I'm going on a van supported tour. The night time temperatures will be in the low 40's. Is a 1 man tent better than a 2 man tent for warmth?

Yes

Minimal if at all. Tent's purpose if to protect from the elements (wind and rain). The difference in warmth between a bivy vs an arena is inconsequential.

If you are concerned WRT to the warmth of your sleeping bag, consider a bag liner (if you can source Alpha direct, you can get a surprising amount of additional insulation at low cost/weight/volume).

Other avenues include: (1) purchase a warmer bag; (2) purchase a quilt to drape over your bag; (3) wear (dry) clothing, perhaps long johns, a puffy, down booties, warm beanie

Low 40s is still quite comfortable. Most sleeping bags will be enough (what's your bag rating?). Personally I'd consider a liner (helps keeping your bag clean) and wearing additional clothing: puffy vest + beanie + warm base layer, top and bottom. should keep you warm.

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My sleeping bag is rated at 30 degrees. I was planning on socks and full pj's for sleeping. I have a puffy jacket I can lay over the bag plus a light towel.

It won't make much difference for warmth, but I think the right size for a tent is N+!, where N is the number of occupants.

That extra room is really useful if it rains overnight (do you want to sleep on or under your gear bag(s)?). It also gives you a bit of extra room, useful for dressing or undressing in the tent. And if you're tall, it gives you room to stretch out without mosquitos biting your hands or bare feet through the tent wall.

Pdlamb for the win again.
Modern tent fabrics are so light, the weight savings from going from a two to one person tent are probably about equal to a full water bottle. I like the extra room.
Here in the northeast, rain is not uncommon 25% of the time, mosquitoes and their hungry relatives about 100% of the time in the summer.

That warm? I would stick with a 2P. Any advantage you might gain in the way of warmth would be outweighed by the loss of space, as noted immediately above. When the GF and I did supported tours, we always took the 4P. Didn't regret it one bit, including on Cycle Oregon when we woke up to ice on the tyent on two spate morning.

Ifr you re really cold, wear the jacket. Don't drape it over the bag.

I largely agree. Weight and packed size differences are minimal. (150g, 1L between 1p and 2p).

One benefit of a smaller tent, though, is footprint. Easier to pitch in crowded spaces (such as some hike and bike areas) or between bushes.

For cold nights I double up with a cheap light sleeping bag over my regular 3-season bag. The difference is huge!
In Europe I buy this one from Decathlon.

As to tent size, I agree with others that a tent big enough to sit up in and get all your gear into is preferable in inclement weather.
I’ve got a Hilleberg Soulu, which is officially 1,5 persons tent.

Oh, and IME sleeping bag ratings are usually incredibly optimistic… stupidly, even dangerously optimistic if I’m being honest.
Some people sleep warm, others need more insulation, so ymmv

Beg to differ. I’ve had recent cause to use a Fly Creek UL1 (my “normal” tent) and a Big Agnes Copper Spur 3 several times for direct comparison. The Colorado Rockies are never very warm at night and overnight temperatures often fall below freezing. That includes the high plains. I use a 20° bag in both. At 10,000 feet with frost on the ground in the morning, the Fly Creek was reasonably warm using that bag while the Copper Spur was uncomfortable cold at 35° to 40°. The only difference is the size of the tent. Even when I shared the tent with my daughter in Arizona in early April, it was incredibly cold.

Wore a jacket in my bag when I used the Copper Spur. Didn’t help.

I would hope a van supported tour would offer better places to pitch.

I think having a little more space will be more comfortable in the end but a smaller tent will be better for warmth to a point. I think a 1-2 won't be as big as a 1-3. If you have a lot of open space in the tent you will be colder but if you have the space filed either by yourself and gear or you and a friend you will be in better shape.

In terms of keeping warm:

• make sure you have good moisture wicking breathable layers (no cotton)
• keep your head warm
• leave space in between those layers (so no super tight stuff). Just adding more layers won't help if there is no air to trap the warmth. Throwing on a jacket in your tighter sleeping bag won't necessarily be warmer just because both are warm,
• have a good sleeping PAD to insulate you from the ground (the higher the R value the warmer it will be)
• know that sleeping bag ratings are all over the place sometimes but generally expect something at the temp rating it is outside will be tolerable but might not be comfortable.
• Sea to Summit makes various sleeping bag liners including thermal ones to up the temp rating there might be others but StS makes really great stuff that I use and reccomend
• keep your head warm (not a typo I wrote it twice because people forget this and you lose a lot of heat through the head)

If you are van supported then take some extra stuff, If you don't need it maybe someone else might find it useful. If you are the type to get cold have a water bottle that you trust to be leak proof and fill it full of hot water and keep it in your bag.

If you really really get cold a 4 season mountaineering tent works nicely but you need to vent it or you will get condensation but I used a 2+lots of gear North Face solo in some snow near a stream and was quite warm without the benefit of the stove that others had. It was quite amazing. However is a heavy tent and very much overkill for most things. You could also add in a cot with a pad on top that is generally what I do for short trips or supported rides when carrying way too much crap doesn't matter as much. You and your pad are off the ground and more comfortable but most of that is generally my bad back.

