Upgrading mechanical disc brakes to hydraulic

[si_c]

What am I missing.. why need new wheels ?

He doesn't, a suggestion was made that turned out to be inappropriate and would have required new wheels. The OP doesn't need new wheels.

 

[Milkfloat]

What am I missing.. why need new wheels ?

Most likely a 9 speed freehub on Sora equipped bike, not a guarantee though.

 

[Pwald]

I've just swapped my Spyre calipers for 105 7020 STI hydraulics and it's a massive massive improvement. Not that the sypres were bad (they do need attention on a regular basis to keep them in optimum set-up however), it's just that the hydraulics (as you'd imagine) are so much better. Running them with the stock L02A pads on 140mm rotors (on an Orro Pyro). Maybe it's my legendary wrenching but they seem to have bedded in instantly, and no noise from them in the damp. Ummed and erred about the upgrade for a while but then found a full set on Merlin for £325, so jumped at the chance..

https://www.merlincycles.com/shiman...flat-mount-disc-calipers-11-speed-119868.html

More assured now that should I need to stop in a hurry whilst on the hoods I can do so. The modulation on offer makes the very much increased stopping power very manageable.

 

[SpokeyDokey]

I've just swapped my Spyre calipers for 105 7020 STI hydraulics and it's a massive massive improvement. Not that the sypres were bad (they do need attention on a regular basis to keep them in optimum set-up however), it's just that the hydraulics (as you'd imagine) are so much better. Running them with the stock L02A pads on 140mm rotors (on an Orro Pyro). Maybe it's my legendary wrenching but they seem to have bedded in instantly, and no noise from them in the damp. Ummed and erred about the upgrade for a while but then found a full set on Merlin for £325, so jumped at the chance..

https://www.merlincycles.com/shiman...flat-mount-disc-calipers-11-speed-119868.html

More assured now that should I need to stop in a hurry whilst on the hoods I can do so. The modulation on offer makes the very much increased stopping power very manageable.

I've found those pads to be quiet as well - even in the wet (not that I ride much in the wet).

My bike (Trek) came with 160mm Ice-tech rotors front and rear although I would probably have preferred 140mm on the back - I don't use the back very much but it is all too easy to lock it up*. I did toy with the idea of changing it but it fell out of the bottom of the 'must do' list.

*Although maybe I'm just not a very sensitive braker.