busrydr

If I get time this weekend, I have a Bontrager Node 2 that I will dig up and give a try with the DTS. I have not used it since I got my Garmin a couple of years ago, but it worked fine when I had it paired with the original DT.

rpenmanparker 

Personally I believe you are onto something with the transmission distance idea. I see that kind of thing all the time with old school wireless bike computers. I think there is a lot of variability in both transmission strength and reception sensitivity so that it is quite possible to be on the edge of poor functionality with a larger bike. They are purposely trying to limit the range of the devices probably to avoid interference as well as to conserve battery life. Sometimes they just get too close to the edge. (Ha ha, good pun!)

af2nr

Be interesting to see how the new unit works, although mine is old enough it probable won't help me if that is the case?! I'm also on the SL, size 56.

txags92

Ok, I was able to take my new Emonda SL out for its first ride today. I have the Duotrap S and a Garmin 500. The bike is an SL frame in size 56. I had a couple of dropouts...nothing significant...both times I noticed it, it happened when I started up a steeper section of an incline and shifted to an easier gear. At times when climbing, my knee dips inward, and I suspect my leg was blocking the transmission briefly. My next ride will be on flatter terrain and I will see if the issue repeats.

af2nr

@txags92 I don't think anyones have been significant just repeated? It seems as thought there is some issue, and mine does it regardless of whether or not I'm climbing, riding flats, or going downhill YMMV. As much as I didn't think much of this before @RNAV brought it up it seems pretty common on Emondas, with a small data set anyway. Know if I could just remember to bring it up at the LBS instead of shopping/bs'ing...

RNAV

I received my replacement Garmin Edge 500 unit yesterday. Garmin was pretty easy to work with -- they even let me have my choice of color for the replacement unit (which was nice, because when I bought my original unit the white/blue scheme was the only color available, which doesn't go with my black/red bike).

I paired the new unit to the DTS and took it out for a spin today. I got the same auto pause malfunction at around 15 mph just 3 miles into my ride. Then the unit was fine for 20 miles. Then it gave me four back-to-back auto pauses while maintaining 18 mph. For the record, the unit arrived with the latest software pre-installed, and for fault-tracing purposes I did not sync the device with my computer prior to pairing it with the DTS or going for a ride. I just wanted to eliminate the possibility of some sort of malicious code transferring from my computer to the device.

Considering that both my original Edge 500 and the new Edge 500 do not drop my other ANT+ devices (Garmin's own GSC-10 sensor and two different heart rate monitors), I think it's reasonable to conclude that the problem rests with the DuoTrap S sensor. Does anyone see another conclusion that I'm not seeing?

rpenmanparker 

No. Sensor. I wonder how you could test if it is position of the sensor. Can you move the Trek sensor to the fork and put the magnet on the front wheel? Do you still have the original one that Trek replaced?

spdracr39

The duotrap sensors are integrated into the left side chainstay and can't be relocated.

Just an update .. I ride a 56cm Madone and at 2000 miles I have still had 0 issues with my connection to the Garmin 810.

spdracr39

That last post gave me an idea. You can't move the sensor but you could attach the Garmin temporarily to the seat post and see if your issues disappear. This would confirm if it is a weak signal issue.

RNAV

That's not a bad idea. I think I'll just stick the Edge in my jersey pocket and call it good.

For those who don't have problems with their DuoTrap S: how do you have your computer mounted? Stock garmin mount on stem? Bar-fly?

rpenmanparker 

Right, but how are you going to watch it for 10 or 15 miles? Is there a function on the Garminto display a running graph of the speed and cadence so you could check it after the ride?

spdracr39

There is if you sync your data to Garmin Connect and have auto pause turned off.

RNAV

I have my Garmin set up to make an audible tone whenever it auto-pauses.

I haven't mailed my old Edge 500 unit back to Garmin yet. So I've decided that, on my ride tomorrow morning, I'm going to run both Edge 500 units simultaneously. I'll have one mounted on the stem, and one in my pocket (which should have a more direct line of communication to the DTS sensor).

It'll be interesting to see if one auto-pauses and the other doesn't . . . or if they both auto-pause at the same time. I think that could help narrow down whether or not it's a proximity issue, and whether or not it's a Garmin vs. DuoTrap S problem.

rpenmanparker 

Good plan. Let us know.

