Double ended inner tubes

[Si]

Topics on same subject merged

[De Sisti]

In order to eliminate any possibility of punctures, I’ve been using Tannus airless tyres on one of my winter road bikes for a few years, and I actually quite like them,

Do you need special rims?

[mjr]

Might be stating the blindingly obvious, you actually need 2, one on the bike and the spare.
Few years ago one if my CTC group punctured and was quite chuffed because he had one if these tubes as a spare until someone pointed out (we thought it unlikely he had bought 2!) if he had a standard tube on the bike then the wheel gad to come out anyway. He was quite deflated !

Err, don't you just cut the old one and pull it out?

[Manc33]

As a bodge in an emergency yes. Running them all the time... I wouldn't.

[Bmblbzzz]

The Gaadi bicycle tube, like most conventional tubes, is made from butyl and as such its weight when empty is the same as that of a standard tube.

But is it heavier when full of air?

[kylecycler]

The Gaadi bicycle tube, like most conventional tubes, is made from butyl and as such its weight when empty is the same as that of a standard tube.

But is it heavier when full of air?

Or even lighter!

[9494arnold]

Just had a thought on 'making your own'. The manufactured ones have, as has already been stated , have a pretty solid 'bung' at the flat bit.
But I could envisage a tube being cut, thoroughly cleaned inside (they use something like chalk in the manufacturing process to stop the tube fusing inside so that has to be got rid of ) and gluing flat. The idea being you overlap the 2 flat ends. Tube would be a bit shorter but tubes on the whole will stretch quite a bit, a 700c tube (provided it's not a super skinny one) will fill a 27" quite adequately. But not sure if there would be enough grip for it to work over a comparatively large area like that .

[Marcus Aurelius]

In order to eliminate any possibility of punctures, I’ve been using Tannus airless tyres on one of my winter road bikes for a few years, and I actually quite like them,

Do you need special rims?

No, just standard clinchers. You do need to be wary of the inner diameters of the rims though. Oddly, both the 23 and 28mm Tannus Aithers will fit in a 16mm inner width rim, but the 25mm Aithers need a minimum 17mm inner width.

[Brucey]

The Gaadi bicycle tube, like most conventional tubes, is made from butyl and as such its weight when empty is the same as that of a standard tube.

But is it heavier when full of air?

Or even lighter!

Tyres are indeed slightly heavier when they are full of air, and the higher the pressure the heavier they get. Air at STP is about 1.25g/l and a fattish tyre (~50mm section) holds about 4l of air. If it is inflated to 4bar (say) then it contains x5 this amount (one to fill it, the other four to pressurise it). This means you could have ~25g of air inside the tyre. A tyre half the width contains 1/4 the amount of air at the same pressure, or maybe 1/3 as much at the higher pressure required with the narrower tyre, so maybe in the region of 8g of air instead.

So if you were a complete pedant you would perhaps insist that wheelsets (with tyres) should only be weighed when inflated to the usual working pressures, else errors of ~5-20g may occur.

This isn't much but in the relentless quest for 'marginal gains' it hasn't stopped riders inflating tyres on track bikes using helium instead of boring old air, in order to shed a few grammes. Tyres so inflated are only suitable for short events though; Helium leaks out of tyres (by diffusion) rather quickly.

cheers

[KTHSullivan]

Just looking on the interweb for some inner tubes came across the above. Anyone ever used them? If so what was your opinion?

[[XAP]Bob]

I have one with me at all times for the ICE trike (the wind cheetah has all three wheels cantilevered, so no need to remove any wheel to deal with the fairy).

With the various things going on in the rear wheel I'd rather switch the tube out roadside (tying the "normal" tube to the chain stays for the remainder of the journey and then doing a proper repair in the warm and calm of home/work.

I didn't use it often (I can only recall using it once actually), but it was an absolute joy. I didn't leave it in there forever though - I can imaging the ends chafing somewhat whilst riding so replaced with a 'normal' tube later that day.

[Mr Tom]

Could have saved me a lot of pain on my Dutch bike

[rogerzilla]

I have patched a tube in situ when on a fixie without an axle nut spanner. This only really works in the dry.