Chainset Swap

Sutton_Rider Posts: 493

October 2019 edited October 2019 in Workshop

I've got an Ultegra 6800 50/34 chainset and want to swap out the 34 for a 39. I assume it will all fit and work. Can anyone confirm please?

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Comments

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  Ben6899 Posts: 9,686

  October 2019

  I think a run-of-the-mill Shimano 39 inner will have a 130mm BCD whereas your compact cranks will have a 110mm BCD. You might be able to get your hands on a 39 with 110mm.

  Ben
  
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  shirley_basso Posts: 6,195

  October 2019

  Will be fine for a 4 arm chainset. BCDs all the same. Ben is incorrect in this case as 6800 is a 4 arm chainset.

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  Ben6899 Posts: 9,686

  October 2019

  Ah I see! Happy days, OP.

  Ben
  
  Bikes: Donhou DSS4 Custom | Condor Italia RC | Gios Megalite | Dolan Preffisio | Giant Bowery '76
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