Nuttin' beats leather, but anythin' beats nuttin'...
You'll probably get the distinctive, black left toe, biker syndrome on yer' pretty tan boots...

...
I think they'll do fine if you go down, but I don't know if they melt against a pipe...
I like boots with some ankle flex in them, and combat boots are good for that. (Flex can save your knee and hip joints in a crash)...