Chain link: SRAM Power Link (and similar designs by other brands). Makes removing and putting on your chain a breeze (for cleaning, lubrication or even untangling it from your frame when you drop your chain and it jams in your cranks). You no longer need a chain-breaker tool.
Frame pump: Topeak Road Morph – works like a mini floor pump. T-handle, fold-out foot-peg and thumb-lock head let you pump up to 100 psi (7 atm, 700 milliBar) without a struggle or risk of bending your Presta valve stem (also adapts to Schrader valves). It’s been called “the smug pump” by cyclists who don’t have one (and wish they did).
Fender (rear): Supergo Aireon MTB – inexpensive, also fits road bikes (650C & 700C) and Air Fridays (20”) too. [Performance Bike, the parent company, has retired the SuperGo brand as of early 2006.]
Hydration packs: (CamelBak, Hydrabak, Platypus, etc.) I drink more consistently and regularly than when I carried water bottles in frame mounted bottle cages and had to reach down between my legs to get at them. Many packs are also well-suited to carrying tools, inner tubes, energy bars, route sheets and extra clothing that would otherwise require a saddle- or handlebar bag. I even carry my frame pump in my hydration pack instead of on the bike.
Pedals: Bebop pedals have 20° of float, two-sided entry, lifetime sealed bearings requiring no maintenance, and long-wearing metal cleats. The cleats work with both road and MTB shoes, although on MTB shoes you’ll probably have to cut away the outsole near the pedal axle for clearance.
Prevent dropped chain: The Third Eye Chain Watcher mounts on the down tube, sits near the inner chainring to prevent the chain from falling (and jamming) between it and the frame. Another choice (I’ve only heard about) is the N-Gear Jump Stop.
Tire lever: Crank Brothers Speed Lever – a portable, lightweight, collapsible version of a shop tire lever, faster & easier to use than the typical 2–3 stubby plastic or metal levers.
Bug bites and stings: Therapik is a 9v battery-powered device that uses scientifically proven infrared heat therapy to treat painful stings and itchy bug bites. I’ve been stung by bees often enough while biking to carry one with me.
Heat-shrink tubing: great for keeping cable ends from fraying. Lighter than traditional metal crimp-on caps for cables, easy to remove when you want to, requires less skill to install than soldering cable ends or crimping metal caps.
Merino wool base layers, socks, arm-warmers, full-fingered gloves. Merino wool is non-scratchy and machine-washable. Wool doesn’t stink like synthetics, breathes well and keeps you warm even when wet. Lightweight merino wool base layers work great for cool weather/high altitude. Zip-T neck undershirts keep your carotid arteries warm, which make you feel warmer than if they were exposed to cold air. On the downside, wool can be saggy, which is why I still wear synthetic jerseys, lycra shorts and synthetic knee/leg warmers.
Be-seen lighting: A UK study said that some 60% of automobile-bike collisions happened because the motorist couldn’t see the oncoming cyclist in daylight and turned into them. I now use daytime blinkies always, mounted on my helmet. Blackburn Flea 2.0 are small yet bright multi-LEDs that recharge via USB. In intermittent blink mode, the front/white light lasts about 6 hours; the red/rear supposedly lasts 12 hours but I haven’s had occasion to run mine that long yet.
Performance Century gel shorts – the gel pad is too thick and retains heat.
Italian jerseys – many brands tend to be cut too long for their girth (and I’m not a big guy). Consequently, they bunch up at the waist and things get pushed out of the back pockets.
Italian cycling socks – tend to lose their shape faster and wear out sooner than, for example, DeFeet socks.
Polypropylene as a base layer fabric – feels greasy after many washings, retains odors. Thermax costs the same and performs better. Merino wool is even better: not scratchy, warm when wet, doesn’t smell.
Rain jackets without “pit zips” – no matter how “breatheable” a fabric is (even GoreTex), it won’t fully cope with the heat and perspiration you generate from cycling. Underarm zippers and vents on the back help tremendously.
Packable full-size bike: S&S Machine Bicycle Torque Couplers (BTC™) – allow a full-size frame to disassemble and fit into a 26”x 26”x 10” case for long-distance transport. Rigorous tests demonstrate that BTC equipped tubes are stronger and stiffer than the unmodified tubes. My regular road bike has BTCs on it and feels and performs just like a normal bike.
Folding travel bike: Air Friday – made-to-measure high-performance bike, fits into a standard hard suitcase. Quickly folds in half around a pivot near the bottom-bracket to fit inside subcompact cars. Its titanium cantilever beam top tube acts as a suspension system to cushion its rider from road shocks.
Commuter bike: Brompton – folds/unfolds completely in < 15 seconds. Compact enough when folded to stash under a cubicle desk, and go as a piece of carry-on luggage on trains and buses.
Garmin Forerunner 201. Designed for runners, but works for cycling too. See my Amazon.com review for a detailed evaluation. Garmin to date has not released a firmware update to address the US Daylight Saving Time change starting in 2007: use the manual DST settings March/April and October/November.
After many years of steady service, my ForeRunner 201’s display began to fail intermittently. I’ve replaced it with a Garmin Edge 705.
LoadMyTracks is freeware from ClueTrust.com for Mac OS X which transfers data between GPS devices and Macs. It can save GPS data in GPX and KML format. TrackRunner, donationware from Laniesoftware works with LoadMyTracks to display tracks on Google Maps (without using a web browser), as well as graph and keep a log of your performance.
GPS Visualizer is website which will map uploaded GPS data onto satellite/aerial photos, as well as produce elevation profile graphs, for free. It can also convert GPX files into KML/KMZ to display in Google Earth and Google Maps.
A guide to chain wear measurement tools.
Chain-suck – an extensive and thorough discussion and investigation of its causes and how to prevent it.
Indexed steering – what causes it and the solution to the problem.
Soul bikes gears/drivetrain calculator. It’s quite flexible and elaborate enough to initally appear confusing; however, the interface becomes clear with use.
If you believe that “aluminum is harsh” or “steel fatigues and becomes soft” you need to read Sheldon Brown’s page on bicycle frame materials. For greater depth, read the 7-part series on metallurgy for bike frames by Strong Frames.
The 15% deflection rule-of-thumb for tire inflation pressure: Read how we may be overinflating our tires and why you might want to run front tires at lower pressures than rear tires. My tire pressure calculators page has one based on the article, as well as one based on Michelin’s recommendations, and a link to Rivendell’s chart.
Product images are © their respective manufacturers.