BICYCLE EQUIPMENT, PARTS, ACCESSORIES
Overview.
During the last half of the-1960's a radical shift in bicycle purchases took place. The
modern lightweight ten-speed bicycle began its domination of the bicycle market in
America. The new user was the adult. In the next ten years more than 45 million new bikes
were added to the market, more than doubling the number of bicycles in America. Today,
following light sales in 1975 and 1976, strong growth has returned to the bicycle market,
with annual sales during the next five years projected at 8-10 million per year. A healthy
percentage of these will be ten-speeds (50%) .
This section of the report discusses the handling characteristics of the adult
ten-speed, safety factors, safety accessories, bright clothing, and what effect equipment
has on cause and prevention of accidents.
The Bicycle.
The bicycles used by the participants of Bikecentennial were lightweight ten-speed
machines. A few participants used three-speed bicycles, and one person cycled across the
country on a single-speed bicycle. Ten- and fifteen-speed (a variation of the ten-speed
that has an additional chainring) bicycles, in fact, comprised 98.9% of all bicycles in
use on the trail. All but 10% of the bikes in use on the trail had 27-inch narrow tires
(1¼-inch). The bikes averaged 28-30 pounds in weight.
This bike is often selected for long-distance touring for its lightness, low rolling
friction, responsive handling, and flexibility for meeting the challenging terrain. Used
properly, the bike allows greater bicycling efficiency. Following a few days of practice,
distances of 40-60 miles can be handled with relative ease, and a day of 100 miles is
within the reach of many.
Equipment Features.
There are many options in equipment on the ten-speed, and several play an important
role in its handling and the safety of its use for touring. The most basic part of the
bike, the frame, is one of the more critical factors. The predominant frame type used on
the trail was the diamond (traditional men's frame). Although nearly one-third of all
riders were women, only 2.9% of the frames were the (women's) dropped tube frame; another
3.6% were the slanted mixte frame.
The diamond frame accounted for 91.2% of all frames in use. Another 1.6% of the frames
were tandem. The diamond frame has excellent handling characteristics, is the lightest in
weight and the strongest on the commercial market. Few people pay attention to their frame
selection, other than to buy a size that feels right. However, when purchasing a frame for
touring purposes it is important to choose a model that is not likely to shimmy. Bikes
which are designed primarily for racing, or have a short wheelbase, thin gauge tubes, or
short fork rake, are all prone to shimmying on fast downhill descents. This phenomenon is
especially likely when 20-30 pounds of weight is added to the rear of the bike (panniers),
and sets up a swaying motion when the bike is turned. The hazard is especially pronounced
for tall people who require frame sizes above 23 inches. Bicyclists are cautioned to check
with their local bike dealer and announce the intended purpose of the bike, so that
characteristics that lead to shimmying can be avoided. Also important in handling, a frame
should be "tracked" when the bike is being set up by a bike shop. This simple,
but precise, procedure is rarely done, but adds dramatically to the overall performance of
a bicycle.
Wheels.
Most of the bicyclists (90%) rode the trail on the thin 27" x 1/4" tires
found as standard equipment on most ten-speeds. Although this wheel is
one of the most efficient and responsive in use, it is more fragile and prone to abuse.
The wheel will not hold up to potholes, debris, and gravel as well as the once standard
lightweight (26" x- 1 3/8"). We do not have sufficient data to suggest which
wheel performs with greatest safety. For the time being it is suggested that bicyclists be
informed of the different handling characteristics and be alerted to the specific hazards
that may cause trouble.
Other Parts.
The drop style handlebars made up 95.7% of all handlebars along the trail. Brakes were
hand controlled in 97.4% of cases, with 22.1% of the riders using the brake extension
levers as an added feature. An unusually high percentage of riders (94.8%) used toe clips
for added efficiency. Used properly, toe clips cut down on accidents by preventing foot
slippage.
Breakdowns, Part Failures.
Bikecentennial riders were asked to list any parts that failed during the summer. The
ten-speed bike, if well maintained, continues to perform well. However, many riders
started out on ill-maintained bikes, and subjected the machines to severe conditions. The
"working parts" of the ten-speed bicycle are exposed to the elements.
Derailleurs, chain, crankset, sprockets, freewheel, and brakes are all components that are
vulnerable to damage from impact, mud, grit, maladjustment and wear. In order to enjoy a
bicycle to the fullest extent and with the greatest safety, the rider must have at least
some basic knowledge of the mechanical principles required to keep a bike well maintained.
Derailleur cables and brake cables need to be set at the proper length, front and rear
derailleur adjustment screws have a proper setting, spokes must have the proper tension to
provide wheel alignment and roundness, tires must be kept at proper inflation pressure, and all bearings, including those found in the headset, bottom bracket,
pedals, and axles, have a proper adjustment.
The influence of a trained leader and the environment of a small group were ideal for
the instruction of basic maintenance and impromptu seminars on the care of various bicycle
components. We feel confident that this was a contributing factor in reducing bicycling
accidents for the long-distance cyclists.
