One measures power everywhere you ride; the other measures it only indoors and also makes indoor riding tolerable.
Verdict
Buy the smart trainer first if most of your structured training happens indoors, because it gives you power plus controlled resistance plus a reason to actually do the session. Buy the power meter first if your key sessions and events are outdoors, because a trainer measures nothing once you leave the room. Pedal-based meters move between bikes, which is their quiet advantage.
Both give you power, which is the measurement that makes structured endurance training work, because it is immediate, objective and unaffected by heat, fatigue or caffeine in the way heart rate is.
What differs is where. A trainer measures only indoors and also controls resistance, which means a workout runs itself. A power meter measures everywhere, including the climb, the race and the group ride, and controls nothing. Riders who train indoors in winter and race outdoors in summer usually end up with both, and the order depends on which half of the year you care about.
~$549.99
Check Backcountry → Check Wahoo Kickr Core 2 Price~$604.99
Check Backcountry → Check Favero Assioma Duo power meter pedals Price| Wahoo Kickr Core 2 | Favero Assioma Duo power meter pedals | |
|---|---|---|
| Measures power outdoors | No | Yes |
| Controls resistance | Yes | No |
| Moves between bikes | No | Yes, unscrew the pedals |
| Also useful for racing | No | Yes |
| Makes indoor riding bearable | Yes | No |
| Typical price | About $550 | About $605 |
Your structured work happens indoors, particularly in winter, and you want the sessions to run themselves. A direct-drive trainer with ERG mode holds a target power regardless of your cadence, which removes the discipline problem from interval training entirely. It also replaces the wheel, so there is no tyre wear, and it is quiet enough for shared housing.
Check Backcountry → Check Wahoo Kickr Core 2 on Amazon
You race, do your intervals on the road, or ride outdoors year round. Power measured on the road is the number that matters for pacing a time trial, a climb or a long event, and pedal-based meters unscrew and move to another bike in five minutes, which crank-based ones do not. Dual-sided measurement also shows left and right balance, which is useful after an injury.
Check Backcountry → Check Favero Assioma Duo power meter pedals on Amazon
A trainer and a power meter will not read identically, and that is normal rather than a fault: they measure at different points in the drivetrain and each has its own stated accuracy tolerance. Do not compare absolute values across devices, and do not re-test your FTP on a different device and conclude you have lost fitness. Pick one device as your reference for a given context, calibrate it as the manufacturer instructs, and track trends within it.
Not if you train indoors, since a smart trainer measures power. You need one if you want power outdoors, which is where racing and most long rides happen. Many riders start with a trainer and add a power meter when outdoor events become the priority.
For tracking training load and pacing, generally yes, and they cost considerably less. They measure one leg and double it, which is inaccurate if you have a genuine imbalance. If you are returning from an injury on one side, dual-sided measurement is worth the difference.
They measure at different points in the drivetrain, each has its own accuracy tolerance, and drivetrain losses sit between them. Differences of a few percent are expected. Choose one as your reference for a given context and follow trends within it rather than comparing across devices.
Consistency matters more than absolute accuracy for training purposes, since you are tracking change over time against your own baseline. Most current trainers and power meters state accuracy within one to two percent, which is more than adequate. Calibrate as the manufacturer instructs, since a device that drifts is worse than one that reads slightly high consistently.
Comparison based on published manufacturer specifications and the general consensus of owner reports. We have not tested these units side by side. Confirm current prices and specifications before buying. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.
We review them on their own too, in full detail: the Favero Assioma Duo, the Wahoo KICKR CORE 2 and the Tacx Neo 2T.