Road Plus makes a splash at the Taipei Cycle Show

March has barely begun, but yet the trade show season is already in full swing. US technical editor James Huang is at the Taipei Cycle Show checking out new products and upcoming trends from the heart of the industry’s manufacturing sector.

Big, bigger, biggest

The road bike market has been steadily moving toward broader tyres in recent years with even top pros now reaching for 25mm-wide rubber instead of the once-standard 23mm size. Recreational riders have been moving even further in that direction, finding that 28mm-wide setups (or wider) offer better comfort and traction on the road; tyres once only thought appropriate for cyclocross now let them reliably and safely roll across dirt and gravel. Lab tests have determined that all other factors being equal, wider tyres generally produce less rolling resistance than narrower ones, too.

For some long-time roadies, moving off-pavement can inject some new excitement into a pastime that may have grown a bit stale, while for others, it’s an easy way to get away from the hustle and bustle of an increasingly populated world while also avoiding vehicles.

Whereas stiffness, weight, and aerodynamics were once the primary concerns when choosing a new bike or frame, now the question many are asking is how big a tyre will fit.

The thinking behind so-called ‘Road Plus’ is simple: Pairing even wider tyres (around 45-48mm) with smaller 650b wheels yields an outside diameter nearly identical to a conventional 700x32mm setup, but with the traction and versatility advantages of generous air volume and a larger contact patch.

According to the concept’s advocates, Road Plus comes with only a modest weight penalty, is fairly easy for frame manufacturers to design around given the familiar total diameter, and still mostly feels like a regular road bike when riding on tarmac.

As an added bonus, disc brake-equipped bikes built around Road Plus will still accept more conventional road setups without any drastic changes in geometry since the total diameters are the same, effectively making for two machines in one.

In other words, with Road Plus you can supposedly not only have your cake and eat it, too, but it’s moist, extra chocolatey, super-sized, and still won’t make you fat — or at least so goes the hyperbole.

Limited options, but not for long

There may be some fresh buzz surrounding Road Plus, but the concept is hardly new. In fact, it’s based on an old French wheel size that was common decades ago and is still supported today by plenty of custom builders and a host of smaller tyre brands such as Compass, Soma, and Panaracer.

It’s only recently, however, that major labels have tossed their hats into the ring. Last year, Cannondale launched its decidedly unconventional Slate around the 650b format, and now WTB is diving in with the first of what is expected to be many compatible mixed-terrain tyres — not to mention a catchy marketing-friendly label for the concept.

WTB’s new Horizon 47 tyre is reasonably light at 515g, shod with a versatile slick centre tread and slightly exaggerated herringbone shoulders, and tubeless-ready with dedicated bead shapes for a secure lock on the rim. And although WTB isn’t disclosing the thread count, a quick squeeze suggests a comparatively supple casing (at least for a vulcanised tyre) so rolling resistance should be fairly low.

None of the major labels such as Michelin, Hutchinson, or Continental have announced compatible rubber just yet but we expect to see more options soon.

Clement, for example, told CyclingTips that two of its latest models — the X’Plor USH gravel tyre and the X’Plor MSO — aren’t even widely available yet for 700c wheels but 42mm-wide versions for 650b hoops are already being finalised.

“I think [Road Plus] is interesting,” said Clement product and marketing man Johs Huseby. “I’ve talked to a lot of manufacturers who are going to make smaller [frame] sizes in 650b and larger ones in 700c, and I like that a lot. One hundred percent, it’s already getting a lot of industry support. I have three customers that are already planning to go down that road. I see the value in it.”

Road Plus rims are already widely available given that they’re what’s being used in the mountain bike world, where the size is more commonly categorised as 27.5in. That said, those rims will generally be designed for far more demanding loads than what will be seen by most Road Plus users, so most will be heavier than needed for this application. Many 27.5 mountain-bike hubs aren’t compatible with 11-speed Shimano and SRAM cassettes, either, and almost none are available with Campagnolo bodies.

3T has already jumped in with dedicated wheel options for two models previewed at the Taipei Cycle Show, both with tubeless compatibility and freehub body and axle configurations to fit virtually anything.

The US$1,800 Discus Plus Team will be built with a 28mm-wide (internal width) and 28mm-deep carbon fibre rim and weighs 1,700g, while the US$900 Discus Plus Pro gets a slightly narrower 24mm aluminium rim and shallower 21mm depth — and although aluminium is heavier than carbon, the narrower width actually will make it lighter at 1,620g for the set.

“We were already working on the 650b gravel wheel before we heard from WTB,” said Dave Koesel, general manager for 3T’s recently formed U.S. subsidiary. “A bike with 700x47c tires instead of 650x47b tires simply has very big wheels that take up a great deal of space, which means the fork blade length and chainstays have to be long, the front center has to be long, and your handlebars can’t be as proportionally placed, especially in the smaller sizes. As a result, bikes won’t be as agile, and for smaller riders, they simply don’t fit, at least not with a sportier or road/performance-oriented rider position. Road Plus really picks up where 700c drops off.”

Other wheel companies have yet to announce any Road Plus options, and the list of mass-produced frames with sufficient room between the stays is decidedly brief (WTB has already published a list here). Given the bike industry’s recent history, however, that’s likely to change quickly.

Many companies (particularly those based in Europe) initially greeted the idea of 29in-wheeled mountain bikes with skepticism that bordered on ridicule, but the format caught fire, and late adopters had to scramble to catch up. Contrast that with more recent trends like 27.5in-wheeled and ‘plus-sized’ mountain bikes with 2.8-3.0” tires, both of which have been wholeheartedly supported almost overnight.

It remains to be seen if Road Plus really will catch on to the same degree, but if history is any indicator, bike companies are no longer willing to risk missing the wave. There may or may not be a Road Plus bike in your future, but rest assured that there will soon be plenty of choices out there.

“It’s going to be big,” said WTB PR and content editor, Clayton Wangbichler. “It’s being received really well.”

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