VeloClub is CyclingTips’ membership program which brings us closer to our members, and connects likeminded cycling enthusiasts.
by Matt de Neef
November 15, 2013
TECH NEWS BROUGHT TO YOU BY BIKEEXCHANGE
The road tubeless tyre market has grown since Wade tested Hutchinson’s Fusion 2 tyres in 2009. Hutchinson now offers three tubeless models for the road, while other companies such as Bontrager and Maxxis have recently added tubeless tyres to their range. At the same time, the number of tubeless-ready or -compatible wheelsets has grown considerably and now includes a few carbon wheelsets. The new format may still be in its infancy, but it is poised for mainstream use.
There are at least three good reasons to consider tubeless tyres: first, they are more resistant to pinch flats and punctures; second, the absence of an inner tube promises to reduce weight and improve rolling resistance; and third, tubeless tyres perform better at lower air pressures. Such benefits are ideal for off-road use and some have argued that the format is well suited for on-road use too.
So is there any evidence that tubeless road tyres are an improvement over standard clinchers?
At the moment, there is little data on the rolling resistance (Crr) of tubeless tyres, though Al Morrison’s data set from 2010 placed IRC’s Formula Pro tubeless tyre in the top 20 (Crr=0.00260 versus 0.00220 for the fastest tyre, a Vittoria track tubular) while Hutchinson’s Fusion 2 tyre was well down the list (Crr=0.00331). Thus, the absence of an inner tube does not guarantee low rolling resistance, though I’m sure installing a tube in either tyre would increase its rolling resistance.
The other benefits of tubeless tyres remain to be proven on the road and their relevance may depend on the rider’s needs. Among the negatives are the extra time and effort required to mount, seat and inflate tubeless tyres along with a restricted range of tyre choices.
New tubeless tyres are appearing on the market though. Schwalbe recently introduced a tubeless version of their Ultremo ZX tyres and they claim it is both the fastest and safest tyre they’ve ever made. The tyres are supplied in a kit that includes two 23mm tyres, 60mL of sealant, and a bottle of “Easy Fit” to help seat the tyres on the rim, all for a recommended retail of $169.
There are actually two types of tubeless tyre systems on the market. The first is the UST system patented by Mavic that comprises a purpose-built rim and UST-compatible tyres. This system is designed to work without a sealant.
In contrast, the second system depends upon a sealant, but it can be used with essentially any road rim/wheel on the market. Stan’s No Tubes pioneered this system, which utilises airtight tape to seal the rim and serve as a bed for the tyre. Converting a wheelset for tubeless use is both simple and cheap (expect to pay around $60 for a roll of Stan’s tape and a pair of tubeless valve stems) however some conversions are easier than others and extra time and sealant may be required to properly seal a tyre.
For this review, I used Stan’s rim tape and valve stems in combination with their Alpha 340 rims. The Alpha 340 rims employ Stan’s so-called Bead Socket Technology that is well suited for tubeless conversion. Indeed, the shape of the rim bed vaguely resembles Mavic’s UST design with pronounced humps butting up against the sidewalls of the rim.
Some tubeless tyres are notoriously difficult to mount but I found the Ultremo ZX tubeless tyres easy to install. Once I added the sealant to the tyres (30ml/tyre), I was able to inflate the tyres with a standard floor pump, though it required more time and effort than a standard clincher. An air compressor would definitely ease this process, as would a second set of hands to help with seating the tyre. Schwalbe’s “Easy Fit” was invaluable in this regard — it is a detergent solution that is applied to the sidewalls to help the tyre pop into place during inflation.
There wasn’t much mess associated with installing the tyres, and removing them wasn’t too messy either, once the sealant was mopped up. Tubeless proponents argue that should any puncture defeat the sealant, then a standard tube can be installed. However without a handy rag to take care of the sealant, this wouldn’t be a pleasant job for the side of the road.
The first thing I noticed about the Ultremo ZX’s was the quiet. They make no noise at all. They were also very stiff and provide a mildly dead ride that I normally associate with a robust training tyre rather than a racing tyre.
I found that 80psi was the sweet spot. Higher pressures made for a harsher ride while lower pressures slowed the wheels, though improved road feel. 80psi may seem low, however the Alpha 340 rims function like wide rims and require lower pressures. Indeed, I normally inflate Continental GP4000s tyres to 80psi on the same wheels.
I enjoyed the extra confidence that the stiff casing provided and took to dirt roads and other uneven surfaces without the worry of a puncture. Most road riders live with the fear of a puncture but with these tyres, I could do away with it altogether. The tyres performed well on all terrain and while they didn’t excel on the road like a light, supple racing tyre, they weren’t difficult to ride either.
The tyres showed very little wear after two months of riding, so I expect they will last a long time. This only adds to the appeal of these tyres for training and/or all weather purposes. I didn’t suffer any punctures during the test period, nor did I have any problems with the tyres leaking air. The marketing hype for the tubeless Ultremo ZX is ambitious (the “fastest” and “safest” tyre Schwalbe has ever produced) but I’d recommend them for anyone looking for a robust and carefree training tyre.
Tubeless tyres provide an answer to a problem that road riders rarely suffer: we just don’t need extra performance at low air pressures. There is the promise of extra protection from punctures, especially pinch flats, but if you rarely travel on pothole-riddled roads or other uneven surfaces, is there any value in considering going tubeless?
I have spent roughly equal amounts of time on standard clinchers, tubulars, and tubeless tyres this year, and it has been an interesting exercise. I handled all the installation and repairs, so I was able to compare the demands of each tyre system with the quality of the ride on offer.
High quality (and expensive) tubular tyres provide a superb ride, but compared to a great clincher, the difference is marginal at best. What was more interesting was that a cheap training tubular was far better than a cheap clincher. But, after two punctures in as many days, I could no longer bear the extra effort. Gluing tubs is a labour intensive process and evenly seating the tyre can be tedious.
By contrast, installing tubeless tyres is much easier, but it’s still more difficult than standard clinchers. All the road riders I know have their favourite tyres, and one issue that bears on this favouritism is their ease of installation. I doubt a tubeless tyre will ever tempt them unless it was a stunning performer, and in this regard, they’re unlikely to be impressed by Schwalbe’s tubeless Ultremo ZX.
The strength of the tubeless system lies not with its performance but its resilience. After I returned to riding my regular Continental GP4000s with latex tubes, I immediately noticed that they were lighter, faster and supple, but I also found they felt a lot more vulnerable and the fear of a puncture returned. I’m curious to test other tubeless tyres to see if there are any that are better suited for high performance use, but for now I plan on returning to the tubeless Ultremo ZXs so I can enjoy carefree riding on a lot more dirt roads.