Looking to get a little extra distance so that your derailleur clears your 40 or 42 tooth cog? Look no further. When using the GC 40 with a Shimano rear derailleur, a longer B-screw may be needed. A longer b-screw is almost always needed when using the GC42 with a Shimano rear derailleur.
- M4 x 24mm screw for that extra little push