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LloydWilliams 06-29-12 04:46 PM

Wahoo Fitness iPhone case and Bluetooth vs ANT+ sensors
What are the advantages/disadvantages of using Bluetooth or ANT+ sensors (speed, cadence, heart) with Wahoo Fitness iPhone case?

Is one system better or worse than the other for:
- battery drain
- sensitivity
- other issues

I intend to use external battery charge battery so the phone has a constnt charge. I will charge the external battery with a hub dynamo. This will be on a tadpole trike to do long distance touring and randonneuring.

JohnJ80 07-01-12 06:01 PM

The BT version will use a lot less of the iPhone's battery.

I have the ANT+ version for my iPhone 4 and find the GPS to not be nearly as accurate as my Garmin.

It can also be quite tricky to get the case to not rattle on the bike mount. Tends to hit one end or the other of the stem when stem mounted.


LloydWilliams 07-01-12 08:40 PM

Thank you John. Can you elaborate on the accuracy advantage and what value you gain from it? Thanks.

JohnJ80 07-02-12 06:28 AM

I suspect my iPhone has issues with the GPS but these are noted problem with phone GPS's in general. The iPhone (and any phone's) GPS is not going to be as accurate as a standalone GPS. It's a crummier antenna for GPS and it has a lot of other stuff going on in the case that can impact receiver sensitivity.

For biking, compared to the Garmin units, for example, the vertical positioning and changes are far different. The Garmin is pretty precise and accurate. On one ride, I do, it shows a net change of 246' over the ride (pretty flat and correct). The iPhone shows it anywhere from 1000' to 7000' and grades that I climb of up to 46% - obviously wrong. The reason for that is partly my not great iPhone GPS, but the Garmin 705 also has a sensor for barometric pressure to deal with the micro changes and the iPhone doesn't have that.

But this will get ever better. I like the idea of not having to use a separate bike computer since I have to carry my phone with me anyhow.

I doubt there will be any difference in accuracy between ANT+ or BT. Given the choice, I'd take the BT just for the battery savings. I would suspect that ANT+ will phase out over time in the face of BT being a far more useful and practical standard long term.


LloydWilliams 07-02-12 09:42 AM

John, I too only want to carry one and the iPhone seems the best choice. As long as it shows me on the correct road and close to the right elevations (my experiences with elevations has been much better with my 3Gs) I am happy.

I will be using a dedicated dyno hub to keep it charged on the Trike.

In the mean time since my 3Gs does not work with the new Wahoo Blu I will use the ANT, it also works with TrainerRoad sessions on my Kenetic trainer and that will be good as I train for the 2015 PBP.

By the time I get to PBP in 2015 the technology will have improved anyway. Thanks for your comments and help.

NOTE: does anybody know if the iPhone 4s requires a constant charge from an external battery or can it be charged directly from the dynamo? Thanks all.

Steve530 07-03-12 05:40 PM

I recall reading that people had problems with BT sensors because they use such low power that they need a clear path to the device. Like the signal can be blocked by the body. Perhaps the newer BT technology fixed that.

JakiChan 07-03-12 10:18 PM

What is your long term plan? I started off with the Bontrager Node 2.1 because I didn't know I wanted a Garmin 500. :) But for $70 I got the Wahoo key and run that and the Node 2.1 at the same time (for Strava purposes). The cool thing is when I get the Garmin I won't need more sensors. (Or, since I plan to get the Garmin when I get a new bike, I can have sensors on both bikes.) So Ant+ seems to be the way to go for now.

LloydWilliams 07-04-12 04:37 AM

I would like to stay with an iPhone solution. Since I only have 3Gs currently, I am limited to ANT solution. I will upgrade to iPhone 5 later but for now this seems bet solution. I ordered wahoo bike kit with external battery ang garmins speed/cadence and heart rate monitor. With the Garmin USB ANT tick I now have info while on the road or on the Kinetic Trainer. Seems a good solution. Can all be move to trike later.

Wildewinds 07-05-12 10:22 AM

I have the Wahoo unit in question and I think it works perfectly. Got the $150 setup from amazon with the speed and cadence sensor. I've never had issues losing any data with the Ant+ sensors and receiver. The advantage of using Ant+ is that you can add on other Ant+ devices (namely a heart rate strap) and it'll work no problem. The GPS for me has been very accurate, including altitude. I only go on one to two hour long rides usually, but it doesn't really drain the battery very much that I've noticed. That's with the screen on all the time.

I pair up the system with the Cyclemeter app.

JohnJ80 07-15-12 10:46 AM

WIth the new Bluetooth sensor from Wahoo, I think this case looks really interesting:


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