I do not do road cycling but in LA I went Mountain biking all the time. One tough trail is Schwitzers: you start at La Canada and end up in JPL about a 7 mile taril but some rugged and steep terrain. Road cycling is great in Cali, especially on the coast, one thing I miss about living in Brentwood. You were close enough to bike to Santa Monica. You could do like a nice Brentwood, Santa Monica, Malibu trail and back because it is FLAT. Cycling is good for you because it is easier on the joints than running. Cycling and swimming are the best. Las Vegas has RED ROCK and that is pretty cool but not the same as Cali. Angeles Crest s also awesome for road cycling btw, For those of you in the foothills or West side, take advantage!
only 2 reasons for me to fly to the US right now would be In-N-Out and cycling some California trails.