Eight point V bar. From the moment I bought my first set of high quality road clinchers, I’ve ridden at that pressure. I started with that number because that’s the pressure the sidewall told me to pump them up to; I didn’t yet understand much about balancing the benefits of high and low pressures to optimize comfort and friction; I just pumped them up as instructed and off I went merrily down the road.
I’m not as thin as I’d like to be, which is the same thing as saying I’m fatter than I should be, though I certainly hope I climb well for my weight, especially as my third (and hopefully charmed) ascent up Haleakala is looming large in Vajanuary. The point is, I’m not a whippet and even if I starved myself for the next five months and subsist exclusively on IPAs (I draw the line at cutting beer out of my theoretical diet; I might get desperate, but I’m no savage) I’d still be an Eros Poli at best. Being a big guy, the only factor that mattered to me when it came to tire pressure was avoiding the pinch flats that plagued me during my time riding cheaper tires and that meant maximum pressure, no questions asked.
We always dialed our pressure in for Mountain biking and would pull a few pounds out of our road tires when riding in the rain, but by and large, tire pressure was tire pressure, and as far as I was concerned, more was better. I even had a set of 20mm tires on a makeshift TT bike I had that I blew up to a whopping 10 bar. In the last few years, however, the Cycling world has become obsessed with doing the limbo and seeing how low they can go on tire pressure. It all began with an article in Bicycle Quarterly which conducted an extensive and flawed study on the effects of tire pressure and tire width, and concluded that lower pressure and wider tires are faster and more comfortable than high pressure, narrow tires; the idea is that lower pressure allows small bumps to be absorbed by the tire rather than bouncing the bicycle (and rider) in the air, and that wide tires flex more efficiently than narrow tires resulting in lower rolling resistance. Its important to remember that this gain in comfort and efficiency also comes with an increased risk of pinch flats.
This is all well and good, of course, though we always have to be careful to remember the basic principles of such a compromise; lower pressure and wider tires also mean an enlarged surface area which necessarily means more friction; a perfectly hard, narrow tire on a perfectly smooth surface would have almost zero friction, to the point that you’d be unable to gain enough traction to actually move the bicycle at all. What we’re after, in a practical sense, is a balance between the two extremes which optimizes comfort and tire efficiency against reduced surface area and the risk of pinch flats.
I became infected with Tire Pressure Fever myself as the Cycling world became increasingly obsessed with tire pressure. Down went the pressure in my tires and immediately I felt sluggish and lethargic on the bike. Climbing out of the saddle, I could feel the tires flex as I unleashed the Awesome Devastation of the Toothpicks of Navarone. Cornering was like steering in molasses; turn the bars, weight the pedals and then wait a few moments while the bike got round to responding.
These observations first had me reaching for the pump and then got me theorizing about what is really going on with tire pressure and what pressure is right for a given rider. I say “theorizing”, but most other people would use something closer to “guessing assertively”. But that doesn’t mean I’m wrong.
Basically, it comes down to finding the highest pressure and narrowest tire you can that gives a rider of your weight the right amount of tire flex such that your bike isn’t bouncing as it rolls over the tarmac and allows it to roll efficiently, all while minimizing surface area, risk of punctures, and sidewall deformation when accelerating (cornering and climbing are basically the same as accelerating; the acceleration vector is just in some other direction than forward.) This means that each rider at each weight with different preferences on the sliding scale between the above compromises will find a different optimal pressure. Impressed by Tom Boonen’s tire pressure at Roubaix? Tread carefully; that pressure was dialed in based on very specific criteria and unless you’re eating the same cobbles and weigh the same as he does, you’ll need a different pressure to find the same balance. Bicycle Quarterly has a chart that shows what they believe to be the ideal pressure by rider weight, though I don’t believe a word of it; I do however entertain the possibility that I could be missing something based on the fact that I didn’t actually read the article.
Me? I’m still happily riding at 8 point V. I’m comfortable, I’m not flatting, and I’ve got good control. Besides, it just has a nice ring to it.
I know as well as any of you that I've been checked out lately, kind…
Peter Sagan has undergone quite the transformation over the years; starting as a brash and…
The Women's road race has to be my favorite one-day road race after Paris-Roubaix and…
Holy fuckballs. I've never been this late ever on a VSP. I mean, I've missed…
This week we are currently in is the most boring week of the year. After…
I have memories of my life before Cycling, but as the years wear slowly on…
View Comments
@Batman
have you considered the idea that gatorskins are awful in the rain? that would likely explain your crash; or at least part of it. they're very robust tires for flat resistance (when the pressure's right!) but not treaded well for wet weather. or at least not as good as other tires. i've heard people even say they should be illegal in wet weather!
