Trek FX2 hybrid BB upgrade - help!

ianlewis Posts: 4
Hello, I've got a Trek FX2 hybrid. I'd like to upgrade the crankset to Tiagra or 105. However, I'm not sure what BB I'll need. It currently has quite an old style with spindles sticking out each side, but 105 will need a different one as the axle is wider.

Any ideas will be greatly appreciated


  • kwozzymodo
    kwozzymodo Posts: 45
    You may need a bb with external bearing cups to accommodate the chainset. Depending on bb width (68/73mm), there should be some spacers supplied with the new chainset