Bicycle Dual Inner Tube System




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How to fit a dual tube system to a bicycle wheel that will enable you to deal with a puncture without having to remove the the wheel or need any tools other than a pump until you get home. When you get a puncture the second inner tube is sitting right there in the tyre waiting to be inflated.

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Step 1: Drill Hole

Drill a hole in the rim of the wheel for the second valve stem at about 1/4 to 1/3 of the way around the rim from the original one. If your drill finds the going hard, start of with a small drill bit and gradually work up in size.

Step 2: Preparation

Completely empty the air from one inner tube (roll it up and squeeze). Pump just a little air in to the other inner tube, this will make fitting easier.

Step 3: Place One Side of the Tyre Over the Rim

Place one side of the tyre over the rim and then insert the flattened inner tube as straight as you can. Next insert the slightly inflated inner tube - push back the flattened inner tube to get the valve stem in place then, working from both sides of the valve stem fold the flattened inner tube under the slightly inflated one (as shown in the picture) as you work your way around the rim. It takes a bit of fiddling, I never claimed it was easy.

Step 4: Finishing Off

Fit the other half of the tyre and fully inflate the partially inflated inner tube.
Painting the valve cap of the flattened inner tube will make it easier to identify.

When you get a puncture - simply remove whatever caused it and fully deflate the tube. Then inflate the flattened tube and get yourself home. You may have to hold the valve stem of the punctured inner tube in place until the other is inflated enough to hold it there.

Things to consider - Drilling a hole in the rim will weaken it, ensure that the results of your drilling will be strong enough and avoid drilling directly opposite from the original hole creating a weakness accross the line of symetry.

see also -
For how to make your bike rust proof see

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    37 Discussions


    1 year ago

    I use a slightly less elaborate method of double tubing. It works pretty well for picture proofing. I take 2 Thorn resistant tubes, one for the air pressure, the other for additional armor. I gut the second time so I can wrap it around the first.

    The amount of Thorn and tacks I've pulled out without the inner tube getting penetrated is surprising. This works best with both tubes as Thorn resistant. I've tried with one standard and one Thorn res. It doesn't work as well. And also, tire thickness will determine how doable it is for you. I've been successful with 1.95 cm on 26"s.


    3 years ago

    I never would have thought of this, this is genius!

    Back in the '70s I used to mount a tire inside a tire to prevent punctures. Of course this added more weight to the bike, but at least I never had flats after doing it this way.

    Now times have changed, and bikes are lighter (especially Mountain bikes) so this dual tube idea is best while keeping the bike light-weight.

    Nice ible, Thanks! :D


    8 years ago on Introduction

    Great idea, I have done this in the past and it works to get you home. If you do decide to do this, make sure the valve holes are directly across from each other to maintain wheel balance.

    3 replies

    Reply 8 years ago on Introduction

    Unfortunately, almost all common rims currently available have the seam directly opposite the valve hole; drilling a hole precisely there would do most to compromise the rim. It's less of an issue with a steel rim, but the majority of common rims are aluminum i.e. the joint opposite the valve is pinned, rather than welded--as it is on a steel rim.

    An alternative to double-stuffing your tire with a second tube (and having to do the jiggery-pokery necessary to have the valve of the outer of the two come through any extra hole in the rim) is a variation on 'toughy tape': cut away the beads and most of the side-walls from both sides of a scrapped--even bald--tire of a size to just fit inside the tire you already have on the rim, and lay that in before installing the tube and closing things up by installing the second bead of the whole tire.

    The re-used tire's tread, in this case, is integral i.e. unbroken/uncut, at least along the center line. Choosing the proper size is important, though, as tires don't stretch much at all. If you're using 27" rims, choose a scrap tire from the 700 class. If you're using 700s, you'll almost certainly have to go with a much smaller width tire e.g. a 700x32C tire will need something like a 25C's carcass.

    Another consideration for the bead-removal operation is the extent to which the edge that remains is 'feathered'; if you angle the cutting strokes in such a way that the edge is tapered, it's much less likely that that edge will cause any grief to the tube.

    With this method, you are inserting an integral, second layer of fairly dense rubber between the tube (thin-walled, generally, and containing air under pressure) and the tread of the tire. Rubber cuts (or is most easily punctured) when it's wet, so having a layer of thick rubber, acquired costlessly, between the (possibly wet) tire and the under-pressure, thin-walled innertube means that anything that does get through the outside layer, will have also to pass through a fairly thick, almost-certainly-dry layer of rubber before reaching the vulnerable (but repairable) innertube. This arrangement should greatly reduce the likelihood of a flat, ceteris paribus.

    Obviously, the downside to this approach is that that liner will have a mass, that mass will be at the circumference of the wheel, and you'll, therefore, have to accelerate (and decelerate) that mass in perpetuo. There's no free lunch--but you knew that.


