Fixed Gear Wisdom From The Late Sheldon Brown

Braking

Some fixed-gear riders ride on the road without brakes. This is a bad idea. I know, I’ve tried it. If you do it, and have any sense of self-preservation at all, it will cause you to go much slower than you otherwise could, every time you go through an intersection, or pass a driveway. The need for constant extra vigilance takes a great deal of the fun out of cycling.

You really should have a front brake. A front brake, all by itself, will stop a bicycle as fast as it is possible to stop. This is true because when you are applying the front brake to the maximum, there is no weight on the rear wheel, so it has no traction.

One of the wonderful things about fixed-gear riding is that the direct feel you get for rear-wheel traction teaches you exactly how hard you can apply the front brake without quite lifting the rear wheel off of the ground.

This is a very valuable lesson for any cyclist who likes to go fast; it could save your life.

There is really no need for a rear brake on a fixed-gear bicycle. By applying back-pressure on the pedals, you can supply all the braking that the rear wheel really needs. In fact, it is fairly easy to lock up the rear wheel and make it skid, unless you are running a rather high gear.

Some fixed-gear fans make a point of not using their brake except in an emergency. I am not sure that this is a good idea. Heavy-duty resisting is widely reputed to be bad for your legs, and to be counterproductive for building up muscles and coordination for forward pedaling. Google for “eccentric contraction” for more on this topic. Eccentric contraction is reputed to cause micro-tears to your muscle tissue, so it actually weakens your muscles, unlike other forms of exercise.

This is a lot like car drivers who use their transmission and clutch to slow down, even though the car has a special set of parts made for the exact purpose of slowing down. Brake shoes are cheaper to replace when they wear out than clutches are.

[Exercise physiology is a relatively new science. Micro-tears in muscles are now known to initiate strengthening. Common muscle-building exercises — weightlifting, pushups, sit-ups, Nautilus and Cybex machines, etc. use eccentric contraction — you lift the barbell, or your body, or pull on a lever, then lower it down. But the number of repetitions in muscle-building exercises is much smaller than in cycling, typically only 2 or 3 sets of 10 repetitions, rather than thousands per hour of cycling. Hard resisting is probably a bad idea for the same reason as low cadence. High stress repeated too many times leads to overuse injury, and will deplete rather than build muscle. — John Allen]

Skip Stops

Brakeless riders generally need to master a technique called the “skip stop.” This is a way that you can actually lock up the rear wheel using your legs alone.

  • If you lock one leg at the bottom of the pedal stroke, as the pedal rises it will start to lift your body upward.
  • When the cranks get horizontal, pull up on the front pedal, while pushing down on the rear one.
  • Because your body will have acquired upward momentum, when you yank up with the front foot this will temporarily partially unweight the rear wheel, making it possible to initiate a skid.

Since sliding friction is less than sticking friction, once the tire starts to skid, you will generally be able to maintain the skid until you’ve stopped or at least slowed down as much as you want to.You have to really want to do it, you can’t be tentative! It’s easier when you’re going faster.

The lower your gear , the more effectively you can “brake” by resisting with your legs.

Despite what some folks will tell you, you can not stop nearly as short this way as you can by using a good front brake.

See my article on Braking and Turning for a detailed explanation of this.

Skid Patches

If you make a habit of doing “skip stops” you will wear your rear tire out considerably faster than if you use your front brake. This problem is exacerbated by certain gear ratios, because you may tend to repeatedly skid on the same section of the tire.Riders who plan to do a lot of skip stops should consider the ratio when selecting their chainring and rear sprocket. The mathematics of this is actually fairly simple:

  • Simplify the gear ratio to the smallest equivalent whole number ratio.
  • The denominator of the resulting fraction is the number of skid patches you will have on your rear tire.

Examples:

44/16 simplifies to 11/4, so there would be 4 skid patches.

45/15 simplifies to 3/1 so there would only be 1 skid patch.

42/15 simplifies to 14/5, so there would be 5 skid patches.

43/15 can’t be further simplified, so there would be 15 skid patches.

This is based on the assumption that you always skid with the same foot forward.If you are an ambidextrous skidder, and the simplified ratio has an even numerator or denominator, your number of skid patches will be the same.

If you are an ambidextrous skidder, and both the numerator and denominator are odd, the number of possible skid patches will be doubled.

[Isn’t this brilliant! — John Allen]

Fixed-gear dangers:

I should warn you that there are three dangers related to fixed-gear bicycles that are not a problem with freewheel bicycles. Used and maintained properly, fixed gear bicycles can be as safe as any, but you should be aware of the three danger areas:

Pedal Strike

It is never a good thing to strike your pedal on the ground while cornering tightly. On a freewheel bike, you can coast though the corners with your pedals horizontal, thus avoiding any chance of striking. On a fixed-gear machine, you don’t have this option.

If you do bang a pedal on a fixed gear, the pedal can lift the rear wheel off the road, and down you will go. This has never happened to me, but it is something to bear in mind.

How much of a problem this is will depend on your bottom bracket height, crank length, and the design of your pedals.

Most of my fixed-gear bikes have 165 mm cranks,which give a bit more ground clearance than the 170 mm’s usually used on road bikes. I also make a point of using pedals that don’t stick out too far.

[Avoiding a pedal strike is one reason not to follow Sheldon’s usual advice to keep the bicycle in line with your body when cornering hard. If you lean your upper body toward the inside of the turn, the bicycle will not steer as well, but on the other hand… — John Allen]

Derailment and Wheel Lock

Throwing a chain on a freewheel bike is no big deal, but it can be very dangerous on with a fixed gear. If the chain comes off of the chainwheel, it can get hung up or even loop around the rear sprocket, and can cause the wheel to lock up. If this happens while you are leaned over in a turn, you will almost certainly crash.

This is prevented by making sure that your chainline is straight, and that your chain is adequately tight.

Catching Fingers, Trousers, Shoelaces

The other danger of fixed-gear bicycles is at its greatest when the bike is in a repair stand. If you hand-pedal it and then accidentally have a finger an article of clothing come into contact with the chain or a sprocket, the momentum of the wheel will keep the drive train rolling. You can lose a finger that way.

Sorry to gross you out with these photos, but this is a real danger!

Likewise, when riding, if you are wearing floppy pants, or have an un-tied shoelace, you may get your clothing caught in the drivetrain. On a freewheel bike, this it is a minor inconvenience. You have to coast, then pedal backward to release your clothing. The worst that will happen is that your clothing will get soiled.

With a fixed gear, you have no such option. If you catch a shoelace, it will get torn off or your shoe. If you catch a trouser leg, you can really get hurt.

It is my fervent hope that this article will persuade some of those who read it to give a try to fixed-gear riding, may you learn to enjoy it as much as I do (and I have 11 fixed-gear bikes!)