I eventually gave in and decided that more technology was a good thing and treated myself to the Garmin Edge 800 GPS bike computer. I went for the “Performance/Navigation” bundle, so got the cadence sensor, HR sensor and a better set of maps as well.
Fitting everything was nice and simple. The ‘elastic band’ attchment took about 30 seconds to mount on my stem and seems to have survided a couple of bump rides without rattling or slipping. Fitting the cadence/speed sensor stook a little longer as everything needs to be lined up correctly and within the right tolerances. I think it’s also going to be something that needs checking every so often as I can see the sensor ‘drifting’ slightly around the chainstay and a magnet moving out of range.
There’s plenty of info available and I’ve set up 3 screens for the most common ones. 1 has the sort of thing I’d like all the time : Speed, distance, ride time, real time. A 2nd one for Audax which has: distance to go, average ride speed, distance to next turn. And finally a 3rd one of ‘nice to knows’ which has battery level, heading, cadence and HR on it. By keeping the number of things on the screen to a minimum everything is nice and readable even without the backlight on (not tried it on an overnight yet). Switching between the screens is pretty easy, even with my full finger gloves on.
Navigation is so far less impressive, though I think I’m understanding why now. If you were thinking of just being able to plot a route on bikehike, bikeroutetoaster, etc or just tell the device to go from A to B like I did are likely to be disappointed. This isn’t directly a problem with the unit, but a problem with the way that it computes courses
Routing from A to B it appears that the device wants to avoid Main Roads at all costs, even if a quick 800m blast along an A road saves 5 miles of country lane pootling it’ll pick the country lanes.
Even the better quality City navigator maps that came bundled with the device don’t contain all the little roads than tend to make up training circuits or audaxes, so a gpx trace that does use them can’t be ‘routed’ properly as it doesn’t know about the roads. I’ve started playing with Open Street Maps on the Edge, but that’s not without it’s own problems that I’ll cover later.
And then there’s the quality of the routes that come from GPX files and web sites. Quite oftent the track points are very slightly off at junctions and roundabouts. As the software wants to route through all of the points in order, this can quite often end up in multiple loops of roundabouts or a long detour just to pass through a point that’s not on the main road but hovering in housing estate cul-de-sac 10 metres away. The only way round this it to do a sanity check on the route in MapSource before transferring it to the device.
You can just folow the plot of a gpx on the device (which is what I ended up doing on Roses to Wrags) which is reasonably good, but does mean keeping an eye on the map screen all the time which eats the batteries up quicker. Battery life seems to be OK, though it decreases when using the HRM and cadence sensors, and if you have the map screen on constantly. Though I’ve managed 10 hours without a problem. I’ve got a cheap AA USB charger device from ebay, so hopefully that’ll provide some backup on the longer rides.