Tag: exercise

This document is copyright 1995 by Tom Holub. It may be freely redistributed as long as this notice is retained.
It may not be sold.

This seems like as good a time as any to discuss purchasing and sizing a bicycle. If you already have a bike and aren”t interested in getting
another one, you can skip down to the Sizing section. Having more than one bike is way cool, though, especially if your bike is your only form of transportation.

I”ll start by saying that low-end bike-store bikes have gotten
a lot better over the last 10 years; you can”t really go wrong. As a
general rule, it”s worth spending extra money up to about $700 or $800;
after that you”re paying for stuff you don”t really need. If the
guy at the bike store is telling you about some cool feature the bike
has (like underbar push-button shifters) you are probably paying for
stuff you don”t need. Bike Hint says: The features you need on your bike
are pedals that go around, brakes that work and shifters that work;
everything else is vestigal. That”s not to say that you should buy the
cheapest functional bike; you should just be aware that extras aren”t
really necessary.

Note that I said low-end *bike-store* bikes. Do not buy bikes from
Target, Toys R Us, or any other non-bike store. Those bikes are cheap
in dangerous ways; the brakes are particularly bad. They”re heavy,
they”re constructed by morons, and they are practically impossible
to adjust properly. Do yourself a favor, buy a reasonable bike.
Expect to spend $250; in this case, you get more than what you pay
for.

I should get some terms defined here. Your frame has 4 tubes:

TOP TUBE: The, uh, top tube. The rear brake cable usually runs along it.

SEAT TUBE: The tube which holds the SEAT POST.

DOWN TUBE: The other main tube, the diagonal one on the bottom. It has
shifters on some road bikes, usually has water-bottle brazes, and
the shifter cables usually run along it.

HEAD TUBE: *Not* a cheesy porn flick. This is the short tube which
connects the down tube to the top tube. Inside it are the STEERER
TUBE and the STEM.

STEERER TUBE: The tube connected to the FORK (which holds the front wheel)
and the STEM through the HEAD TUBE.

STEM: Controls the STEERER TUBE and holds the handlebars. It is adjusted
via an allen bolt (usually) on the top.

SEAT POST: Holds the seat. It is adjusted by a bolt at the top of the
SEAT TUBE. It holds the seat in a clamp; the seat is adjusted via
a bolt on this clamp.

I look for the following minimal features in a bike:

ALUMINUM WHEELS: Not only are they lighter than steel, they”re easier to
keep in adjustment, and they are *much* better at braking when wet.
They say that upgrading your wheels is the easiest way to upgrade the
performance of your bike; start off with good ones.

NO IDIOT LEVERS: If your bike is a road bike with the curved “drop”
handlebars, the brakes are mounted on the “hooks.” On cheap bikes,
in addition to the main brake lever, there is another lever that
extends inwards, parallel to the bars. Do not buy a bike with these;
they are extremely dangerous (they don”t brake well enough to use in an
emergency) and they”re a sign that the bike is not designed well.
If your bike has these levers, I suggest removing them. Really.

NO STEM SHIFTERS: Again, this is for road bikes; on some bikes, the
shifters are mounted on the stem (the thing that holds the handlebars).
The idea is that they”re closer to your hands and therefore easier
to use; the reality is that you have to raise your center of gravity
while twisting your body to use them. They also are very susceptible
to being hit by your knees while climbing (a very bad scene), and
in an accident they can wind up goring your throat. Insist on
down-tube or bar-end shifters for road bikes.

As you probably know, there are three main types of bikes:

ROAD BIKES: Dropped handlebars, thin tires, downtube shifters. Road bikes
are lightweight and fast and have significant advantages over the
other types for road riding. They can also ride on packed dirt roads
without much trouble; they can”t ride in loose dirt or sand. One
drawback road bikes have in Berkeley is that, because of their narrow
tires, they don”t handle bumps and potholes as well as the other types.
One advantage they have is that thieves don”t seem to be interested in
them.

Touring bikes, such as the Bridgestone RB-T, are road bikes with
wider tires and a more relaxed geometry to handle bumps better. I find
them to be excellent for commuting; my main commuting bike is a
Schwinn Voyageur (sadly, Schwinn no longer makes it). They are slower
than other road bikes but faster than the other types.

