| Information |
Method
of Inspection |
Reason
for rejection |
| A. Roller Brake Test |
Serious
under inflation of tyres is not a reason for failure however
a tester may decide not to conduct a brake test if tyre
damage is likely.
When using a roller brake tester the wheel not on the rollers
must be braked and chocked against the reaction force. This
is especially important for lightweight machines and those
with small wheels.
In the case of a linked brake system, it may not be possible
to apply the brake of the wheel not being tested prior to
starting the test.
If a roller brake test is repeated, the chock should be
removed, the machine resettled in the rollers and the chock
replaced.
The retardation force of a side car brake is not to be included
unless it is operated by one of the motorcycle brake controls.
The efficiency of each system operated by a single brake
control is the ratio of the total retarding force generated
by that system divided by the weight of the machine and
rider
Total retarding force for one system/weight of machine plus
rider (tester) x 100
Most machines have two controls, one operating the front
wheel brake and the other the rear wheel brake. The efficiency
for front and rear wheels can then be calculated as above
(or checked by a gradient test).
Where a linked or dual system is operated by one control,
the retarding force used in the efficiency calculation is
the total from both wheels when operated by that control
only. In this case, the other control will probably operate
on one wheel. The reasons for failure 1 and 2 apply whether
single or dual systems are fitted.
Motorcycles first registered before 1 January 1927 are only
required to have one means of operating the brakes, which
shall have an efficiency of at least 30%.
The tester may know that a higher brake efficiency
Is normally obtainable for the model tested, although the
machine has passed the performance test. In this case the
owner should be advised that the braking system appears
to require adjustment or repair,
Where there is doubt about the effect
of a defect noted during the brake test, the tester may
at his discretion, carry out a road test. (See Introduction
item 5).
The assessment of bind, grab and judder in sub-sections
3.3C and 3.3D can be
performed at any appropriate point during the test.
|
A. ROLLER BRAKE TEST
With the tester seated on the machine locate the front wheel
in the rollers of the brake tester, ensure that the machine
is lined up in the straight ahead position and settled in
the rollers, (see information column)
Select the correct direction of operation so that the wheels
rotate in the forward direction.
1. Start the brake rollers and allow the front wheel to
stabilise. With the rear brake fully applied (see information
column) gradually apply the front brake until maximum effort
is achieved or the wheel locks and slips on the rollers.
Note the reading at which the maximum braking effort is
achieved and release the brake.
Start the rollers, gradually increase the front brake effort
to about half the maximum reading and observe the way it
builds up. Hold steady and check for fluctuations. Release
the brake and observe the way in which the braking effort
reduces.
Move the machine forward until the rear wheel is located
in the rollers. Repeat procedures 3.3A1 and 3.3A2.
Check the side car wheel brake if applicable (see information
column) as in procedures 3.3A1 and 3.3A2.
2. Calculate the efficiency of each braking system, (see
information column)
|
1.
a sticking or binding brake, (see information column)
b. severe grab or judder, (see information column)
c. a braking effort that does not rise or fal( in proportion
to the lever or pedal force applied
d. excessive fluctuation of brake effort with steady application
of the brake. (see information column).
2.a. an efficiency of less than 30% when one of the brake
controls is operated. This will normally be calculated from
the retarding force at either the front or the rear wheel,
[see information column)
b. an efficiency of less than 25% when the other brake control
is operated. This will normally be calculated from the retarding
force at the other wheel (see information column).
|
| B.
Plate Brake Test |
| As
3.3A |
To
calculate the brake efficiency it is necessary to determine
the combined weight of the motorcycle and the tester while
seated in the normal riding position.
1. At a steady speed of approximately 4 mph drive the machine
onto the plate tester. As soon as the front wheel is on
the plate high friction braking surface gradually apply
the front brake until maximum effort is achieved or the
wheel locks and skids.
Note the way in which the brake effort increases and the
maximum value achieved.
Repeat procedure 1. above for the motorcycle rear wheel
and in appropriate cases (see information column) the side
car wheel.
2. Calculate the efficiency of each braking system, (see
information column)
Repeat procedures 1. and 2. above a second time to confirm
any reasons for
failure.
|
1.
a. a sticking or binding brake (see information column).
b. severe grab or judder (see information
column).
c. a braking effort that does not rise or fall in proportion
to the lever or pedal force applied.
d. excessive fluctuation of brake effort with steady application
of the brake. (see information column)
2.
a. an efficiency of less than 30% when one of the brake
controls is operated- This will normally be calculated from
the retarding force at either the front or the rear wheel
(see information column).
b. an efficiency of less than 25% when the other brake control
is operated. This will normally be calculated from the retarding
force at the other wheel (see information column).
|
| C.
The Floor Test |
| AS
3.3A |
The
apparatus required for this test comprises a spring balance
and system of pulleys so arranged that the effort required
to pull a machine and rider forward against the brakes may
be measured. The spring balance may be used to determine
the weight of the motorcycle and rider.
With the machine held upright and in a straight ahead position,
attach the cable from the spring balance to the front of
the motorcycle using a strap around the front forks or the
headstock.
The tester should sit astride the machine operating each
brake in turn and note the readings while the assistant
operates the spring balance system.
1. With each brake applied in turn record the effort required
to move the motorcycle and rider forward. Calculate the
efficiency of each braking system, (see information column).
|
1.a.
an efficiency of less than 30% when one of the brake controls
is operated. This will normally be calculated from the retarding
force at either the front or the rear wheel, (see information
column).
b. an efficiency of less than 25% when the other brake control
is operated. This will normally be calculated from the retarding
force at the other wheel -reference 1 above (see information
column).
c. a sticking or binding brake (see information column).
d. severe grab or judder (see information column).
|
| D.
The Gradient Test |
As
3.3A and
To check the efficiency of 25% one end of the platform must
be raised to a height equivalent to 25% of the platform
length (ie 700mm for a 2.8m platform). Similarly to check
a 30% efficiency one end must be raised to a height equivalent
to 30% of the platform length fie 840mm for a 2.8m platform).
Each brake must be tested separately and the tester must
not exert any other retarding force.
|
The
equipment required for this test consists of a platform
one end of which can be raised.
Raise the end of the platform by the appropriate amount,
(see information column )
1. Sit astride the 'downhill' facing machine. Apply each
brake in turn and confirm that the machine can be held stationary.
|
1.
a. an efficiency of less than 30% when one of the brake
controls is operated. This will normally be from the retarding
force at either the front or the rear wheel (see information
column).
b. an efficiency of less than 25% when the other brake control
is operated. This will normally be from the retarding force
at the other wheel - reference 1 above (see information
column).
c. a sticking or binding brake (see information column).
d. severe grab or Judder (see information column).
|
| Issue
Date: July 2001 |
