Garmin wheel circumferences

[raptor]

Akneethling

The radius idea works, same as measuring with tape measurement, but now take that measurement and compare it with a weighted run of one rotation.

 

As for GPS, it's only very accurate if you riding flat level, once you start climbing and descending you loose distance. GPS does not account for nicking and descends

 

 

 

Find both garmins i had very accurate, you can just as well buy a entry level computer if you if you not going to use the gps

Edited June 26, 2013 by raptor

[Guest Smimby]

Akneethling

The radius idea works, same as measuring with tape measurement, but now take that measurement and compare it with a weighted run of one rotation.

 

As for GPS, it's only very accurate if you riding flat level, once you start climbing and descending you loose distance. GPS does not account for nicking and descends

 

G

 

I always thought this also but apparently it is not true. Garmin uses elavation "axis" to calculate your distance and speed etc. GPS knows your the distance traveled between 2 points and the height above see level gained or lost.

 

I did a test riding with a normal cycling computer and my garmin. I used the garmin to work out the wheel size for me by setting it to auto then entered that into the cycling computer.

 

The distance on both were within 1-2% of each other over various distances and with flat rides and 1500m + climbing.

Edited June 26, 2013 by Smimby

[chris_w_65]

When I'm indoors I switch the gps function off for the IDT, the Garmin then uses the data from the speed sensor. Not that it is relative since it varies depending on the amount of resistance you initially put on the tyre.

 

If you have a speed sensor the Garmin uses that data with the GPS on or off. Speed sensor is much more accurate - when you lose signal it still measures.

 

Roll your bike and check. I did same on my super motard (digital speedo, not Garmin) and my speed is 100% accurate up to 185km/h (DISCLAIMER: I would never ride that fast because it is breaking the law and I am a member on the hub).

[Helpmytrap]

If you have a speed sensor the Garmin uses that data with the GPS on or off. Speed sensor is much more accurate - when you lose signal it still measures.

 

Roll your bike and check. I did same on my super motard (digital speedo, not Garmin) and my speed is 100% accurate up to 185km/h (DISCLAIMER: I would never ride that fast because it is breaking the law and I am a member on the hub).

There is a reason why I switch it off for the IDT but I can't remember exactly why.

That is one of the reasons why I put it the sensor on, on one of my routes I go under a few bridges. Although it only pauses for a second (on auto-pause), it is still annoying.

[awesme]

stupid question

 

if I set it to auto, and have the unit calculate the wheel size, how/where do I see the result from it's superior math?

 

G

 

The idea is that you set it to auto and go for a ride. Garmin will calculate wheel size fir you that you can then enter.

 

Now take the magnet of again and ride, outside it will use GPS and when you on the idt put the magnet on.

 

Just a note. If you have a magnet on and entered a wheel size garmin will use that and NOT the GPS to calculate speed and distance. GOS is them only used to track your route/course

[awesme]

hmmm

 

 

then this would have been a update along the way, the true distance up incline's, Nice to hear, will with all of this then def be looking at going back to auto.

 

G

 

I always thought this also but apparently it is not true. Garmin uses elavation "axis" to calculate your distance and speed etc. GPS knows your the distance traveled between 2 points and the height above see level gained or lost.

 

I did a test riding with a normal cycling computer and my garmin. I used the garmin to work out the wheel size for me by setting it to auto then entered that into the cycling computer.

 

The distance on both were within 1-2% of each other over various distances and with flat rides and 1500m + climbing.

[Cycling Major]

Akneethling

The radius idea works, same as measuring with tape measurement, but now take that measurement and compare it with a weighted run of one rotation.

 

As for GPS, it's only very accurate if you riding flat level, once you start climbing and descending you loose distance. GPS does not account for nicking and descends

 

G

 

I see where you are coming from BUT the first generation of GPS that came out back in the day (not the cycling ones) had that problem that it did not pick up elevation gained and lost.

 

But the newer ones do, so your problem is NO PROBLEM...

Good luck

[Guest Smimby]

stupid question

 

if I set it to auto, and have the unit calculate the wheel size, how/where do I see the result from it's superior math?

 

G

 

It is just below where you set it auto. It will appear there.

[awesme]

Hi

 

thanks, will try auto again, aware where you set it, just never seen it listed once it was on auto.

 

G

 

It is just below where you set it auto. It will appear there.