Nice! I like them. Not sure what your settings were, but it looks like ISO 400 maybe? I would drop it down to 200 just because of the harsh sun. It will help save the whites in the direct light. You have the knack for timing in the corner too. Very nice set. Thanks for sharing.
Love #4 - the colour/texture is superb. The aspect of the bike dissapearing into the sunset just tops it off.
I'm glad you included some ground in #2 - provides a context and framework for the bike.
Love the low angle perspective of #1 and the bike lean. Don't you just wish that you could sometimes get rid of distracting backgrounds?!! Sometimes you just have to deal with the cards you get.
Maybe slower shutter speed in #3 would give the wheels a bit of motion blur. Sense of movement is there with dirt spray and foot off ground but would be nice if it were a little more prominent.