Wahoo Kickr Snap - Power readings

wrthompson88521FN8Ns

Hi,

So a g few years ago I had a Kickr Snap, now this year I got another one someone in the same block of flats happened to be selling. I've noticed that the power reading issue is still present with this latest Kickr Snap.

So far my Kickr Snap is set up, I've done an advanced spindown also, I've tightened the wheel on (2 turns) ran the spindown and the reading was 14 seconds, between the 9 and 16 recommended.

So all seems fine so far, I've calibrated my Stages power meter and then started to ride to check the power figures.

It seems the Kickr Snap is reading about 20-30W lower than the Stages, same as when I had a previous Kickr Snap. The Stages I would lean towards in relation to which power reading is more accurate, it isn't far off a powertap reading either.

Now I could just stick with the Stages power, but I feel like it's a bit of a shame when the Snap has built in power readings as sometimes I find the Stages a bit temperamental when connecting to apps.

And as far as I know, once a spindown is done and it's in between 9-16 seconds on the spindown then that indicated roller is tightened enough, so that's done and I should be able to ride?

Just hoping the issue isn't causing any other weird things, I do notice in apps like Zwift and RGT Cycling, seems like I'm spinning out sometimes on the flat doing 30mph.


cheers.

Dorset_Boy

All wheel on turbos will have accuracy issues.

wrthompson88521FN8Ns

Is that just in relation to the power? So am I best to forget Kickr's power and stick with Stages?

N0bodyOfTheGoat

Even on direct drive turbo trainers, you'd expect ~3% power loss compared a crank meter to the turbo meter, on wheel-on trainers a consistent setup in terms of tyre pressure and pressure on the turbo roller makes it more likely power variance will happen.

Comparing the numbers from my 4iiii and my Direto has varied through 2021, from 4iiii being ~6% higher through to recently Direto being ~8% higher. Not such a big deal when I'm riding solo and pretty much only riding indoors, but when Zwift racing/TTing or doing outdoor road bike rides, I pair up the 4iiii for perceived consistency (as I've already replaced the Direto belt once over the last ~3.75 years).

wrthompson88521FN8Ns

Do I need to bother calibrating the Kicr Snap every ride if I use my Stages power meter?

Dorset_Boy

wrthompson88521FN8Ns said:

Is that just in relation to the power? So am I best to forget Kickr's power and stick with Stages?

Tyre pressure will change as the tyre warms up, and it is very, very difficult to get the same set up each and every ride with a wheel on turbo, so power will vary.