Do you guys set the wheel size for your Garmin Speed Sensors to auto or manual? What size do you put when running 700c x 25?
Set up new Garmin 520 today. Did a ride and set it at auto. Checked on getting home and it's set to 2096. For 25mm tyres the manual say 2105 and that's how I had it with old 510 model.
Just measured in my garage and it's actually 2160. Can I assume that this is due to the tyre fitted to the wheel and the wheel itself would be more like 2105 or should I be using 2160?
If I should measure without the tyre fitted, then why the different measurement for different tyres?
2096 compared to 2160 is almost 3.1% or 0.5mph higher. Don't want to set it higher than it should be.
Edit: Clearly the wheel without tyre would be a lot more than 3.1% difference?
Set up new Garmin 520 today. Did a ride and set it at auto. Checked on getting home and it's set to 2096. For 25mm tyres the manual say 2105 and that's how I had it with old 510 model.
Just measured in my garage and it's actually 2160. Can I assume that this is due to the tyre fitted to the wheel and the wheel itself would be more like 2105 or should I be using 2160?
If I should measure without the tyre fitted, then why the different measurement for different tyres?
2096 compared to 2160 is almost 3.1% or 0.5mph higher. Don't want to set it higher than it should be.
Edit: Clearly the wheel without tyre would be a lot more than 3.1% difference?
Last edited: