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
@sthilzy
Those are precisely the tires I was describing in the article; Conti Super Sport Ultras. I think they came in a wire and kevlar bead at the time and I bought the wire back then. I was probably in 5th or 6th grade. Glad to see they still make them. Smooth tread in the middle and grippies on side.
@Russ M
Welcome, and sorry that your photo wouldn't load. Not sure what wizardry you were trying to pull off, but if you log in you can just upload a photo or embed one using the little photo button.
@Gianni
It doesn't surprise me because BQ gets it wrong every time, in my esteemed opinion. In the article that started the whole revolution, the author started off saying that rumble strips and cobblestones feel about the same so any test done on rumble strips therefor apply to cobbles. What a fucking load of shit. I could barely keep the vomit down until I finished the article, at which point I chucked the mag in the rubbish bin and puked on it.
@VeloVita
I'm running 25's on my Rain Bike and I run them at 8.V bar just like everything else. They seem more comfortable and seem to have better cornering traction in the wet, though I suppose I'd have to think carefully about if that is actually true given I'm still riding them as hard.
There. Done thinking hard about that and yes I think wider tires have more traction even at the same pressure.
@mauibike
Looking forward to it.
@the Engine
Surely I don't have to tell you that unless a Keeper writes about it, its not recognized as an official discussion.
The Schlecks must head up the mountains at 2 bar in order to avoid blowing their tires this way on the way down.
@Marko
You need a set of tubbies; talk about cornering comfort. You can also go lower without the downside of having things getting sloppy; the round tire just holds it shape better both cornering and accelerating.
I hardly felt a loss in performance on my FMB Paris-Roubaixs when I was all the way down to 6 bar for our rough rides at Keepers Tour 2012. I'll try something in the 5 range this year.
@frank
Less pressure up front, because less weight means you can get away with it. Less pressure allows the tire to deform more, more surface area, more friction,more grip for cornering. The tire can also deform around uneven surfaces more easily, keeping better contact. Not to mention increased suspension. Rolling resistance is so negligible I don't even care, just like hollow/carbon/aluminum/titanium bolts, whoopdy-do!
@frank
Yeah, wider tires still deform more if pressure is held constant between the two.
@frank
I had not read that article so I was living in vomit free heaven until you just relayed it to me....thanks Frank I am now brushing chunks off the keyboard!
Here is something to assist ( http://www.vittoria.com/en/app/ ) from our good friends over in Madone Italy.
@frank
Then what do the collective Velominati think of Jan Heine's Grand Bois (Panaracer) tires? I was considering picking up a set of the 23 or 26mm versions as I'm looking for a gumwall clincher that's relatively light and supple but more durable than the Veloflex, Vittoria or Challenge offerings. I've read good things about the Col de Madelines and Cerfs, but not necessarily from anyone I particularly trust.
@Russ M
I knew this lower tyre pressure thing was an April fools joke...it is telling me I need to set mine at Zero Bar. I think it is saying to me "Fuck off fat boy, you need to go solid rubber, get a Penny Farthing!"
@Deakus
Mmm read the small print...mobile app only does not look like you can use it on your PC! I am afraid I don't have a smart phone......because I am already SMART....so I guess I will have to live with pinching the tyres and go "yeah seems ok let's just ride!"