True, but I’ve always found Kool Stop brake pads, especially the salmon-colored ones, to work quite well in the rain.
Word. Just ordered a set of these for my touring bike.
They vary. Of course even the best mechanical (cable-operated) disc brake has some friction due to the cable sliding inside the cable housing, so it won’t be silky-smooth like hydraulics. But there are good mechanical disc brakes with excellent stopping power and modulation. The Avid BB7 seems to be everyone’s favorite (and mine too), and very reasonably priced. (The BB5 is OK, but the BB7 is noticeably better.)
Thanks for the responses everybody. I’m kind of leaning towards the Crosstrail at this point.
They have one called the Crosstrail Sport Disc that looks good but hopefully I’ll be able to test drive one before I decide whether to spring for the discs.
I put BB7s on my last build and they work great. In dry conditions, V-brakes work fine, but I hate the way they feel when the wheel isn’t true. Either I’ve never ridden with quality cantilever brakes or they all suck.
I’d say V-brakes are fine, but would spring for disk brakes if you can afford them.
I had a similar experience to Princhester. Disk brakes have amazing stopping power compared to V-brakes.
I’d certainly go with disc brakes. I’ve got a K2 with relatively low-end Hayes MX2 mechanical discs and they stop fast and reliably, wet or dry. I do mostly city riding so my primary concern is traffic but I used to do some pretty fast/steep/rutted bike trails and they never once gave me any problems.
Every bike I buy is going to have discs. I just don’t care for rim brakes. If you’re buying a racing bike and every gram of weight counts maybe the decision would be different but it doesn’t sound like that’s an issue for you.
Another nice thing is that they’re very easy to maintain and adjust. The rotors are self-cleaning (wipe them down with some rubbing alcohol once in a while to clean crud off if needed), it’s very simple to adjust the pads in/out (on mine it’s a hex key for the outboard pad and the cable play adjuster nut for the inboard pad, higher-end models need no tools at all) and replacing the pads is no fuss - take off the wheel, pull the old pads with a needle-nose pliers, insert the new pads, done. No toeing in or any of that stuff.
I still question a crossover bike versus a touring bike when the majority of the riding is on a hard surface. both should be test ridden.
I think you can now get a cyclocross bike with discs.
Absolutely not worth it. I am a 300 pound guy riding a Trek FX bike commuting downhill 500 feet vertical every day in Seattle wetness (and snow a couple weeks ago). I hit 42 mph but can stop with the caliper brakes in very very little distance.
The brakes will grip way better than the tires on the road. Just keep your rims clean, your pads tightened and buy new ones when they are needed.
My road bike has caliper brakes that are powerful enough to stop it fine, but it’s nowhere near as powerful as the discs on my MTB. I can stop much shorter on the MTB. If you’re going to stick to pavement, rim brakes are fine, but for off road or anything that might tweak a wheel, I’d stick to discs.
The big win for disks is where mud buildup can hang on rim brakes. On road bikes they represent extra weight.
There is an issue with front disk brakes. The placement of the caliper behind the fork tends to lever the axle downward, and flexes the left and right fork asymmetrically. This tends to walk the front axle out of the fork ends. It usually only becomes a problem on “downhill” type bikes and riding, but the potential is there.
Much of the problem could have been avoided by placing the caliper ahead of the fork. Apparently motorcycle practice was copied to this extent, but motorcycles use a through axle and pinch bolts to avoid the problem. They do not have open fork ends for the axle to walk out of.
I rode quite a bit (on a touring bike) up until about ten years ago, I definitely want to get something that will handle rough pavement, gravel roads, grass and some light trail use.
While I hate pedaling my tank of a mountain bike I have to admit all the shock absorbers feels nice on the tush. I’d be curious if the larger wheels suggested upthread take some of the bite out of uneven trails.
They do.
Hopefully the OP won’t mind a relevant hijack (if that isn’t an oxymoron)? Is there an optimum size for bicycle wheels, in terms of converting the final drive into efficient movement along the roadway? I am interested here in the theoretical example of a perfectly smooth and flat road.
To clarify, it seems intuitively obvious to me that a normal-size bike wheel is much more efficient at translating axle movement into forward motion than a smaller wheel, such as you get on fold-up bikes. But it also seems intuitive that there is an upper limit to this - presumably, a drive wheel the height of a car (say) would not be as efficient. But I cannot explain why this should be, or begin to calculate the optimum wheel diameter. Anyone know?
700c/29er wheels are what I would go with. My current MTB has 26s, but the next one will have 29s.
lb for lb it’s more efficient to have the weight of the tire toward the center. If you take 2 identical size and weight wheels the one with more weight distributed on the rim will accelerate slower coasting down hill.
I think the parameters on a flat road would be rolling resistance vs drag, and will vary with speed.
Short answer: no. Wheel size does not affect powertrain efficiency.
The gain ratio (i.e. how far forward the bike travels when you move the pedal by a certain amount) has an effect, because the human body is most efficient at a certain speed. Just like gasoline engines are most efficient at a certain RPM. However, this is a function of both the wheel size and gear ratio. So if you have a tiny wheel, you can compensate with a very high gear ratio (e.g. very large gear the crank).
But that’s just the efficiency of the drivetrain. The speed is affected by both power and resistance. On a bicycle, air resistance is dominant at high speed, and wheel size has little effect on wind resistance. At lower speeds, the wheels’ rolling resistance can be significant, and here, the wheel size has some effect. Everything else being equal, larger wheels have lower resistance, but on a perfectly flat road, the difference is minor.
In real life, the most significant benefit of a larger wheel is that it smoothes out the bumps and irregularities on the road. This is the main reason why the old-fashioned high-wheelers (penny-farthings) had such big wheels: until pneumatic (air-filled) tires were invented, the high-wheelers were faster and more comfortable than bikes with smaller wheels and chain drive. With wide pneumatic tires, the wheel size is less important, but the difference is there.