Are those Continental Speed Rides, or Cyclocross Speed tires? If those are the 700x42 Speed Rides, you can try the Cyclocross Speeds at 700x35 and get a little more room. Same tread pattern. The wider Speed Rides are great tires, I run 'em on my mountain bike for mixed pavement and gravel. I'd like 'em even wider but there's only a 1/4" clearance with the front derailer as it is now.

If those are Clement LAS 700x33, that's probably about as narrow as you can find in that tread style.