View Single Post
Old 02-19-14, 09:33 AM
  #21  
cyccommute 
Mad bike riding scientist
 
cyccommute's Avatar
 
Join Date: Nov 2004
Location: Denver, CO
Posts: 27,274

Bikes: Some silver ones, a red one, a black and orange one, and a few titanium ones

Mentioned: 150 Post(s)
Tagged: 1 Thread(s)
Quoted: 6147 Post(s)
Liked 4,091 Times in 2,325 Posts
Originally Posted by 3speed
I know you said the LHT doesn't fit your intended riding style, but personally, if I were buying a new touring bike, LHT or something else, I would go with disk brakes. No question. I know the old styles of brakes have been around forever and they do stop a bike, but ride some disks if you haven't before and you'll see that they are a huge improvement. There is a reason lots of touring bikes are showing up with them now. I only own my current touring bike(91' Trek) because I got the frame for cheap and it was cheaper for me to build up than buy new, but I'd swap to a disk fork in a second if I knew of one with the unlikely combination of requirements it would need(1" with mid-fork braze-ons).
I don't agree. I have mechanical disc, hydraulic disc, cantilever, dual pivot and a disc/v-brake equipped bike so I have tried them. Discs aren't "a huge improvement". They aren't an improvement at all. They are a lateral shift to a different braking mechanism but they introduce loads of problems without changing anything for a touring bike. On the rear wheel, you have a steeper angle on the spokes for the rear wheel which makes the wheel weaker and less stiff. Essentially you end up with a wheel that is dished on both sides. Then you have the problem of threading a rack around the caliper. Some of that problem has been solved by moving the caliper inside the rear triangle but the rear rack ends up being placed higher than a cantilever equipped bike.

On the front, you have similar problems with threading a rack around the caliper and you've traded a strong symmetrical wheel for a dished wheel. A dished wheel in the rear causes enough problems, why would you want to put another one on the bike?


Originally Posted by Medic Zero
The reason disc brakes are showing up on touring bikes is people are convinced new is better and that they need more stopping power, i.e. the companies are looking to sell you an upgrade you don't need. Disc brakes are over rated, I've never wanted for stopping power with decent cantilevers that are dialed in right, and I'm a big Clyde who can't pack lightly to save his life. Even on an heavily loaded bike while touring, descending, I've got enough braking power. Disc brakes on tourers is adding a weight penalty for no real benefit.
Pretty much. If hub mounted discs were replacing old Mafac Racer center pull knockoffs or drum brakes or coaster brakes , they'd be a huge improvement. But cantilever brakes with modern pads are a pretty spectacular brake.

Originally Posted by 3speed
No, that's not why disks are showing up on touring bikes. And it's not about the stopping power(other than perhaps the marketing). I guess one benefit to stopping power is reduced hand fatigue if you're doing a lot of braking in the mountains or something, but that's probably not a real issue for most. As you said, a decent brake dialed in right will put you over the handlebars, basically no matter what kind(though disks do indeed have crazy stopping power). I don't think you really understand disk brakes. The modulation benefit of disks is huge. I never realized what a difference it made until I had disks, but it truly is a benefit to have.
Yes, marketing is certainly why disc brakes are showing up everywhere. The fact that you can put a rider over the bars with just about any kind of properly adjusted brake means that you don't need any more "craziness" in the braking system. The bike's brakes are already over-powered so any more power is simply wasted. I'm not sure what you are using to define "modulation" but I've never noticed anything approaching "superior" modulation in any disc brake I own. If anything my hydraulic equipped disc is highly lacking in "modulation". It's nearly digital...going from off to locked with only a tiny bit of input from me.

I'm of the opinion that many people who think hub mounted disc brakes are superior do so because they probably weren't riding brakes that were set up like a hub mounted disc to begin with. Many shops install rim brakes so that the lever has to travel about half way to the bars before the brakes even touch the rim. Full lock on the brakes is somewhere behind the handlebar so the brakes feel really mushy. Hub mounted discs, on the other hand, have to be adjusted so that there is little lever throw before the pad hits the rotor. If you detune hub mounted discs so that they are set up like most rim brakes, the disc sucks too.

Every brake I own (disc or rim) is set so that by half lever throw, the wheel is locked.. That's why I don't see any "improvement" when I use hub mounted disc. Essentially, my bikes are already dialed in like a disc brake.

Originally Posted by 3speed
The ease of replacing a brake disk when it wears out versus a wheel rim is also a great benefit. The brake pads are also much easier to swap out on the cable varieties of disks vs. "standard" brakes. You don't even need tools. And granted prolonged braking in mountain type descents isn't an issue for everyone, but if you are doing a long descent like that, I'd much rather have disks. People don't often have issues with rims overheating and tires blowing or coming off of the rim, but it does happen. It won't happen with disks since you aren't heating up the rim. The last place I want my front tire to go on me is on a long descent with likely a steep drop on at least one side of the road, which is usually on the outside of the turn...
The problem isn't with the brakes but how the brakes are used on long descents. I live in the mountains. I've toured on steep mountain roads and I've never heated a rim to the point where the tire would blow off. I've never heated a rim to the point where I couldn't touch it immediately upon stopping. I did a 1200 mile tour in the Appalachias in 2011 that included 87,000 feet of climbing...and, by default...87,000 feet of descending and I didn't have to replace the pads. I still have them on the bike and they have plenty of life left in them.

Even if you had hub mounted discs, dragging the brakes all the way down a long descent would be a dumb way to use them. The rotors aren't indestructible.

Originally Posted by 3speed
The only real downfall I can think of is possibly warping a disk in the middle of nowhere, but I don't think that outweighs the benefits. And you can get a warped disk straight enough to at least use it(assuming it wasn't really mangled by something) until you can get a new one. I'd Highly recommend trying them out.
If you've ever tried to straighten a rotor, it's more tedious that trying to true a wheel. You make the argument that you don't need tools to change a disc pad but you don't realize that you need tools to straighten a rotor. A small adjustable wrench will work but most multitools now don't have that feature. And the Park rotor truing tool is heavy. And you probably can't use your hands to straighten a rotor for a couple or reasons. First, you need leverage and second you don't want to be getting your greasy fingers all over your rotors unless you want SSSSSQQQQUUUUUEEAAAAAAALLLLL all the way done every hill you run across.
__________________
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!




Last edited by cyccommute; 02-19-14 at 10:06 AM.
cyccommute is offline