Bill,
If you go to the lightning web site, and scroll down to where they talk about tire sizes for different sized frames you'll find some talk about just your situation.
Seems like on a bike with the 700C rear tire, there is a limit of tire width on the front 406 to something like just a 20x1......
http://www.lightningbikes.com/p38htm
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TA
Joliet Il
EZ-1sc, 2 EZ-Sports, TE, CTE#381