum warmth.

[PretendGentleman]

I find that wearing more clothes can make my bag feel more cramped. I've heard people argue that this reduces loft too, as you're pushing out from the inside more. 

I also don't use down because its wet around here and there's just too much risk.  I'm leaving tomorrow morning on my first mtb bike packing tour, which will be for 1, maybe 2 nights.  I use a low-tech rectangle bag on an air mattress in a hammock.  I used a mummy bag for many many trips and once I tried using this low-tech rectangle bag, I couldn't believe how much I enjoyed the extra room. 

[MartinFarrent]

@fotooutdoors:

If it's cold at night, I just go to bed and read - I generally ride alone and stop late.

[Mark_BC]

You still get cold at night if you're biking. My metabolism drops to nothing and I always get cold. The other week I did a winter bikepack and it got to -15 C. I brought two sleeping bags and I slept with multiple layers of clothes. Had my water bottle, alcohol, and boots in the bag with me. Just barely kept warm.

My sleeping bags were half the volume of my whole setup, though I hadn't really worked the bugs out and was a bit disorganized. So the bike looked huge, but wasn't too too heavy.

[jhl99]

.....Wind chill aside, cycling is generally a warmer activity. So, in true three-season conditions I need less clothes than a hiker. .....

I do not follow the logic of the above statement:
1.  Hiking:  0-3 MPH,  Cycling 0-30 MPH.  While riding there is a wind chill... it can't be ignored.  Descend 500 vertical feet at 25 MPH on a dirt road at 40 Deg F... it will cool you down signficantly
2.  Ride in temps >85F with some humidty... at speeds >10 MPH sweat evaporates, aided by wind chill, come to a steep climb and slow to 4 MPH... the wind chill stops aiding the evaporation and you and sweat stops evaporating as easily and you get wet.
3.  Once in camp, either hiking or cycling, major physical exertion stops.... both the hiker and biker need the same amount insulation for comfortable sleep. 

[MartinFarrent]

@Mark:

That was my point: You get cold at night, but not so easily while riding... calling for more bag, rather than more clothes (because they would be single-purpose sleeping clothes, not as efficient as down). Additionally, a cyclist's clothes are more likely to get wet or moist - rendering them useless in a down bag.

@jhl99:

A wind shirt or jacket will handle wind chill. At nights... see above.

[bmike-vt]

Martin,

If you are refuting every comment folks make, it seems you know the answer.

And, you'll get cold just as quickly in camp as you will bombing down a descent in crap weather. Just depends on so many local variables, as well as your body type, etc.

FWIW, I'd rather have an extra layer (or two or three) to wear that is useful if things go sideways, than a dedicated piece of sleeping gear.

[MartinFarrent]

It's not so much about knowing the answer... but about arguing a case to see how it pans out. Sure, if I take extra sleeping clothes to boost my bag, I can use them in daytime emergencies, too. But if I end up only ever wearing them to bed, I will wonder whether the choice was really efficient. Personally, I've never been too cold for too long while riding... unless I was wet. That was due to insufficient rain gear (in the Alps, and I won't repeat the mistake) and to a reluctance to take shelter in a timely fashion. The memory is nasty.

[Mark_BC]

The other thing to consider is that after a hard day of riding I can't curl up in my bag to stay warm because I get leg cramps. I have to stretch them out which means you get colder.

[Done]

Whether bikepacking or backpacking, I often carry a lighter sleeping bag and a down jacket/sweater. While I don't end up riding with the jacket much, it sure can be nice for long descents and for getting up in the morning. If it's cold, I wear it to bed.

As far as which is warmer, riding or hiking, I think a lot depends on the weather, speed, etc. I've frozen by butt off riding down long hills in the evening, while I would have been warm walking the same route. In general, I think that I get colder more often riding, because going fast on descents on a bike doesn't generate heat like walking. On climbs, it's pretty much a wash, since I can walk or ride faster for more warmth.

[vikb]

I took my summer light sleeping bag bike camping a couple weeks ago. Ended up camping on top of the mountain rather than my lower planned camp as the sunset on my slow ass...

I wore all my clothes and a puffy jacket, toque, etc...worked fine until 3-4am or so at which point I didn't sleep again...

If I had a do-over I would have taken my 3 season bag. It probably wouldn't have made any difference at all on the ride, but I would have felt better the next day with a solid night's sleep.   

Wearing all your clothes at night is smart, but having some fudge room in terms of the temp range of your sleep system is smarter! You might camp in a colder spot than planned, weather can change or some of the clothes you planned to wear could get wet and be unusable.   

