Ask 100 people what bicycle brakes
are for, and likely 99 of them will respond with a blank look and then
say, “For stopping.”
Well… yes. But there’s a bit more to it than that.
A brake is a device that converts kinetic
energy to heat. Roughly (and very
loosely) a cyclist in motion has a kinetic energy. This energy can be measured and is equivalent to E = ½ mv2. In that equation, E is the kinetic energy, m is the combined and total mass of the
vehicle (cyclist + bicycle), and v is
the velocity at which the vehicle is traveling. (Please take a deep breath and relax! We’re not going to turn this into a Physics lesson.) The important thing to remember here is
that two things affect the kinetic energy. They are the mass of
the vehicle and its speed or velocity. Of these velocity has a much
greater effect.
There are a great number of
situations where a cyclist would want to decrease velocity without stopping.
Examples abound. Here are a few:
- I’m going to fast to make that turn!
- That truck won’t be out of the intersection before I get there!
- I’m going as fast as I can, and that idiot Honda is moving into my lane!
- I can’t hear what my riding companion is saying, and she is the one who knows how to get home.
- I’m going too fast to read the street signs, and there is an important turn coming up.
- If I go down this mountain much faster I risk becoming “street pizza”!
- Yipe! They stopped pedaling!
Personally, I’m not fond of
braking. I prefer to make my ride
fluid, using deceleration only as
needed to adjust the line in a curve, or to make necessary full stops at
intersections. Sometimes, when
riding with others, I find it necessary to brake, just to stay in contact. It’s a mild annoyance.
There are those times… The ones
when we are following someone up a
hill, and they, for no apparent reason, abruptly slow down so much that we must apply brakes, while climbing. Lordy!
Most folks don’t pay a lot of
attention to their bike brakes… until they stop working.
Fortunately these devices are fairly reliable. That wasn’t always the case.
When the Tour de France race
started, in the very early days of the 20th century, all the bikes
were fixed gear, and rim brakes were
still a thing of the future. Oh
there were bicycles with brakes, but
these were deemed too heavy and too clunky for serious racing.
The early Tours did include significant climbing sections, but mountain descending was not a feature. The advent of the first rim brakes made
two things possible. A cyclist
could mount a lower gear on the bike for climbing purposes, and freewheels became practical. Still, those early brakes weren’t
much. Remember, the rims of racing
bicycles were made form bent wood.
The first rim brakes were crude, “single-pull,” and the pads were a sticky
laminate of leather and tarry rubber.
I have ridden authentic
reproductions of those early bikes.
I can state that the brakes were only slightly more effective than
dragging one’s feet along the ground.
By the late ‘40s metallic rims and rubber had improved things
considerably. Road bike brakes
were then up to the level of miserable performance. That’s where things stayed for a while.
When I first got into road riding,
the best that we could obtain worked only fairly well. A good set of roadbike brakes, with the
best pads available, was good for three hard applications, they heated too much and faded to near
useless. And rain? Fuggedaboutit!
Today’s brakes, road or mountain,
are marvels. And, like it or not,
disc brakes are coming for the lightweight road bikes.
A bit of wordplay:
To Brake = to slow down.
To Break = to damage beyond
function
I braked = I slowed down or
stopped.
I broke = I damaged beyond easy
repair.
I braked hard, and the brakes
broke, and then I got all broke up.
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