Smartphone as power meter head unit?

[kulivontot]

Hi.
Just recently purchased a second-hand stages power meter, I'm planning on using my iphone to record ride data. I've got a ANT+ compatible wahoo RFLKT+ display which is basically a dumb display that shows the current data my phone is recording.
My question is, will this kind of setup record appropriate power data for training purposes? I had a Garmin edge 305 that had an option for 1-second recording and "smart recording," the latter of which was terrible for training purposes because it would mess up your averages. Does this kind of issue happen with the strava/wahoo apps? As far as I can tell, they do a consistent 3-second poll of the data being recorded. I'm also slightly concerned about some sort of lag or synchronization issues between recorded speed, cadence, HR data, etc.
Any comments on this setup?

[glepore]

I've used it in conjunction w/ Golden Cheetah. Email the pcx file to myself using the Wahoo app, save it then open in GC. My issues aren't around recording but the fact that often (almost all rides) there is a loss of com at some point which results in totally screwed up NP numbers etc. Its easily fixable by going into the edit function, locating the bad cells (its obvious) and then deleting them, both content and rows. It works fine then. I have to say though that its a pita, and I do it simply because I'm invested in BT sensors for speed on 2 of my 3 bikes due to their cheap availability on ebay, search for Scoche. Oh yeah, just an fyi, using this setup will result in the pm working in the BT mode,for what that's worth.

If you've been using the system for a while you're probably aware of its glitchy nature, so it may not be a big deal. There's also a battery consumption issue at the moment that Wahoo is working on a firmware fix for. I love the concept, will continue to use it, but its definitely one of those things that you'll feel like sort of a beta user.

The strava app doesn't give you the nice configurable windows that the Wahoo does for the RFLKT, which is one of the major pluses to the system for me.

PM or email me if you want some more info on quirks/workarounds that I've found.

[dgran]

PM or email me if you want some more info on quirks/workarounds that I've found.

Please keep sharing your thoughts on this. I'm presently using an iPhone with a Rflkt+ and it works out well for me, but at present I'm only using it to record GPS data. I'm keeping watch on a deal for a Stages PM and considering the Wahoo Tickr HR monitor. The battery hasn't been a problem so far. I can go nearly 7 hours with an iPhone 5s. I'm curious if more devices create more drain.

On the matter of drop out, are there techniques such as putting the phone in the left jersey pocket or anything that seems to help?

[glepore]

Yes, the right jersey pocket is a help. Not having anything between the phone and the outside of the pocket helps. My issue has been that if there's anything in the left pocket (in my case tools or a spare tubie) that causes the jersey to shift, you can get a dropout that you don't notice until the next glance at the rflkt which shows a np number (I keep that on the main screen) of like 4500 (!). If it goes on long enough, the rflkt freezes. I need to make sure that the jersey is "balanced" and that the right pocket is always to the outside of my body.

The other issue for me has been connectivity at the start of a ride if I'm time pressed with a group waiting. I find that sometimes not all of the sensors connect etc. I find that making sure that the app is fully closed after each use (ie not still running in the background on the phone but "stopped") is a big help. An occasional restart of the phone is still needed. also, the availability to save different sensor profiles for multiple bikes is very nice, but you need to make sure you pick the right bike when you start the app

Battery life not an issue for me, as I don't use gps routinely at all, I do have an old wahoo case and battery if I need the gps for any length of time.
With a 4s and two sensors (on the main bike one ant speed and the stages for speed and cadence) I'm seeing 4-5 hrs, drops to less with gps. If I stream music to a bluetooth headset I see maybe 2/3's that life.

[dgran]

The other issue for me has been connectivity at the start of a ride if I'm time pressed with a group waiting. I find that sometimes not all of the sensors connect etc. I find that making sure that the app is fully closed after each use (ie not still running in the background on the phone but "stopped") is a big help. An occasional restart of the phone is still needed. also, the availability to save different sensor profiles for multiple bikes is very nice, but you need to make sure you pick the right bike when you start the app

This reminds me of a problem I had once. I started the ride before the screens were fully loaded. I figured it would just synch up since the iPhone app was running, but the altitude and gradient (both reading off the barometer in the Rflkt+) stayed at zero the whole ride. I fiddled around trying to see if I could get them to rejoin each other after starting but didn't see any way to do it.

I do get the sense it feels like beta testing something. Wahoo does a pretty good job but clearly they are still working through error conditions out in the field. Thanks for all the good feedback. There aren't many of us trying this setup but I have a feeling it will catch on.