    Reply 8 years ago on Introduction

    Well there seems to be a bit of controversy on this subject. I guess the easiest solution would be to use a puncture resistant tire and a slime tube.


    Reply 8 years ago on Introduction

    Puncture-resistant tubes ('thorn-proof' tubes) have something to recommend them--not least being that they're a purpose-fit manufactured item. However, the benefits have to be weighed against the costs: they're more expensive than conventional tubes; they're a bit more difficult to install and remove, especially on good-quality/tight-fitting clinchers; and, the additional mass still does have to be accelerated and decelerated. Net gain, if any, is small over the use of a liner as described in my earlier post.

    As for slime, I don't recommend it, generally; I've found that its presence tends to make patching any eventual hole in the tube more difficult.


    8 years ago on Step 4

    i think This is a great idea! but what if a nail when completely thru both? i think a full proof system would be a dual inner tube system such as yours coupled with a seat belt lined on the inside inside of the tread. To me that sounds like an awesome peace of mind.


    9 years ago on Introduction

    whoa whoa the Plan B tire inflates itself around the valve of the initially inflated tire? Doesn't this raise the likelihood of a pinch flat, lead to uneven inflation, etc? This is a good idea, but there are kinks. Why not just patch it? The extra tube weighs about the same as a mini pump...


    9 years ago on Introduction

    Firstly, Excellent 'Ible' tyre redundancy :) genius!

    Although If you want to make your bike tyres almost close to invincible, line the inside of the tyre with the Seatbelt from a car, the weave is so tight on a car seatbelt (to pass safety requirements) that a thorn wont get through it, especially not a nail.
    unless you are breaking the sound barrier on your pushbike!

    I grew up in rural Australia where the thorns and Bindys are huge, and using a good quality thick inner tube and the seatbelt,  I only changed about 3 pushbike tyres in my life. 

    2 replies

    Reply 9 years ago on Introduction

    awesome idea when i find a scrapyard in my area and have the cash i will most definetley try this out on my old and new bikes. :)


    9 years ago on Introduction

    Great idea, how ever i just line my main tyres with another tire that is smooth like a road tyre, ive road over glass, pins nails and no punctures. Not only that, once you have 2 tires per rim, if you ever did get a puncture say from a snake bite, then when your flat you can still ride comfortably, i rode my bike with both tires flat on purpose to test it, when flat there still = to roughly 20 psi. Just takes patients to get them on the rim lol.. I ride 100's of miles a week though so its worth it.

    Not a bad idea..although i wouldn't drill a hole in my $200 rims...and my 3 ply downhill Maxxis tires work do my 3 ply Michelin X-Treme tires..haven't had a flat with them yet...and they ~sort of~ prevent pinch flats whare are the worst kind of flat... I also have extra thick tubes on my bikes...and knobby treads too :P if i had a cheap rim lying around i'd probbaly try it..but not on my $200 way in hell.. good idea though

    1 reply

    10 years ago on Step 4

    It would be a cool Idea to make a ready made doubletube. would be a killer at the expeditions. Great work mayte!

    I have some far better alternative but you may need to find alternative to these as i just so happened to work for my dad industrial tyre fitting for years and theres a product we sold under the name of bulletproof (belfast) made by polycil which is a ployurethane liquid pumped in to tyres that makes them ride like pneumatic but completely invincible (the tyre casing can come off and you'll still get home). If you plan to attempt this one yourself with makeshift equipment please message or comment me it's dangerous like dead dangers. Another interesting option is closed cell foam filling, it's cheaper and lighter and is well proven for less brutal applications like wheel chair and shopmobility tyres, no idea how the pressures work with it. For a puncture sealant I suggest going to an industrial tyre place and ask about the black slime puncture sealant, its like the gooey stuff some bike use except it works and keeps the tyres really well balanced, I have seen this stop massive holes and seal a bolt onto the tyre because it was still in it

    3 replies

    the green slime you can get at walmart work wonderfully! I like to ride my bike through forested terrain and no trail riding which would have been impossible without the slime. You can tell that it works when you notice a lower pressure in the tire when you get home but its not flat. just add some more air and its good to go for next jaunt. I ran over some barb wire and it punctured my tire but the slime performed superbly. There is also a orange colored slime but I don't think it works as well.

    There's a similar white stuff meant for cars that comes in spray cans. It saved me today. I got two flats in five minutes, can you believe it? Nasty thorns! The only thing that I can complain about was all that white foam spraying me and my bike.

    Eh the green slime is ok, this balck stuff I speak of is unholy though, it's like witchcraft... also I still have a bulletproof bike tire sitting here... The green one is decent but the orange one is a simple waste or money...