Disc or no disc?

Every year in cycling there is an innovation that is supposed to change the way we ride. For years it has been the increase in gears from 5 to now 11 and in some cases 12 gear cassettes. Then came electronic shifting. That took a few generations but it is clearly here to stay in many forms. On the road right now the big change is disc brakes. Do we need them? Are they better? Are they dangerous? Like all innovations time will tell, but here are my thoughts.

As a point of order, let’s just say it has been coming for some time. Disc brakes changed the shape of mountain biking and it has now become a must in cyclecross. Now road and even recreation bikes have seen the light. There is no question that a spinning disc can be dangerous. The edges while not sharp, have an edge that will in the right circumstances literally cut your finger off. But then again get your finger stuck in any wheel at speed and the outcome could be the same. The racing scene worries that they will be more dangerous in a mass pile up. Have you ever cut your leg on a greasy dirty chainring? If not, you probably will, or you are a new cyclist. Reality is, get a group of high intensity athletes together going 30 mph and when there is a crash, bad things can happen. So instead of focusing on that let’s look at how it performs.

The bike I am riding now is the 2016 Cannondale Evo HM Ultegra disc. The frame is the same proven race frame that comes in a non-disc version but of course with the flat mount caliper system rather than rim brake ability. My bike is pretty stock except for saddle stem and handlebars. Admittedly the bike is heavier than the non-disc version, weighing in around 17. 2 pounds. Most of that I contribute to the Mavic Aksium wheel set that comes stock on the bike. They are lighter than a rim version since there is no built up brake track, but still heavier than you would expect on a $4,200 bike. Although heavy the ride quality is surprisingly smooth for these rims. I have not yet tested a carbon set of disc wheels but think that would make a weight and performance difference in the bike.

2017 Cannondale EVO HM Ultegra Disc

2017 Cannondale EVO HM Ultegra Disc

The Shimano RS685 Hydraulic brake shifters have the same shape and feel as a non-Hydraulic system so there is no adjustment there. The big difference really comes when the brakes are applied. To say the application of braking power is smooth would be an understatement. It takes about ¼ of the pressure to engage the brakes and stopping is sure and precise. There have been all kinds of tests done to show the difference in braking between rim and disc but the brake down is simple. Under any sort of adverse condition, be that wet, sandy, muddy, bumpy roads, the disc brake will stop you faster and more precise. Where rim brakes can fade under extreme use, like coming down a steep mountain descent or when wet, the disc will not fade and is much easier to apply hard when needed.

Okay so we don’t have a huge steep descent other than Mount Lemmon, and we certainly don’t get much adverse weather, so why do we need disc brakes in Tucson, Az? It all goes back to feel and application. I have done my share of climbing and descending on the mountain and on all kinds of bikes. I am not what you would call a daredevil descender and I do check my speed around corners. At times with windand traffic by the time I get down the mountain my hands are sore from using the brakes and constantly feathering to check my speed. First ride down on the Disc bike and I set a new personal record for speed. It is so much easier to have slight modulation and apply the brakes. It is smooth, only takes a finger and so much less pressure. Knowing how good the brakes are I found myself braking later and being able to take a better line into a corner. Part of that can be attributed to the fact that with the disc brakes there is a 15mm through axel rather than the usual quick release skewer thus resulting in a stiffer front end and sharper steering abilities. I can honestly say I really enjoyed the feel of the brakes and the performance confidence they provide.

So really, who is ideal for a disc brake bike? Easy, everyone. Those who might benefit most are people with smaller hands who don’t have the reach to apply greater pressure on a traditional brake system. Anyone with arthritis or other hand issues greatly benefit from the easy application and it might allow them to continue riding long after they would otherwise have to stop.

 

The take away from all this as I see it is that disc brakes are coming. They will be more available and if the racing world adopts it, it won’t be long before rim brakes will only be on entry level bikes. Maybe the industry is forcing this on consumers and sure, it means you have another bike to buy and even more wheels to upgrade to but the benefits are there. Weight will continue to come down to where it is a non-factor. If you have the chance, take one out for a test ride. If you have been a skeptic, you just might change your mind. 

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