Cyclocross - 30mm or smalle 700c tires?

I may just convert my backup bike to a light trail bike by switching to a tire with a knobby tread. I don't think my bike would fit anything wider than a 30mm tire. Are there any knobby tires 30mm or narrower?
Thanks

You might reconsider the need to have knobbies in the first place. The other day I put on Michilen Transworld Cities with inverted tread and rode them pretty aggressively on a sandy and steep trail here in Boise. I was impressed... http://www.bikeforums.net/showthread.php?t=357127 . My father and I do a 100 miler every year that is about 60 highway miles and 40 offroad miles on rocky mountain roads. This will be my tire of choice for that ride next summer.

The reason I bring this up is because they come in a 28 and are way faster on the road than knobbies.

Ritchey speed max: http://cgi.ebay.com/Ritchey-Comp-Speed-Max-Cross-Bike-Tires-700-x-30-C_W0QQitemZ320175499644QQihZ011QQcategoryZ42334QQcmdZViewItem

Michelin Jets http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180161584052&ssPageName=MERCOSI_VI_ROSI_PR4_PCN_BIX_Stores&refitem=320175499644&itemcount=4&refwidgetloc=closed_view_item&refwidgettype=osi_widget

My 700x30 Mich Jets are almost as wide as my 700x35 Speedmax. Not every 30 is a true 30.

I have been able to stuff 700x30 speedmax under normal short reach calipers.

No personal experience, but I think the Transworld City would make a good option as well. There are quite a few options like that if you search for touring tires.

I'll recommend the Speedmax also. I was able to run 32mm speedmax on an old steel frame road bike from about '89. Had no margin at all for mud or a bent rim, but never had a problem either.

Ron

Vittoria MasterCross 27s.

Good luck finding them. They clear my caliper brake and frame on my track bike.