Eclipse Road Tube 20/25mm

The Eclipse Road 20/25 Tube is not only a very cost-effective way of shedding grams from your bike, it also makes for a surprisingly compliant ride and palpably lower rolling resistance than a butyl tube when accelerating or climbing.

The tubes are made from thermoplastic polyurethane (TPU) and welded rather than bonded like some TPU tubes, which theoretically gives them an edge on the durability/longevity front. I've certainly been pleasantly surprised by their pressure retention and durability, and should they succumb to the dreaded hiss they can be repaired using dedicated patches – though I'd keep a butyl spare snoozing in the seat pack since the patches have a long curing time.

The Eclipses also pack down remarkably compactly compared with traditional butyl, which is another draw.

> Buy now: Eclipse Road Tube 20/25 for £21 from E.Dubied & Co

The patches, also made from TPU, are of the peel and stick genre, employing a polyurethane adhesive. They do demand that the affected area is surgically cleaned, ideally with an alcohol-based wipe, and left to cure overnight.

The removable 40mm valve stem permits extenders for deep-section aero rims; though 70mm options are listed on the website (for £1 more), they're currently out of stock.

I decided to pair the tubes to my arguably quaint road bike, built in 1991. This features a period-typical wheelset based around Mavic MA2 rims, running a set of 25mm Vee Rain Runner tyres which give a supple, grippy ride, although mine are becoming less resistant to flints and other sharps these days...

Fitting was very straightforward using my standard technique of inflating slightly to 15psi to avoid pinching, and feeding into the tyre. As the Eclipse felt a very snug fit, and light to the point of fragility, I was careful to double check the seating at various points of inflation, 60, 90 and 120psi – no issues with pinching or similar mischief.

From the outset I noticed an increased zip to the bike compared with the mid-range butyl tubes the Eclipses had replaced, most palpable when climbing or accelerating. And although there was no discernible difference in ride quality to other TPU models I've used, including Pirelli's SmarTubes (albeit in bigger section tyres), they felt smoother than decent quality butyl and latex – and without the latter's need for almost daily inflation. In fact, pressure retention is level pegging with premium quality butyl from the likes of Schwalbe and Michelin.

Over rougher tarmac the ride quality was similarly compliant, and I also noticed some improvement in my fatigue at the close of longer rides of 50-70 miles, compared with using butyl.

The rougher roads didn't induce any subtle rattling from the threadless valve stems either – another pleasant surprise.

Experimenting with the pressures a little during this period, between 100 and 125psi, had negligible impact upon ride quality or acceleration.

Around 200 miles into our test period – during which I'd deliberately whizzed through silty, gritty stuff with the odd bead of glass – and about 20 miles from home, I saw that one of the Rain Runners' casings had finally succumbed to fatigue and was beginning to peel away – ordinarily not great, but in this instance an ideal opportunity to test the tube's potential vulnerabilities... We made it home on time, no hiss.

After consigning the Rain Runner to landfill, I switched to a chunkier tyre – a 25mm Freedom ThickSlick Sport – which confirmed my hypothesis that the Eclipse's qualities were best appreciated with lightweight race rubber. Neither tube missed a beat in the following 250 miles – I've not punctured or noticed any structural weakness – but the sprightly, responsive properties were somewhat muffled; save for shaving a few grams, acceleration and climbing prowess felt little different than running a typical mid-range butyl.

Value

At £21 apiece, they're expensive compared with bog-standard butyl but pretty good value alongside other TPU tubes. Pirelli's P Zero SmartTube, for instance, which is available in road, mountain bike and gravel sizes, will set you back £27.99, and Schwalbe's Aerothan – also available in several sizes – is £24.99, and though it offers an excellent ride quality, our test suggests there are question marks over its repairability.

> Buyer’s Guide: 10 of the best inner tubes

Tubolito's Tubo Road inner tubes also come in various sizes, but at £27.99-£29.99 they're getting on for a tenner more than the Eclipse.

Conclusion

There's a lot to consider here. I've been suitably impressed by the Eclipses, which do offer some tangible performance benefits over traditional tubes. They are also competitively priced, by genre standards. I wouldn't say I'm universally converted to TPU, and will happily continue running butyl on my tourer and fixed gear winter/trainer, but for those with already feathery bikes who want some additional performance gains without massive outlay, these are a very good way to go about it.

Verdict

Very good cost-effective and seemingly durable upgrade for lighter wheelsets