by Phil L » Thu Dec 27, 2007 4:50 pm
I have a Edge 305 and owned it for about 18 months and can't fault it (except the cadence sensor battery doesn't last long though - so spends most of the time out of action). Compared to the Forerunner 301 I had before, it makes you realise how much of a difference having a good quality GPS receiver makes. The 305 only looses it signal going through tunnels, whereas inferior receivers will loose signals under thick tree cover (so they would be cr@p for mountain biking - never really had any issues with 305 with thick tree cover) and big fluctuations in GPS accuracy would give awful spikes in the speed (e.g. often recorded a max speed of 250mph!!! - again not a problem with the 305 and newer Forerunner).
On seeing the features of the new Edge 705, it is very tempting to buy, especially as it: supports power meters; can take a memory card to save very long rides or even whole cycling holidays (305 internal memory saves only 15 to 20 hours); and is able to upload maps which can be viewed in colour and have a "Sat Nav" style navigation (305 has no mapping capability, records tracks only, and can only have pre-planned routes uploaded as a "Garmin" training course, and no Sat Nav).
I looked into the price of some of the compatible power meters and couldn't justify the cost - I think the cheapest was at least £500 odd and many over £1000. A set of digital maps would set you back a couple of hundred quid as well. So to best utilise the extra features of the Edge 705 means spending a hell of a lot of extra dosh on top of the initial £300 odd outlay.
The deals on the Edge 305 are so good now that it is a must for consideration before looking at any high end Polar or bike computer. I'm no expert on the alternatives and what other metrics they provide, but GPS recording allows you to view your performance at a particular location on your ride and compare with previous instances. There is also loads of third party software to use in addition to the rather limited Garmin Training Center thrown in, and if you are technically minded and a dab hand at software development, then you can have endless fun with the XML based .gpx output, in particular feeding it into the Google Maps API so that you can publish your recorded tracks (though there is a growing number of sites to do this for free now).
The cadence meter is relative cheap and doubles up as a backup speedo sensor (on the rear wheel) for when you loose the GPS signal (e.g. cycling under a motorway or through a tunnel) - so would recommend it (if you can get a cheap source of batteries mind).