Of the accessories and parts that did fail, the components associated with the power
train (sprocket, chain, freewheel, cluster, and derailleurs) failed most frequently.
Power Train Parts that Failed |
|
|
Rear Derailleurs. |
8.8% |
|
Front Derailleurs |
5.9% |
|
Chains |
9.0% |
|
Freewheels |
9.0% |
|
Cranksets |
6.8% |
Non-Power Train Parts that Failed |
|
|
Pedals |
5.5% |
|
Brakes |
3.4% |
|
Rims |
6.4 % |
|
Seats |
4.1% |
|
Seat Posts |
0.6% |
|
Handlebars |
0.2% |
|
Hubs |
4.6% |
|
Spokes |
29.6% |
|
Headsets |
2.5% |
|
Other Items |
10.9% |
Accessories.
The common accessories used by a bicycle tourist include a rear carrier, rear panniers,
front handlebar bag, water bottles, and a tire pump. In addition, tents, sleeping bags,
camp stoves, and cooking pots are often strapped to the rear of the bicycle with shock
cords. Since we noted a nearly triple accident rate for bicyclists transporting equipment
with packs and carriers, we examined accessories closely.
Carriers. Most everyone used a bolt-on carrier,
which lacks rigidity under a load and tends to allow the weight to shift back and forth,
especially when climbing a mountain or in a sudden turn to avoid a pothole, gravel or
debris. An unexpectedly high percentage (13.8%) of riders reported that their carrier
failed. A well-designed carrier system should include:
- Rigidity
- Low center of gravity
- Secure frame attachment (brazed or clamped at two points)
- Structural stays capable of supporting load
- Level top
- Access to brake mechanism
Panniers and Handlebar Bags. Bicycle panniers, packs, and handlebar
bags received a thorough workout during the summer's activities. Most of the problems with
these accessories centered around the fastening devices. Velcro straps came loose, and
some metal snaps sheared off. In either case the bag could fall into the wheel, causing a
serious accident. The failure rate for panniers and handlebar bags was 15.1%. Our feeling
is that considerable study is needed toward reducing the frequency and seriousness of
these accidents.
Safety Accessories.
To encourage safety, Bikecentennial recommended basic safety equipment to aid in
visibility of the cyclist, detection of overtaking traffic, and protection of the head.
These safety items and their value is discussed below.
Rearview Mirror. The most popular mirror is a small one-inch square
glass mounted on eyeglass frames or the visor of a helmet. The design resembles the
standard dentist's mirror. Worn two inches from the eye, the mirror provides an excellent
view of approaching traffic with a slight twist of the head. This allows the rider to be
aware of any potential hazard without having to turn around, a maneuver
that causes the rider to sway into traffic. It is difficult to estimate how many accidents
were avoided through the use of such a mirror; however, about 16% of the riders used such
mirrors, and no riders using such mirrors were hit by an overtaking motor vehicle.
Further, it was through the use of a rearview mirror that a cyclist had information to
testify at a coroner's court in Dillon, Montana, about the events that led to the death of
one of the TransAmerica bicyclists. Other types of mirrors in use include a wrist-mounted
mirror and a standard handlebar-mounted mirror. The handlebar-mounted mirrors are not
popular among bicycle tourists due to their ineffectiveness due to vibration, difficulty
of adjustment, weight, and potential of being brushed by an overtaking auto.
Helmets. Bicycle helmets are credited with having protected several
riders from serious concussions. About 270 of the riders reported they used a helmet on
their trip. However, those having accidents disclosed that only 22% were wearing a helmet
at the time of their accident. Hot weather and other factors led to a number of helmets
being carried on the back of the bike, leaving the rider unprotected. Getting adequate
ventilation and head protection is a real dilemma for the bicyclist, since most tourists
ride during the hot summer months. Inadequate ventilation could cause heat exhaustion or
other illness.. Additional study is needed in helmet design. Important characteristics of
the well-designed helmet are as follows:
- Lightness in weight
- Protection from axially and radially directed impacts
- Ventilation
- Light color and reflectivity
Fanny Bumpers and Safety Flags. Bikecentennial issued a fanny bumper or safety flag to
all group cyclists to increase their visibility on the road. A fanny
bumper is an orange fluorescent triangle, international symbol of slow-moving vehicles.
These items, along with bright clothing and equipment, are credited with reducing the
number of overtaking accidents., About 70% of the riders stated they frequently wore
bright clothing. In contrast, 52.3% of the accident victims said that they were wearing
bright clothing on the day of their accident. Fanny bumpers and safety flags could be seen
from distances of 200-600 yards, often well before the actual rider was clearly
distinguishable. Motorists have been reported to be more cautious in their approach to
riders displaying these added safety devices. Based on our observations, it is our belief
that bright clothing and reflective safety devices such as fanny bumpers and flags are a
helpful deterrent to bike/motor vehicle-related accidents. The value of such items becomes
especially important during twilight, in fog, and on cloudy days. It is recommended that
bicycle touring equipment such as packs and handlebar bags be manufactured in bright
colors, such as yellow, orange, or red. |