Join Date: Mar 2010
Location: Miami, FL
Bikes: 08 Giant OCR C2, 05 Specalized Hardrock Sport Disk
I tried putting my Nuvi 550 on the mountain bike. It did not work so well. It is just a little large for a bike.
The 225 is not waterproof, so there is another problem. My 550 is waterproof, and I use it in my car and in the Waverunner.
The Nuvi series GPS units are designed for cars. They will route themselves, so you do not need Google. They are stand alone devices. They have different modes (my 550 has car mode, bike mode, walking mode, and boat mode) - but all the bike mode does is avoid major roads, and all the walking mode does is ignore one way streets.
Anyhow - if you want a large GPS unit attached to your bars, the Nuvi is OK. I would HIGHLY suggest the 550 however, as it is the only Nuvi that is waterproof. Plus, you can change out the battery in the 550 so when you are on the bike if the battery gets low you can pop in a spare.
Better yet, just get one of the Edge GPS units. I have the Edge 305 and it rules.