Just wondering what a Garmin does that my iPhone4 doesn't as a cyclocomputer? Anyone use both? Would it be worth it to even get a Garmin? The only problem with the iPhone cycling apps is that none of them accurately measure incline (I like to know how steep the hill is), and the total accent measurements are usually different than my friends who use Garmin.

I've found the iPhone to be OK if you don't need much more than rudimentery GPS data. I like having power, cadence and HR info though, so that kinda rules out the iPhone for me because it needs an external adapter for ANT+ and I don't have much faith in its battery life when used like that.

I don't have an iPhone, but my android phone does pretty much everything that my simple cyclocomputer doesn't, except three things:

1. it doesn't know my heart rate because I don't have a way of monitoring it;
2. it doesn't measure power output; and
3. it doesn't log data, which would be nice to have over time.

What we really need is a cycling computer that keeps all of these data + the knows gear the bike is in, etc. Figuring out how to do that without adding an unreasonable amount of weight might prove a challenge though.

Iphone is not waterproof, and also some folks
complain about battery drain on longer rides.

Garmin dont have Siri to talk to you during long solo rides...

The iphone has nearly all the tech specs to be the BEST bike computer on the market, even compared to Garmin's top of the line apps. It's simply way more powerful in terms of software/hardware than even the best Garmin units.

The one thing that's severely limiting its use on bikes preferentially: BATTERY LIFE.

Most accounts of use of GPS-apps on the iphone (like runkeeper), report near completely battery drain after an hour of use when recording data points as a Garmin would. An hour is really short to begin with, but then add the fact that you've now drained your phone to near zero, and you can see why it hasn't taken on broad appeal.

I can pretty much guarantee that if the iphone could get its battery life to go 6 hrs in "GPS-Garmin" mode without totally wiping out the battery, it would start to dominate the entire cycling computer market. The wireless abilities alone (such as real-time GPS tracking of athletes, sending workout data to the cloud in realtime, peer-to-peer communications) would kill anything Garmin could do in a cost-efficient way.

I use both, a Garmin 500 and iPhone4 with cyclemeter. Without exception the iPhone records speed and elevation less than the Garmin. The Garmin doesn't have cyclemeters email alerts - you can set it to send a recipient list regular updates as you ride. I have those kind of features turned off when I ride, so I have no problem with battery life. I did a 200km ride, seven and a half hours, and the phone didn't go flat. The Garmin is a better training tool, but if you don't need cadence/heart rate the iPhone with cyclometer is a good chice. I find cyclemeter to be a very good programme, with plenty of features and report options such as comparisons, best-worst-average, and is handy way to show your mates where you've been riding.

If the iphone had better battery life it wiuld record as frequently as your garmin.

The only reason it doesnt is battery life.

Check out the iBike Dash (I am a bit biased to it), but it really does have all the features you guys have stated you are looking for.
It comes in a solid waterproof case.
Rechargeable, replaceable battery (it'll drain the external battery before your iPhone)
Heart rate, cadence, hill slope, even power available (It's ANT+ Sport compatible)
You can just push a button and it'll email you a ride file, no more manual downloading. Last I talked to the owner they are starting to work on one-touch integration with the Strava website.
They do have a few different levels of the product available, everything from just a case to a full blown power measuring device.

I've used both the iPhone (various cycle tracking apps) and a Garmin 800. I experienced all of the issues the others talked about -- low battery life (resolved by connecting an external battery), no heart rate or cadence monitor, etc -- however, there is one issue that hasn't been brought up yet. It may or may not be important to you; it was very important to me. The iPhone apps that display your GPS-tracked location on a map depend upon a data signal to render the map, otherwise you're just a got on a blank, gray grid. As I often do extended rides into unfamiliar areas that have no data signal (or any signal at all), the map would sometimes not render, leaving me effectively lost. It was for that reason that I switched to the Garmin with the internal maps.

The main thing it does is it keeps me from needing an I phone and paying humongous, unnecessary phone bills!
Sorry, but I am cheap that way! I am way too busy in my life to spend it on a silly phone, don't text me, I've blocked all text, internet, downloads etc... My phone is a phone...period.

battery life

my garmin doesn't cost 90$/months and it does everything at least as well as an iphone if not, better. I carry my iPod nano for some music when I want to and my silly dumbphone that cost me about 15$/month with unlimited sms.

So I can get more bike schwag that way.

For Droids there's an app called MapDroyd with which you can d/l maps to your phone. There might be an iPhone equivalent.

I have the same setup. Do you notice Cyclemeter always computes a faster average time than the Garmin 500, all else being equal? For me it's usually 0.2-0.3 mile/hr faster.

Some of us occasionally ride more than 6 hours. I'd want at least an 8-hour battery life. With the Garmin 500, I never have to make sure it's charged to 100% immediately before a ride (as I would with an iPhone).

Also, I wouldn't mount my iPhone on the handlebars--too much of a chance of getting damaged whenever the bike went down. Yeah, I keep mine in a jersey pocket, but at least it feels safer there.

Even if the iPhone could do everything just the same as a top of the line Garmin, would the display be as visible? Wondering ... I've never tried to use an iPhone mounted on the bars.

not drop calls?

In addition to having too little battery life and being significantly larger and heavier, iPhone is not nearly as sturdy, water resistant, nor will it be as easy to operate. That you can spend a few hundred bucks to add HR and sensors (or $750 to add this stuff and measure power as well) does not change this. Not working where there is no data signal is a big deal. Plus the iPhone costs a lot more.

Android and iPhone will never represent serious competition to the cycling computer market even if the batt problems are solved (this won't happen because these devices need to be more powerful). A phone touch screen is really a lousy way to control things. If you get something that has sensors, the price starts approaching a real computer fast. The size, weight, and fragility are inherent to the devices.

I would lose half of my data if I used an iphone. In the hills and valleys of West Virginia there are times that you go without cell phone signal for over half of the ride.

Even with the weather proof Case the iPhone will overheat and turn off on long summer rides.

The Garmin website is an exceptional training tool, it gives you the ability to overlay your route graphically with Cadence, Heart rate, speed and elevation. You can also compare the same ride to track your performance and fitness level. Not sure if there are iPhone apps that do the same.

Despite all the caveats, I'm fairly sure that a iphone-like phone/GPS device with superior battery life will eventually supplant Garmins. Might take a long while, but when they get the power issues figured out, it'll be a Garmin beater. Garmin will have to make major advanced on wireless and cellular technology to keep up, which is far less likely than the wireless guys making battery advances.

The GPS and software issue is moot - it can be done already, and in fact, I'll bet the 'app developing' environment of the phones will allow for faster and better innovation that the Garmin stuff.

That said, I really love Garmin units and don't think they'll be going away anytime soon.

The GPS doesn't require a phone signal.

You cant hold the Garmin wrong

For some reason when I didn't have a signal I couldn't use the GPS to get directions when I was lost on the way to a race a month or so ago. I guess it was just my iphone and the iphone that belonged to the guy I was with.

I'll keep my Garmin, it works great with my powertap and my quarq.

One other point, if I crash and ruin my Garmin I just buy another Garmin. No contracts to sign, no worrying about not being eligible for an upgrade, etc, etc...