Many a weekend bicycle rider has had the same unsettling experience: You ask a friend to ride with you along some scenic, low-impact route. You show up wearing shorts, Sambas and a T-shirt, and he shows up dressed for an Olympic time trial. Sambas? On his torso is a very tight shirt slashed with a half-dozen garish colors and logos irrelevant to him. His helmet, decorated with flames or stripes or both, is equipped with a rearview mirror. A rubber straw dangles around his neck like a fur stole, through which he can drink fluids from a container on his back. And then there are the spandex leg-­enclosures. These have patches of yellow on either flank, giving the impression that your friend is wearing chaps. Yellow-and-black spandex chaps.  

All this for a 10-mile ride on a bike path. Now that's one well-dressed straw man. (But I agree on the spandex chaps.)

If you can identify with the more casually dressed biker described above (what if you identify with neither?), or if you want to go biking but have been scared away by the sport’s cult of gear and equipment (or traffic?), then your bible has been written. Grant Petersen’s “Just Ride” is a wonderfully sane, down to earth and frequently funny guide to riding, maintaining, fixing and enjoying your bicycle. That so much common sense will be considered revelatory, even revolutionary, is a testament to how loony the bike world has become.

Petersen opens with this salvo: “My main goal with this book is to point out what I see as bike racing’s bad influence on bicycles, equipment and attitudes, and then undo it.” And he goes on to prove, conclusively, that most of what ails the world of cycling comes from nonprofessional riders pretending, or being bullied into pretending, that they’re professionals. The solution, he says, is to emulate kids and other “Unracers” — people who bike for fun and not profit. What if you bike for transportation? What if you bike commute? Is that dealt with at all? Aren't bike commuters, like, 90 percent of the cyclists most people see? (Or, more often, don't see.)

The accepted orthodoxies are upended, one after another.  Petersen is skeptical of special biking shoes. I felt the same until I ruined too many tennis shoes biking in the Seattle rain. Bike shoes are much more rain resistant. He is pro-kickstand, pro-mud-flap. Definitely pro-kickstand. Where did that go? Bring it back! He thinks a wide, comfortable saddle is O.K. Who doesn't? He doesn’t see why anyone needs more than eight gears. Well, he's a professional. Biking up some of Seattle's hills at the end of a long day, at the end of a long week, I don't mind having those extra low gears. He thinks fragile carbon-fiber bikes and ­super-narrow tires are impractical for just about everyone (“Getting paid to ride them is the only good reason I can think of to ride that kind of bike”). I guess. I have a hybrid. He has nuanced thoughts on helmets (he wears his at night but not during the day) and reminds us that biking is “lousy all-around exercise” and shouldn’t be considered a stand-alone regimen. I didn't wear a helmet until I took a header against a car's bumper in '94. Now I wear one all the time. Then again, I bike in traffic. But most satisfying is his takedown of the tight-shirt, ­spandex-shorts phenomenon. Does that include tight cotton shirts? Is it the tightness or the fabric of the shirt that we're objecting to here? I'm confused.

“In its need for special clothing,” he writes, “bicycle riding is less like scuba diving and more like a pickup basketball game.” A regular cotton T-shirt and a pair of shorts will ventilate better, he says, and if you’re not trying to shave seconds off a world record, the microscopic aerodynamic advantages of tight synthetic clothing just don’t apply to you. Again, I'm not a fan of spandex shorts--especially on guys. But shirts? You know how long it takes a cotton shirt to dry after biking with a backpack on a hot day? Too often I'd bike to work in the morning in a cotton T and by evening it was still damp. Ick.

Coming from just anyone, this kind of thinking wouldn’t carry much weight. But Petersen raced for six years, then worked at Bridgestone, Japan’s largest bike maker, as a designer and marketer.  When the company closed its American office, he opened his own shop, Rivendell Bicycle Works, in Walnut Creek, Calif. It would seem, then, that Petersen, as the ultimate insider, would be the first guy to push expensive racing gear on every would-be enthusiast to walk into his shop. And yet!

But with this book, he’s trying to bring biking back to a state of moderation and rationality. If you like the gear, he’s fine with that, and if you don’t agree with all his advice, no problem. But he makes the case that at its core, biking should be a simple, democratic, sometimes ludicrously enjoyable means of getting around. It should be. But what prevents that, more than cyclists who over-gear and somehow “shame” the rest of us, is this: traffic. It's that we've designed a society for automobiles rather than for cyclists and pedestrians. What keeps most people in their cars, I've found, is people in their cars.

“No matter how much your bike costs,” he says, “unless you use it to make a living (or unless you commute?) , it is a toy, and it should be fun.” I use my bike to commute. It's fun. But it's not a toy.

Amen. Ride safe.