The most important thing you are NOT paying attention to? | SILCA

Tire Pressure: The most important thing you are NOT paying attention to..

We receive a lot of great comments and email through the website and one of the most common questions is something on the order of 'how important can tire pressure really be?'  This often comes in the form of a statement trying to refute the idea of our expensive floor pump something like "I have a 4 year old BrandX that cost me $80 and it does everything perfectly, your expensive pump is stupid and unnecessary."  We enjoy reading these as they generally include colorful language, but what has really become clear to us over the last year is the belief that tire pressure is more or less non-critical, most people seem to believe that tire pressure is a topic that has been 'solved,' just put it at the MAX on the sidewall and go!

 Fortunately for us, Pro-Tour mechanics, teams, pro Cyclocross mechanics, national track teams, and many others have understood this and have been utilizing our 'stupid and unnecessary' pump to win dozens of championships and events around the world, so we ask ourselves, why the discrepancy between conventional wisdom and pro-level experience?

First, it isn't just cycling, at the top levels of pro racing, road, mtn., cyclocross but even moreso: motorcycle, IndyCar, F1...tire pressure is one of the most difficult and time consuming optimization problems faced by engineers and teams.  In Formula1 for example, CFD, FEA and other computer technologies allow the engineers to build entire virtual engines, predict horsepower, torque, temperatures, model aerodynamics with incredible accuracy and even model suspension kinematics including damping rates...however, to complete the virtual racecar, requires a series of data plots from the tire manufacturers which can only be created by producing very real prototype tires that are actually tested in laboratories at varying pressures!  Make no mistake, the dynamics of a real tire are incredibly complicated and are far from 'solved'.  

So how and why does pressure matter so much?  For one, the tire is the ONLY thing connecting the bike (or racecar for that matter) to the road.  ALL forces must be translated through the tires, which serve as both traction device to the road, suspension to the bicycle, protection to the rim, and do so in multiple axes as the tire is capable of deforming and squirming not just vertically, or laterally but fore-aft and rotationally.

It is through these deformations that the tire forms the contact patch with the road.  This patch allows you to put traction down to drive forward, provides the negative of that force to allow braking, handles the lateral forces that allow cornering.  During this time the casing deforms around small and large imperfections in the road to provide compliance for the rider, while maintaining contact patch consistency.  Anyone who has ever tried inline skating on a rough road knows how critical this is, those hard urethane wheels that are so efficient on smooth surfaces are both slow and nearly impossible to control as they bounce over increasingly rough surfaces.

Ultimately, the reason tire pressure doesn't get much thought or publicity is that it isn't an easily solved problem, and the 'answer' will vary rider to rider, and course to course.  Most of what we love to talk about in cycling are Maximize and Minimize type problems, these have the easiest marketing message, are most easily conveyed and are most easily remember: Weight: minimize, stiffness: maximize, Aerodynamics: minimize, compliance: maximize, etc.  (Interestingly these are the same things we love to discuss when we buy new products, in effect, Max and Min can be bought). However, tire pressure, is an 'Optimize' type of problem, and one that has numerous variables including: rider weight, road surface roughness, rider weight bias, tire width, rim bead width, tire diameter, tire construction, and more!  Pressure isn't an advantage that can be bought, it is something that must be learned, experienced and understood, potentially representing an advantage (or disadvantage) that cannot simply be purchased.

Starting with the spring classics we will be launching a weekly series discussing the very real effects of tire pressure on performance (rolling resistance, aerodynamics, comfort, tire durability and punctures) as well as the factors which play into defining your optimal tire pressure.  Please join our mailing list or like us on Facebook to be the first to know as each article goes live.  We'll also be including inside information from the spring classics regarding the decisions the top pro cyclists and their mechanics are making (and why!).

Thanks for listening and please keep sharing your thoughts and opinions with us: sales@silca.cc

Josh


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