RNAV

I went on my fault-tracing ride this morning and I'm hoping some of you are savvy enough examining route files to help me understand the results . . . they were not what I was expecting.

Here's how I accomplished the test:

• I ran Strava on my iPhone connected to both the DuoTrap S (DTS) sensor and my HRM via bluetooth.
• I ensured that both the replacement Garmin Edge 500 (henceforth referred to as "Edge A") and my original Garmin Edge 500 (henceforth referred to as "Edge B") were connected to the DTS and my HRM.
• Edge A was mounted on the stem using Garmin's factory stem mount.
• Edge B was in my left rear jersey pocket, providing a nearly direct line-of-sight to the DTS sensor, which is located on the non-drive side chain stay.
• I started recording on Strava first. Then I began moving, and upon receiving the "press start" notification on Edge A, I pressed "start" on Edge A, then reached into my jersey pocket to press "start" on Edge B about 10 seconds later.
• Whenever the speed sensor dropped, which would result in an audible "auto-pause" and an audible "auto-restart" notification, I would depress the "lap/reset" button on the respective Edge. For Edge A, time from auto-pause/auto-restart sequence to pressing lap/reset button was about 2-3 seconds. For Edge B, the response time was longer (8-10 seconds) since I would have to reach into my jersey, remove the device, and then press the button.

Results:

• Edge A dropped two times. Once at ~01:48.2, and the second time at ~51:02.
• Edge B dropped three times. Once at ~02:40.0, second at ~51:59, and third at ~1:16:57.

So, I'm not quite sure what to make of the data. It's clear that Edge A & B dropped relatively close to one another . . . within a minute of the other both times (it seemed closer than that while on the road, though). That said, they didn't drop simultaneously, which is frankly what I was expecting to happen. And then you've got the outlier third drop by Edge B, which again goes against what I was expecting -- considering it was closer to the DTS, I was expecting more reliable communication.

I'm going to make all three data files public in the hopes someone can analyze them and help make sense of this data. Please don't make fun of my terrible average speed -- the wind was 18 knots gusting to 28 knots during the ride, and was quite demoralizing!

Strava file: https://www.strava.com/activities/257859127/analysis
Edge A file: https://connect.garmin.com/modern/activity/702475706
Edge B file: https://connect.garmin.com/modern/activity/702479605

If someone wants the actual files, I can email them out.

So . . . what do you all think of this?

Up North

I have had zero problems with my SLR and my 810. I'd say you have a duotrap or edge issue. Is there any chance you have a radio tower or something similar on your rides which might mess with signals?

spdracr39

I didn't notice it mentioned but do you have any other electronics or lights on your bike? I know someone that can't use his cat eye when his led headlight is running. Other than that is has to be a weak signal from the duotrap.

RNAV

I doubt it's a radio tower. My reasoning is that the drop outs don't occur at a specific location; they're location agnostic. Additionally, neither Garmin unit has drop outs when paired with Garmin's GSC-10 speed/cadence sensor.

RNAV

I do run a knog blindr r tail light. That said, I experienced drop outs when I first got the bike, and I didn't get the tail light until a couple months later.

spdracr39

Well the only thing I can think of is borrowing another model of Garmin and see if that fixes it. Perhaps it is just an issue between the two specific models of devices. Mounting the garmain sensor is a pain on the duotrap ready frame and with the new duotrap s design it is even harder to keep it adjusted.

af2nr

It isn't specific to his model of Garmin as I have the same issues with my 800 and SL6 with Duotrap S. To add to the mix I've also used 3 different mounts since getting my bike and it doesn't change anything, Garmin stem mount, out front mount and now using the KEdge combo mount. I haven't noticed any changes since adding my Garmin Virb either, for the better or worse? I do find it interesting that that the drops are related when pairing both units, although not exact?!

rpenmanparker 

Do you put the Garmin sensor on the rear wheel or the front when you test it?

RNAV

The Garmin GSC-10 sensor was installed at the rear (non-drive side chain stay, pretty much same location as the DTS).

Trucker Dan

No problems with my 2014 madone 7. I'm using a garmin 810 mounted with a k-edge mount.

rangerdavid

I have a duo trap on the Domane I got last April. I had issues at first, but since then everything's worked fine. I think in my case it was user error as I seem to have been the weak link between the duo trap and the garmin.