Thought it might be useful to offer a list of differences between the Zumo 450 and 550, since this is oft-asked and doesn't seem to show up anywhere in one thread. And others can chime in on the differences and other considerations for selecting a motorcycle GPS.
- Zumo 550 comes with AC charger. Zumo 450 does not. [They're available for $20 MSRP, $13 delivered on eBay.]
- Zumo 550 comes with both auto and bike mounts. Zumo 450, just bike. The auto mount has a cigarette lighter power supply.
- Both have a motorcycle-specific, waterproof cradle with secure mounting of the power cable and a pigtail mount for the bike. They come with a RAM handlebar mount: other bases are available for less than $10.
- Both bike mounts have a security screw but don't have a security lock for the cradle. I just replaced the knob with a nylok nut, but Garmin sells a lockable knob as an accessory.
- Zumo 550 says name of street audibly. Zumo 450 says, "turn right in 100 feet" but doesn't give street name audibly - just on screen. If you're not listening, doesn't matter...
- Zumo 550 has Bluetooth, 450 does not.
- Zumo 550 supports XM Navtraffic and FM traffic, 450 does not.
- They both come with the MapSource® City Navigator North America NT DVD (full unlock) disk so you can make routes on your PC. PC only - no Mac version, I'm told?
- The screen is very visible in daylight.
- They both have an internal battery.
- They both have the high-sensitivity SiRF receiver.*
- They're both "waterproof."
- They both have an MP3 player.
- They both support 500 waypoints and 50 routes.
- They both support custom POI's.
- They both support routes with multiple waypoints and will both auto-sort a series of waypoints to optimize it.
- They both support SD cards for sharing routes, waypoints, POI's etc.
- They both automatically save data in GPX format for easy transfer to other units with SD slots.
- They both have power cords held in with a screw so they don't shake loose.
There are some other excellent GPS's out there at really low cost these days: less than $200. What they may lack for motorcycle use or require additional purchases to do:
- Screen visible in direct sunlight.
- Secure motorcycle mount and power connection.
- Ability to create a route with multiple waypoints.
- Software and mapset to be able to create a custom route on your PC, then download it.
- Bluetooth support (if you care)
- Traffice support.
- MP3 player, picture viewer, other doodads.
If you are looking at a Garmin product, don't just go but the features or comparison display. Also look at the Specs tab and the "In the box" tab. If you just compare the Zumo 450 and 550, it will show that the 450 doesn't support Bluetooth - but you won't pick up that it comes without an AC wall charger (you can charge it via USB - eventually).
*They license this technology from SiRF Technologies