Tarp Tent, how would you have it?

[Ray Young]

If you were to design a tarp tent for your own use what criteria would be important to you? I am thinking of making one and would like suggestions as to what you think is needed and what is not. It's for bikepacking so it needs to be reasonably light. Should I go for a side entrance or front like in a hooped bivi, how high should it be, should I use the bike instead of poles, ventilation slots or the sides raised off the ground etc, you get the general idea. I look forward to your ideas and input.

[Bearbonesnorm]

I would require the following things, most of which are already incorporated in some tarptent designs.

1/ Enough headroom to sit up.
2/ Must be midge proof.
3/ Set up with single pole, tied off to tree or bike.
4/ Minimise the amount of pegs required - 6 should do it.
5/ High and low vents to minimise condensation issues.
6/ Fully weatherproof, so a sewn in bathtub groundsheet ... although it could be 'floating'.
7/ Some out of the rain storage/cooking room.
8/ 800g(ish).

The simplest form of tarptent I can really imagine (doesn't meet the above criteria) would be a 2.5 x 2m A frame tarp with a groundsheet joined to it by midge netting, which would also form the door/end.

[gairym]

I struggle with this as if I'm thinking about what characteristics I'd like 'the' tarp-tent to have then I come up with a list along the same lines as Stuart's but, once I look at the associated fabrics, costs and weights that this tarp-tent would need I end up thinking that my existing tent (the SMD 'Skyscape Scout') already ticks all of those boxes.

My tent comes in at just under 1000g (excluding poles and pegs) and wasn't expensive and so, for me, a tarp-tent might need to be more of a compromise between a tarp and a tent than most peoples version of the ideal.

I'd most likely want to use a bivi bag with a tarp-tent unless it was 100% waterproof and so given the added weight of the bivi bag there's no solution I can think of that comes in lighter (without heading towards cuben) than my semi-cheap tent.

Maybe I need something more like what you've already created - a more rain friendly tarp to increase comfort whilst in it but without heading down the road of a midge net and bathtub flooring etc...

It's a tricksy one for sure and I'll be a happy man when I find the perfect solution.

[Chew]

Tarp/bivi setups are very versatile, as reguards to pitching options, more connected with the outdoors, but can be a bit miserable in poor weather.
Tents give you more protection from the elements, but you only have a single option pitching wise.

A Tarp Tent, should bring together the best of both worlds and be a more versatile solution. In effect you're making a more versatile tent.

Dont think a perfect solution exists from the 'i'm a tentaholic' tread :?

[Ray Young]

Well i've been having a think, been looking at the bike and done a design sketch of an idea I like. I am going to have the bike upside down with the front wheel still in the fork, the tarp will be set up at a 90 degree angle to the frame, the rear wheel will be removed to use at the bottom end of the tarp. Doing it this way will give a sloping design with plenty of height and width at one end. It will have sloping sides to give storage space and a side entry for ease of access . The entry will be on the other side to that pictured so the bike doesn't get in the way of the views when it's open or even one on both sides to take into account the prevailing wind. A full height, half length, tie in bug net that hangs to the ground is also an idea. At the moment I am not sure how close to the ground I will bring the tarp, I want to make a model so I can see how much material will be involved (my maths isn't up to doing it any other way and it will give me an idea to shapes) as I still want to keep it light.
Hope it makes sense.

2005_0202sketch0001 by youngray50, on Flickr
Only doing this as there's no sign of cushion cover material yet .

[Ray Young]

After having made a model with graph paper and doing sums :? till my brain hurt :x I have come to the following conclusions :
Max height 105cm, more than enough.
Width with average flare 60cm at head height, 130cm at the floor, plenty
Internal space with average flare 3m square, looking good.
Tarp area 6m square including beaks.
Weight 600-900g without guys depending on the material used.
I think that this could be a goer as it's roomy and a bit more weathertight than an A frame. Also there are no complicated shapes and I like the fact that the rounded ridgeline does not encroach into headspace like an A frame does.

[Chew]

Couple of things from my own experience, you may want to consider, is that your pitching point from the top if the wheel is not above the load points of the bike (wheels & bars) so it can be quite unstable, due to leaverage. Also the wheel wants to spin which doesn't help either.

[Bearbonesnorm]

Few random thoughts Ray (sorry).

You'll have quite an expanse of unsupported nylon on the non door side ... might be worth adding a mid-point tie-out along it for an additional guy. Also adding a slight curve to the bottom edge will make it pitch much tighter than a straight edge allows.

Where your foot end guys are (all 3 are low) there's nothing to stop the supporting wheel falling inwards. Have you thought about adding some velcro straps to the inside to hold the shelter to the wheel and adding another guy point at the apex? ... It could be a shared line with the bottom, central point?

And just to throw a spanner in ... Have you thought about making it symetrical and using both wheels detached from the bike? I reckon it'd make producing it much easier and should make for a much more stable shelter although you'll obviously lose some headroom.

