Bicycle Dual Inner Tube System

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Introduction: Bicycle Dual Inner Tube System

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.

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.

Outro:
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
http://chrisblogforever.blogspot.com/2006/06/no-rust.html

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    37 Comments

    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.

    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

    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.

    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.

    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.

    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.

    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.

    whoa whoa who...so 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...

    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. 

    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. :)