He'll folks pardon the ignorance as this as been probably been asked numerous times. I,m currently riding a cannondale sl four with acera shifters and front mech together with an Alvio rear derailleur.I,ve looked at shimano compatability chart and can,t make head nor tail of it.I intend to upgrade the drive train bit by bit , possibly deore.Question is will deore work with acera and Alvio until I can afford to change each piece.Also will different deore variants work together.All I currently know is that they,ll obviously have to be same speed.Cheers in advance for any advice.