Fixies outlawed?
By John Stevenson
There’s been a bit of hoo-ha in various bike forums around the net in the last few days about a case in Portland, Oregon where a rider was fined for not having a separate brake on her fixed-gear bike. According to bikeportland.org, bike messenger Ayla Holland was ticketed on June 1 and charged with violating Oregon Revised Statute (ORS) 815.280(2)(a) which states:
A bicycle must be equipped with a brake that enables the operator to make the braked wheels skid on dry, level, clean pavement. strong enough to skid tire.
Ms Holland’s lawyer Mark Ginsberg attempted to argue that a fixie’s transmission constituted a brake. The judge was having none of it, and in his decision said:
„The brake must be a device separate from the musculature of the rider. Take me for instance. I don’t have leg muscles as strong as a messenger… how would I stop safely?“
This has led to some rather alarmist talk about the future of fixies. „Will the cops now feel emboldened to go out and ticket everyone on a fixed-gear? Are fixed-gears now essentially illegal? Are fixed-gears truly a public safety hazard?“ asks Jonathan Maus in bikeportland.org.
Well, no. The issue here is a badly-written piece of legislation being interpreted by a judge so that it achieves its aims, rather than what the absolute letter of the law says.
A fixed-gear bike with no brakes cannot stop in as short a space as one with a front brake, because only the rear wheel is providing the braking force. As a vehicle on the road, it’s therefore clearly less safe.
This is a matter of simple physics. In the third edition of Bicycling Science, David Gordon Wilson demonstrates that the maximum deceleration of a crouched rider on a standard bike (that is, not a recumbent) on a dry road is 0.56g. Try to brake any harder than that and you go over the handlebars, which is the limit condition, as the limit from tyre adhesion of vehicles that don’t pitch over (tandems, recumbents and cars) is about 0.8g.
If you brake with only the rear wheel, according to Wilson, the limit is 0.256g, because braking effectively shifts your weight forward, reducing the load on the rear wheel to the point that it skids at that deceleration. Once a tyre is skidding, its braking effectiveness is reduced because you no longer have sticky solid rubber in contact with the road, but a lubricating layer of molten rubber. (Which incidentally demonstrates that the Oregon legislation was written by someone with no clue at all about bikes.)
Therefore, however good a fixie rider is, stopping distance is roughly doubled without a front brake. In practice, it’s probably more than that.
In some jurisdictions, better-written laws make this issue moot. In the UK, for example, the law requires a bike to have two independent braking systems. I used to ride a fixie in the winter in the UK, and I knew quite a few fixie riders who dispensed with a rear brake on the grounds that the transmission was a braking system, but I never met anyone daft enough to have just a rear brake.
This judge has clearly decided to ignore the letter of the law in favour of enforcing its obvious intent, that bikes have at least one maximally effective brake. That’s the sort of thing judges are handy for: turning idiotically badly-written legislation into rules that make sense in the real world.
All that fixie riders have to do to conform is slap on a front brake; hardly rocket surgery, and a long way from fixies being suddenly illegal. And to fixie riders who are about to reach for the email to defend riding brakeless fixies, I refer you to Cmdr Montgomery Scott: „You canna change the laws of physics!“
aktualisiert.
