New wheels - power increased (?)

[munkster]

My winter wheels have been getting increasingly "crunchy" in the hub bearing dept so I decided to build some new ones (I had replaced the bearings a couple of times before so thought drastic action was needed) and quite apart from immediately noticing anecdotally the difference in smoothness and apparent speed the average power for the ride (according to Strava) was 220W versus 187W the last time I rode that route.

Now I doubt I've got *that* much fitter since last time (only a couple of weeks ago) so what should I do in terms of PP and its calibration? An out and back? Check calibration? Or is it possible that this new reading is actually the accurate one given how the old wheels must've been adding to unexpected resistances? They are comparable wheels in terms of width, weight etc, albeit completely different components.

I can post the ride files in a bit, can't connect up at the moment, if that would help? Thanks!

[Velocomp]

Ride files (data) is always good...

[munkster]

Wow, that was quick, before I'd even got in the obligatory initial "edit after posting"!!

Will post ride files presently, thanks.

[munkster]

Ride files attached. The most recent one is from today (and if I do a "Check Calibration" it is suggesting a change hugely into the red, which is probably no surprise) and the older one is the last time I rode this route a couple of weeks ago.

nb - this is not technically an "out and back ride" although the first ~9km and last ~9km are effectively the same but in reverse.

[Velocomp]

Your two files are revealing. I analyzed the first 7.5 miles, where your HR strap was working for both:

1) Your 2/2 ride file shows an average speed of 18.0 mph

2) Your 2/14 ride has an average speed of 18.8 mph

3) Your heart rate for the first 7.5 miles of your 2/14 ride is 140; for your 2/2 ride, 139. This means that (according to your heart) you were working equally hard (applying equal amounts of power).

So I think the answer is yeah, your new wheels have lower friction; this means that, for the same value of applied power, you'll go faster with the new wheels.

Have fun with your new wheels!

[munkster]

OK thanks - but what do I need to do with the PP? Do I need to Check Calibration or do an out and back? Leave alone?

The old wheels are shot (bearings anyway) so it's not surprising that the new ones are markedly less resistant... I could tell this just by simply riding and feeling it.

ps - new battery in the HRM - Garmin picks it just fine... I seem to have had periodic dropouts from sensors on my PP...

[Velocomp]

Leave your calibration alone. Your "old" ride files with the extra friction were too low in power.

[munkster]

OK will do.

Just so I understand though, if "Check calibration" is suggesting a change that puts it into the red is that not a problem?

Would you expect an out and back ride to be less extreme?

Thanks for your help, these questions are only because I want to make sure I'm using it properly!

[Velocomp]

For some mysterious reason Check Calibration is adjusting your riding tilt. I would not touch anything...