One problem you”ll have buying a road bike is that most bike stores
don”t carry inexpensive ones, so you”ll find it difficult to get a
test ride on anything cheaper than $500. Since I highly recommend
a test ride, this is a significant drawback.

MOUNTAIN BIKES: Straight handlebars, big knobby tires, handlebar shifters.
Mountain bikes own the lion”s share of the new bike market; they”re
fun to ride and cool to look at (people who want to look at their bikes
rather than ride them tend to buy mountain bikes). They are great at
handling bumps and can also ride in loose dirt or on singletrack trails.
They are significantly slower than road bikes on roads; just yesterday
I was riding my mountain bike and felt like I had no energy at all.
They also are targets for theives in Berkeley; if you own a mountain
bike, be prepared to take extra precautions to protect it.

Mountain bikes are viewed as being more comfortable because your riding
position is more upright; this is incorrect. This position is more
comfortable only while you”re looking at the bike, or perhaps sitting
on it in the bike store. It puts more strain on your lower back, and
the lack of extra hand positions also causes problems on long rides.

Mostly because of the theft issue, I can”t in good faith recommend a
mountain bike for commuting in Berkeley. If you”re looking for a bike
you can take anywhere, or if you specifically want to ride off-road,
mountain bikes are great, but I think taking them to campus every day
is a bad idea unless you have a private office where you can keep them.

HYBRIDS: After the mountain bike boom of the early 80”s, people started
realizing that they weren”t riding their mountain bikes off-road.
Since mountain bikes have significant disadvantages on-road, hyrbids
were created to combine the features of mountain bikes and road bikes.
They usually have an upright riding position but less so than mountain
bikes. Their tires are wider than road bikes” but usually not too
knobby. They often have handlebars with more hand positions than
mountain bikes do.

As you might expect, they are faster than mountain bikes but slower
than road bikes. They are theft targets more than road bikes but
less than mountain bikes. They are better in loose dirt than road
bikes but aren”t really appropriate for serious off-road riding.
I find that hybrids make decent commuting bikes, but the upright
riding position makes them undesirable for long rides. For around-town
riding they”re good though. There tend to be a lot of hybrid selections
under $500 since they”re aimed at casual users; the Bridgestones (if
you can still get them) are nice bikes.

There are also recumbents (bikes on which you sit on what looks like a
deck chair) and tandems. Recumbents are comfortable and attract a lot
of attention; they are bad at climbing hills but good at flats and
downhills. There”s a growing recumbent market. Tandems (two-man bicycles)
are the most fun you can have on two wheels, but good ones are expensive.

HOW TO CHOOSE A BIKE

First, obviously, you need to decide how much money you are prepared to
spend. I advise being generous; as I said earlier, spending extra money
will get you a better bike. Expect to spend at least $250; you won”t
get many choices at that level so realistically you should expect to spend
$300. If you can”t afford to spend that much, you can get good deals
on good used bikes if you look around; lots of people never ride their
bikes and eventually wind up just dumping them. A used quality bike
will serve you much better than a new Target junker.

Once you have a price range, head to a bike store. I personally like
Missing Link, but any bike store with a lot of bikes in stock is fine
(except Hank & Frank, they suck rocks). Do not allow yourself to be
rushed; test-ride a number of bikes and don”t skimp on the rides (details
on test riding below). Consider theft resistance; does the bike have
a quick-release seat that you”ll need to buy a cable for, or take with
you? Look at the frame joints; are the welds (or brazes) clean or
sloppy? Are the wheels true? The brake lever end should have a maximum
travel of about 2 inches (a little less for mountain bikes) and you should
not be able to bottom it out. Are the brakes sidepull or cantilever?
(Cantilever brakes are mounted on pivots on the fork and seatstays, with
the main cable pulling a transverse cable which straddles the wheel.
Sidepulls are mounted directly above the wheel with the cable pulling
them together on one side.) Cantilever brakes are good if you plan to
put fenders on the bike (which immensely improves cycling in the rain).
Sidepull brakes tend to work more smoothly and stay in adjustment better.

HOW TO TEST RIDE A BIKE

The main things you”re interested in on a test ride are to find out how
the bike handles bumps, to find out how the brakes and shifters work,
and to see if it was well-built. Before you go to the bike shop you
should have a plan for where you intend to take the bikes you test.
Take the bike on Hearst or somewhere similar; how much does it jar you when
you”re going downhill? When it hits bumps, do you hear unexplained rattles?
You should expect your rear derailleur to snap when you hit bumps, but if
other things on the bike are rattling it”s a sign that something is
cheap or poorly fitting.

