Welcome back, loyal bikebrethren. Hope the week's been kind and your central AC's still humming. May cool tidings and Arctic blessings be upon thee in these last sweltering days of Seattle June.
But keep an eye on the calendar, folks, because we're fast approaching the single biggest deal of the year in cycling: The Tour de France.
On July 4th in Utrecht, Netherlands, the Tour de France returns to us (at frighteningly HD levels of epidermal detail if you swing by The Shop), and with it comes the largest exposure our sport receives all year, making international news and headlines as the cycling equivalent of the World Cup/Super Bowl/Monaco Grand Prix. Accurate viewership ratings are always a bit dodgy, but depending on whom you ask, TdF gets anywhere from 1.4 to 4.5 billion viewers every year. I prefer to think optimistically, but that's still a healthy lower bound.
If you’ve never watched, read about, or wagered Ultegra parts on the TdF, we recommend immediately acquainting yourself with cycling’s biggest sporting and cultural event. While it’s not the easiest to to dive into for the uninitiated, it’s an important part of being a cyclist, and it deserves at least a portion of your daily allotted Aimless Internet Wandering Time. So if you expect you’ll be heading down a Youtube or Wikipedia rabbit hole today, trust us—the TdF is well worth your time. But if you happen to be one of those neophytes that doesn't know a col from a peloton, we recommend doing a little bit of pre-race research. This is a great place to start; it'll help you discern some jersey colors, the various stages of the race, and even how the crikeyhell all those cyclists relieve themselves in the middle of backwoods Europe with a time trial on the line and the whole world watching.
But among the month’s abundance of cycling awarness, EPO/doping discussion, and endless Livestrong jokes, TdF always generates some lively gear-talk and debate among our mechanics.
This week it’s been all about tires—tyres if you live In Europe. Or if you're just a huge Europhile. Or if you're Canadian.
Wait, what does Canada use for tires anyway?
Just kidding, Canada. We love you.
Today’s question: Wider tires on your road bike—are they worth it?
Short answer: probably.
Let's dive in, shall we?
Your typical everyday-use road bike is likely outfitted with something like 23mm tires (that's width, mind you). Maybe more, maybe less, but that's basically the median. These days, however, we're seeing more and more road cyclists going the way of mountain bikes and upping their tire width to the high 20s, 30s, and even some low 40s.
The most common misconception regarding tire size is that wider tires are simply “slower” than thinner tires. Anecdotal evidence and armchair mechanicking assert that a wider tire rolls slower due to its heavier weight and greater surface area of ground contact, i.e., more rubber means more resistance. You're just going to have to work that much harder in the saddle.
Plus, they may look a little goofy on your retro 1985 aluminum frame.
It's a solid, comon-sense theory, but for the majority of the cycling populact that's riding fewer than twenty miles a day on sub-40mm tires, it simply doesn't float. Excluding egregiously oversized sand, snow, or Bat tires that weight more than your whole setup, this theory is conclusively busted.
Let’s talk tires.
One of the best metrics for determining the efficiency of your tire setup is rolling resistance. This refers to the energy lost while the tire is rolling due to its constant deformation against the ground while under load. A piece of your tire always flattens a little when in contact with the ground, and this concept is the linchpin of today's topic.
True, wider tires are going to be heavier. There's more rubber there, and if you're out on a century ride, you're going to start feeling that full pound of difference dragging on you around mile 20 or so. But if you're among the legions of short distance weekenders or daily commuters, you can probably afford to have a little more weight on your setup without sacrificing comfort. In fact, you'll probably enhance your comfort. Even the pros are doing it.
(PSST! Now is when you start taking notes.)
Ready? Here we go.
1) A wider tire actually has the same surface-area contact with the ground as a skinny tire under the same tire pressure.
One of the biggest complaints about wider tires is that more rubber will be touching the ground, which causes greater drag and deceleration. Your itty-bitty 21mm tires will undoubtedly have a thinner contact spot, this is true, but it's also going to be longer (that's front to back, if you're in the saddle). Wide tires won't have nearly as long of a flat-zone, and even though the ground-touchy part is wider than the skinnies, the overall result—if we do the math—is the same amount of deformed surface area in contact with the ground. Myth busted.
2) Yes, you sacrifice accelleration, but a wide tire keeps its speed better.
What's more, bike techs have discovered that due to that shorter length of deformed tire, it actually keeps its speed better. Think of it this way: A wheel works because it's round. The less round it is, the more it slows down. Skinny tires—because that flat spot is longer—have an overall greater total deformity in the "roundness" of the wheel and are now being found to require more energy to keep at a constant speed than their wider counterparts. Even many TdF pros are bumping up to 25mm.
3) With wider tires, your handling and grip on the road will improve.
For several years, mountain bikes have been going the way of wider tires with less pressure. Guess what? The principles are absolutely the same for road bikes. When taking corners, the extra lateral rubber is more important for stability than the long contact rubber of the skinnies, and a wider tire casing will provide more of that lateral contact. Plus—and this is where it gets really cool—wide tires can handle less air pressure. This makes them a much better fit for rougher roads as less pressure directly translates to fewer punctures and a smoother ride (better distribution of shock).
Don't believe me? Check this out (especially around 1:36):
If you're on a road bike, we recommend choosing a tire size that conform to the amount of acceleration you need from your ride. If you deal with lots of traffic lights, hills, and reasons to quickly accelerate off the gun, skinnier might be for you, meaning somewhere under 25mm. But these aren't for everybody! If you've got long stretches of straightaways, if you're don't care if you beat cars off the red light, if you're not much of the hard-cranking, speed demon type, you should absolutely look into some of the newfangled 30+s. You won't have to work as hard, and you may find the smoother ride more enjoyable overall.
Ultimately, as with any bike tech, it all comes down to personal preference. Stick with what you feel safest on, and you won't go wrong. Hey, friend, as long as you're on a bike, we're happy.
Don't close yourself off from new advancements in R&D. Regardless of what your old-school, 20mm, 140psi road bike specialist says—the wide tire is here to stay.