Bottom bracket for Specialised Sirrus X 5.0

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Mackiemill
Posts: 11
Joined: 4 Aug 2020, 7:15pm

Bottom bracket for Specialised Sirrus X 5.0

Postby Mackiemill » 6 Jan 2021, 7:15pm

Hi - looking to replace the bottom bracket for my Specialised Sirrus X 5.0. On the bike's technical spec online it simply suggests 'BSA for 24mm spindle'. Grateful if anyone could provide an actual make/model I can just buy and fit. Thanks very much

Brucey
Posts: 42208
Joined: 4 Jan 2012, 6:25pm

Re: Bottom bracket for Specialised Sirrus X 5.0

Postby Brucey » 6 Jan 2021, 8:11pm

problem is that there is more than one 24mm BB spindle 'standard'. Eg both shimano and FSA use 24mm BB spindles, but they are fractionally different in size.

My advice is to get a BB which matches the crankset, and the frame threads. Note that BSA threaded bottom bracket shells can vary in width and not all BB cups will fit all widths of BB shell.

hth

cheers
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Valbrona
Posts: 2394
Joined: 7 Feb 2011, 4:49pm

Re: Bottom bracket for Specialised Sirrus X 5.0

Postby Valbrona » 6 Jan 2021, 8:23pm

State what crankset ...
I should coco.

Mackiemill
Posts: 11
Joined: 4 Aug 2020, 7:15pm

Re: Bottom bracket for Specialised Sirrus X 5.0

Postby Mackiemill » 6 Jan 2021, 9:54pm

Thanks for replies. Crankset is 'Forged aluminium, 2-piece, 24mm spindle, direct mount chainring' (from the bike's tech spec sheet)