Bobby opened the weathered journal to its back page, the place of doodling, and showed me among the jumbled lines and stray thoughts a simple, even innocent question: How many bikes does it take to pull an SUV?

Our friend Lois was going to block off Detroit Avenue in Lakewood so people could walk around and ride their bikes without competing for their space on the pavement with the noise and the gassy expulsions and the sheer metallic hulk of all those cars. Our friend Tim was setting up his portable bike-parking rig for the day. There would be all kinds of music and other entertainment on the street. We were supposed to do something fun involving bikes. That's why Bobby had been scratching ideas on the back page of his journal.

Some questions are not meant to be asked. Some are not meant to be answered. Some questions, once posed, carve the questioner's destiny into his brain in the form of a "tenacious hankering for answers." We knew what we had to do. We called Kiley and some other friends. We set a date at Tim's house.

Pulling an SUV with bicycles is not the kind of thing you do to win arguments about the cost of gasoline or the worthiness of bicycles as a transportation option. There is no practical purpose and no reasonable excuse for the effort. It may bestow some kind of bragging rights, the kind of story grunted in between beers, or it may serve as testimony to the brawniness of a messenger's thighs, but it's not what you would call a "good" idea.

Sure, gas costs more than four dollars a gallon these days, and sure, your bicycle gives you complete freedom from bus routes and schedules and fares and gas pumps, and sure, it doesn't pump out smoke, and sure, you get your exercise without spending your hundreds of dollars at the gym. But none of those things really plays into the decision to try pulling an SUV with bicycles. Indeed, all that sounds just a little preachy, even if every word of it is true. Pulling an SUV with bicycles is a more innocent thing.

And so we all felt pretty good about pursuing the idea. Refining it, even. So to add an order of magnitude, we decided our tow job shouldn't involve just any SUV, but the granddaddy of them all, that 200-proof symbol of gluttony and arrogance, a Hummer. Or better yet — and since no Hummer would consent to be lampooned by a peloton of whack-job cyclists — why not just go ahead and get an honest-to-goodness military-issue Humvee? Forget about civilian wannabe knockoffs, and get right to the battlefield.

Once someone suggests something like that, and someone else says out loud, "Hey, I know a guy," there is no way to take it back. So we set out to practice with Tim's minivan.

When you take up a project like this, it is important that you pause and think things through. Don't just use whatever materials you may have on hand, for example, no matter how convenient. If, for example, you figure that because you have some ropes and a two-by-four in the garage, and the minivan happens to have a trailer hitch, and someone happens to have a daughter who is small and light, it might seem like you have a good start.

But in fact the effort might reveal the following: A) Nylon rope is elastic and when used for towing creates a sort of rubber-band effect, which causes the cyclists and their heavy cargo to go woooo-wheeee, wooooo-wheee, back and forth, and you never get any decent momentum; B) A two-by-four yoke attached to a central trailer hitch is prone to a teeter-totter effect, which is not good at all; and C) While a young and unlicensed teen daughter might seem the perfect "driver" because she doesn't weigh very much, her skills might not be up to steering in reverse, which might result in what the truckers refer to as a "jackknife."

I'm not saying it went that way for us. What I am saying is that after some persistence, after switching vehicles, and with some changes in the proprietary towing technology, we found that four cyclists with moderate skill were able to pull a Honda CRV with relative ease. Down the street and around the corner we went, to the confusion and delight of Tim's neighbors. But we were just warming up.

There are at least 17 different versions of the Humvee, the Army's High Mobility Multipurpose Wheeled Vehicle. Manufactured by AM General starting in 1984, the basic model has an 8-cylinder, 6.5-liter diesel engine. It is 15 feet long, 7 feet wide, 6 feet high and has a curb weight of 5,200 pounds without armor. To pull one of these will be a little different. The wannabe version that consumers drive, the H2, gets 10 to 13 miles per gallon. The real deal gets in the realm of four miles per gallon in the city, and eight on the highway.

Meanwhile, a typical bicycle weighs 20 to 30 pounds. According to David Gordon Wilson's 1977 book Bicycling Science, a typical person riding at 12 miles per hour produces about one-quarter horsepower, which is about enough energy to power two 100-watt light bulbs. It is not enough to break the inertia on a Humvee. Not even if it's in neutral with the brake off. Which brings us back to that question: How many bikes does it take?

Theorize with Bike Lakewood at the Celebration of Walk + Roll at 8 p.m. Friday, July 18, at the Lakewood Phoenix Café (15108 Detroit Ave.). Derica performs. Proceeds benefit Bike Lakewood.

Then find out how many bikes it takes to pull a Humvee - and take in musical and other performances - during Walk + Roll Lakewood from 4-9 p.m. Saturday, July 19. Detroit Avenue will be closed to motor vehicle traffic. Bike Lakewood provides secure, monitored bike parking.