edge 705 issue

[berty bassett]

I have been doing a fair bit on rollers just lately and turning satelite connection off and going by cadence and magnet on wheel . last night i tried and the 705 was giving a reading of about 15 mph while i was going like the clappers - i went right into settings and found that the wheel size was on auto but also reading 1034 - how come it would read that after all this time and being right for years - anyone else had this happen

 

[Svendo]

Two things come to mind:
You could try going for a ride outside with GPS, see if the auto setting recalculates properly, and then when you have the 'wheel size calculated' message (can't recall the exact wording) check the setting and if OK change it to custom. If it's a problem calculating the auto wheel size without GPS that should solve it.
Otherwise check the sensor battery. Push the little grey button and spin the cranks and back wheel and see if the LED lights up red and green. If the battery is fine the sensor could be on its way out, I've had one die after 3 years (speed sensor went) and another after a couple of weeks (replaced by Garmin under warranty).

 

[Andrew_P]

I have been doing a fair bit on rollers just lately and turning satelite connection off and going by cadence and magnet on wheel . last night i tried and the 705 was giving a reading of about 15 mph while i was going like the clappers - i went right into settings and found that the wheel size was on auto but also reading 1034 - how come it would read that after all this time and being right for years - anyone else had this happen

I think the Garmin 705 recalculates the wheelsize as a constant using GPS with GPS off it might be confusing the system I would suggest taking the bike out and letting it recalculate using GPS then enter that value on manual and leaving it on manual. or if it is a 23mm on a 700c wheel 2096 or 2098 will be pretty darn close. When I had a 705 near the end of the battery life it started making my wheel progressively smaller!

 

[berty bassett]

Two things come to mind:
You could try going for a ride outside with GPS, see if the auto setting recalculates properly, and then when you have the 'wheel size calculated' message (can't recall the exact wording) check the setting and if OK change it to custom. If it's a problem calculating the auto wheel size without GPS that should solve it.
Otherwise check the sensor battery. Push the little grey button and spin the cranks and back wheel and see if the LED lights up red and green. If the battery is fine the sensor could be on its way out, I've had one die after 3 years (speed sensor went) and another after a couple of weeks (replaced by Garmin under warranty).

thanks for reply
i aint constantly in the shed and it was working fine a few days earlier , change the battery on sensor and light works . Luckily i borrowed another 705 and that worked fine so i dont think its the sensor but for some reason the 705 reduced the size of my wheel to 1030 - teenie tiny i just wondered why it done it - we shall see what occurs over the weekend
thanks again

 

[berty bassett]

I think the Garmin 705 recalculates the wheelsize as a constant using GPS with GPS off it might be confusing the system I would suggest taking the bike out and letting it recalculate using GPS then enter that value on manual and leaving it on manual. or if it is a 23mm on a 700c wheel 2096 or 2098 will be pretty darn close. When I had a 705 near the end of the battery life it started making my wheel progressively smaller!

thanks for replying
i was under a lot of tree cover the last time i used it and saw it flicking from about 18 down to 9 but didnt take much notice - i had set the magic number at 2096 and will ride with 2 garmins on saturday to check - thanks again

 

[Andrew_P]

thanks for replying
i was under a lot of tree cover the last time i used it and saw it flicking from about 18 down to 9 but didnt take much notice - i had set the magic number at 2096 and will ride with 2 garmins on saturday to check - thanks again

I think the problem might be with your cadence\speed sensor then. All Garmin bike units default to the speed/cadence sensor for speed and distance 100% of the time if the tree cover was affecting the speed it was not getting any or only getting intermittent signal from the speed sensor, this is a classic symptom that the speed arm is either faulty or not lined up properly. It would also explain the wheelsize issue, and the turbo problem.

The easy way to tell if it is the sensor is to set autostop at 3mph and then go out for a ride, if the sensor is only giving intermittent signals autostop will keep flashing up when you are moving.