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Tech
cont'd
8. If you disengaged the brake quick-release mechanism, re-engage it to restore
correct brake pad-to-rim clearance.
9. Spin the wheel to make sure that it is centered in the frame and clears the
brake pads; then squeeze the brake lever and make sure that the brakes are
operating correctly.
B. Seat Post Cam Action Clamp
Some bikes are equipped with a cam action seat post binder. The seat post cam binder
works exactly like the traditional wheel cam action fastener. While a cam action binder looks like
a long bolt with a lever on one end and a nut on the other, the binder uses an over-center cam
action to firmly clamp the seat post (see fig. 8a).
WARNING
: Riding with an improperly tightened seat post can allow the saddle to
turn or move and cause you to lose control and fall. Therefore:
1. Ask a certified bike mechanic to help you make sure you know how to correctly clamp
your seat post.
2. Understand and apply the correct technique for clamping your seat post.
3. Before you ride the bike, first check that the seat post is securely clamped.
Adjusting the Seat Post Cam Action Mechanism
The action of the cam squeezes the seat collar around the seat post to hold the seat post
securely in place. The amount of clamping force is controlled by the tension adjusting nut.
Turning the tension adjusting nut clockwise while keeping the cam lever from rotating increases
clamping force; turning it counterclockwise while keeping the cam lever from rotating reduces
clamping force. Less than half a turn of the tension adjusting nut can make the difference
between safe and unsafe clamping force.
WARNING
: The full force of the cam action is needed to clamp the seat post
securely. Holding the nut with one hand and turning the lever like a wing nut with
the other hand until everything is as tight as you can get it will not clamp the seat post
safely.
WARNING
: If you can fully close the cam lever without wrapping your fingers
around the seat post or frame tube for leverage, and the lever does not leave a clear
imprint in the palm of your hand, the tension is insufficient. Open the lever; turn the
tension adjusting nut clockwise a quarter turn; then try again.
C. Brakes
There are three general types of bicycle brakes; rim brakes, which operate by squeezing
the wheel rim between two brake pads; disc brakes, which operate by squeezing a hub-mounted
disc between two brake pads; and internal hub brakes. All three can be operated by way of a
handlebar mounted lever. On some models of bicycle, the internal hub brake is operated by
pedaling backwards. This is called a Coaster Brake and is described in this manual in a further
section.
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