bokes

i have 3 wheelsets for my cross bike (road riding 700x23, commuting 700x32, and off roading 700x45). the 23 and 32 have the same rim width, but the 45 has a wider touring rim, so every time i switch back and forth i have to adjust the brake cables, which is a nuisance. I keep thinking about how much quicker wheel changes would be with discs. I don't race so no rules.
The only neg i can think of is the added theft risk, because i run errands with this bike. Ignoring the other factors of a little extra weight and the conversion cost (hey i'm obsessive), would you go for discs?

ghettocruiser

You might need some thin improvised spacers on the rotor bolts to move the disc out a bit, unless you have the exact same type of hub for each wheel. The distance is supposed to be the same, but there are minor variances between manufacterers that will cause rub.

Once you go through that hassle, it should be a lot faster.

stapfam

The cost of converting 3 sets of wheels to discs will not be worth it- Unless you have disc ready hubs already. Then the frame and forks will have to have the Disc caliper mounts already.

Cheaper to get a new wheel to replace the 700x45.

Then on top of that- will the disc brakes actually be necessary for braking effect?

BlazingPedals

I love my disc brakes because they stop so well and I can even change wheel sizes without worrying about the brakes reaching the rim. Mine are Avids and I can quickly adjust them to compensate for small differences between hub spacing. But like Stapfam says, they're expensive to retrofit.

Wouldn't it be easier to put the same width rim on each of your wheels?

mav67

This could be a potential problem depending on what kind of disc brakes you get. On some models, such as the Avid Juicy Sevens I have, it is a hassle if the rotors are not at exactly the same distance. You can get around this problem, without shimming, by getting a model which has quick pad clearance adjustments. An example would be the Avid BB7's. I'm sure there are other models which have adjustments but I only have experience with this one. Hope this helps.

ghettocruiser

I think the pad clearance adjustment would at least partially defeat the purpose of the fast wheel change. It wasn't worth the hassle for me, and I just moved the one rotor out a bit.

And guys, he said to IGNORE the conversion cost. I think this is a thin excuse to buy disk brakes and whole bunch of new wheels, bit I could be wrong.

DCCommuter

I do just this on my foul-weather commuter. I have two sets of wheels -- narrow rims with slicks for rain, and fat rims with studs for snow. Disc brakes make it much easier to change wheels, and I have no adjustment issues. I have Avid mechanical brakes.

In general, disc brakes are a major convenience item -- I hardly ever have to adjust them, adjustment is much easier than rim brakes, and the pads last about six times as long.