My youngest student and I are building the 4*60 kit right now and one of the things I noticed was the shear webs are built in and part of the spars, front and rear. The built in shear webs are cut out of Hortizontal grained balsa and each is A seperate one piece part running the length of the spars. I didn't say anything to him about shear webs at all, the build is hard enough on his young mind and it can wait until his next build.