# Edge 305 cadence sensor not working. Help



## wvmtb (Jan 16, 2004)

I just recently bought a used 305 and I can not get it to pickup the cadence. I have a friend with another 305 that they have never used the cadence sensor with thier edge. And we tried to get it to work without any luck. Tested batteries and they are fine. But the edge flashed an "X" over the cadence symbol. I have tried hitting the reset button on the sensor and nothing happens. From all of what I have read when you press the reset button the there is a led turns red then to green. I don't see a light on either sensor. Any of you have this problem or know what to do to fix it? I just find it hard to believe that with two 305's and 2 sensors that I can't get one to work.


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## LoIQ (Apr 26, 2007)

Your unit might not be synchronized to your sensor. You might try going to the menu settings> general> accessories>cadence sensor> restart scan Restarting the scan will resync your unit with the sensor
good luck


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## wvmtb (Jan 16, 2004)

I tried that on both units and it didn't do any good. I am starting to wonder about the quality of garmin products. I have a 205 and bought this 305 because the 205 kept shutting off on me and I wanted the extra features that are on the 305. Of course the 205 is in the hands of Garmin for repair right now. But with my new (well used) 305 not working correctly and seeing the same problem with another unit, I am starting to wonder about these things. Are they really worth the $$$? I am still hoping this is a user error but just can't figure it out.


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## dnoyeb (Sep 23, 2007)

im not sure exactly what wakes up the sensor. i would do a reset immediately followed by a scan. also get your friend to test both sensors with his unit so you can blame your unit. do you have a heart sensor?


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## ToddM (Feb 3, 2004)

If the Sensor is not flashing Red to Green once when you press reset on the sensor something is wrong with the sensor, or the battery is dead/dying, or put in backwards etc.....as you said you tested the battery we can rule the later out. The little LED is actually behind the white reset button, so it's the button itself that flashes red/green. If it does flash red to green once after you push reset (you really have to push it or get something small to push it), then after that when you pass the cadence magnet by it should flash red, if the speed magnet green. I've also noticed that it takes a strong magnet to trip the garmin sensor, and I've tried non-garmin magnets in the past with poor success. 

If the unit is turning red/green when you reset the sensor, and it's flashing red/green with the magnets passing by, the unit should see it.


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## wvmtb (Jan 16, 2004)

The bad:


dnoyeb said:


> i would do a reset immediately followed by a scan. also get your friend to test both sensors with his unit so you can blame your unit. do you have a heart sensor?


Tried exactly what you said and yea I have a HR strap it works fine.

The bad part 2:


ToddM said:


> If the Sensor is not flashing Red to Green once when you press reset on the sensor something is wrong with the sensor


Neither were flashing whick is why I checked the batteries. And I thought that's where the led was (behind the button).

The GOOD:


ToddM said:


> If it does flash red to green once after you push reset (you really have to push it or get something small to push it)


I brought it to work with me this morning so I could mess with it on company time :nono: and maybe I "really pushed it" this morning or did something different but it's working fine now! Cadence & speed. Although I still don't understand how the speed works without setting a wheel size. I am guessing it just has a average wheel size programed to give you a estimated guess to fill in the gaps if and when the GPS isn't picking up.
Bottom line. It is working now for some strange reason. It will be interesting to chek the other later.


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## ToddM (Feb 3, 2004)

It may have a default setting for the wheel size to start, my understanding is it automatically calibrates the wheel size by using the GPS speed when you are moving and the GPS has good signal. 

In any case, glad to hear it's working!


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## GEOMAN (May 30, 2006)

The cadence sensor is the part we sell that requires the greatest explanation and customer interaction. 

Sorry I was so late to this picnic, these threads move very quickly! 

Good job!


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## wvmtb (Jan 16, 2004)

I was wondering when geoman would chime in. Now that I think of it I think I remember hearing that before about how it calibrates the wheel. But now that we are on the subject...... Let's say I go for a MTB ride then the next day I ride the trainer on my road bike. Does that screw with the distance? Maybe you could give me a link to some info on how this works.....just for curiosity.


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## GEOMAN (May 30, 2006)

wvmtb said:


> I was wondering when geoman would chime in. Now that I think of it I think I remember hearing that before about how it calibrates the wheel. But now that we are on the subject...... Let's say I go for a MTB ride then the next day I ride the trainer on my road bike. Does that screw with the distance? Maybe you could give me a link to some info on how this works.....just for curiosity.


You can solve this issue by creating a second profile in Training Center (assuming that's what you're using); one for your mountain bike, another for your roadie.


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## Psycho Mike (Apr 2, 2006)

Hey Geo...does the 305 keep the calibrations between bikes if you have them set up as seperate bikes? I.e. if I put a Cadence/speed sensor on my SS roadie, would it keep them separate or just recalibrate each time I switched between the bike profiles on the 305?


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## wvmtb (Jan 16, 2004)

Psycho Mike said:


> Hey Geo...does the 305 keep the calibrations between bikes if you have them set up as seperate bikes?


