Training on a dumb trainer

I’m not in a position to purchase a power meter or smart trainer so I have been getting by using an old Kinetic trainer with their virtual power hardware (InRide) based on a good review from DCRainmaker.

I’ve logged many hours of indoor training with this set up and it’s resulted in some good power increases.

However, lately I have noticed that my workouts are feeling “off”. I peaked at a threshold of 320w in 2018 and have dropped down to 302w based on a ramp test taken last week. I dialed back the riding quite a bit in December after CX season, and have only averaged 150ish TSS since

In the last couple of weeks I have noticed 2 things.

  1. The trainer spindown number (time?) has gone from averaging 1.6s to 1.9s. (what does this indicate?)

  2. Coinciding with this, my workouts feel tougher. PRE/HR for sweet spot workouts feels like threshold.

  3. Could this be a mis-calibration of my trainer/InRide unit?

  4. Are my legs fried after being 6-weeks into a weight training plan, making everything seem harder?

  5. Could this be due to me not being as fit as I was 6 weeks ago (during cross season)?

Help me understand how accuracy can be affected by wheel tension, cold vs hot spindowns, tire pressure, and any other factors I’m not thinking of. I want to find a consistent and repeatable set up for this trainer.


I have a Kurt Kinetic that at one time was set up in a non-insulated garage. When I compared average speed for intervals with Powertap-measured wattages I noticed this relationship had a lot of scatter which I attributed to the resistance of the KK being dependent on temperature. I believe I’ve read this elsewhere as well. This can even happen within your workout. At the beginning of my workout the KK was at garage temperature (typically pretty cold), but the KK unit itself would heat up relative to the garage temps as the workout went on. Might this be an issue for your setup?

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Super insightful. I just moved the trainer indoors, it was in my garage, which was much cooler… I do always do my spin down after the warm up period so hoping that brings consistency.

Tyres will also make a big difference. If you have changed tyre, pressure or even tubes this can make a significant difference to calibration amd throw your numbers off.


I’m religious about checking and maintaining consistent (+/- 5psi) tire pressure on my trainer tire.

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I use a dumb mag trainer with a Quarq Dzero. Honest Q…how does tire PSI matter here? Power is power is power correct? Spin down calibration? What is that?

edit: I do run the same psi to keep the gearing/shifting consistent from session to session. Again, this is on a 15 year old mag trainer…

Doesn’t matter for you as power is being measured at the crank or whatever. It does matter for those of us using the Kinetic Inride. Tire pressure, how tightly you’ve screwed the unit to your tire and temperature all affect power calculation.


@mrjustinpitts ok whew! Thought I was missing something. Sorry for the stupid q. Thanks.


It sounds like you’ve been quite consistent with calibrating the InRide, so that would not be my first guess for the cause of the change. Also, seeing the calibration value change after changing the environment is consistent with the purpose of calibration, and suggests it is properly calibrated.

But since your peak you have reduced training stress, started weight training, and changed to training in a warmer environment. If it’s warmer, you can absolutely expect your heart rate to go up, and if you aren’t getting adequate air flow you can absolutely expect RPE to go up significantly as well. And yes, weight training will affect how your legs feel on the bike, especially if you are on the bike after a weight session or before you’ve adequately recovered from it (after six weeks, though, you probably won’t be too affected a day later).

@Landis No worries! And as my old teachers always said, there are no stupid questions. :wink:

@anthonylane I also use an InRide and recently started to use it outside where temperature fluctuates a bit more. Because of this, I’ve started doing two calibrations per workout. One after the initial warmup session and another after the first interval. A bit of a pain, I know, but I’m a little obsessive like that.

Thanks, for context, the previous environment (garage) was around 45-50º and the new location is a good 15º warmer. I didn’t think that would make a big difference, but you could totally be onto something there. In fact, it might be THE difference as the RPE of any given workout a has gone up a lot since moving this operation indoors. I don’t give a lot of thought to heart rate, but I have also noticed it’s up quite a bit, even at 50% of FTP it’s a good 10 bpm higher.

I feel like my legs have adapted to both lifting and riding during the week, granted, I can tell they are a bit more cooked than they would be if I wasn’t doing strength training, but definitely not cooked to the point where RPE is as high as it is during a given workout.

Should be interesting to move things back to the garage where it’s cooler and see if things change.