Noticed yesterday that ridewithgps has an iphone app now. Turn by turn navigation only works with a subscription, so I signed up to test out this feature. I have used co-rider for turn by turn on a couple of occasions and didn't love it, so I'm curious to see whether ridewithgps yields any better results

The issues are secure mounting on the bike, having enough battery for the full time GPS scanning on a long ride as well as the other accurate functions you get with a dedicated bike computer like cadence, heart rate, and actual measured speed from the wheels (rather than approximate speed and distance by GPS). Wahoo and others make mounting kits, signal sending kits, recievers, and I think auxiliary battery packs etc. to make the iphone truly functional on a bike, but the cost is horrific IMO.

Let us know how it works.

What I've found most frustrating about turn-by-turn navigation for bikes is that it's designed to only be useful getting from point A to point B, versus point A -- circular route -- back to point A. It seems like something that would be so simple for app developers to incorporate, but they don't. And I don't feel like spending $400 to get this feature when I've already got an Edge 500 and a $600 iPhone.

Do you really need GPS to tell you how to get somewhere on the bike? I thought it was mostly for determining ride results. Are the instructions different for a bike than a car? Does the software know which routes are suitable for bikes and which are not. Otherwise for this purpose the Maps app that comes with the phone would be just as good. I wonder if you can run two GPS apps at the same time, a cycling app for results and the Maps app for turn-by-turn although I still don't see the point of the latter.

For me, I move a lot, which means I'm constantly trying to find new cycling routes. What I want to do is create a route, send it to my iPhone, and have my iPhone provide me with both turn-by-turn navigation AND cycling data. As it is now, I can either get cycling data, or I can get turn-by-turn navigation from one starting point to a different starting point. What I can't do is dictate the route I want to take, starting and ending at the same location.

When exploring a new route, even with a cue sheet, I've sometimes had to stop on the side of the road, pull out my phone, verify where I am, put the phone back in my jersey, and press on. It'd be really nice if someone could leverage the iPhone's technology to enable route navigation & cycling data.

It's not the GPS directions per se. It's about following a predetermined (and bike friendly) route. People upload maps to ridewithgps with specific distances, and turning points and following specific roads to avoid the higher traffic roads and highways. GPS apps won't give you loops.

Google Maps app gives you "Bicycle" option when you look up directions. There is no Bike Data though, I'm sure Google developers will get there soon. I have a mounting kit for my iPhone, however, reflection from the sun makes it impossible to see anything.

I agree that turn-by-turn direction is helpful in various situations. I sometimes do group rides in unfamiliar territory and don't like pulling out the cue sheet or the phone to look at my location. Although I almost never need it, its nice to know when and where the next turn is coming up. It helps to gives others in the group the heads-up on an upcoming turn so there are no quick surprises.

But if you have the Edge 500, then why bother using the iPhone for this feature? Also, ridewithgps allows you to design a looped route or and out and back. This route can then be loaded onto the Edge 500 with turn-by-turn directions, so don't see the problem.