The Moveee team
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A wheel speed sensor is a genuinely good way to start riding indoors. It costs about thirty pounds, it turns any trainer into a real route in a 3D world, and it saves rides to your calendar. We wrote the case for it in riding indoors without a smart trainer, and we meant it.
It is also a starting point rather than a destination, and it is worth knowing what the next step buys before you spend anything — including the case for not spending at all.
Four signs you have outgrown the sensor
You keep wanting a number that is not there
You finish a session and want to know whether it was harder than last Tuesday's, and heart rate is not settling the argument.
You are following a real plan
A structured plan is written in load. Without power, none of your indoor rides can feed it, so half your training is invisible to it.
You are riding indoors a lot
Two sessions a week through a winter is 40-odd rides. At that volume the measurement gap starts costing you real progress.
You want ERG to take the decision away
If you keep easing off in the last two intervals, a trainer that simply holds the target is worth money.
Notice what is not on that list: riding indoors and finding it dull, or wanting better scenery, or wanting a route you actually know. Those all work perfectly well on a speed sensor, and a new trainer will not fix any of them. Upgrade for measurement and control, not for atmosphere.
What power actually unlocks
The moment any power source is connected — a power meter or a smart trainer — several things that were simply absent switch on:
- Watts, and everything built on them. Normalised Power, Intensity Factor, TSS, your power curve and your best efforts. Your FTP estimate starts moving from indoor rides instead of only outdoor ones.
- Your plan can see the session. An adaptive plan re-tunes around measured load. Power rides feed it; speed-only rides cannot, because there is no load figure to feed.
- Comparisons that survive a kit change. 250 watts is 250 watts on any trainer, in any room, at any tyre pressure. Nothing else you can measure indoors has that property.
And with a smart trainer specifically, two more:
- ERG mode. The trainer holds the target through the interval whatever you do with your gears.
- Resistance that follows the road. Off a workout, the trainer gets harder on the climbs, taken from the route's real elevation. This is also what makes the on-screen hill slow you down — the thing that does not happen on a speed sensor.
Three routes, honestly compared
Power meter on your bike
Good: Works indoors and out, moves between bikes, measures YOU rather than a trainer. Your outdoor rides get power too.
Cost: No ERG and no automatic resistance — your dumb trainer stays dumb. You get the measurement half, not the control half.
Wheel-on smart trainer
Good: ERG, gradient-following resistance, no separate sensor. The cheapest route to the full experience.
Cost: Tyre wear and noise, and power accuracy depends on a calibration you have to remember to do.
Direct-drive smart trainer
Good: Quiet, accurate, no tyre, no calibration drift, strong enough for sprints. The thing you stop thinking about.
Cost: The price, and you need a cassette and the right axle adapters.
The route people overlook is the first one. If you ride outdoors most of the year and indoors for two wet months, a power meter is the better buy at a similar price: it gives you measurement for every ride rather than only the ones on the turbo, it outlives any trainer you own, and your existing dumb trainer carries on doing its job underneath. You do not get ERG, and for a lot of riders that is a fair trade.
Go for a smart trainer instead if the indoor sessions are the serious part of your training, or if you know that ERG is what stops you quietly easing off.
The case for staying where you are
If you ride indoors half a dozen times a winter to keep the legs turning, a speed sensor is the correct amount of equipment, and spending six hundred pounds to measure those rides more precisely would be a waste. Nobody got slower for training by feel.
Equally, if you are new to indoor riding, ride the sensor for a season first. You will learn whether you actually enjoy it, which sessions you keep coming back to, and how often you really ride — and those answers should decide the purchase, rather than the other way round. The sensor keeps working afterwards on your outdoor bike, so nothing is wasted.
What to do on the day you upgrade
Two small things. First, expect your speed numbers to change, because a smart trainer computes speed from power and the route's gradient rather than reading your wheel — so the comparison with your speed-sensor history breaks on that day. That is fine; the power numbers that replace them are better. Second, if you keep the wheel sensor on the bike, Moveee prefers the power source automatically, so there is nothing to unpair.
Then go and do the session you have been approximating all winter, and find out what the numbers say.
Sources 6
Where this article summarises a study, the study itself is linked — not a write-up of it.
- 1 Zadow EK, Kitic CM, Wu SSX, Smith ST, Fell JW Validity of power settings of the Wahoo KICKR power trainer · International Journal of Sports Physiology and Performance · 2016
- 2 Maier T, Schmid L, Müller B, Steiner T, Wehrlin JP Accuracy of cycling power meters against a mathematical model of treadmill cycling · International Journal of Sports Medicine · 2017
- 3 Jobson SA, Passfield L, Atkinson G, Barton G, Scarf P The analysis and utilization of cycling training data · Sports Medicine · 2009
- 4 Passfield L, Hopker JG, Jobson S, Friel D, Zabala M Knowledge is power: issues of measuring training and performance in cycling · Journal of Sports Sciences · 2017
- 5 Fitness Machine Service 1.0 (FTMS) · Bluetooth SIG · 2017
- 6 McIlroy B, Passfield L, Holmberg HC, Sperlich B Virtual training of endurance cycling – a summary of strengths, weaknesses, opportunities and threats · Frontiers in Sports and Active Living · 2021
Your own roads, indoors, in a browser tab
Moveee Indoor pairs your smart trainer over Bluetooth and rebuilds a route you have saved as a 3D road — real gradients, ERG for the intervals, and the ride saved with full power data. Nothing to install. Free while it is in alpha.
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