This July 9 and 10, some 10,000 bicyclists will ride the Group Health Seattle to Portland Bicycle Classic, a two-day, 204-mile trip that the more hardy will complete in one day. As of today, it’s sold out. Just to make it clear, today is March 21. The ride is in July.

That’s right, spending the weekend doing 200 miles on a bike is something you can “sell out” over three months in advance, even with a $100 adult registration fee. 3,000 feet of elevation gain? Not a hindrance. Procrastinators, your only chance now is to see if the number of refunds demanded between now and the ride prompt the Cascade Bicycle Club to re-open registration. If that happens, registration will reopen no sooner than June 9.

The ride starts at the University of Washington E-1 parking lot on Montlake Boulevard, and finishes at Holladay Park in northeast Portland, near Lloyd Center, with a festival that includes showers and a massage tent.

Last year the oldest rider was 87, and participants from 43 states rode, in addition to cyclists from Australia, Canada (Alberta, B.C., and Ontario), the Dominican Republic, England, Germany, Japan, and Singapore. You may not know that Bicycling Magazine says it’s one of the top events in the nation (yes, yes).

Now, granted, this is one weekend in July, which is in theory the beginning of summer in the Northwest. But despite being a “weekend ride,” STP says something important about the utility of bicycles. First, you probably don’t want to ride more than 100 miles per day. But think of all the places you could get to that are under 100 miles away. Now think of all the places you get to that are under 10 miles away. What’s one mile away?

Secondly, about 20 percent of the STP riders have never done it before. It’s a pretty good bet that they wouldn’t just strike off on their own one weekend. What’s the difference? Everyone else is doing it. There’s safety–and guidance, comfort, support, repair, extra water bottles–in numbers. When “everyone” is doing something, barriers that were previously insurmountable tend to vanish.

These are important lessons, so let me restate them.

1) It’s not distance or speed, it’s mainly access that keeps bicycling from being a legitimate mode of transportation.  If the average American drives 33 miles per day, it’s eye-opening to realize the average day could be biked. Yes, you’d be sweaty, and no, I’m not suggesting that as a goal. I’m just pointing out that distance isn’t the barrier it’s cracked up to be. People who don’t bike consistently underestimate what’s within the range of the average person on a bike (or, imagine that once you get on a bike, you can’t get back off it those days you might need a car).

2) Any individual cyclist can be ridden off the road (literally or metaphorically) by a motorist. There’s far more than safety in numbers, when it comes to cycling. There’s authorization. There’s “taking the road.” Do most commuter cyclists ride singly? I’d be curious what a Microsoft car bike pool program might accomplish. Bikes have an advantage over cars in this–riding in a group is fun. A group of cars is just traffic.