Still looking for the right tires

Jan Heine Measuring Speed

My first serious adult bike (an entry level Raleigh, circa 1971) had 27 in wheels with gum wall tires that carried 75 psi pressure. I was happy with this “high performance” arrangement until I visited Bud’s Bike Shop while teaching in a summer session in Claremont, California. There I saw (and bought) skin wall tires that became my standard from that time forward.

I soon upgraded my bike and started using 700 cc wheels with presta valves. For many years 23 mm tires, with folding bead, pumped to 120 psi were my normal equipment. This arrangement, I believed, was a nice compromise between high performance and high dependability. Except for the steady rise in price, I was content.

Then I started reading Bicycle Quarterly, edited and published by Jan Heine in Seattle. With an earlier career in racing and continuing active involvement in top-level randonneuring, Jan knew bicycle technology and performance very well, both in the United States and in Europe. He and his cycling friends in Seattle were especially interested in the design and performance of classic European road bikes.

I was surprised by the conclusions they were drawing concerning the effect of tire width and pressure upon performance and comfort. Contrary to conventional wisdom, skinny tires (20 and 23 mm), pumped to pressures well above 120 psi did not contribute to fast times except in highly specialized conditions.

On the open roads where most of us ride, even when racing, wider and softer tires are actually faster. They support their conclusions with carefully documented procedures for timing the performance of tires of various sizes and types by well-known manufacturers.

As a result of their studies, I changed how I equip my bikes. On my classic Mercian, which I unwisely modified fifteen years ago, the largest I can carry are 25 mm. On my Waterford winter bike, I use 32 mm tires, and on my Davidson I am currently riding 28 mm but have been thinking of changing to 30 or 32.

The new issue of Bicycle Quarterly (Spring 2013) updates the studies that the Seattle group has been doing. It contains ten articles on the general topic of tire performance. Some of them revise and republish earlier reports. The writers compare clinchers and tubulars, the effect of tread on speed, the comparative performance of specific tires on smooth vs. rough roads, and the effect of “drop” on performance.

Although I do not fully understand the technical material that is included in some of the entries, I come away with four conclusions.

First, there are measurable differences in performance of tires related to materials out of which they are made, their design, their weight, and the pressure they carry. The combination of these factors interacts with road surfaces so that some tires are measurably faster under some circumstances than under others.

Second, for most cyclists the variations are hard to discern under normal cycling conditions. Several of the essays in this issue carry statements similar to this paragraph from “Choosing the Correct Tire Pressure.”

“Fortunately, tire pressure makes only a small difference in tire performance. It is far more important to choose your tires well. Once you have mounted supple high-performance tires on your bike, then you don’t need to worry much about pressure” (p. 44).

Third, several factors affect how fast cyclists can ride and how long they can stay in the saddle. At this stage in my cycling career, the benefits of wider and softer tires, light weight and supple in design, are increasingly persuasive.

Fourth, tires with these characteristics are also reliable on the road. Of course, flats are always possible given the character of streets and highways, but tires that combine comfort and performance are probably more resistant to punctures than the skinny, high-pressure tires I used to ride.

I want to bicycle in carefree fashion, which means, in part, that I don’t want to worry about my tires. Even checking pressure is a bother. That’s why I like the way Jan concludes one of his essays. There are no “hard and fast rules,” he writes.

“On my own bike, the tire pressure changes over time, because I only inflate my tires when the pressure obviously has become too low. As it turns out, that seems to put me right into the sweet spot of tire pressure” (p. 44).

And that’s the very spot in which I want to ride! 

Cycling with harmonic unity and energy

Planing is a term from water sports that Jan Heine and Mark Vande Kampe have applied to the riding characteristics of road bicycles. It refers to a smooth, efficient matching of the cyclist’s rhythms and the dynamic properties of the bicycle itself. When bicycles plane, they seem to move with the cyclist with such harmony that speed and endurance are increased to a significant degree. A synonym might be the word soar.

I remember times when I seemed to plane, going back at least thirty-five years and recurring now and then ever since. The most recent episodes were during the 2010 Grand Canyon Ride with PACTour. On most days of this 1,100 mile trip, I had to push in order to stay in touch with the slow contingent that trailed along toward the end of the pack.

On three or four afternoons, however, something happened: harmonic unity and energy appeared. I found a pedaling cadence (probably around 90 revolutions per minute) that felt exactly right and which I could maintain with occasional gear changes according to the undulations of the course. Despite having cycled for several hours, I could stay in this mode for an extended time during which I gradually moved past other cyclists who ordinarily rode faster than I did. My body and my bicycle seemed to blend into one smooth movement forward.

On this trip, I was riding my Co-Motion road bike, with short wheel base and Woundup carbon fork. On other occasions, however, I was mounted on my forty-year old classic Mercian touring bike with steel fork. The sensation of harmonic unity and energy was much the same despite the different properties of the bicycles.

Jan and Mark most often refer to planing when they are climbing steep grades. Some of their test bikes plane and some do not, at least not when they first ride them. My trouble is that climbing is when I most need the help that this harmonic efficiency produces, but that is when I am least likely to achieve it.

On this season’s first ride up Newberry Road to Skyline Boulevard in northwest Portland, I thought about the fact that neither of these bikes seems to plane when I take them on this two-mile stretch of road with its 8% and 9% grades. The reason, I’m guessing, is that planing can happen only when the rider produces enough power and maintains the rhythm that releases the harmonic interaction. Low gears are part of the answer, but my low gear on this most recent ride was a 26-27 combination and even with this I couldn’t maintain the cadence. Even if I keep a cadence, I suspect, there would not be enough stress on the bike to stimulate the sense of planing.

Planing or no planing, I will keep on climbing these challenging grades as they come along. After all, I do want to get to the top and down the other side. But after the road evens out a little, I will try to find that zone when everything comes together and I feel as though I can ride effortlessly for the rest of the day.

Note: Jan and Mark publish their test reports, technical studies, and opinions in “Bicycle Quarterly.” Links to this journal and many other related matters can be accessed at Jan’s blog. For my blogs on the Grand Canyon tour, check the archives for September 2010. The cyclist pictured above happened along just when I was taking a photo break half way up the steep part of Newberry Road. I don’t know if he was planing, but he was riding a lot faster than I.