There’s been a few interesting bits and bobs going on recently (not included in this category: me taking three goes to get a decent tube repair on the smallest puncture ever seen). Definitely pushing the bizarre envelope are the events last week in the depths of Nevada, where a bunch of folk were attempting to go as fast as possible in a Human Powered Vehicle (HPV) at the annual Battle Mountain get-together.
HPVs cover anything powered solely by human effort, whether it be on/under the water, on land, or in the air (see the University of Toronto’s glorious Ornithopter). Land-based HPVs therefore include every single bike you see around and about you (barring those with electric motors). However, some people want to go fast. Like, really fast.
The mountain bike in the garage probably isn’t going to cut it.
You need something like this.
The annual Battle Mountain races (for want of a better word) are pretty simple when you get down to it. There’s a long, flat piece of tarmac called the SR305 running south-west from the town. Every morning and evening during the event the road is closed, and the HPVs are launched one by one. As the rider is completely encased within a carbon fibre shell they all require some kind of support whilst they get up to speed; some kind of launching trolley or helper on roller-skates seem to be the common options.
Four miles down the road the bike hammers through a pair of optical speed guns 200m apart, and the time is calculated by various electrical wizardry.
Considerably further down the road, the HPV has hopefully slowed down enough to be caught by another team of helpers. This doesn’t always work – on Monday the brake lever in the Cygnus bike failed, so 60mph of carbon-fibre torpedo sailed past all the helpers before Jan-Marcel van Dijken finally managed to bring the thing to a halt on its side. Aurélien Bonneteau in Altaïr 4 managed the same trick on Monday evening, albeit this time through not spotting the catchers in the gathering darkness.
There’s been some extra publicity this year as a result of Scotland’s own Graham Obree taking along his new HPV Beastie. He’s scaled back his somewhat optimistic 100mph claims, but did reach a highly respectable 55ish mph on his first run. He spent the next day adjusting the ratios of his fixed-gear drivetrain, but sadly didn’t manage to post a faster time.
The final day of this year also saw a new world record – 83.13mph (133.79kph) by Sebastiaan Bowier in VeloX3. That’s a speed set on the flat, with no pacing, wind assistance or other external help. Just one mad Dutchman on a hugely geared recumbent inside a very, very slippery carbon fibre shell. Amazing.
I’m going to waffle on a bit more about two of the machines I found particularly impressive (including the VeloX3), but if you want to read more there’s a couple of places to check:
- The Biking In A Bike City blog has the daily results.
- Dave Larrington’s highly entertaining Automatic Diary has a somewhat less serious summary of the daily events.
- The International Human Power Vehicle Association has all the rules and regs, if you’re struggled to get to sleep at night.
Right. Nerd time.
Human Power Team’s VeloX3
There are a number of HPVs that follow the same design philosophy as the VeloX3, but none seem to carry it out with quite such style (although Bluenose gets points for its Canadian-flagged shark fin). A Dutch enterprise, the bike is built by a team in Delft and then conjoined with a rider trained by a separate team in Amsterdam. The result is an HPV that reaches 83.13mph, powered by only a single (albeit fairly impressive) human.
VeloX3 is, somewhat predictably, the third in the line of VeloX machines produced by the Delft group, all of which have been remarkably successful. The design is just glorious – I can’t think of any human-conveying vehicle that is more ruthlessly aerodynamic except maybe some of the highest performing gliders. The windscreen was ditched as the bubble canopy created too much drag, so the small periscope on top feeds a video screen that the rider uses to guide themselves down the straight. There is a small window on either side (just behind the ‘B’ of ‘Brunel’ in the photo above) in case the camera fails, although I wouldn’t fancy trying to use that method at top speed!
The only other gaps in that pristine carbon shell are two tiny slots for the wheels, and an air duct in the centre of the nose to prevent the engine boiling/suffocating.
By all reports, HPT have got the entire system nailed, with very few false launches, crashes or drops. As a result that smooth skin stays unblemished, and Sebastiaan Bowier used it to good effect to create that new world record of 83.13mph on the last Saturday.
Different approach to above.
The top speed of an HPV will come down to the power the rider can produce, measured against the aerodynamic drag of the machine. If we keep everything else the same, your aerodynamic drag goes up as you increase the cross-sectional area you expose to the headwind. There’s a limit to how much power we can get out of a rider, no matter how many tins of spinach we force down them.
The logical next step?
Glowworm puts two riders back-to-back inside 14 feet and 6 inches of streamliner. Some frontal area. Double the power. There’s an account of the build and design process here.
Sadly the riders (Larry Lem and Tom Amick) had a pretty unlucky time this year. They managed a highly impressive 73mph in one run, but as the windspeed was outside the official limits the run didn’t count. Later on, they crashed at close to top speed in truly spectacular style; thankfully both escaped relatively unscathed.
A video of that crash is below, recorded by the chase car for Bluenose. A few comments:
- The video has some pretty strong language. Mute for kiddies.
- Glowworm had launched in the slot after Bluenose (the white streamliner in shot at the beginning of the video). Glowworm is the green missile that overtakes from the left.
- Look at the crosswind.
Glowworm smashed into a set of plywood screens that covered some conventional crash barriers where the road bridged another. The bike is apparently pretty much written off, but happily Larry reports that he has another tandem almost ready to take its place.
Biking in a Big City have an overview of the rest of the bikes is here in their Battle Mountain roundup.
All photos except the Adam Ince Glowworm shot were kindly provided by Bas de Meijer. He’s got a couple more, including one of Obree’s Beastie, right here. All the images are copyrighted by the creator – text is mine and follows this blog’s usual policy.