derailleur - rear - rapid or traditional
 

I was looking to throw on a mountain style rear and was looking to get an XT short cage. What is the diff between the rapid and the traditional styles? WOuld one be better than the other?

and I wanted to make sure. will the XT rear work with a 105 front? running fsa goss 48/38 cranks. 105 brifters

a rapid rise rear derailleur is at rest at the largest cog in the cassette, rather than the smallest. it would require a rapid rise specific shifter. not going to work with the 105 shifters.

you should be fine mixing a standard xt rd and the 105 fd.

It will work fine with a brifter just backwards, assuming everything in the setup is 9 speed. The inner lever will switch to larger cogs, outer to smaller.

Josh is correct it will just be backwards. I ride a bike with a rapid rise LX RD and Tiagra brifters. 105 brifters would work the same way.

well, it'll work, but i wouldn't say it would work fine or well. your downshifts will be limited to one at a time. bummer. however, you'd be able to jump multiple gears on the upshift if you so well choose... sort of like campy, only way crappier.