We just spotted these from Eclipse, the big Swiss cheeses of all things tubeless are bringing out an inner-tube. How odd. But not just any old inner-tube, seven years in development and the world’s lightest bicycle inner tube apparently. The tubes are made from a special plastic so if you do get a puncture you’ll need to repair it with one of the special Eclipse adhesive patches.
Not only are these tubes the lightest but they also pass and exceed the DIN PLUS Test. Did you know there was a test for inner-tubes? We didn’t (some people around here did. Honest - ed). Anyway, the DIN PLUS Test checks for nail resistance, snake bite avoidance and rolling resistance, so that’s reassuring.
The 700Cx18-25 tube has a claimed weight of 29g, which is a fraction of the weight of any of the random road tubes we pulled out the pile which range from 71g for the ones that feel a bit thin and nervously light to a more sturdy 108g for the more everyday tubes. A quick look at weight-weenie websites suggests that butyl tubes out there listed as ‘flyweight’ heft in at a mighty 50-60g, so there’s quite some weight saving to be had with these Eclipse ones, relatively speaking.
The downside to this, of course there’s a downside, is that a tube costs 65 Euros which is, um, quite a lot, assuming that their website is correct and this is the price for one and not a box of ten. At that sort of money we're not sure who these are aimed at. A tube for the cost of a nice tubular tyre or two clinchers is going to be tough to sell, so maybe the light weight and claimed lower rolling resistance will get your clincher tyres close to the silky feel of a tub without the need to buy a new wheelset and entering the scary dark world of glueing tubs. Or maybe as Eclipse are tubeless this will offer you the puncture-shy, smooth-rolling benefits of tubeless but without the fiddle and mess of fitting and the need for dedicated wheels and tyres, or maybe it's simply just for serious weight-weenies. Whatever, for that price we'd expect to feel some definite speed, feel, and deflation-free improvements, and maybe for the the tubes to make us a cup of tea at the end of a ride.
The tubes are available in the following popular sizes: 20”x1.5-2.125, 24”x1.5-2.25, 26”x1.5-2.25, 26”x2.25-2.6, 700Cx18-25, 700Cx28-45 and 29”x1.5-2.25.
We’ve had previous experience with super-light inner-tubes that needed special patches to mend, which is why we don't use them any more, so it will be interesting to see how these behave. We'll see if we can steal some to play with, 'cos we ain't paying.