I actually haven’t cared much about what people thought of me based on the terminology I used, and this was never so true as when I started biking. I didn’t want to become one of those spandex-wearing, car-hating bike jocks, so it really wasn’t a priority for me to talk like them. With the benefit of hindsight, though, I now realize I would have been able to get my ideas across (and more importantly understood the ideas conveyed to me) better, had I known some of the terminology universal to bicycles. Most of these terms (unless noted otherwise) are more or less international and apply to all kinds of bikes, which is helpful if you’re riding in another country or region. There are tons of good bike diagrams online, and I encourage you to use those, but if you like words or are just lazy, I’ve got a partial glossary for you below. These terms are in no particular order, and I will most likely have additional posts with more terminology.
Saddle: if not sounding like a newbie is important to you, get the word “seat” out of your vocabulary (the ironic exceptions are other parts of a bike such as seatstays, seat rails and the seatpost). A saddle is what bike people call a seat.
Chain ring: this is what bike people call the big gear/gears turned directly by pedals and cranks. Bike people avoid the terms “gear” or “sprocket”, unless talking about all gears generally, since these are technically not specific to any one part of the bike.
Cogs / cassette / grupo: the gears on the back wheel are called cogs. A group of cogs together is called a cassette, or if you want to show off with some Italian, a grupo. Which, if I’m not mistaken, is Italian for “group”. Pretty fancy!
Bottom bracket or BB: the bottom-most part of the frame, this is the center of the circle that the pedals orbit around. The BB houses a bunch of ball bearings and stuff that has to be replaced from time to time…depending on the bike a replacement B.B. can be super cheap or hella expensive. (It’s been cheap on all the bikes I’ve had.)
Seat rails: these are on the underside of the saddle, and they keep the saddle in place via little clamps on the top of the seatpost…but remember, it’s a saddle not a seat!
Dropouts: no, these are not hardcore bikers that left high school. Rather, they are the part of the frame that your quick-release wheel hubs attach to. If the bike is right side up on a shop stand, when loosened the wheel will just drop out of this part. Hence the name. Clever!
Seatstays and chainstays: these are the two pairs of tubes on the frame that attach to the rear wheel. The top pair are the seatstays and the bottom pair are the chainstays. Which makes sense, sort of.
Top tube: the horizontal (some times diagonal) frame bar that you straddle when you stand flat-footed astride your bike.
Down tube: the diagonal bar directly below the top tube. Makes sense.
Seat tube: the frame bar that starts at the BB and goes upward to the seatpost, which attaches to the seat rails, which are attached to the SADDLE, NOT THE SEAT!
Head tube: the front-most part of the frame, to which the forks attach. Many bikes will have a logo called a badge emblazoned on the head tube.
Bars: handlebars, or where you go with your pals after a long ride. Drop bars are the curly bars you see on road bikes or some gravel bikes.
Stem: the more-or-less horizontal piece that connects the handlebars to the frame. The short vertical piece at the other end of the stem is called the headset. Most road bikes today have an integrated headset, which means the brake levers also function as gear-shift levers (by pushing them sideways instead of pulling straight).
Brake hoods (or just Hoods): the rubbery nubs above the brake levers on a bike with drop bars. A lot of road bikers ride with their hands resting on the hoods instead of gripping the drop bars.
Crankset: the entire assembly (usually 4- or 5-pointed) that connects the pedals and the outer chain ring. The part I usually call the crank is actually the “crank arm”.
Caliper brake versus disc brake: caliper brakes are the classic version, with rubbery brake shoes clamping on the wheel rims to slow you down. Disc brakes are not new to mountain biking; they consist of a metal disc on each wheel that runs in between clamps mounted on the frame. I’m seeing disc brakes on more and more road bikes lately, hinting at their growing popularity.
Next post: Disc Brakes? Fancy drive train? Through-hubs? Kickstand? Which of these (if any) should you demand in a bike?