[Blammo]

For whatever reason --let's call it experience --I seem to favor more sleeping gear then I actually need.  A good nights sleep beats lack of sleep every time.  For me, it's usually the tent verses bivy rather than the sleeping bag but it's the same thinking.

[MartinFarrent]

@vikb:

Agreed - much smarter.

Take the WM Summerlite or the Ultralite to the Alps in July/August.

You will sometimes be able to use the Summerlite at high(ish) altitudes. Sometimes, you'll be forced into the valleys. And if winter decides to visit August (which it sometimes does in the mountains, albeit not too frequently), the bag may not even work at the lowest reachable altitude... forcing you to take a room.

By contrast, the Ultralite will usually work at high altitudes and will just about always suffice lower down.

For around 300g weight difference, it's a no-brainer. Attempting to breach the gap with (additional) clothing is going to cost you a lot more grams and won't even always work. And no, you won't generally be needing the additional clothes at daytime, because things will warm up fairly quickly after a freezing night... that's unless your luck is really ghastly, in which case the additional clothing will most likely get moist during the day and be worse than useless in your bag the next night. You'll probably end up taking a room. ;-)

So, in my opinion, boosting your bag with clothes "you are taking along anyway" doesn't sound all that convincing in this real-life situation. The heavier bag would be the lighter, more comfortable and more versatile solution - offering freedom and peace of mind.

Conversely, you might be taking the lighter bag because it's the more convenient and comfortable option for the longest part of a multi-region trip... say, because you are spending a few days crossing the Alps and then heading to the Med for a hot sunny fortnight. So you might take a few extra items of clothing because you are taking the lighter bag anyway - the exact opposite of the usual UL rationale. That would make far more sense to me. But in that case, I still wouldn't count on fully breaching the gap between the two bags. I'd be prepared to make altitude compromises and even take a room in freaky cold conditions.

[Jason Elsworth]

I have been backpacking for decades, ultralight for about 10 years.  I am a complete newbie to bikepacking though. However I dont  plan on taking much different in the way of clothes than for backpacking. I do somtimes wear my puffy jacket  inside my quilt and carry possom down socks and merino leggings for sleep wear only. Fot wet cold conditions I also carry a 100 weight fleece that can be worn whilst moving if things get really nasty or in camp if I am soaked through during the day. generally I am not looking to push my quilt beyond its ratings by much - instead I am just providing a bit of wiggle room if things get colder than plannned. if I am looking to really push my quilt to a lowet rating I take down booties and trousers. if you really are just cycling, sleeping and then cycling and don't need a puffy jacket for camp wear then I agree adding a few extra ozs to your bag is a much more efficient than using a puffy.

as regards down loft in damp conditions this is not usually a major problem unless conditions are wet for multiple days with no chance to air your bag. if I was really concerned about this I would use a synthetic bag rather than a heavier down bag.


I have read reports that 900 fill down is particularly susceptible to moisture and in damp conditions quickly becomes no better than 800 fill. A number of moisture resistant down fills are now becoming available. with various performance claims. It s stil too early to say how well they work in the field. I have a moisture resistant 800 fill down in my current quilt and it seems great so far.

[MartinFarrent]

@Jason: I'd also be interested in knowing how well those down treatment methods work. Incidentally, the situations when moisture might play a decisive role aren't necessarily predictable in my biking life. The Alps in summer can be very dry or decidedly wet - in hourly intervals or for days on end. Given that crossing them leads to much warmer (and dry) territory in southern Europe, choice of sleeping bag can be tricky. My tentative solutions are a) a lightish three-season bag for trips confined to the mountains, or b) a good summer bag, some extra underwear and possibly a silk liner for trips that continue beyond. In both cases, I'd prefer less sensitive down. But I'm aware that the evidence for lower fill power (< 800) meeting that condition is controversial.

Apropos of nothing else in this thread, has anyone else noticed that the Mountain Equipment Helium 250 (2013 model) now boasts the same EN ratings as the WM Summerlite?

This is interesting if you are around/just over 6' tall like me. I don't fit in a regular-size Summerlite, but have ample room in a STD Helium. So the weight comparison would be between a large Summerlite (officially 560g, but apparently often over 600g) and a standard Helium (officially 710g incl. stuff sack - mine weights just over 660g without). The price difference is 100 euros. Additionally, the Summerlite has continuous baffles, which I don't really appreciate as a restless side/stomach sleeper. So the choice seemed fairly straightforward to me. I've also discovered that the 3/4 zipper doesn't really prevent use of the bag as a quilt, as some people have commented.