Which bottom bracket do I need?
gopher1369
Posts: 3
Firstly, hello all, my first post 
I have a knackered bottom bracket. My LBS has confirmed, but said that it would be much quicker if I buy the replacement myself online and get them to fit it, rather than the store ordering it in themselves (I didn't ask why, frankly I enjoy shopping around online for a bargain).
problem is that there seem to be an awful lot of very similar, but not quite compatible BBs and I want to make sure I get the right one.
I have a 2010 Specalized Sirrus Expert. The chainset is a Shimano FCR-553. The current BB is a FM-FC4500. Picture here:
https://app.box.com/s/0hv5zp32i47lgl1d2e5e
I understand from the shop that this is a Tiagra branded and not a particularly great BB. The seals and bearings not great. Looking online higher spec BBs don't cost much more. I've found this: http://tinyurl.com/qfka57h and if I'm reading it right could go with a 5600, 6600, 6601, 7800 or 7801. Am I reading it right? Which one should i go for?
Also looking online some BBs are listed as Italian and some as British thread.
Also they have various measurements listed, eg 63mm thread.
Quite confused now. Please help. Thanks in advance, Richard.
I have a knackered bottom bracket. My LBS has confirmed, but said that it would be much quicker if I buy the replacement myself online and get them to fit it, rather than the store ordering it in themselves (I didn't ask why, frankly I enjoy shopping around online for a bargain).
problem is that there seem to be an awful lot of very similar, but not quite compatible BBs and I want to make sure I get the right one.
I have a 2010 Specalized Sirrus Expert. The chainset is a Shimano FCR-553. The current BB is a FM-FC4500. Picture here:
https://app.box.com/s/0hv5zp32i47lgl1d2e5e
I understand from the shop that this is a Tiagra branded and not a particularly great BB. The seals and bearings not great. Looking online higher spec BBs don't cost much more. I've found this: http://tinyurl.com/qfka57h and if I'm reading it right could go with a 5600, 6600, 6601, 7800 or 7801. Am I reading it right? Which one should i go for?
Also looking online some BBs are listed as Italian and some as British thread.
Also they have various measurements listed, eg 63mm thread.
Quite confused now. Please help. Thanks in advance, Richard.
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Comments
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Since your crankset is a triple, to save any confusion just go for the 5700 105 BB which is listed as compatible with both double and triple cranksets
http://www.ribblecycles.co.uk/sp/road-t ... himbtbr720
Not expensive.
You will almost certainly require the English threaded version an your Specialized.
Servicing tools are pretty cheap also - you'll need this or something similar.
http://www.halfords.com/webapp/wcs/stor ... yId_242558
Look on YouTube for plenty of guides on how to swap a Hollowtech BB.0 -
Hello Arlowood, thank you for your quick reply.
That was exactly the BB I was looking at originally and nearly ordered. The reason I paused, and indeed the reason I posted on here is because the Shimano compatibility chart (linked in my original post) seems to show that it isn't.
The 5700 that you linked does appear on the "Front Drive Chain Interchangeability" bit of the chart, but scroll down a bit and you see a separate chart for flat handlebar bikes, and the 5700 isn't listed on there...and I do have flat handlebars.
If you're sure it will fit though, I'll go ahead and order it.0 -
Your bike came with a Tiagra HT2 bottom bracket. You can definitely replace it with any other HT2 road BB (Sora, Tiagra, 105, Ultegra, Dura Ace) Just buy the cheapest one.
(I just replaced my 105 BB with an Ultegra one cos CRC were selling them off for £11 a while ago)
eg http://www.chainreactioncycles.com/shim ... -prod67221
Just select 68mm and English thread0
