Leading bike industry figure Keith Bontrager believes that disc brakes on road bikes are the future and we believe that Bontrager’s parent company, Trek, will almost certainly be launching a disc-equipped road bike in the near future.
“The basic problem is that rim brakes for bicycles were developed around aluminum rims and rubber brake pads,” said Keith Bontrager. “All of the part dimensions, leverage, etc depend on the fundamental physical properties of those two materials. And the state of the art is pretty good.
“Now we are substituting a rim material with much less thermal capacitance and heat conductivity. That changes everything from a thermodynamic point of view.
“Disc brakes will solve that problem. They will also solve wet braking, another situation that the carbon rims performance is limited and always will be (also for fundamental reasons).
“The UCI could change the rule soon because the major component makers will have well developed braking systems available. I have no insight into whether the changes will occur at any particular point.”
We used to hear from bike industry insiders that the introduction of disc brakes in the pro peloton was at least two or three years away, but over recent weeks we’ve been told by two different wheel manufacturers (neither of them Bontrager) that they expect a shift to happen sooner than that, largely in response to changes in the senior echelons of the UCI and an apparently increased willingness to embrace technological innovation.
“Having worked with Fabian Cancellara, I’ve watched him destroy a pair of carbon rim pads in a single Vuelta stage,” Keith Bontrager said, quoted recently in Bike Biz. “From a thermodynamics point of view it was a big mess. The weight of discs on pro bikes won’t be an issue, I mean at present we’re adding weight just to meet the regulations.”
Bontrager is here referring to the UCI’s 6.8kg minimum bike weight limit. It’s not legal to race a bike that weighs less than this in a UCI sanctioned event, despite every major manufacturer having the technical capacity to build bikes considerably lighter.
With Keith Bontrager’s comments in mind, we asked Trek UK whether they had plans to release any disc-equipped road bikes in the near future.
“Since we don't have a model year any longer, we'll be introducing bikes as and when they are ready,” said Chris Garrison of Trek UK. “We are working on disc-equipped bikes and Keith Bontrager is part of that development.”
And what’s the timing on that? Trek aren’t saying on the basis that unforeseen delays can happen.
Trek do already have disc-equipped cyclocross bikes in the range, one of which is the the £2,400 Boone 5 Disc (above). The Boone bikes feature an IsoSpeed decoupler which isolates the seat tube from the rest of the frameset to provide more compliance and comfort. The obvious launch point for Trek in the disc brake road bike market would be for them to offer the existing Domane, the bike that first featured the IsoSpeed decoupler, as a disc option.
When we showed you the Trek 2014 range (the last one in which Trek will stick to a product year), some people were surprised that there was no Domane disc option included. At the time, Trek UK commented, “No disc road bikes for us right now. We are researching them, but we won't bring something to market unless we're satisfied that it's done right. We haven't reached that comfort level with disc road bike design, so nothing from us in that category at this time.”
That time could be approaching. Trek is, of course, one of the most influential bike brands in the world thanks to a large marketshare and the Trek Factory Racing WorldTour team, among other things. If they introduce disc-equipped road bikes, it’s likely to have a significant impact on the market and the future direction of road bike design.
Out at Taipei Cycle a couple of weeks ago, we reported that Reynolds is extending its range of disc brake wheels for road bikes, treating the whole disc thing as a serious shift in the market. Plenty of other wheel brands are doing something similar.
Another indication that the pros will be using discs at some stage in the not too distant future comes from the World Federation of the Sporting Goods Industry (WFSGI), a body that represents many of the major cycling manufacturers. Earlier this month we reported that the WFSGI has discussed disc brakes with Dimitris Katsanis, the new consultant to the UCI’s Equipment Commission.
“Dimitris... showed an openness towards this topic,” said Yves Mori, the WFSGI’s Communication and Bicycle Manager. “There is already a specific disc brake group inside the Technical Committee of the WFSGI and Dimitris has mentioned that he is willing to work together with this specific disc brake group to speak about the possible introduction of disc brakes in road racing.”
So, it’s looking increasingly possible that disc brakes could be introduced in pro racing in the fairly near future. Of course, the rest of us are free to ride disc brake road bikes now, whether or not they’re permitted in top-level racing, but if the pros start using discs it’ll certainly influence their popularity in the marketplace.
Mat has worked for more bike magazines than anyone else in the known universe, dating back to a time when this was all just fields. He's been road.cc technical editor for four years, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. When he's not cycling around Wiltshire, he's running around it, or possibly swimming (sadly, he's one of those 'triathletes'). Mat is a youthful 42-year-old Cambridge graduate, GSOH etc.