1P tents suck, IMHO. For a few more ounces and 50 cm wider footprint you can sleep more comfortably , have room for gear and if you're stuck in the tent due to bad weather, you won't get claustrophobic.
The insulation value of a tent is close to zero so the warmth difference of 1 vs 2 man is almost non existent, condensation is another consideration.
Other than a suitable sleeping bag, be sure to have a suitable insulated pad with an R value of at least 3

No... Been just as cold in either one or two. But having room to stow all your ship in your tent with you is great. And of course in a two man you can get your nose a little farther away from your stinking boots too...

I prefer a larger 1P tent so I can keep my more important gear inside with me. This is largely to protect it from the weather, because rain seems to follow me wherever I go. I can keep my gear dry, pack or unpack it without it getting wet.

To help keep warm, I have a quilted top and bottom filled with down. These are very light, and can be rolled down into a very compact size.

You should do ok. Some tents are warmer than others, depends on the layout of the netting and venting in different wind conditions. I agree with the others, your insulation is much more important. A stocking cap is REALLY nice to have on a chilly night. If it is windy, all tents will not hold much warmth in them, size does not help much in wind to hold warmth. I pack my stocking cap with my sleeping bag, so they do not get separated.

If you start out biking on a 40 degree morning, do you have the right clothing? I like an insulated ear band but the helmet has to still fit over that insulation.

On a van supported trip, you might have lots of room one night and really crowded spaces the next.

Ground can be soft grassy soil and the next night packed gravel. And if it is really flat, make sure you did not pick the bowl shaped spot for your tent before the thunderstorm.

Photo is from the last van supported trip I did on a sub freezing morning.



I left my water bottles on my bike overnight, a mix of ice and water in the morning.

Thanks for the photo. It doesn't look sub freezing.

I just don’t get this whole “I have to store my gear inside my tent” thing. Every tent I’ve owned since the late 70s has had a vestibule that is more than adequate for gear storage. Roughly half of my load…the food cooking part…never comes within several meters of my tent to begin with. The rest of the stuff is just fine on the bike in water proof bags. The only thing in the vestibule is my helmet, water pack, and shoes.

Creepy crawly things like to get in my gear

For solo hiking and camping a Tarp has always been essential. And the packing and weight difference between a one man and two man tent was insignificant.

BUT DO NOTE: I have never Bicycle Toured. And I do regret it...

I just got back from touring on the Delta Heritage Trail in southeastern Arkansas and yet a couple nights got down into the upper 20's. (at least my water bottles didn't freeze this time) I like a 2 person tent so I can sleep at somewhat of an angle ensuring my toes and head don't touch the tent's walls as that's when I get really chilled. My 30 degree down bag keeps me comfortable at these temps but only if I wear some clothing to bed including my lightweight down jacket.

Didn't read the whole thread, but [MENTION=21724]cyccommute[/MENTION] has hit on the answer - heat transfer through walls is a function of temperature difference on either side of the wall, insulation value of the wall, and surface area where greater surface area allows more heat to pass through. Temperature difference is assumed to be the same when comparing two tents, as is insulation (R) value, so a larger tent has more surface area and will absolutely be harder to keep warm.

Theoretically a smaller tent can be warmer, all things being equal. All things are never equal in real life. You have a smaller space to warm up with your body heat, but of course you lose heat in al tents, so eventually it is probably a moot point. I do find my 1 person tent a bit warmer than my 3 person tent, but they have never been set up at the same time in the same place.

As others have said your pad, and bag will be more important than the size tent you choose. One issue than can occur with a 1 person tent in the cold, is more condensation building up inside, if it doesn't vent well, and I have found my 1 person tend doesn't seem to vent as well as my larger tent. Of course the larger tent is a 3 person tent.

I do use a one person tent quite a bit. I like it. It is larger than most 1 person tents though, and has four right angled corners so it isn't tapered at one end. As a result, I can bring in my bags if I want, though when bike touring I generally don't. On a motorcycle trip a couple years ago I took the one person tent and my hammock. I ended up using the tent, and was able to bring my large tank bag, and a 40 liter Ortleib duffle bag inside with me. As I said, the one person tent I have is a bit wider than most. It is an REI Passage 1 tent. I bought it on a whim when it was marked down, and I am glad I did. I really like it. It also has a vestibule where I can put things, keeping them out of the weather. The poles fit perfectly attached under the top tube of my LHT, so I can pack the tent smaller. It's a great little tent. They no longer offer it, but they have the Trailmade 1 tent which seems to be its replacement.

Get better bags

My concern is less with small creepy crawly things than large ursine things.

I’ve never carried a tarp and never found a need for one.

The weight and packing difference depends on the model. The Fly Creek UL1, for example weighs 2lb and has 5” x 18” pack size. A Fly Creek UL2 weigh 2.25 lb and has a pack size of 6” x 20”. The Copper Creek UL2 weighs 3 lbs with a similar pack size to the Fly Creek UL2. A Fly Creek UL1 bikepacking tent is 5” x 14” for a similar weight to the nonbikepacking UL1. When carried on the handlebars, the significantly shorter size makes the bikepacking tent a lot easier to carry.