It’s race day, and I wake up to rain. The Weather Channel
confirms my fears: the rain is headed right toward today’s race. I immediately
envision the race course and its really fast, tight turns, and my thoughts turn
to tire pressure. If it doesn’t stop raining, what pressure should I race with?
The answer to that question may be one of the most critical
choices I make today. A few weeks ago I conducted a very informal survey of
riders in my area, mainly in retrospect to my rear wheel skipping on me going
through a turn in a race on a dry road. Several crashes occurred in that same
turn during the course of the race. What I found in my survey was that the tire
pressure choices our local riders make are as diverse as the riders themselves;
they ranged from filling the tires to maximum pressure (no matter the
conditions) to a philosophical discussion on rubber compound, temperature, and
road conditions.
What is the correct tire pressure you should run? When I
started to race back in the days of hairnets, chrome box rims, and handmade
silk cast tubular tires, I just cranked the tires up to what was on the
sidewall of the tire. To me, the novice, this made perfect sense. High pressure
equaled lower rolling resistance, and that was fast! This idea was reinforced
when Continental started introducing tires you could inflate to 120 psi. We
figured we could exceed the maximum by as much as 20%, so we were cruising
around on 21-pound steel bikes with 140 psi in the tires and not a care in the
world.
It wasn’t at all efficient, however, and doesn’t provide the
grip needed to go around corners at top speeds. According to James Stanfill
with Specialized Bikes, about the only place suited for maximum tire pressure
is a wooden Velodrome. He makes sure that the tires of each rider he supports
are properly inflated before each event. This is dictated by tire type, rider
weight, and weather.
Lots of miles, road rash, and current research later, those
old beliefs and practices have most definitely changed. If you do a quick
search on the web about tire pressure, you’ll find many references to wider
tires with lower pressure, especially during those cobbled spring classics in
Northern Europe. For example, in Paris–Roubaix tire pressure can be as low as
60 psi.
But these are extreme conditions. What is the correct tire
pressure for you? Your weight, the road conditions, and your tire type should
all factor into your choice of tire pressure. Some of the tire manufacturers
have recommended tire pressures on their websites, such as Michelin’s chart
pictured below.
Don’t want to carry a chart around? Yes, there is an app for
tire pressure. If you have a smartphone, check out Vittoria’s app. For my
weight and riding style, it’s right on.
So the next time you’re about to roll out of the house or
line up at the start line, take a moment to consider your tire pressure. You
just may be able to carve that tight last turn and have a podium finish in your
future.
