In last week's column, I mentioned suspension as a likely Next Big Thing in road bikes. I also promised another prediction this week. This one I think is coming, but it’s going to take awhile.

First, however, I should mention that when I talked to both Gary Fisher and to Peter Chisholm of Vecchio’s Bicicletteria in Boulder about their opinions on the Next Big Thing in road bikes, I got an entirely unexpected answer, particularly from a gear designer like Fisher.

Their answers are so pivotal and important that I’m mentioning it first lest I get too far away from what it’s all really about when talking about gear. Both discussed access to riding and efforts in that regard as being the most important development on the horizon. Chisholm says that, while it’s “not very sexy and not very likely, I think (hope) the next big thing won't be about equipment but about where we ride. As energy gets more expensive and actually approaches what Europeans pay, perhaps a more centralized way of living, complete with paths and 'LANES' to use alternative, non-car forms of transportation. I can understand why some drive when the snow is flying in CO, but to ride a bike in say, Tampa, is downright dangerous (I lived there for 2 years), same for Pensacola, same for Phoenix. Warm places where you would think riding would be common but...nope.”

So, let’s all not only hope for that but actively engage in bringing about that future. And then the equipment developments will be even more fun to use.

Now, on to gear. Here it is: a Next Big Thing will be disc brakes for road bikes. The first thing that comes to mind when writing this is that Ed "Scotty" Scott, the originator of the red Scott/Mathauser brake pads and Scott brakes would roll over in his grave if he heard me predicting this. Scotty told me decades ago that disc brakes on bikes were stupid, given that there already was a perfectly good braking surface already on a bike, namely the rim. However, though their demands are far different, nobody would ever make that argument regarding a motorcycle or a car, and drivers of those vehicles do not expect to lose their brakes in the rain or after going through a big puddle, as bike riders with rim brakes must, nor do they expect grabbiness or fade on a hot day.

Of course, the real reason to even consider disc brakes is improved braking. And the fact that so many mountain-bike cross-country races use discs despite the weight penalty, even on dry courses, indicates that better braking can actually make you ride faster.

Road disc brakes periodically make a brief splash at a bike show, but they always disappear again because of their Achilles heel, namely that they are considerably heavier than current road brakes. And it is not just the weight of the brake itself; keep in mind that the fork would need to be beefed up at the ends and have integrated mounts, the hubs would have to have a rotor-mounting flange, and the spokes would need to be more numerous and laced in a crossing pattern to counteract the torque on the hub. On the other hand, the rims could be lighter if they did not have a brake track, and tires could conceivably be a bit lighter as well, if they did not have to deal with as much heat buildup. Less weight out at the edges of the wheel translates into faster acceleration, which everyone other than a time trialer or triathlete of a straight course can appreciate.

There is one other weight-related problem road discs must overcome; given the weight constraints that road disc brakes will have to meet, the rotors will be very small. Small rotors and high speeds means that heat buildup will be an issue.

Technology may still be able to deal with these issues, and given the rapid development happening with composites on bikes, it is not had to imagine that it could be soon. Argued to be only one-third the weight of their steel counterparts, carbon-on-carbon brakes saved 600kg off of the weight of the Concorde airplane (and decades ago, too!), and carbon-on-carbon brakes are standard in race cars. I don’t know how these would work at bike speeds, but in race cars, they are claimed to not fade under heavy usage like steel brakes.

There is room with the UCI weight limit to allow for somewhat heavier brakes and still meet the 6.8kg barrier teams would insist on in order to use them. Better braking and lighter rims might be good enough reasons for them to adopt them if the weight came down enough on the whole system. But then you have to worry about inciting a ban by the UCI, given that Eddy Merckx and Fausto Coppi never used them.

The UCI, slapping Cannondale’s hand, already banned disc brakes for cyclocross, stating that it was a performance advantage. That advantage is quite obvious to anybody who has compared the two on a muddy course. However, given the lower speeds and softer surfaces to land on, you don’t often see career-ending injuries from crashes in cyclocross, which you do in road racing, so there is not a counterbalancing safety argument to be made there.

However, with the proliferation of superlight carbon rims, there is a strong safety argument to be made on the road, and I actually think the UCI would be open to it. Nobody likes to see the kind of crash that eliminated Joseba Beloki in 2003 (http://www.velonews.com/article/4520) from ever being a Tour contender again. I am convinced that it would not have happened, had he been using disc brakes. The day was hot, the road surface was soft and melting, his brakes grabbed on his carbon rim and locked it up, causing it to skip sideways and tear the tire off of the rim when it hit. Disc brakes do not tend to grab in conditions like that.

I think that it is important how it is presented to the UCI whether road disc brakes will be rejected out of hand or not. As I said, I think that the UCI is open to safety arguments; it used that as justification for requirements for the use of hard-shell helmets and for the banning of Cinelli Spinaci clip-on handlebars. But if some upstart guy starts winning races on homemade disc brakes (remember the UCI’s cool reception of Graeme Obree’s innovations?) or on those of some small manufacturer, the prospects for getting it past the UCI do not look good.

And once the UCI has said “no” to something, it is hard to reverse that to a “yes.” However, if a big company in good standing with the UCI – a Shimano, Campagnolo, or SRAM, for instance – were to make a nuanced argument to its rules committee ahead of time, before riders appeared in races with them, there might be a different outcome.

And contrary to what some may think, the UCI has not already closed the disc-brake door. In the UCI CYCLING REGULATIONS, this is the rule on that subject:

1.3.025 Freewheels, multiple gears and brakes are not permitted for use on the track during competition or training. Disc brakes are forbidden in cyclo-cross training and competition.
(text modified on 1.09.04; 1.01.05).

Disc brake makers have already been around the block a time or two with road bike product managers and have not gained a foothold yet. The Avid BB7 mechanical road disc brake is still in SRAM’s line, but I’ll bet you’ve never heard of it. I think nobody has yet invested the resources to solve the weight problems that must be overcome to get them on road racing bikes. Nonetheless, I think somebody will; I do foresee a future for road disc brakes.

FEEDBACK FROM LAST WEEK'S COLUMN

Dear Lennard,
I just read your article on the "next big thing" - road bike suspension - and I'm surprised you did not mention the Moots Vamoots YBB. This is exactly the sort of subtle suspension that you conclude will make it big! And you're from Colorado! In fact, I believe that somebody did or was going to ride the Vamoots YBB at Paris-Roubaix (you'd have to verify that because that one comes from the dark cobwebs of my memory).
-Kevin

Dear Lennard,
I agree that just about everything on a bike is not an invention but a modification of something already in existence (and sometimes even an improvement!!). Comfy bikes via design and materials have been around for a long time, but I wonder if the "compliant" frames seen at P-R will be viewed as "vague" by the weekend warriors. The market drove Campagnolo to redesign their ERGO to make the effort softer, only to now be inundated by requests for “RED” shifters (Ed.: Record Ergopower levers with a harder shifting feel)...the cycling community can be and is fickle.
-Peter

Technical writer Lennard Zinn is a frame builder (zinncycles.com), a former U.S. national team rider and author of numerous books on bikes and bike maintenance including Zinn and the Art of Triathlon Bikes and the pair of successful maintenance guides Zinn and the Art of Mountain Bike Maintenance – now available also on DVD, and Zinn and the Art of Road Bike Maintenance, as well as Zinn's Maintenance Tips and Skill Building for Cyclists.

Zinn's regular column is devoted to addressing readers' technical questions about bikes, their care and feeding and how we as riders can use them as comfortably and efficiently as possible. Readers can send brief technical questions DIRECTLY TO ZINN. Zinn's column appears here each Thursday.