Airplane Wing Lift/Stall

If I had two Identical 18' Lenght & Width, Ultalight Airplane Wings, made out of the same 6061 Tube & Fabric, where the only difference was the front Wing Rib Radius of 6 1/2" vs 5 1/2" how much would that change the Wings lift? Would the 6 1/2" Radius produce more lift, and a better Stall Speed, than a 5 1/2" Radius?

What if I narrowed this Affordaplane Tube Wing from 54" wide to 51 3/4" to fit another similar tube airframe. Both Ultralight airplanes airframes weigh about the same 254lbs. Would that change things dractically?

2 Answer

Actually the Affordaplane Wing is 13' 3/4" long 27.5' Wing Span. Weight is a legal 254 pounds, with a gross weight of 540 pounds. This airplane can easily accommodate 6' plus pilots that weigh up to 240 pounds.
http://affordaplane.com/about.html

A T-Bird I, with a Rotax 277UL useful load is around 285lbs. use's a 18' Wing.

My T-Bird I, use's 18' wings, with Ribs 16" OC, that are 51 3/4" wide wing, with a 5 1/2" LE Radius, and a Affordaplane, use's a 16' wings, with Ribs 16" OC, that are 54" wide wing, with a 6 1/2" LE Radius. Both Airframes, with a Rotax 277UL is about the same, 254lbs. The T-Bird I has a little higher useful load. The Wings are basicaly built the same. Most Ultralight/Kitplanes were never Engineered. If it broke it was made stronger. Most of these wings have never been load tested.

So to increase Lift on the T-Bird I 18' Wing, I should go to a 6 1/2" Radius?

To increase the Lift on a Affordaplane 16' Wing, is to make it Longer, 18'?

Rich