[Ray Young]

Hi both, I am going to add tie points underneath the tarp to tie to the wheels, this coupled with three guylines each end should I believe sort out stability/wheelspin. I'll test the stability out first though without sewing anything if you think it might pose a problem. If wheelspin is a problem then I could use a strap (which i'll be carrying anyway) around the brake lever to lock it on. Mid guy points are on the list and shared lines are a good idea, I used to have a one man tent with them and the thing never budged in any conditions. The reason i'm going for the wheel in fork design is so I get good headroom, just using the wheels would as you say lose that. Thanks for the advice, it's all a big learning curve :D .

[Ray Young]

Couple of things from my own experience, you may want to consider, is that your pitching point from the top if the wheel is not above the load points of the bike (wheels & bars) so it can be quite unstable, due to leaverage. Also the wheel wants to spin which doesn't help either.

Hi Chew, yes your right, it is too unstable so scrapping this idea. It also needed too much material if it was to come all the way to the ground.

Have you thought about making it symetrical and using both wheels detached from the bike? I reckon it'd make producing it much easier and should make for a much more stable shelter although you'll obviously lose some headroom.

Hi Stu, begining to like this idea, add a pole (I know it's extra weight) to get the height for sitting under.
Question, what material would you suggest for the floor?

[Bearbonesnorm]

Question, what material would you suggest for the floor?

If you want to keep the weight down I'd go with silnylon rather than PU coated or Polyester. 50gsm is possible but it won't leave much margin for wear and tear. Much of the US stuff is 1.1oz which is just over 30g but it's quite fragile. 80gsm would be fine but you could push that up to 120gsm to make it more robust without adding too much weight.

[Mike]

Your sketch is the kinda setup i use most of the time with my siltarp, if u use a bit of old inner tube on the brake levers it will stop them from spinning and ive found if u peg the big away from the tarp it holds up :0)
this i will be my prefered bivy cover this weekend along side my new bivy bag

[Ray Young]

As you can probably tell by the following i've had a bit of time on my hands today. After Stu mentioned using the wheels out of the frame I initially dismissed the idea because I would not have enough room to sit up but then it occured to me to add a 1m pole giving me the height I wanted (worth the weight of the pole if you ask me). At this stage i'm not sure if i'm going to add a sewn in floor, if I do then I would need to add some bits at the sides to stop rain getting in and forming puddles when the front is open. The walls flare out slightly from the widest points on the wheels giving a 1x2.5m floorspace. The wheels will sit outside of each end to keep mud/sheep pooh at bay and each end will have some sort of rainproof ventilation to help with condensation. Without the floor the material needed would be 2x2.5m, with floor 3x2.5m plus whatever is needed for the ends (can't do Pi so i'll have to count the squares ).






You can see the gaps at the sides that will need filling if I go for a floor. Thanks for the initial idea Stu and like you say, a much lower profile.

[sillybigfella]

Loving the pictures. Just like those old Open University programs that used to be on at one in the morning.

[Ray Young]

Whilst the wife's away ~

and out of shot on the table are several empty beer bottles and a new OS 1:50,000 map showing the Lammermuir Hills amongst other things 8-) .

[Bearbonesnorm]

What are the big holes for Ray ?

[Ray Young]

Ventilation.
Extend the roof over the wheels and peg out at 45 degrees. This gives 2 covered storage areas allowing me to reduce the length of the tarp by 400cm because i don't need to keep everything inside. This in turn reduces overall area (less bowing in strong winds), improves aerodynamics and allows large covered ventilation holes.

[Bearbonesnorm]

Top job ... makes perfect sense.

[Zippy]

Put some holes in the top of it to stop the wind whipping it away and also get a nice view of the sky


'll get my coat

[pushbikemike]

Ventilation.
Extend the roof over the wheels and peg out at 45 degrees. This gives 2 covered storage areas allowing me to reduce the length of the tarp by 400cm because i don't need to keep everything inside. This in turn reduces overall area (less bowing in strong winds), improves aerodynamics and allows large covered ventilation holes.

Will you put midge proof mesh on them there ventilation holes?

[Ray Young]

Fully midge proof is the order of the day. How ya doin Mike? We'll need to get out again sometime.

[pushbikemike]

Fully midge proof is the order of the day. How ya doin Mike? We'll need to get out again sometime.

Sounds good. Looking forward to seeing the finished product. I'm heading out for a local overnight bivi tonight. Got some time off last week in march and looking to do a 3 day trip somewhere. You free around then?

[Ray Young]

[quote="pushbikemike"You free around then?[/quote]
Not sure at the moment, will keep in touch.

[Ray Young]

Taking shape. It is far roomier than I expected so I may just make covers for vent holes and tie out the ends on guys, undecided yet. Still lots to do and hope to finish it by sunday. Curves add difficulty and frustration, some of the seams are rather untidy but still functional.

[99percentchimp]

Ray - that looks excellent.
I don't think you'd need to make the vent 'covers' to big. I have a Hilleberg Akto and the vents at both ends are covered by about 10cm of overhang on the fly (the end walls slope inward though and are close to the ground). Plenty of ventilation from hole about half the sze of yours but these will be combined with the vented entrance too.
Is is sized for 26" or 29" wheels? Did you cut the length to pretty much suit your own height (plus a bit!)
When do the production runs begin? :)