Exercise bikes, judged on the ride

Exercise bikes are the best value in home cardio and it is not close. A bike has no motor, takes no impact loading, and has almost nothing that wears. Every failure mode that kills a cheap treadmill simply does not exist here, which is why a $300 bike is a genuinely good machine and a $300 treadmill is a compromise.

Decision one: which format

Be honest here rather than aspirational. An hour on a recumbent beats fifteen minutes on a spin bike you resent, and the activity guidelines reward accumulated minutes rather than maximal efforts.

Decision two: resistance type

Magnetic has now reached even the sub-$300 bracket, and for most buyers there is no longer a reason to choose friction. Resistance types explained covers all three properly.

Decision three: fit range — the spec that quietly ruins bikes

Four-way seat adjustment (up/down and fore/aft) and, on a spin bike, four-way handlebar adjustment. Two-way bikes fit one body shape and no others. If more than one person will ride it, this is not optional, and if you are over six feet it is the spec most likely to catch you out — most bikes run out of seat post travel, not frame. See exercise bikes for tall riders.

The specs that matter less than marketing suggests

• Flywheel weight. 30-40 lb is the studio standard; above about 45 lb it does nothing. A very heavy flywheel on a very cheap bike usually means the budget went into the one number buyers compare. Full explanation.
• Drive system. Belt is quieter and maintenance-free, chain is cheaper and universally repairable. Neither affects how hard the workout is. Full explanation.
• Console features. You need cadence, time, distance and heart rate. Everything else is decoration.
• Built-in screens. A tablet holder and the device you own is cheaper, replaceable, and not tied to a subscription.

The spec nobody lists: frame mass

Use shipping weight as the proxy. A light bike rocks when you stand on the pedals, and no flywheel figure compensates. Under $500 we would not consider a spin bike whose total shipping weight is under about 70 lb if you intend to ride out of the saddle.

Subscriptions: the bike case is cleaner than the treadmill case

A bike's resistance is a knob and its console reports locally, so a subscription on a bike almost always sells content rather than function. That makes the rule simple: buy the bike that broadcasts standard Bluetooth, then choose your content separately — Peloton, Zwift, a free app, or nothing — and change your mind later without changing your bike.

At a representative $39 a month, three years of membership exceeds the entire price of a Schwinn IC4. Exercise bikes without a subscription and the subscription cost calculator do the arithmetic.