rmchambli

Hey! I'm currently building a rear bike rack using aluminum tent poles, that will serve a dual purpose as both luggage carrier and tent support for my ultralight trekking-pole tent. My goal is to reliably carry 8-10 lbs of gear on it, as well as make the poles easily removable for setting up the tent. I haven't seen any other folks trying this, so I figured I would ask the community about making this thing more functional.

Turns out I can't add pictures yet

andrewclaus

One failure causes multiple problems. If you break a tent pole, which happens, you have a hard time loading your gear. If you break your rack, which happens, you have a hard time pitching your tent. It's a valid UL goal for stuff to serve multiple uses, like my sleeping pad is my pack frame, some use a poncho as a sleeping tarp, a hiking pole is a tent pole or splint, a bandanna can be a bandage, sling, water pre-filter, etc. But I'd be concerned about a structural failure in this case.

jvt

I have though about something similar, but settled on one if two options:

1. Ultralight single pole tent
2. A tarp configured to hang from the bike.

I'm currently leaning towards option 1, and using half a fishing rod as the tent pole. Although, to be honest, the single tent pole is pretty light and the tents pack down well.

Goal is a full week long setup in a comfortable 5kgs.

rumrunn6

impressive goal!

djb

Perfectly adequate, inexpensive aluminum rear racks are available that will work perfectly for the light weight you want to carry.
Doesn't make any sense to compromise both uses.
from a totally practical side, you're just increasing the risk of losing a mounting bolt etc from repeated "on and off" and that's not even touching on the structural angle of trying to make a rack out of tent pokes.

saddlesores

might be good reasons for that.

daily removal/attachment of rack legs/bars means lotsa wear-n-tear on the mounting bits.
a bad oopsie dropping your bike today could mean your tent won't go up tonight.
a bad oopsie tripping over your tent tonight could mean you can't carry your stuff out tomorrow.
setting up camp for a couple days means you don't have a rear rack without breaking camp.

how 'bout one of these puppies? 10 ounce carbon fiber rack.
https://www.tailfin.cc/product/panni...s/carbon-rack/

staehpj1

I'd have to see it before I'd be so quick to dismiss it. If the "rack" is a regular rack using the poles I have a hard time imagining it making much sense, but as I said I'd have to see it. If the poles are more like stiffeners to support a cantilevered bag off the back of the seat post or something I can imagine it more easily. Can you post a link to photos shared from a photo sharing site?

John N

Cool concept but I would be very concerned about the poles breaking if these are regular tent poles. Then you are royally screwed. When you get it made, be sure to post pics.

Happy Feet

I would like to see the design idea too.

Someone mentioned using the bike as a pole. I did this (sort of) one trip as an experiment.

I used a cheap Canadian Tire 2 man tent ($29) and an A frame fly I've had for years. The original fly for the cheap tent did not provide very good rain cover.
I used my bike as support on one end and tied the tarp off to a tree etc on the other. In reality the hoops of the inner tent held the fly up but, if I were to use a bivi instead of the tent, the system would have worked well by either typing the opposite end off to a tree or using a single pole (extending nordic walking stick).

One thing I liked about this setup was being able to see my bike at night clearly through the mesh of the inner tent.

staehpj1

We just don't know enough to say. Poles are not a high breakage item in my experience though and splinting them or improvising something to limp through may not be too hard in either function. It just depends. Some tents can be pitched easily with the bike on one end and some stationary object on the other in a pinch, some not. Depending on what he has in mind for the rack vulnerability to breakage and ability to patch and go may both be widely variable.

One thing I have found is that you can pretty much always find a way to limp along to the next place where you can get a proper solution.

Tourist in MSN

I think a good rack needs to be a single purpose device. It needs to be stiff, not have a bad resonance that could cause bike shimmy, is strong, ideally be light weight, and be able to suffer a lot of abuse. After you crash with a load on the rack, it still needs to be just as good as new instead of being bent or in pieces.

I understand the concept of wanting to use trekking pole tents, I have a few and use one for bike touring. Trekking poles do not pack well on a bike so I cut my own poles for that tent. I cut the segments short enough that they fold up and are short enough to fit in my front panniers.

I also used the same tent poles to make a substitute for a click stand, short enough when folded to fit in my handlebar bag. That was my first project in buying a cheap tent pole and cutting to length for a purpose.

I bought some long tent poles on Ebay shipped from Asia, used those to cut my pieces for my bike stand and my trekking pole tents. Calculated how many segments I needed and the lengths to cut them. And also bought some trekking pole rubber tips for the ends of the poles. Initially started with 11mm poles, but decided later that smaller diameter ones also work.

John N

I guess I have seen too many tents with broken (or split) poles. When I read the OP originally, I immediately thought of side to side sway and then _IF_ the rack/pole does break, it could easily get caught in the spokes doing even more damage much. Again, I think the concept is cool. I just would want to see it in use in real world conditions before I got one. Then you would have to have tent makers make a tent based on the pole sizes/lengths.

zandoval 

Worthy Task... But I think you need to prioritize. Think rack that can be used as tent poles and not tent poles used as rack. Even my old heavy steal rack on my Western Flyer was subject to breakage. I do think that a sturdy, proven rack that could brake down into tent poles could have a place.

I love little projects like this, they keep the mind ticking. Consider 3D printing your connection rods???

https://www.thingiverse.com/thing:293830

staehpj1

He did say he is talking about 8-10 pounds so I thought he may be thinking about something less than a regular rack. Maybe supports for a seat bag?

