Electric bikes.

Almost every bad electric bike purchase starts the same way: somebody sees a deal, buys the bike, and only afterwards works out that it does not fit the life they actually live. A 70 lb fat tire cruiser is a wonderful machine and a miserable one to carry up two flights of stairs. A folding commuter is brilliant on a train and hopeless on a sandy beach path. The frame style and wheel format decide far more about whether you enjoy the bike than the badge on the down tube does.

So the sensible order is type first, then class, then brand, then price. Work out how you will store it, how far you ride in one go, whether you carry anything or anyone, and what the surface under your tyres looks like. Those four answers narrow eight or nine categories down to one or two, and only then does it make sense to start comparing motors and warranties.

Most US states have adopted a three class system for electric bicycles. Class 1 is pedal assist only, cutting out at 20 mph. Class 2 adds a throttle you can use without pedalling, also capped at 20 mph. Class 3 is pedal assist up to 28 mph, usually with a speedometer required and often with restrictions on where it can go. Anything faster, or anything with a throttle above 20 mph, generally stops being an electric bicycle in the eyes of the law and starts being a moped, which brings registration, insurance and licensing into play.

That matters more than it sounds. Plenty of shared-use paths, state parks and beach boardwalks allow class 1 and 2 but ban class 3. If the ride you have in your head is a rail-trail, check the trail rules before you buy the fast bike. Our guide to whether you need a licence for an electric bicycle goes through the detail, and how fast electric bicycles actually go covers what those caps feel like on the road.

We weight four things heavily. Battery quality, because a cell pack is the single most expensive component and the one most likely to end a cheap bike's life. Brakes, because a 65 lb bike doing 20 mph needs hydraulic discs, not the cable-pull calipers that came off a 25 lb hybrid. Frame and fork, because a suspension fork that costs the manufacturer 30 dollars is worse than a rigid one. And support, because the difference between a five year bike and a two year bike is usually whether you can still buy a replacement display, controller or battery.

Wattage claims are the least useful number on any listing. A "1000 W" hub motor from an unknown factory can easily produce less usable torque than a well-tuned 500 W mid-drive, and it will drain the battery far faster doing it. Look for nominal wattage, torque in newton metres, and battery capacity in watt-hours. Those three tell you almost everything the marketing copy is trying to hide.