If you ask any mountain biker to name the single most effective development in their riding career, the chances are that they will say – with very little hesitation – that making the switch to hydraulic disc brakes was the best thing they have ever done.
We all know the fear which comes with knowing you are not going to be able to stop in time. An obstacle appears, the trail tightens unexpectedly or someone slows in front of you, requiring a panic-y grab at the brakes.
Then there’s those other occasions when you’re riding downhill and slowly – but surely – the momentum starts to build. What starts as a steady descent becomes increasingly wayward until you are just hanging in there for dear life with your backside way off the back of the bike.
Well, hydraulic disc brakes won’t stop any of that happening. Those scenarios can happen whatever brakes you are using. Physics is physics at the end of the day as many of us have discovered the hard way after putting too much faith in our skills and equipment.
But without doubt, disc brakes provide a much, much wider performance envelope in which to operate. This is a truism that every mountain biker knows but it wasn’t always so. In the early days of disc braking there were many who doubted it would ever have a value beyond downhill racing with many XC riders clinging to their V-brakes for years after most ‘normal’ riders had made the switch.
Now it’s the turn of road riders to have the same debate.
There’s quite a rumpus going on at the moment in the world of road cycling over the possibility that there may be a move to disc brakes for road bikes, despite no manufacturer actually having a disc brake set up to sell. What’s so striking to me is that all the arguments against are pretty much identical to the arguments made against disc brakes on mountain bikes over ten years ago.
Up to now, the issue just hasn’t been there. Pro road cycling, governed by strict rules on the type of equipment allowed for racing has banned disc brakes; so no disc brakes, or rather, they’ve never been explicitly authorised. Added to which the technology just hasn’t been there to build a lightweight hydraulic setup into the cramped confines of road ‘brifters’ (combined brake and shifter units).
With manufacturers gaining expertise – and following a relaxing of the disc ban on cyclocross racing – UCI (the sport’s governing body) have let it be known the only reason discs are banned is because no-one has seriously petitioned them to lift the ban. So the stage is set for disc brakes on road bikes.
Manufacturers are making noises about developing hydraulic disc brake models for road bikes (expected to be for the 2013 model year), with SRAM and Shimano’s braking expertise looking to be a strong advantage. Campagnolo certainly lack this at the moment but interestingly Magura have just launched a hydraulic rim brake for the new Cervelo P5 time trial bike. Quite an investment unless you have long term plans in this market.
For the benefit of the roadies then (who may have stumbled across this article), what are the benefits of hydraulic disc brakes?
Arguments for hydraulic road disc brakes
- Power. Much, much greater power than you can ever generate using a cable set up which will stretch and absorb more of your braking input. But we all know that anyway.
- Modulation – hydraulic brakes are very responsive and provide great feel through the lever, meaning you can finesse your braking efforts very accurately. The combination of increased power and greater delicacy allows a rider to brake much later into turns and carry more speed through to the next straight.
- Consistency. The performance remains pretty much constant whether it’s wet or dry or anything in between. It is possible to boil the fluid on long off-road descents but that is now increasingly rare on MTBs and road bikes will unlikely put anywhere near those levels of heat into the system. Compare that to over-heated, sticky, grabby brake pads on rim brakes.
- Weight. Yes, really. A complete top end Magura MT8 disc brake for MTBs is 310g including a 160mm rotor and fluid, whereas Shimano Dura-Ace road brakes come in at 285g plus the shifter/brake units of 366g. When you’ve averaged it all out there would be little difference between the two systems I’d predict. And throw into the mix the opportunity to save weight off the wheels, which don’t need braking surfaces at the rim – for example, a relatively low cost, everyday, aluminium MTB wheelset can easily weigh under 1650g these days and that’s not without turning to carbon technology which saves even more weight.
- Reliability. Disc brakes rarely go wrong. OK, so the odd fluid bleed from time to time to keep them working at their best but that’s once in a blue moon stuff. I’ve had brakes that I haven’t touched for years at a time. As for pad wear, properly bedded in brake pads will last for many, many miles.
I’m sure I could go on but you get the picture. Disc brakes are a mainstream technology for MTBs and no-one I know would ever seriously argue against them – be they professional racer or the proverbial weekend warrior.
Looking at discussions on road oriented websites though you’d think it was 1999 all over again as in the face of all these benefits people are variously arguing that.
Arguments against hydraulic road disc brakes
- I’m not putting ugly discs on MY road bike. They’re a hideous abomination against the purity of the traditional road bike. Nasty. And I bet they’re not aero-dynamic!! (Hmmm, I guess. Never seen an ugly fast bike though…)
- They will make it slower to change wheels in a race as nothing can be as fast as rim brakes to change (would that be rim brakes which require the new wheel/tyre to be deflated BEFORE inserting it into the dropouts? Versus drop in and go?)
- Don’t want the weight penalty (neither do I and I doubt there will be one)
- I’ve never needed more power from my cable rim brakes (well maybe, but power is nothing without control)
And so on. You can read a representative discussion on the road.cc website where they were discussing Dura-Ace rumours recently. Obviously I’ve paraphrased for effect – I apologise for mocking – but really these arguments are nearly identical to everything we’ve heard before.
It works both ways of course (not every mountain biker is convinced by carbon for off-road bikes) but I can’t help feeling disc brakes are the way forward for roadies, especially when they see how much time they will save on those Alpine passes.
What do our readers think I wonder?