I've got the garmin 800 and I love it. I love the fact that I can record cadence, hr, speed, elevation, grade and mapping all in the same small footprint unit. Furthermore I need to be able to see my numbers while I'm rolling, and having the device crammed in my pocket just wouldn't do. I host some rides and load maps into the garmin which gives me turn by turn directions, which is nice to have when I've got others counting on me to direct them through a new course.

On my solo rides, depending on the course, I'll use the ipod function on my iphone and listen to music. Beyond that my phone is only there to be a phone. I've tried MMR and it killed my battery on a 40 mile ride. Last week a few friends and I rolled 100, which would have exhausted my iphone battery, therefore I find the iphone as my data collection device an unacceptable solution.

In a pinch the iphone and associated app will work, but for my money having a dedicated bike computer/gps is essential.
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An external battery will take care of the insufficient battery capacity of the iPhone and other smartphones. As I mentioned before, an USB battery powered my Android phone for over 20 hours. I keep it on the handlebar with a smartphone holder, always in sight, unless it's pouring down with rain (if it drizzles, I wrap it in cellophane). Google Maps does a great job showing me routes that I want to follow, uploaded as a KML.

If you already have a smartphone, a phone holder and a USB battery are much cheaper than even an entry level Garmin, let alone the 800.

Where the 800 makes sense is if you also want to record cadence and pulse, not just your speed and course.

As for the iPod, I can't think of many places where I would consider using headphones on a bicycle because they insulate you too much from your environment. I would not want to put myself and others around me in danger. The first two rules in our group rides are "wear a helmet" and "no headphones!"

Do you run into overheating issues with the iPhone? Especially after wrapping in cello? On warm days mine will shut down ... I had under the clear map cover on my front bag and figured there just wasn't enough air flow to keep it cool. However I've also run into that same issue on rides over ninety minutes with the phone not under the cover. Really curious to find out if it's just my phone and local conditions or if it's a persistent problem for everyone.

I've been having good like with Strava on an iPhone 4. I turn off the screen and tuck it in my under-seat bag and it seems to read the GPS and Ant+ sensors quite well without losing a charge. Putting it on the handlebars worries me, more because I drive a fairly populated suburban area. Multi-tasking with cars on the road can be painful!

When the bike is in motion there is airflow, so heat should not be too much of an issue. I only wrap it in cellophane on days of drizzle, i.e. when it's overcast and usually not that hot anyway. I've heard of people having problems with GPs units when leaving the bike parked in the sun, but when I leave the phone on the bike when I pop into a shop (I don't live in a high crime area), I put the helmet on top to shield it from both the sun and strangers' eyes. I don't know about iPhones, but over the last 6,000 km neither of the two different Android models (Google Ion and Google Nexus S) that I've used on the bike has had any heat related issues yet, such as reboots or apps crashing.

The number one power draw on the phone is the display and I keep that off most of them time because my eyes are on the road.

On Saturday did a 165 km (103 mls) ride with daytime highs of 30-32 C (86-90 F) during which I went through 5 l of water and sports drinks. No problems at all with the phone on the handle bar!

I use 'Runtastic Roadbike' on my iPhone (best biking app out there imo). More than I need. With today's smartphones and the wealth of apps out there, I don't see a need for a dedicated computer.

I was surprised how cheap a battery replacement/extra battery for my Android cost. On Ebay
I can easily find my battery for around $3 or $4. Or the battery and charger combo for well under $10.
For me Strava doesn't eat much battery at all. Today I rode for 2:30 hours with Strava while playing mp3's on the highest volume (Sinatra, it makes the chicks smile:thumb:) and came home with a battery life not even half gone. I do have my monitor brightness all the way low and no vibration that helps.
Hope it helps.
http://www.ebay.com/sch/i.html?_from...ptimus+battery

Agree. I would never use my iPhone as a substitute for my Garmin... unless I forget the Garmin for some reason.

http://bikeforums.net/attachment.php...hmentid=276050

There's a screenshot of an app I'm working on. I just put together the selecting the point on the gpx to start from and the highlighting tonight. I started with the overall timer function that will track the time until the next 1, 2, or 3, turns (it's selectable in settings from 5-60 seconds) and then alert people to the turn. It's speed sensitive so it uses your speed to calculate the time until the next gps point and then alerts you at the alert intervals you've set.

The "Next" button is going away soon since I now know how to programmatically click and you can select a row in the list and start from any GPX point.

It does the audio text to speech for directions as well but I have found that I'm going to have to run things through a translator of sorts so "Grouse Dr" becomes "Grouse Drive" instead of "Grouse Doctor". :)

One thing to note... it doesn't use map downloads at all. It's made to be EXTREMELY frugal on battery usage.. even going as far as using passive updates (it pulls gps updates from other apps on the device) and slowing down GPS updates when there's a significant distance till the next turn.