Back on Solid Pavement: 650B

Back on Solid Pavement: 650B

A few recent posts in Pull of the Day have used The Bicycle as a springboard for metaphysical musings. Nothing wrong with that, I guess, but for each topic I conceive, two or three materialize and clamor for attention. For instance, I stand by my reading (31 October) of Eddy Merckx’s transcendent career as represented in the photo of him blasting down the cobblestones of Paris-Roubaix—those cobblestones being abstracted as symbols of the challenges and hardships you and I face throughout our lives, which in some ways resemble a race to an inconclusive goal. But I could have just as easily used the picture of Merckx as an occasion to probe the dangers of self-destructive competitiveness. I can’t imagine that a person who wins 450 professional races, or even forty-five of them, has much time for cookouts with friends or vacations with family, and the toll on that racer’s body has got to be staggering. Same with my piece “Yoga Wheel; or, Riding the Binary Cycle” (27 October), which is a meditation on the illusions inherent in dualism. An equally convincing sermon on mortality—end of spin, inertia, death of motion—could be derived from watching a beautiful bicycle wheel come to a stop, slowly, as if mirroring a person in the throes of a lingering disease that keeps him suffering in a hospital bed for a long time. Hear him cry, “It’s taking too long, just let me die!” And speaking of death: my reflection on the loss of Robin Williams ... I must say, it’s too early in this blog for me to become bogged down in disquisitions about suicidal ideation, but I could do it, I surely could.

But other less philosophical thoughts about the bicycle beckon. True, the bicycle, like Merckx, is a metaphor, and from metaphor we make meaning. It’s also a machine, a remarkable one, perhaps the greatest invention of humankind. This amalgam of tubes and rubber and plastic, weighing (in the peloton) about seventeen pounds in toto, not only can support a human being weighing well over two hundred pounds but it can also carry him whatever distance he wishes, or is able, to go—all without the help of an internal combustion engine. Needing little in the way of replacement parts or maintenance, a well-wrought bicycle will last decades (a steel frame seems to be the best choice for longevity). Human beings got it right with the bike.

As a cycling enthusiast, I love working on my bike, looking at it, talking about it, and writing about its individual parts. I’ll be doing a lot of the latter in future posts. Upon receiving an issue of one of the cycling magazines to which I subscribe, the first place I turn is the review section of new bikes, components, and accessories. I also enjoy technical articles about any aspect of the machine. In sum, I relish the bicycle as an object. That it lends itself to metaphoric fancy only makes its concrete and practical elements more compelling to me.

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I ride a 650B Rivendell. I’ve been on it for eighteen months. Twenty-two months ago I started looking for an all-purpose lugged steel bike and within an hour muckled onto Rivendell’s website. It’s where I found out that the best bike for me would be a 650B. I still go there two or three times a week because it’s packed with unique products, videos, information, and opinion.

If you’re reading this you’re probably a cyclist, and if you’re a cyclist then you’ve heard the debate, especially among mountain bikers, over 650B.¹ 650B is the wheel size between the smaller 26” wheel and the larger 700C (i.e., 29”) wheel. Rounded off, the 650B is 27.5”.

650B is not a popular size, at least not where I live and ride. (In the last seven years I’ve seen one 650B bicycle—a recumbent.) But a growing number of industry insiders think it’s been overlooked, that consumers need this third choice, that it occupies the elusive sweet-spot of bike-sizing.

This 1.5” difference has a huge ripple effect on the frame’s geometry. On specs ranging from standover height to toe-overlap, wheel-size plays a big part.

The best thing about 650B road rims is they’re perfect for wider tires. Check out the tires on the 700C bikes that you and your friends are pedaling in your paceline. They’re 23mm in width. You might be able to squeeze a 25mm between the forks and rear triangles of some of those frames. It would be a tight fit. Bigger than that is unlikely, which means 700C bikes are limited to whatever fusion of speed, handling, and comfort the narrow and hard (100-120 psi) 23mm tire provides. There’s also no fender clearance, which is fine since 99% of 700C riders don’t want them anyway and 100% of 700C race-configured bikes are incompatible with them in other ways—these percentages decreasing sharply with urban-style bikers and bikes.

The 650B bicycle is ideal with tires in the 32mm to 42mm range. 38mm is the bomb. What you get are speed, stability, and most of all comfort that, despite its other virtues (and there are plenty), the typical 700C bicycle can’t match.² Wide contact-patch, 45 psi, supple—my god, how my 38’s roll.

650B is a default size for randonneur bikes, which for the most part are made by artisans in custom shops, many of them located in the Northwest (there’s a big randonneur network in Washington and Oregon). So cyclists interested in conventional racing and/or training—these purposes demanding featherweight carbon frames and components, narrow tread, short wheelbases, etc.—won’t be looking at custom 650B (or even 700C) randonneur bikes (usually made of elite steel) anytime soon. The lugs alone would scare them off.

The first time I took my Riv on a group ride, one of my technically savvy pals did a double-take when seeing the wide gap between seat-tube and rear tire. It looks odd in the company of 700C machines. But that gap is there for two main reasons: to give the rider the option of installing (1) a 42mm tire and (2) a fender, which, in the words of master cyclist and author Jan Heine, needs “at least 12mm between tire and fender.”³

It may be true that the longer chainstays that create this clearance slow down the bike because of the added flex (remember, these are steel frames) in each stay. Some authorities dispute this claim, saying there’s no scientific evidence of such speed/energy-loss. I wouldn’t know. I will say this: once you have that fender and a 42mm back there (the tire in the photo above is 32mm), the gap shrinks. Randonneurs (i.e., timed-event “brevet” cyclists covering hundreds of miles, often on rough stuff and in bad weather) and lifestyle riders (guys like me) couldn’t be more content with this setup. Most of the ideas for Pull of the Day occur to me while spinning on my 650B.

Notes

¹ In issue 180, 1 Oct. 2014, reviewers in Dirt Rag assess four new 27.5” mountain bikes—the Swobo Mutineer, Yeti 575, Rocky Mountain Thunderbolt 770, and Santa Cruz Nomad (60-68). In “Inside Line: Bike Companies Going Big: 650B Wheels Dominate Summer Product Launches,” an article published exactly two years earlier (issue 166, 1 Oct. 2012, 28-29), Eric McKeegan writes, “It is amazing how quickly I adapted to the ‘tweener’ size. It simply disappears beneath you, allowing you to focus on the trail, not the bike” (29).

² For a technical look at this subject, see “Wheel Size and Bicycle Handling” by Jan Heine, Hahn Rossman, and Alex Wetmore, Bicycle Quarterly 8.3 (Spring 2010): 14-18.

³ Jan Heine, “Does My Bike Take Fenders?”, Off the Beaten Path, 27 Jan. 2013, http://janheine.wordpress.com/2013/01/27/does-my-bike-take-fenders/. In “The Danger of Fenders” (Bicycle Quarterly 13.1 [Autumn 2014]: 66-69), he writes, “My René Herse has between 15 and 20 mm of clearance between the top of the tire and the inside of the fender” (68).

Roadysseus

11.4.14