To test the shifters, start by riding on a flat road and shifting through
all the gears. Does it easily shift into the lowest gear? If you
overshift into the lowest gear, does the derailleur sound like it wants
to self-destruct into the spokes? (if it does, stop overshifting, but
that”s a count against the bike.) Does it shift cleanly into the
highest gear, without jumping over the end? Can you shift between the
front chainrings easily, without the chain jumping off? On a triple
crankset it can be expected that the chain will jump off sometimes
when shifting to the smallest chainring, but on a double it should never
hop off and it should never hop off when shifting to the large chainring.
Try out each cog for a while; does the chain run smoothly and quietly
on each cog, or does it chatter or jump off one or more?

Try to downshift while pedaling uphill; it”s harder to shift with tension on
the chain and cheaper shifting systems will fail to. If you”re spending
$500 or more, though, you should insist that the bike be able to make this
shift cleanly.

When you”re riding uphill, do you hear pinging sounds in the wheels?
If you do, they were poorly built; the sounds will eventually go away
but the wheel will need to be retrued.

Head downhill and hit the brakes; do you stop smoothly? Do you feel like
you have control over your deceleration? Cantilever brakes are somewhat
rougher than sidepulls and feel spongier, so expect that.

Walk the bike while turning the handlebars; do they turn smoothly through
their range of motion, or does it feel like there are notches at various
points (especially straight ahead)? Try some medium-speed turns on
pavement; does the bike corner solidly (if a road bike; knobby-tire bikes
corner horribly on pavement)?

If you are planning on riding off-road, find a dirt trail or two (there
are some on campus) and see how the bike handles them; can you accelerate
from low speed on the dirt? Can you turn without skidding? Can you shift
on a bumpy section?

As I said, try out a number of different bikes in your price range; there”s
no way to measure how good a bike feels to you. And most importantly,
once you buy it, RIDE BIKE!

SIZING A BIKE

There is no formula to determine perfect bike size and adjustment; there
are plenty of rules of thumb, but really bike adjustments are a highly
personal thing. You are the only one who can determine your perfect setup.

That said, here are some rules of thumb: Your seat height should be adjusted
so that your leg is almost fully extended at the bottom of your pedal stroke.
Test this by sitting on the bike leaning against a wall. Put your heels
on the pedals and pedal backwards; your leg should be fully extended at the
bottom. Most people adjust their seats too low; I”ve seen “cycle safety”
manuals that recommend keeping your seat low enough that you can put
both feet on the ground while sitting on your seat (HINT: Do not do this).
Low seat height is the major cause of cycling knee injuries.

You can adjust the tilt of the seat by loosening the bolt on the clamp
underneath it. Most people are comfortable when their seat is level, or
tilted just slightly forward, but again, this is mostly a matter of
personal preference. I”ve ridden comfortably with a seat tilted back.

Stem height is another preference thing; most people are comfortable when
the height of the stem is about the same as the height of the seat; higher
will give a more upright riding position, lower will bend you over more.
Mountain bikes usually have stems that place the handlebars a little
higher than the seat to promote the upright riding position.

Stem extension is a measure of how far in front of the head tube the
stem holds the handlebars. It cannot be adjusted without buying a new
stem, but you might be able to get a good bike shop to swap stems on a
new bike. If it feels like the handlebars are too far away, a stem
with a shorter extension (ahem) might be good for you. If you have a
long torso, a longer extension could help.

If you have dropped handlebars, the tilt of the bars can also be adjusted;
usually the bolt is under the stem where it clamps the handlebars. As
a general rule, the end of the bars should be aiming at a point somewhere
between the top and the center of the rear wheel, but again, that”s
a preference thing. Some people do whacky things with the bars, pointing
the ends straight up in the air or having them upside down. I recommend
against that; it invites impalement. Also, ALWAYS keep something stuffed
in the end of your bars, whether it”s the plug that game with the
handlebar tape, a fancy expander plug, or a champagne cork.

That”s about it for the adjustments. Always remember that your gut
feelings are more important than the rules of thumb; if you are more
comfortable, especially on long rides, with some non-standard setup,
by all means use it. And Ride Bike!