Motorcycle parking near Moscone Center?

Hello,

I'll be attending a conference at the Moscone Center in September, and am renting a motorcycle for a ten day trip after the conference. I am planning to pick up the motorcycle on Wednesday, September 18th, and need to park it somewhere either near the Moscone or my hotel (the Axiom hotel, which is right by the Powell St. cable car turnaround) overnight on the 18th. I'll then be leaving on the 19th.

Any tips for cheap/free (ha!) motorcycle parking in that area?

Thanks!

  Doug