Keep 105 5700 front with 5800 rear

[bike_rider]

Hi
Currently got 105 5700 setup with a tiagra 10 speed cassette and a KMC chain
If I upgrade the right shifter and the back end to 11 speed 5800 will it still work with my 5700 left shifter and FD-5700? I read that 11 speed chains are slightly narrower so probably swap that too
Thanks

 

[adamhearn]

If you swap out the cassette and rear derailleur then you'll need to swap out the chain too. Even if you didn't need to I would always put a new chain with a new cassette.

The front setup will be fine as is.