My Smart 2 Trainer Won't Calibrate

If you're on a Smart 2 trainer and seeing "Preparing Calibration" continuously without a successful calibration, your calibration attempts are taking longer than about 45 seconds and end up back at square one, or you just can't get a successful calibration the following information will help you get going. Please go through each of the lists below and follow all the steps to be sure you're using calibration best practices and that you haven't potentially overlooked an important step to have consistent and accurate calibrations.


The Software and Firmware:

  1. UPDATE THE FIT APP: Be sure that you have the latest version of the Kinetic Fit app running on your device. Check the Apple App Store or Google Play.
  2. REDUCE BLUETOOTH INTERFERENCE: Make sure your Control trainer isn't paired to any other apps.
  3. UPDATE FIRMWARE IF NEEDED: You're not likely to need a firmware update with Smart 2 trainers. Here's the process though: Launch the Kinetic Fit app and pair with the Smart Control trainer and check for firmware updates by selecting SENSORS from the menu and then selecting your trainer and the GEAR ICON. Select UPDATE FIRMWARE if prompted.
  4. Update device OS: Check your general device settings to make sure there isn't an OS update available for your device.  If one is available, please install it before your next trainer session.  

The Hardware and Bike

  1. TIRE PRESSURE: For regular 700x23-25c road tires, we recommend 100 PSI. For tires that have a max pressure rating of less than 100 PSI, always inflate to max pressure listed on the tire casing. For the most consistent data, check tire pressure daily.
  2. USE A TRAINER TIRE: We recommend using the Kinetic Trainer Tire or a similar slick-treaded, soft-compound tire.*
  3. TIGHTEN YOUR ROLLER PROPERLY: Be certain that you've tightened the trainer's tire roller tension knob to 3 to 5 FULL turns past the point at which the tire and roller make good contact. You might need additional roller pressure to hit the spindown targets even though your tire may not be slipping. If you get a "speed up detected" message, add 1/2 turn of roller pressure and attempt another calibration. Repeat until successful.
  4. CLEAN THE TIRE AND ROLLER: If you have isopropyl or window cleaner, clean your tire and the roller before calibrating. 
  5. 1.75 SECONDS IS THE SWEET SPOT: Now, just select your workout in the Fit app or Free Ride and go through a normal 10-MINUTE warmup and calibrate. You want to get a calibration number between 1.5 and 2.0 seconds after warm up. If your calibration time is lower or higher than the range, we recommend tightening or loosening your roller tension accordingly and trying to get closer to 1.75 seconds.

If you've done the prep steps listed above and you're using a slick tire you should have a successful calibration.


*Some issues we've seen causing calibration failures include:

  • Low tire pressure. Set tires to manufacturer specifications.
  • Trainer roller tension too loose against the tire, you may even need to increase roller pressure even though your tire is not slipping. Optimal calibration spin-down time is 1.5 to 2.0 seconds after a warm up. A "Speed Up Detected" message is an indicator of inadequate roller pressure.
  • Jumpy our out-of-true wheels will often cause calibration issues
  • Puncture-resistant tires and tubes are poor choices for indoor training. The added plies of casing and thicker, stiffer rubber make them unsuitable for trainer duty. Try a trainer tire and standard tube.
  • Knobby tire tread will make it very difficult to get a good calibration in addition to the added noise and vibration.
  • Not accelerating up to and/or past the target speed. If you're never prompted to stop pedaling, increase speed while shifting thru your gears until you're prompted to do so.
  • The mounting/pivot bolt that holds the resistance unit to the frame can be too tight, which pinches the resistance unit and prevents it from easily pivoting forward into the tire. The acorn nut on the right side of that bolt only really needs to be finger tight.  

Any of these can cause a calibration failure. If you continue to have issues, please submit a ticket via our contact page or even better yet, through the Fit app.


Calibration Tips: 

  • SAVE YOUR PREVIOUS CALIBRATION: You may not need to calibrate the resistance unit every time you ride if you're using Zwift of another compatible app. Just DON'T loosen the roller between rides, clean your tire with isopropyl and refill your tire to the same pressure it was before before your last ride and go. Calibration numbers are saved in the Control trainer firmware and won't be affected if the roller tension and tire pressure are the same as the previous ride.



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