i would love to move up to 21/18. i don't really know what u meant by aluminum though. i know the front will clear the 21 but im not sure if the rear will clear 18. will post pictures of chain and sprockets when i have the chance. I'm also looking into handle bar risers because they sit way to low for me. (
http://www.ebay.com/itm/Tusk-Handleb...2d95f1&vxp=mtr)
any information about modding this bike will be taken into consideration.