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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 (1-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:

  1. Rigidity
  2. Low center of gravity
  3. Secure frame attachment (brazed or clamped at two points)
  4. Structural stays capable of supporting load
  5. Level top
  6. 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:

  1. Lightness in weight
  2. Protection from axially and radially directed impacts
  3. Ventilation
  4. 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.


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