I have a Sintesi Hale-Bopp XC frame with a Altus front derailleur (bottom bracket mount). Can I change this out with a normal frame mounted derailleur or do I have to continue to use BB? Do the Shimano BB mounts (I think they're called E type or something) work with this setup? Also, I have an 8-speed Acera rear derailleur... can I swap this out for a Mega-9 without changing anything else? Sorry, but I'm pretty much a novice with bicycle mechanics. Thanks.