[kulivontot]

I find the battery life of BT HRM, GPS and RFLKT to be lacking. I've finished 5-6 hour rides with about 5% left from full battery. Still this is preferable to starting a ride with a garmin that's 100% dead at the start of the ride and needing to charge 2 separate devices. Just bought an extra battery case for this purpose. I'll let you know how it goes once my stages PM comes in this weekend. I'll experiment with ANT+ and BTLE mode.
Can you run your phone in airplane mode and still get GPS + Bluetooth for battery life improvement? I imagine a lot of it is due to roaming in areas with very poor reception.

[glepore]

I find the battery life of BT HRM, GPS and RFLKT to be lacking. I've finished 5-6 hour rides with about 5% left from full battery. Still this is preferable to starting a ride with a garmin that's 100% dead at the start of the ride and needing to charge 2 separate devices. Just bought an extra battery case for this purpose. I'll let you know how it goes once my stages PM comes in this weekend. I'll experiment with ANT+ and BTLE mode.
Can you run your phone in airplane mode and still get GPS + Bluetooth for battery life improvement? I imagine a lot of it is due to roaming in areas with very poor reception.

http://support.apple.com/kb/ht1355 It appears this allows you to turn BT on. I don't think the cellular consumes much power, but try. Clearly, having the gps on versus gps off makes a big difference. I don't strava, so I don't care about gps, and if I get lost I can reenabl

The RFLKT is open source, it'd be great if someone would develop a way to enable some sort of turn by turn or other gps function with it-nice for club rides etc. but irrelevant for data logging.

If you want to use the stages via ant you'll need to kill the bt on the phone and pair it as a separate device using the RFLKT bridge. No point in that, really, as it uses more, not less, power as I understand it. Plus, if the RFLKT freezes or dies you don't necessarily lose power logging, just mileage and speed if your speed sensor is ant. Hence why I'm switching to all BT.

I'm curious as to whether the extra battery adds interference with the already marginal RFLKT reception....let me know. I've never actually used my aux battery with the RFLKT.

[TheKaiser]

Only peripherally related to the conversation here, but I just wanted to chime in that I use Strava on my Android phone, and have found that running it in Airplane mode with GPS enabled has dramatically increased my battery life. I do ride in a lot of rural valleys which have poor cell reception, so I think my phone was working overtime trying to maintain a cell signal, but GPS only seems to be far less demanding. It has made the difference between having my battery die 3-4hrs into a ride, and finishing the same ride with 40% capacity left over.

[kulivontot]

As an update, I gave up on the RFLKT. The thing was far too unreliable in initial pairing and also would randomly crap out on the road. In addition it seems my power meter Bluetooth signal was slightly too low and would drop out on rides.
So I bought an edge 500. Apparently the best GPS computer was made in 2009. Who knew.

[glepore]

Me too-as much as I like the form factor of the RFLKT, I was given a dead 500 to use, formated it, got it working and I must say, it is so much more stable and reliable. Wahoo has some stuff in Beta that might woo me back, but for now, I'm in the Garmin camp for my main bike. Still using wahoo for the other 2, as they have bluetooth sensors.

[aaric]

I had a rflkt+ for a while. it just wasn't reliable enough for training with power. Drop outs, crashes, etc.

It also wouldn't read the cadence from my SRM for some reason. Read my quarq fine though: so it wasn't a setup issue. Tried dealing with wahoo support, and they never did manage to fix it. Sold it and bought a 510. I've had both the 500 and 510: The 510 is much nicer if you have multiple bikes you use it with, or want multiple screen setups based on activity (Trainer, power, maps, etc). The 510 also syncs much better with satellites as it uses glonass in addition to gps. My 500 would routinely show me offroad when riding in tree covered mountain roads with some treecover, where the 510 has been dead on.

[natefontaine]

Check out the RIDE WITH GPS android app, 1sec data recording. It recognizes Bluetooth devices only atm, has options to use the phone as a display.

[glepore]

Just as an fyi for those that have rflkt, Wahoo has firmware in beta along with an improved app in beta that will both improve rflkt battery life and supposedly greatly improve connectivity...beta testers using it now and reporting positive results.

[bdcheung]

It also wouldn't read the cadence from my SRM for some reason. Read my quarq fine though: so it wasn't a setup issue. Tried dealing with wahoo support, and they never did manage to fix it. Sold it and bought a 510. I've had both the 500 and 510: The 510 is much nicer if you have multiple bikes you use it with, or want multiple screen setups based on activity (Trainer, power, maps, etc). The 510 also syncs much better with satellites as it uses glonass in addition to gps. My 500 would routinely show me offroad when riding in tree covered mountain roads with some treecover, where the 510 has been dead on.

Sorry to dig up an old thread but I'm having the same issue (RFLKT+ won't read cadence from SRM, but reads it fine from Power2Max Type S, 705 reads cadence from SRM). Did you ever get a resolution from Wahoo? I've filed a support ticket with them.

[aidenmoon]

oh that's an idea. i will try that too. thanks guys.