Bottom bracket chan...
 

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[Closed] Bottom bracket change question

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Hey!

So I'm planing on updating my group-set coz the one I have is pretty warn. I had already updated the typical things.... cassette, chain, and rear-derailleur.
My main reason is I want to change the shifters for the more modern ones with in internal wiring - the ones I have at the moment have the wire coming out the side.

Another big reason is the chainrings are wearing.
All in all, I'm in the market for a new groupset, and am looking at the shimano 105 5800.

My question is will the BB which comes with it (BBRS500) be compatible with my frame?

My frame has the internal threaded shell and currently uses the Shimano BB-5500 105 Octalink Bottom Bracket.

So my doubt is - is my frame compatible with the BBRS500 which comes with the most recent version of the 105 groupset? 

Thanks!!


 
Posted : 22/03/2018 4:20 pm
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As long as you buy it with the appropriate thread, then yes (BSA or italian)


 
Posted : 22/03/2018 4:24 pm
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Almost certainly your frame will have a 68mm BSA bottom bracket unless its Italian exotica - measure the exterior width of the BB shell, if its 68mm its BSA, whereas 70mm is ITA.


 
Posted : 22/03/2018 5:00 pm
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Yeah its 68mm for sure because the octalink BB that's installed is for that exact size.

My doubt was more will my frame be compatible with the different kind of BB (BB RS500) ?


 
Posted : 22/03/2018 5:07 pm
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If you’ve got a 68mm threaded (screw in) BB shell on your frame then all the 68mm BSA shimano hollowtech (external) road BB & cranksets fit. Your frame is “compatible” in the sense that it has threads for the newer BB to screw into, but you obviously then have to use a compatible crankset (in this case a 24mm spindle shimano one like 5800).

I did the same switch from square taper to 5800 on my bike, was v easy. I used the BB-R60 one because that was advertised as 105/ultegra level but I’m sure the tiagra one you mentioned is fine.


 
Posted : 22/03/2018 6:21 pm
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If you’ve got a 68mm threaded (screw in) BB shell on your frame then all the 68mm BSA shimano hollowtech (external) road BB & cranksets fit. Your frame is “compatible” in the sense that it has threads for the newer BB to screw into

Awesome. Yeah I wanted to get that confirmed.

but you obviously then have to use a compatible crankset (in this case a 24mm spindle shimano one like 5800).

Yeah - I presume its the type which comes as standard with the 105 5800 groupset.

I used the BB-R60 one because that was advertised as 105/ultegra level but I’m sure the tiagra one you mentioned is fine.

Glad you mentioned that. On the groupset listing on wiggle (for example) it says:
"comes with the BB RS500 botton bracket". I searched for it online and as you say it's Tiagra level.
If I'm spending a bit of cash on a new groupset I'd want all the components to be at least 105 level.


 
Posted : 23/03/2018 9:39 am

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