That's just what I was thinking. And what how do you use "bike 3"? There is settings for it but no way to pick it.


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## slocaus (Jul 21, 2005)

wvmtb said:


> That's just what I was thinking. And what how do you use "bike 3"? There is settings for it but no way to pick it.


Press and hold the "Mode" key. It will pop up the three bike profiles to choose, with Up / Down and then Enter. :thumbsup:

I use mine on three different bikes. One FS 29er, an SS 29er, and a road bike. Never ride the trainer now (that is why I came to California  ), but I have no doubt on accuracy.


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## wvmtb (Jan 16, 2004)

OK, I got that. But it brings up a new question. You can set different display fields up for bike 1 and 2 but not bike 3. When I am at the screen that displays the data if I press the top or bottom button on the right side it changes from between bike 1 & 2. Why is bike 3 not there? I am thinking maybe it is really just a display page and not really the bike setup. Am I correct on this?


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## slocaus (Jul 21, 2005)

wvmtb said:


> OK, I got that. But it brings up a new question. You can set different display fields up for bike 1 and 2 but not bike 3. When I am at the screen that displays the data if I press the top or bottom button on the right side it changes from between bike 1 & 2. Why is bike 3 not there? I am thinking maybe it is really just a display page and not really the bike setup. Am I correct on this?


You just have two different display screens to quick toggle, they are not related to the bike 1 or 2; the info will be the same for both (actually all three bikes). It is just a way to have easy to toggle screens with the info you want. Customize them under Settings, Data Fields, Bike Computer 1 / Bike Computer 2. I see the confusion thinking they are related to the bike (I had not been to these screen customizations for months and months - I just ride and record now. 

You can go to Setting, Bike Profile and change the weight and whether the (cadence/speed) sensor is mounted, and either tell it the wheel size or auto calibrate. I have bike 1 as my roadie with sensor auto calibrate, bike 2 is my 29er SS no sensor, bike 3 is my FS 29er no sensor.


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## wvmtb (Jan 16, 2004)

That's what I was thinking. I don't know why they didn't just put it as Diplay 1 & 2 or something like that. Like I said before I had te 205 for a while and just upgraded to the 305 so I have just been messing around with the different features. But now I think I have a good grasp on it. Thanks to you all! I'll be back to the set it and forget it mode real soon.


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## GEOMAN (May 30, 2006)

Thanks Slocaus! Your input is terrific.


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## dnoyeb (Sep 23, 2007)

Its my understanding that the speed sensor is ignored unless the GPS is turned off.


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## GEOMAN (May 30, 2006)

Partially true.

The speed sensor will fill in if there are "holes" in GPS reception, as well, even with the GPS turned on.


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## PCC (Sep 5, 2005)

With regards to the speed/cadence sensor, the battery drained on mine and I replaced it with much the same results of the OP. I decided to just ride the bike since the GPS would track my speed and progress anyway. About five miles into the ride I noticed that the thing was working and it worked great until my next ride when I noticed that the battery was dead again. I think it was the result of parking my bike with either the wheel or crank magnet sitting over the sensor, causing it to not turn off over the next few days.

Thanks, slocaus, for the information. I was wondering how to access the third bike profile. Now I need to change that setting to a more meaningful setup as I duplicated my first profile on the third one.


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## lkgeo (Oct 31, 2006)

Hi, thanks for all the useful info - just got a FR 305 & I'll look into the multi-bike setup.

I hope this is not too OT for this thread - any suggestions where to find info for aligning a garmin GSC10 sensor on FSBs where the crank doesn't overlap much with the chainstay + spokes (see picture)? It's a SC Juliana; should be similar to a small SC Superlight. I know there's debate about usefulness of cadence on an mtb but I'd like to include it for training purposes it if I can. 

I don't have a sensor for my mtb yet but it looks like there's about 2" between the cadence & spoke lines on the sensor and a bigger gap between a usable part of the crank and spokes. I'm wondering if there's much lateral sensing if the magnets are farther apart than 2", or if anyone has had success putting the sensor somehow at the end of the crank, or if two sensors would work if necessary (preferably not, due to $s). thanks -

(later edit: p.s. closest possibility is under the chainstay but an above-chainstay mount seems better - less exposed to rocks etc.?)


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## dnoyeb (Sep 23, 2007)

My Fuel Ex7 crank does not overlap much either. It works though.
I don't think you can go under the chainstay. Anyway the crank signal is more important that the speed signal. But if you miss the speed signal you will get the flashing sensor on the 305.


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## lkgeo (Oct 31, 2006)

Oh - to clarify, by "under" I meant toward the ground, not towards the wheel - hoping to protect it from flying rocks, etc. as much as possible.

Glad to hear yours works - I'll be working on mine this weekend. Thanks!



dnoyeb said:


> My Fuel Ex7 crank does not overlap much either. It works though.
> I don't think you can go under the chainstay. Anyway the crank signal is more important that the speed signal. But if you miss the speed signal you will get the flashing sensor on the 305.


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