Want to knock half a pound off the weight of your bike? The answer’s clear!

Lighter wheels mean faster acceleration, but if you haven’t got several hundred notes to spend on new hoops your options are limited. You can risk using lightweight tyres or tubes, which tend to explode the moment you so much as look at a sharp-edged rock, or you can go tubeless, with all the extra faffing that entails. Well, now there’s a third option – these amazing Eclipse inner tubes.

Made from a similar material to children’s paddling pools, they weigh next to nothing – just 69g for the trail-friendly 26 x 2.25in+ version. Compare that to upwards of 200g for a standard butyl tube or around 85g of tubeless sealant per tyre (and that’s not taking into account the weight of rim strips and tubeless-ready rubber) and things are looking rosy.

Eclipse reckon they’re more puncture-resistant than a standard tube too, and have lower rolling resistance. So, what’s the drawback? At €49 / £45 they’re far from cheap, but we reckon you’d struggle to find another way of saving this much weight for that amount of cash. And this is both rotating and unsuspended weight, which has a big effect on your bike’s handling. Check out the photos to find out more.

World's lightest inner tube? With weights starting at just 29g, we're not going to argue. Picture by James Costley-White

World’s lightest inner tube? With weights starting at just 29g, we’re not going to argue

Whatever type of riding floats your boat, Eclipse have a tube to fit. Picture by James Costley-White

Whatever type of riding floats your boat, Eclipse have a tube to fit

They pack down smaller than regular butyl tubes – this is the 1.5-2.25in 29er version. Picture by James Costley-White

They pack down smaller than regular butyl tubes – this is the 1.5-2.25in 29er version

These things are really quite weird to look at, but if you puncture it should be easy to locate the hole! Picture by James Costley-White

These things are really quite weird to look at, but if you puncture it should be easy to locate the hole!

They're less stretchy than regular butyl tubes but don't feel flimsy despite their low weight. Picture by James Costley-White

They’re less stretchy than regular butyl tubes but don’t feel flimsy despite their low weight

Normally if you can see this end of the valve things have gone badly wrong! Picture by James Costley-White

Normally if you can see this end of the valve things have gone badly wrong!

If you factor in the weight of a couple of spare tubes, a full set could reduce bike-and-rider weight by over 1lb. Picture by James Costley-White

If you factor in the weight of a couple of spare tubes, a full set could reduce bike-and-rider weight by over 1lb

The only caveat is that you can't use them with carbon rims, as heat build-up on long descents could cause them to burst. Picture by James Costley-White

The only caveat is that you can’t use them with carbon rims, as heat build-up on long descents could cause them to burst

Eclipse's tubes have beaten 400g butyl competitors in nail puncture tests but if you do get a flat, patch kits are available. Picture by James Costley-White

Eclipse’s tubes have beaten 400g butyl competitors in nail puncture tests but if you do get a flat, patch kits are available

The tubes are available from www.eclipse.ch / www.silverfish-uk.com (UK distributors). Head to BikeRadar for more info.