PIRELLI CENTURATO REINFORCED SMART TUBE
68g 700x28-35 (as tested) £27.99
The Pirelli Cinturato Reinforced Smart Tube is the slightly beefier sibling in the family. The bigger section lends itself to touring, cyclo cross, Audax and sportives. General off-season duties, too, for that matter, given the superior puncture resistance and weight advantage, compared with butyl. However, more care is required when fitting and the price may be another turn-off.
Pros: all-rounder, weight and puncture resistance advantages.
Cons: expensive compared to others, needs careful fitting.
These are made from Thermoplastic polyurethane-TPU for short. TPU is used for many inflatable products, including pack rafts but only recently embraced by the cycling industry- Schwalbe’s Aerothan being another example springing to mind. In its raw state, TPU is stronger than butyl, so can be made thinner and consequently, lighter.
To my knowledge, the lightest butyl tube is Continental’s Supersonic, weighing a mere 50g but is only available in 20-25mm. Talking of size, there is also a gravel and 650b version for bigger section (33-45mm and 40-45mm) rubber. Interestingly, the latter is reputedly 45g.
The valve stem comes in any length you like., so long as its 60mm, which may look a little giraffe-like on a traditional rim, such as my fixed gear winter/trainer’s Mavic Open Pro but then I’m not known for getting too excited about these things and it’s a sound choice, given the move toward deeper sections.
Those needing greater length will need to go the valve extender route. The other consideration is patching. In the event of flatting, you’ll need a dedicated repair kit- that butyl patch kit won’t save the day. Oh, and curing times are reckoned about the 30minute mark, so patch and switch to another tube, by the road, or trail. Not that I’ve succumbed in 600 miles testing, but best to invest at the time of purchase.
For the most part, this is little different to a humble, common, or garden butyl but take extra care to avoid running the risk of pinch-flatting. Inflate very slightly, then ease inside the tyre casing. I’ve had no problems with these 32mm Bontrager, the 35mm Schwalbe Marathon GT and indeed, the 32mm Kenda Kwick Journey KS Plus.
Admittedly, the Schwalbe and Kenda wouldn’t be the most obvious choices, given their weight and design brief but they were close comparators, section-wise. I used a single, composite lever when coaxing the final sections home and double-checked seating before getting busy with the floor pump.
Ride Quality 4/5
Given you can buy a bargain butyl for £3, I was expecting some discernible difference for nigh on £28. Credit where its due, there was. Aside from saving a few grams, ride quality felt smoother at the upper and lower pressure range, which was particularly welcome along the quiet but decidedly washboard tarmac, adding some additional fatigue busting refinement to an already compliant, yet frisky bike. As a guide, I’ve run ours between 95 and 60psi. Predictably, things were more compliant at the lower end but either way, I’ve enjoyed the compliance without giving things such as riding style a second thought. There’s been some additional, rewarding zing when accelerating along a sudden climb, or pulling away from the lights.
Puncture Resistance & Pressure Retention 3.75/5
I wasn’t sure what to expect initially but again, having got past the “new component” syndrome and concentrated on racking up the miles, I’ve been pleasantly surprised. Though generally durable, the bike’s Bontrager AW3 Hard Case Lite, succumbed to a metal shard along a very wet, greasy road a few months previously. Farmers had been paving the pock-marked sections with dung, which is not only slippery and smelly but a sharp magnet. Bottom line, no flats in over 500 miles- I’ve stayed on course through shards of broken indicator lens, thorns and similar detritus too see if they could cause mischief but thankfully, no.
I’ve run latex in the past, with middling results. Excellent puncture resistance and low weight has been somewhat tempered by the need to re-inflate tyres every other day-even with bikes hung from the garage rafters/ceiling. Pressure retention has been equal to that of bog-standard butyl. I’ve checked every 7 days but having switched to Ursula for a couple of weeks, when I came to check the fixed’s pressure it had lost 7psi, which isn’t something most of us will lose sleep over.
There’s no getting away from the fact that £28 is a lot to shell out on a tube. However, performance to weight and cost analysis means they’re cost effective compared with the weight savings achieved from a lighter set of wheels. That is the point, riders looking to this end of the market will want every, last performance gain from their new, higher end wheelset. Four seasons working/winter bikes are best served with a tyre upgrade. These factors in mind, £28 is still comparable with rivals, although being pedantic, at £25, the Schwalbe are a few quid cheaper.
I’ve been pleasantly surprised by the Pirelli Cinturato Reinforced Smart Tube, which has proven reliable and added some other, minor performance gains. Personally, and on balance, traditional butyl tubes still represent best value for my riding needs. Some riders may feel switching to tubeless systems a better investment and I can see that argument. That said; if you weren’t looking to take that route and wanted optimal gains from a high end wheelset, the Pirelli Cinturato Reinforced Smart Tube is worth a closer look.