Curious if anyone has an opinion on whether using threaded or unthreaded pegs makes any difference as far as bending axels? Any secrets as to how to extend the life of an axel (besides not riding)? I assume that the shorter the axel the better?

Thanks for the help.

Threaded pegs will bend more axles--the weight from grinding (or even standing) on the peg is place on the axle, wheras w/ a non-threaded peg much of the stress is distributed to the dropout. If you're doing a restore, threaded are more period correct for certain bikes. Wouldn't recommend too short of an axle for either application.

Also, I hear a low carb diet helps.

Interestingly enough, I'm 32, 6' 3" and weigh about 185. I don't think it is my excessive girth that would cause the axels to bend.

depends on what kind of pegs,and for what. pegs to grind on NEED 14mm axles. the money spent 1 time for the right parts will save you in the long run.
thread on pegs are crap! but if you must use them. make sure you have a real long axle. enough to thread on the peg,with enough axle poking through,to put on an axle nut to back it up.... and they will still move over time. really any peg will.
dk made a peg with a chain adjuster built in. i havent tried one out,but it seems like a good idea. probabally lasts a little while .
all in all ,i would go with a slide on peg,and dbl bolt it,if you have enough axle. good luck with it.