@Gianni
On my cross bike road wheels I have this setup, 25 out back, 23 in front. I like it but the main reason for this orientation is that I happened to have these two extra tyres on hand. Wouldn't mind trying it out with 25s on both, but maybe 23/25 is good for me, especially since I relatively light.
And Peer Pressure? Hell yes. Any of us adhering to The Rules is being kept in line by some common sense, a reverence for some decency, an appreciation for tradition, and, of course, a willingness to do some stuff just 'cause it seems to work and keeps ya lookin' cool.!
I usually run around 110 psi in my Ultremo R1's, and if its lower than that for any reason, I obsess the entire ride about how my "V" is not achieving it's full potential due to the increase in friction; about how my tires are overheating and wearing prematurely, and if they do wear out, how I'll never be able to afford to buy them again. I think I should switch to a less expensive pair I have sitting in my basement, but I'm too lazy for that.
@chiasticon
I think you will find that what is given with one hand is always taken away with the other. Personally I love my Gators, the rolling resistance is relatively low, the puncture resistance is good if you look where you are going and I am always very careful in the wet on corners...I would imagine human error is far more likely here that the difference between a gatorskin or any other tyre for that matter....some days you can spank that corner in the wet and get away with it....other days you can't....there are too many variables to be that simplistic, oil or grease, leaves, gravel, angle of attack, movement of bars to name but a few...
I would suggest stick with the gators till they are worn out, then if you like change for something else, but don't expect that this will stop you falling off...it is by falling off we learn how to stay upright. A bit like military air crashes...it is always pilot error!
@Nate
I ride the same pressure front and back. In fact, I don't know why people ride the front lower. The front tire has less weight on it and isn't used for traction; you just need enough for steering ans some suspension. With less weight on it, it will be less susceptible to loss in rolling efficiency.
@mouse they are 2.2's. I have no idea what I weigh though.
@Batman i'm a firm believer in the conti gatorskins. i'm 88kg, 193cm tall, & ALWAYS ride them at 110. i've never had a pinch flat (of course, having said that, i'll get one on my next ride) in the 4 sets i've had. the trick on installing new ones is that once you get it on the rim, pump it up to a very low 20-30psi. then hold the wheel up so you can look along the bead as it spins away from you, spin it in your hand & eyeball the bead/little groove as it spins away from you. it should maintain the same distance on the edge of the rim as it turns. if not, deflate & try again. it may take a time or two, but this works for me. when the little groove maintains the same distance from the rim on both sides, pump it to full pressure. double-check your work, then ride.
@frank
Because it's what the pros do. It's not for us to question, but to follow, just as we wear our sunnies with the earpieces outside the straps.
In all seriousness, it suits the roads I ride -- and I will posit that the velominutus should carefully weigh several factors in reaching optimum tire pressure: chiefly, the tires chosen; the weight of himself and machine; the terrain to be covered; the quality of the roads; and the weather. There is also the deeply subjective matter of tire pressure philosophy: is more pressure more, or is less pressure more? Early in my travels I subscribed to the latter philosophy. The bike felt fast on smooth pavement but I found myself avoiding rough roads and was chickenshit descending on poor surfaces.
I have now learned that to attack the rough sectors (which are prevalent around here) and carve the descents on these same roads with the grace of a skier, partly because I have better bikes, but also because I believe in running my tires at considerably lower pressures. Because there is less weight on the front, it can be run softer, improving ride and grip on the rough stuff. You think front wheel traction doesn't matter. This is true up until the point it does and the front washes out in some gravel at the apex. Not fun!
My previous tires were Gatorskins. Very tough and durable. I can't remember how many miles I got out of them, but it was a lot. Very few flats, and those were my fault for hitting potholes, etc. Good tires, I thought.
But 4000s's feel so much better to me in turns that I'll sacrifice a bit of money and time. I did experiment with different pressures in the Gatorskins, but they were never going to feel any better than they did. Turn entrances felt really sudden, and it wasn't all that great after I'd entered my line. On the 4000s's, the transition is smooth and predictable, and it's easier to relax and hold my line all the way through the turn.
I used to, and occasionally still do, ride an older "sport bike"--i.e., motorcycle--with good rubber on it, and the 4000s's come way closer to giving me that feeling of smoothly carving a turn on two wheels. If I were commuting, I'd stick with the Gatorskins and be happy as a clam.