Headset Bearing 0.5mm larger than original

Escher303 Posts: 342
edited April 2015 in Workshop
I'm trying to replace the headset bearings on a Felt B18 TT bike, it is older than 2012 so has a 1" steerer. The original bearings are rusted up so I can't read the bearing code but I'm pretty sure that I've bought the right one to replace. Same manufacturer, look identical but it is just a tiny bit wider in diameter, everything else is the same. Tiny but it does mean the bearings do not slot in easily like the orginals do.

Should I press them in with a headset press or could that damage the headtube? It's headtube carbon with metal headset cups pressed in. Or do the cups need reaming?



  • nicklouse
    nicklouse Posts: 50,675
    TBH sounds like you have the wrong bearings.

    what year frame?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • dgunthor
    dgunthor Posts: 644
    bearing names are based on their dimensions, so you could measure your old one to work out it's name/code
  • frisbee
    frisbee Posts: 691
    Sounds like the frame/fork is JIS and the new headset is ISO (or the other way around). And assuming the problem still exists with threadless headsets.
  • Monty Dog
    Monty Dog Posts: 20,614
    Wrong bearing IME - some only vary by 0.6mm in diameter between the IS/Campagnolo and Cane Creek standards
    Make mine an Italian, with Campagnolo on the side..
  • Escher303
    Escher303 Posts: 342
    Sorry for not replying to my own post, have had a computer meltdown since courtesy of BT! Thanks for the help, didn't realise bearing sizes could be so close. Removed seals for now and cleaned and regreased and will investigate different bearings. Ta