It was while riding downhill on a steep section of road in San Diego, California, that the architect John Alridge, 69, decided that his regular road bicycle simply wasn’t doing its job. “It was a fairly steep hill, and I expected to go really fast, but I wasn’t. It was difficult to just keep going, and I knew I had to get down lower so there wouldn’t be so much wind resistance.”
So, when he arrived home, he sketched out what he calls the Bird of Prey Bicycle, a prone bike that has the rider practically diving, in a swimming-like position. That was back in 1991. “It took me 15 minutes to come up with the sketch of this bike”, Alridge says “and 25 years to have it built.”
Another reason to create his “raptor” was safety said the sexagenarian, who’s based in the South-Californian city of Carlsbad. “I had a few accidents on a normal, sit-down bike. I went over the handlebars a couple of times, once hit my head and was really lucky to survive.” With the Bird of Prey, the center of gravity is much lower, so the rider is not thrust forward when he brakes, says the inventor.
But isn’t the cyclist going heads-first anyway? “It obviously looks that it is more dangerous, but you have your head up, completely aware of where you’re going, unlike when riding a regular prone bike. And if you hit a bump, won’t go over the handlebars.”
Aldridge says “I get a lot of questions about if my neck gets tired, comments about the ride being uncomfortable and so forth, but the position is very natural”. He goes on to say “I’ve ridden the bike for quite a long distance and it’s not your neck or shoulders or anything that get tired at all, it’s your legs.”
The body weight of the rider is supported by an aero bar-like rest. “You’re laying down on the front of your hips [the iliac crest]. You don’t get tired at all, and when you push your pedals you can shove your body against those bones and they counteract the push on your pedals”, says Alridge.
Caleb Thompson – a pro mountain biker and cyclo-cross racer from Colorado – is one of Aldridge’s first customers and says “It’s extremely aerodynamic. With a bit of practice and getting used to, I could see it being faster than a time trial bike.” Regarding power, Thompson says that he believes he could “potentially generate more power, because of the [leg] position. I have a very big gear [60-tooth chainring], but I’m able to turn it over fairly easily once up to speed.”
In fact, while the aerodynamics matter more when the speed is higher (going downhill or on flats), the architect and bike commuter says another reason to build the Bird of Prey was to go faster than “those young guys who were beating me all the time” — on the hills.
“This laying down position gives you much more powerful position to pedal. Uphill, the stability when you’re stretched out makes you crank more easily, at 90, 100 rpm, and that takes you to the top in a shorter time”, says Alridge, who got 7th place overall and first in his age category using a Bird of Prey in the Long Beach Triathlon this year.
So far, Alridge and Russ Denny – the framebuilder behind the project who’s based in Texas – have put together only three bicycles, although they guarantee that they could manage to scale up the production of the Bird of Prey, which cost from $5,000 (£3,270) and $8,500 (£5,560), depending on the parts chosen –all of which are regular bike components.
“It was a little tricky finding the right angles and the position of the rider to be comfortable at first”, says Denny, who claims to have thirty years of experience building frames. “One thing I did when we started this project was not going to the web and look at a bunch of prone-style frames — I didn’t want to be influenced by someone else’s design.”
He says he could build as many as 35 regular bikes of the same size per day in his workshop, and that with the Bird of Prey rate that would be cut by about half. “The first one took a long time, but the second and third ones probably took twice as long than a regular frame.”
Both Denny and Thompson, the cyclist, say that what attracted them at first was building and riding something different than the offerings found on the market. “I like it because it challenges me”, says Denny. “I had ridden it before and [found it] fun to try something new”, says Thompson. “Someday I might try setting some records with it.”
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