A bit OT, but I have drum brakes on one of my rides. Damn things are infallible, maintenance-free, and can get me down a mountain safely with full gear.

I've never understood why anybody would want to use anything else. They always work, they always work in the same way, rain, cold or dirt, and they will always work in the same lovely way with a good feel for the required stopping power. There's always more stopping power than you need.

Once every 2 decades you have to replace the brake shoes, that's if you brake a lot. And I have rod operated ones so I don't have to get my tools out to adjust them for wear, once a year. I just turn the round nut by hand that connects the rod to the lever on the brake to compensate for wear. When there's snow and ice I loosen the front brake in the same way, because you don't want you front tire slipping.

Those modern ones have a cooling disc attached, so now they won't overheat when you're descending a high mountain with a fully packed cargo bike.

I agree. Work well in all weather conditions, low maintenance. Been using them daily for 15 years.

But you don't have any evidence to back up that claim. The reality is, discs don't stop any faster in dry weather. The GNC video shows discs stop faster in the dry, but only with carbon rims.

I didn't see a link, is this the video?


The video is not very clear but it appears they are trying to say disc brakes stop from 40 kph 3 meters sooner in the dry and 7 meters sooner in the wet?

I'm trying to find a measure of bicycle braking distance, I found this thread: http://www.bikeforums.net/advocacy-s...-distance.html

Which seems to suggest that a difference of either 3 or 7 meters would be between 30%-50% difference in stopping distance.

Anyway, I started riding on the road with clips and straps and was perfectly happy, then I tried clipless pedals and shoes and liked those so I started riding with them instead.

I started riding my MTB with cantilever front brakes and u-brake rear and within the span of 12 months I went from mechanical discs to hydraulic discs and was blown away by how much better discs were on dirt. So now I'm riding those and it makes perfect sense that my road bikes would be disc as well. They work great on dirt and they would great on the road.

But I don't expect anyone to share my sentiment without experiencing the different types of brakes as well. :thumb:

The proper measure of a braking system includes the system's ability to shed heat. A single stop from a
given speed isn't a good metric. 10 stops in quick succession with minimal intervals is a typical metric. In
those type of test the build-up of heat with be significant and the advantage of disc will be apparent.

When I'm lift assisted mountain biking in a venue such as Vail, disc brakes are the only system that's
capable of shedding heat without blowing out a tyre. The rotors will boil water after a single decent.
Anyone running rim brakes is going to see the limits of rim brakes.

On the road, when descending on tight switchbacks in a group, rim brakes can see their limit too. It's
interesting how many old farts remark how discs would be nice to have in that circumstance. About half
of the new bikes in my road club are discs now, esp since hydros became standard.

I have disc on my commuter/tourer/gravel grinder and both my mountain bikes. I just dumped the drums on
my bar bike because I never rode it in the rain and drums/fenders were adding ~5lbs to my bike.

My road bike is still rim brake and I have no plans to upgrade it. I don't like the idea of a stiff fork and I have
no funds for a new bike in any case.

You are way off there. The difference in dry conditions on smooth roads is zero. With gravel roads, the difference is two meters. With wet conditions on dry roads it's three meters.

I did a similar test myself on two bikes I have and it pretty much confirmed the results. If you ride on decent roads and it's not raining, the difference is minimal. This isn't on mountains but just flat to rolling roads.

The video shows the results a little less than halfway through

And you aren't producing any evidence that they do not. I am just speaking from my experience with both. But then again I ride more off road than on.

Also, all of those tests are at 40 km/h. My experience is integrated over many speeds.

I'm not sure I've ever ridden in wet conditions with dry roads. ;)

Just for reference.
https://drandalls.files.wordpress.co...2_10-49-08.jpg

But really, like mentioned above, overall stopping distance is not the only metric. Among the reasons I like discs is because the feeling of increased control, they're cleaner to run (especially in wet weather) and the few times I've broken a spoke there were no issues getting home as the wheel wobbled about.

That's almost exactly what my tests with my bikes showed. I did get a little better (15 feet) in very wet conditions by tapping the brakes first and then hitting them hard with rim brakes. That seemed to dry the surface before hard braking. I noticed the video just hit the brakes.

Look at post 284. Same braking distance in the dry. Actually, the GCN test is not really fair--the rim brakes are paired with carbon rims, hardly an ideal combination. In other words, with alu rims and proper braking technique (a quick squeeze in the wet to squeegee the rims first), results are essentially identical.

For me, on moderately fast downhills (around 35 mph), a soft squeeze on the levers produces excellent braking power with my rim brakes.

GCN needs to conduct a fair test: rim brakes paired with alu rims. Carbon rims provide a notoriously poor braking surface for rim brakes. It's likely the rim brakes provide slightly shorter steps in the dry, and are very very close in performance with some higher end wet condition pads such as salmon kool stops.

I could take them or leave them. Strictly on aesthetics I would leave them. I would never upgrade to get them. If and when I ever bought a new bike I would likely learn to like them, maybe even be pleasantly surprised. Some years back (less than 10?) I switched to clipless. It was fun for a while. Now I'm like, meh, straps were just fine and more flexible, didn't necessarily need cycling shoes depending on where and why I was cycling. I suppose I did my part for consumerism. I like my friction shifters just fine. I find them easier to maintain and more reliable than my indexed mtb. Contrary to what I think is popular from other threads I love cantilever brakes. I have mix of cantilever and side pull.

I can understand how and why you'd feel this way when you compare hydraulic discs vs rim brakes on a carbon surface in wet weather.

I'd like to see GCN or someone else compare rim brakes on an alloy surface vs hydraulics in various ride conditions. GCN has already found that in dry conditions, even rim brakes on a poor braking surface such as carbon stops just as well as hydraulics.

My bet is that a top end set of rim brakes such as dura ace 7900 would brake almost nearly as well as hydraulics in wet conditions. Stopping from 40km/hr I would estimate that the difference in stopping distance would be 5 feet or less (approx 1.5 meters). It's likely that rim brakes would have a slightly shorter stopping distance in dry conditions as well.

Hydraulics give you a bit better performance in wet and very wet conditions on rough roads. In other words, they are great for mountain biking and cyclocross, or for riders who ride frequently in wet weather. Most people ride in dry conditions negating any possible advantages of discs.

I have rim brakes on all my bikes. I would, however, like to have disc brakes on carbon rims when riding in the mountains. That said, Lennard Zinn puts the weight penalty for a disc brake equipped road bike at about 1Kg over a rim brake equipped bike. That is going to have to come down a whole lot before I'm going to go to disc brakes. But when it does, I will.

J.