I remember that mostly from the figerglass poles from cheap tents from years ago. I have not seen a pole fail in ages.

So again it depends. If he is talking about making a typical rack and using the pole to replace the uprights and have them do double duty, then yeah, probably a bad idea.

For 8-10 pounds of stuff seat bags with no rack are a decent answer. I have also used those tiny Sunlite racks that mount to canti bosses with no legs for loads like that. They are meant as front racks, but work on the back. I have improvised mounting with p-clamps when there were no canti bosses.

Tourist in MSN

Yeah, I saw that too. But I usually start out in the morning with between 6 and 7 pounds of water on my bike, when someone says they want to carry 8 to 10, I question how realistic that is.

With your history of ultra light weight, I would trust you to have only that much, but I don't buy that from a lot of others that say that.

A saddle bag with no rack should handle that much weight without any problem.

staehpj1

Well there is that, but I tend to take thing at face value most of the time. In any case I hope we get more details and some pictures eventually. So often we get a question like this and never hear anything back when more details are required or we would like to know how they made out.

Pratt

What is the capacity of those racks that attach to just the seat tube?
My non-ultralight load is about 40 lb including stove, cookware, and some food. I could easily reduce the weight by 10 lb if I made cold camps, if I only ate in restaurants, or from markets, another couple of pounds. If I credit card it, another 6-8 lbs of tent, sbag, mattress, etc.

John N

I saw a Big Agnes tent (a super-light version) and a MSR Hubba Hubba each with a broken pole this summer. To me, I don't think poles are as durable as they used to be as everyone races to the bottom saving weight. I am all for weight reduction if durability can be continued. In my opinion, new tents are just not very durable anymore. I would prefer a slightly heavier tent that had material that held up, a la the original BA Seedhouse.

staehpj1

You have a point about lighter poles meaning less durability and that would tend to increase the likelyhood of issues. That said, I am pretty careful about choosing sites with a bit of shelter when winds are likely and have been using bivies much of the time lately so I figure issues are unlikely even when I do use a tent. Still I don't remember the last time I had a broken tent pole. It might have been 50 years ago. None of my family members have had any broken tent poles that I know of either.

I did have a close call on the TA with a big cheap tent when unexpected winds suddenly kicked up, but we quickly knocked it down and moved it to where there was a bit of shelter.

There were probably people in camp where I was that I either didn't pay attention to or forgot about though.

Miele Man

I have one I bought from Canadian Tire and that seatpost mounted rack is rated for 20 pounds (9 Kg). I have an Axion Trunk bag that I use with it.

Cheers

rmchambli

Link to photos of the rack 'concept', as it stands now: flic.kr/ps/3XSrSG (Bike Forums has a strange limitation on posting URLs)

I realize that these tent poles are pretty weak, and I would not trust them much even for the trekking pole-style tent. They were handy, and actually were split at the ends already from use with a free-standing tent. Before I take this on any real adventure, I plan to replace them with more robust aluminum poles, or perhaps carbon fiber.

The key issues I have right now are
1) Securing the rack to the bottom eyelets, by the axle
2) Side-to-side stability, though perhaps this isn't much of a problem with little weight.

Rubberized suspension clamps seem like a good way to go for attaching poles to the frame.

I have already installed a couple of those on the eyelets next to the seat post, and they seem to be holding well. Ideally, I could loosen up the mounting screws just a few turns and slide the pole out.

indyfabz

The BF limitations on posting photos and links is aimed at cutting down on spam. It works well.

And imagine 10 bags of pasta swaying side to side while you ride.

djb

Interesting concept idea here that is fine on paper, but in real life, it just ain't gonna cut it--or certainly not worth the time and risk of problems while on the road. Problems of which there are a few, as has been mentioned.

A $15 perfectly fine aluminum rear rack will be secure, easily carry credit card minimum stuff and you can use p clamps if your bike doesn't have eyelets. And you can put heavy grease, wax or loctite on the bolts and they won't loosen.

but hey, have fun experimenting if you want, just be aware that this idea doesn't get used for a reason.

staehpj1

Having seen it, I wouldn't advise it for the reasons folks have already mentioned. If you do try to go ahead, my suggestion is to keep the cargo limited to a small area just behind the seat post, for a very short rack. I am thinking the horizontal pole sections should be no more than half as long and maybe less. That might keep it a bit more rigid, stress the poles less, sway less, and limit the ability to overload it. It does raise the question of whether it has any advantage over just using a saddle bag and strapping the poles to the top tube.

I will add that I have used the little Sunlite racks that are only 9" long and found that you can get more gear on them that you might guess. I think your rack could be a little longer than the Sunlite. If you have a decent sized bar roll on the front you could carry a reasonable amount of gear for an UL traveller.

Looking at the pictures it looks like you have a joint in the tube above the dropout. Is there anything to prevent it from bouncing and coming apart on a rough road?

Prowler 

+1. Many designs will work under ideal conditions. It's the unexpected that will "git ya". Anticipate the unexpected - rough roads, gravel roads, no roads, severe weather and wipping winds, heavier loads than planned, bike falling over torquing the rack to one side, etc. Consider the impact of hours of vibration or lateral sway on the rack. Many stresses are upwards or sideways, not just downwards.

And be be sure the design delivers BOTH a reliable rack and reliable tent poles. Consider the loads and stresses on a tent in a storm or when your stumble and fall onto the tent at a campground. I assume you know that all alloy tent poles are not the same. Use the BEST pole stock you can find and the best splice material/design if you move ahead with this idea.