Are disc brakes more effective on rainy weather? I had a close call riding my road bike during a morning rain and almost collided with a parked car. My road bike is steel and has tektro branded caliper brakes. Should I get a disc brake commuter bike?
Disc brakes are generally more effective in the rain than rim brakes, but using rim brakes properly in the rain has served people well for many years.
You need to feather the brakes to remove the water+crud from the rims. Softer brake pad compounds can also help you brake more easily. Also, having good quality brakes that are well adjusted is always a good thing too. Remember that you also need to brake earilier in the rain, regardless of the type of brake, and be more careful than in the dry.
If you have small hands, make sure also the small hand inserts are in for your brake levers (if it has them).
I've done my motorcycle test and know all about defensive riding techniques - and you apply it no matter what bike you are riding.
I ride both rim and disc brake bicycles on my winter training and on my commuter bike. On the winter bike I have swapped out the pads to a softer compound for better braking performance (but not so good for longevity). Even with this change - I often find wanting for more power on descents or rapid & predictable braking in wet conditions.
My commuter bike has discs (Avid BB5) - and the braking in the wet is significantly better - I also feel safer in that I know I can stop reliably in any conditions. The downside is the weight - it doesn't sound like much but it doesn't translate into a performance ride. Which is why I have to maintain a winter training bike for club and group rides and a commuter for solo rides to work.
And remember - your brakes are only as good as the rubber contact patch under your wheels. So decent tyres and a half-decent width - I'd say 25mm minimum or better still 28mm if you have the clearance.
The delay period you normally experience with caliper brakes is much less noticeable with disc brakes, especially a good quality pair.
Even more noticeable is that on much steeper inclines and especially in damp conditions caliper brakes, as I'm sure you've noticed, tend to have an all or nothing attitude when it comes to applying pressure. Disc brakes on the other hand will let you finesse the braking power and keep your wheels from locking up.
The only downside really is that you won't be able to swap your wheels between your disc-brake commuter and your caliper-equipped road bike.