Quick Hello & noobie first question

Hi and Good Evening,

So I’ve started this evening with Zwift, set up in my shed with an old traditional Elite mag trainer, so pretty basic. I’ve got a Garmin speed sensor attached to the rear hub and that’s about it…HR monitor battery went so waiting on Amazon for some 2025s. I’m using a notebook pc with on board Bluetooth and I’ve bought and plugged in an ANT+ receiver for the Garmin sensor. So far so good.

So I did the intro ride plus a bit for a total of 7.55 miles. The game reported about 200W for the most part with 330W for the sprint section, came out with an average of 186W throughout. I don’t yet have a cadence sensor so did a rough count of revolutions while watching the clock on the PC, came out to about 85rpm.

My total time came in at 28:12 with the game reporting an average of 18mph for the most part. This seems quite high to me. I’m by no means a fit cyclist and predominantly a mountain biker. I average about 10 mph on an easy trail or road, even on semi-road tyres. So 18mph seems…enthusiastic!!

What could I have done wrong??


This could help you: https://forums.zwift.com/t/how-does-zwift-determine-my-speed/

Speeds in Zwift seem to be higher than in real

Was your trainer available in the list of supported trainers when you paired your sensors or did you have to choose the unlisted version? Wheel-on classic mag trainers aren’t necessarily the most accurate for Zwift to estimate your watts, so this could be part of the problem if it is inflating your power due to inaccuracies.

1 Like

I would think that it’s just down to the dumb turbo trainer giving you some free power.

Not a problem for your free riding and for training as its all relative but will give you false results if you want to race. In which case I would recommend getting a cheap smart trainer. They make the whole experience so much more immersive too


Excellent, thank-you.

Not the exact one, no. But Zwift offered an Elite wheel-on mag trainer, no bells or whistles so I selected that. I think, when I paired the sensor, I had to add some info, wheel size etc., so figured it would calculate from that info.

I expect if I add a cadence sensor, that will improve the accuracy??

Thanks. I doubt I’ll be racing tbh. But yes, I guess in the grand scheme of things, it is all relative. Any improvements will still show as improvements.

No, cadence has no impact on speed or accuracy in Zwift, it is just nice to have.

The trainer you chose in-game will have a set power curve that will estimate your watts based on wheel speed. It may be wildly inaccurate, the only way to know is to test with an actual power meter. That isn’t necessary unless you plan on racing as Adam said.

Fair enough. Ta very much.