I have just bought a new OCR3. 8 speed with triple chain ring. The shifters are shimano sora flightdeck. The derailleurs are sora.

My old bike was an Avanti Kona, with shimano 105 running gear. It was a nice bike, but a bit old and heavy.

I am wondering if the derailleurs on the old bike (105's) would be better quality than the sora ones on my new bike, and if so would they be compatible with the sora flightdeck shifters.

Could i do it myself and would it be worth the hassle.

Advice welcome.

Thanks