The LBS owner is offering me a complete XT Drive Train (brakes, shifters, ect) set for $500. He is upgrading to XTR’s. It is coming off his racing bike. What do you guys think? And will it make that much of a difference?
Brakes, shifters, full crankset, front and rear ders? $500 is a fair price if they are in like new shape. You’ll feel the difference in the shifters, brakes, and front der for sure. The crankset will be lighter but you probably won’t notice a huge difference. Your rear SLX der is almost as nice as the Xt so you won’t notice a huge upgrade there either.
I agree with Goose about the rear dérailleur. But about cranksets. I have ridden xt cranks and I own slx cranks. The only real difference that I could identify was the xt’s are a little lighter(maybe 20g idk ha). But the xt front der. compared to your current one will be like night and day. So much faster down shifting and so much more smooth. The xt brakes will definately be like a push button stop compared to your current brakes though. I have also used xt shifters before and I chose slx shifters for my build instead because they are acctually the same bang for your buck. The only difference is the thumb push trigger is metal on the xt. The slx is lighter though. Really weird…
About the crankset. Your stock one is probably internal and the xt is an external so you will be able to tell a difference in stiffness of the cranks.
I would check to see how used it would be. But if it looks like trash, it is most likely trash.
If you do buy them from him, try to get him to install them for you for free.