I am about to receive a job in restoring a cannondale bike with apparently shimano 105 component group. The guy who wants me to do this is thinking he wants to see what involves converting it to an integrated shifting system. I'm aware that in order for this to happen you have to replace the rear sprockets, front chainrings, chain, and maybe even derailleurs in order for all of this to happen?
Is this due to the integrated shifters usually being indexed? If so, does this mean I can't use the old derailleurs if they were friction? Why is this?
I know the reasoning to change the cogs and stuff if it is indexed.
Aside from this huge issue, I want to know, if integrated friction shifters exist? If they do do they still require all the replacement?
Thanks alot, this is the first time i'll be attempting to even analyze converting the shifting system on a bike, but i feel confident as long as I get all the info I need.