Coaster brake or three-speed hub? The checks that settle it before you pay
How to decide between a coaster brake and a three-speed hub by checking the hill you ride, the marks on the hub shell, and the frame's dropout spacing.
Upright utility and comfort bicycles from the mid-twentieth century onward: their design, their modern reproductions, and how to choose and maintain one
Terms
- Sturmey date stamps
- Sturmey-Archer hub shells carry a stamped month and year, so 68 4 means April 1968. Comparing that date with the frame serial is the quickest test of whether a bike is original.
- Bendix band colors
- Bendix coaster hubs are identified by a painted band on the shell, with red band and blue band the two most often encountered. The band tells you which parts diagram and which shoe set you need.
- Second-gear slip
- A three-speed that slips in middle gear is usually telling you the indicator chain is out of adjustment rather than that the hub is finished. Adjust the cable before pricing a rebuild.
The choice between a single-speed coaster brake and a three-speed hub is usually presented as a question of gearing, and it is not. It is a question of what the rear wheel has to do on the route you actually ride, how the frame is built to accept it, and what you are prepared to do to the hub every few years with the wheel out and a rag on the bench. A careful buyer checks all three before agreeing a price, because the wrong answer is not dangerous so much as permanently mildly annoying.
Start with the grade, not the gear count
A coaster brake gives you one ratio and one braking surface, both of them inside the hub shell, and on flat ground it is excellent: nothing to adjust, nothing to freeze, nothing dangling from the handlebar. The moment the route includes a sustained descent, the calculus changes, because a coaster brake dumps heat into a sealed shell with no airflow, and the grease inside thins as it heats. A three-speed with a rim brake, or a modern three-speed coaster like the Sturmey-Archer S3C, spreads that work. Ride your commute once and count the hills that need braking for more than five seconds.
The gearing side matters less than people expect on an upright bike. A three-speed's useful spread is roughly a low for starting from rest with groceries, a middle for everything, and a high for a tailwind, which is a genuine improvement on one ratio if you carry loads or live somewhere with even modest rises. If your ride is flat and your loads are light, the coaster's simplicity is not a compromise. It is the correct answer, and the money saved buys better tires.
Read the hub shell before you read the seller's description
Every hub worth buying is marked, and the marks tell you more than the ad copy. Sturmey-Archer AW shells carry a two-digit month and year stamp, so a hub reading 68 4 is April 1968, and that date should sit within a year or two of the frame's own serial if the bike is claimed to be original. Bendix coaster hubs are identified by the band on the shell, red band and blue band being the common ones, with the red band the two-shoe version. Shimano Nexus and Nexus Inter-3 hubs are marked on the shell face. An unmarked hub is not a deal breaker, but it is a bargaining point, because unmarked usually means no parts diagram.
With the wheel in your hands, spin it and listen. A healthy AW clicks evenly in high gear and freewheels without grinding; a coaster hub should engage within a quarter turn of back pressure and release cleanly. Slippage in second gear on a three-speed is the classic symptom of a worn pawl ring or a maladjusted indicator chain, and the indicator adjustment is free, so check it before you condemn the hub. On a coaster, a pedal that keeps turning under braking means the shoes or the clutch cone are worn past service.
The frame has to agree with the wheel
Dropout spacing decides whether the swap you are imagining is a ten-minute job or a cold-set frame. Old single-speed coaster wheels commonly run around 110mm over the locknuts, while a Sturmey three-speed wants roughly 114 to 120mm, and modern internally geared hubs run wider still. Measure the frame, not the wheel currently in it. Then look for the small things that a factory three-speed frame has and a coaster frame often does not: a cable stop or clip boss on the top tube, a brazed-on lever mount, and clearance at the chainstay for the brake arm strap that every coaster and every hub with an internal brake requires by design. The Consumer Product Safety Commission oversees the federal requirements that govern how bicycles are sold in this country, including foot brake performance, and that reaction arm is part of how a coaster hub meets them.
What service will actually look like
A coaster brake wants disassembly, a cleaning, and fresh grease roughly every few thousand miles or whenever braking gets grabby, and the parts inside are large, few, and forgiving of an amateur. A Sturmey AW wants a few drops of oil through the port on the shell every month or two, which is easier still, and a full strip only when it starts slipping. Both are rebuildable on a kitchen table with common tools. Availability of small parts favors the three-speed for older stock and the coaster for anything currently in production.
Check the hill, check the stamp, check the spacing. The hub that survives all three is the one to buy.