Do the plastic spacers come with the chainset or bottom bracket.
And although there are Tiagra, 105, Ultegra and many more variations are they basically the same?
I was about to buy a CX50 chainset and a non Shimano bottom bracket.
spacers with BB
no idea re the rest as still square taper on my roadie bike
All Shimano road cups are interchangable. But they don't come with spacers as you don't use them on a road bike.
And the Shimano road cups are wider than MTB ones(about 1.5mm if I remember correctly), so technically not a straight swap.
Non-Shimano BB will be ok as long as its not GXP, and FSA can be a bit of a minefield!
AS above had problems with FSA BB on shimano cranks,
now running a Pace BB with spacers on a surly pacer frame with Ultegra chainset.
