Pacific Cycles FROG - Manual (Page 9)

riese und müller GmbH Frog Manual
Use both brakes simultaneously and note that because of the weight transfer effect, the front brake needs to provide the vast
majority of the braking power. But you also need to avoid locking the front wheel, which could lead to going over the bars or an
uncontrolled slide.
When your Frog is delivered, the
left brake lever will activate the front brake. Be sure to get familiar with this arrangement, or
ask your dealer to swap the brakes over to your preferred set-up.
Danger
: be careful as you get used to your brakes! Practice emergency stops away from traffic, until you have the bike under
complete control. This can be vital for avoiding accidents in traffic.
How they work, and how they get worn out:
When you apply the brakes, using a hand-operated lever or a back-pedal (coaster) brake, a fixed brake pad presses against a
rotating braking surface, and friction occurs. The bike is slowed down through this friction. Alongside the force with which the
blocks push against the rim, another important factor is the so-called coefficient of friction between the two surfaces.
If water, dirt or oil get onto the braking surface, this coefficient of friction will change. This is why a rim brake has poorer
performance when it’s wet, and doesn’t stop you as quickly.
Friction also causes wear on both brake blocks and rim. This wear is accelerated if you ride a lot in the wet. If the rim wall is worn
away far enough, the pressure of the tyre can blow the rim apart. The wheel can then lock up, and the inner tube split: in either
case it can lead to a crash.
Once the wear indicator on the rim is not visible anymore, you should take the bike to your dealer and let him change the rims.
Warning
: Wet conditions diminish braking performance. You need longer braking distances when it’s raining! When you change
brake blocks, use only approved brands compatible with your rims. Your dealer will be happy to advise. Ensure that your braking
surfaces remain absolutely free of wax, grease and oil. Watch the wear indicator at the rims. Worn-out rims can lead to blow-out
punctures and dangerous accidents!
PAGE 22
To ensure effective stopping at all times, brakes should be checked often and, if necessary, adjusted.
Danger
: Damaged brake cables, with, for example, individual strands poking out, must be replaced immediately, to prevent brake
failure and possible accidents. Ask your dealer for advice!
Checking, adjusting and balancing brakes
V-brakes consist of left and right-hand arms, mounted separately each side of the wheel. When you use the brake, the two arms
are drawn together by the cable. The arms pivot inwards on their mounting points and the blocks rub against the rim walls.
Function check:
· Check that the brake blocks are aligned precisely with the rim, and have plenty of braking material left. If the grooves in the
block are worn away, it’s time to replace them.
· The brake blocks should touch the rim with the front part of the block making contact first. The rear part of the block should
at that point be one or two millimetres from the rim. Seen from above, the brake blocks should make a V-shape. This V-
shaped adjustment helps avoid squealing brakes.
· The brake blocks should both hit the rim at the same time when you pull the lever.
· The brake lever must have some movement in reserve – when applying full braking power it must not reach the handlebar.
Danger
: Adjusting brake blocks against the rim requires a good degree of mechanical skill. Errors could lead to brake failure and
accidents. If in any doubt, leave the adjustment of brakes or changing brake blocks to your dealer. Poorly adjusted brakes can lead to
serious accidents!
PAGE 23
To balance the brakes, use the adjustment screw in the side of the brake arm body. Adjust this screw until the blocks are the same
distance from the rim on each side.
To adjust the brakes, loosen the knurled locknut where the cable enters the handlebar brake lever. Turn the knurled and slotted
adjustment screw out by a few turns. The ‘dead’ lever motion before the brakes bite will be reduced.
Hold the adjustment screw in place, and turn the knurled locknut tight against the brake lever housing. This stops the adjustment
screw vibrating loose.
Check that the slot in the screw does not face upwards or forwards, as this can allow water and dirt to get in.
Danger
: It is essential after any brake adjustment that you carry out a static brake test, and that you ensure that the brakes are
hitting the rim with their full area. Brake failure or a locked-up wheel could otherwise cause an accident.