So after about 10,000 miles with my bike I bought in 2015 the bottom brackets have had enough. I need to switch them out, and considering they're quite cheap in retail and also does a lot of the heavy lifting I thought I could upgrade to a better series.
And here's where my problem is, I have no idea whether a BB I'm considering will fit the bike or not.
The original Bottom Brackets are Shimano SM-BB4600, which seem to be the Tiagra series. (https://www.chainreactioncycles.com/se/en/shimano-tiagra-4600-bottom-bracket/rp-prod67221)
The Bottom Bracket I hope to upgrade to would either be
Shimano Dura Ace BB-R9100 (https://www.wiggle.se/shimano-dura-ace-bb-r9100-vevlager/)
Or the Shimano BB-R60 Bottom Bracket (Ultegra, 6800/105 5800, Hollowtech II) (https://www.wiggle.se/shimano-bb-r60-vevlager-ultegra-6800105-5800-hollowtech-ii/)
Would you say these bottom brackets are interchangeable? And if so, for me who mainly use the bike for a high pace 12 mile commute (in sun, rain or snow) each day, what BB would you recommend? Never mind the price difference, I only focus on durability and performance.