Bearings with stainless steel balls, are they worth it

sextoke1 Posts: 133
edited December 2018 in Workshop
Stainless steel ball bearings have a 20% reduction of loading than the standard ball bearings, does this make a huge difference and do they prolong the life of the bearing or does the bearing races rust away anyway?


  • sungod
    sungod Posts: 16,547
    see response on angular contact
    my bike - faster than god's and twice as shiny
  • manglier
    manglier Posts: 1,211
    Stainless steel balls are typically around 57 Rockwell (hardness) whereas non-stainless are 60-67 Rockwell. This explains the reduction in load capacity of a stainless ball in comparison to a standard ball. The reduction in load capacity means that for a specific load (within it's limits) a stainless bearing will have a reduced life expectancy.
    The grade of steel used in a stainless ball is usually 440 C which although technically stainless can mark up. It's not the sort of stainless that your kitchen taps are made of, that sort is not hard enough.
    Providing you can keep your non-stainless bearings properly lubed and sealed there ar only disadvantages to be had by going stainless.
    Here' a handy little video by GCN:
  • earth
    earth Posts: 934
    Apparently they are prone to galling.
  • You want 52100 steel balls.
  • No expert but it seems to me one of the most important parts is good seals keeping everything well lubed. If water gets in non stainless are more vulnerable ? Out of interest would titanium have suitable qualities ? Ignoring that they would be really expensive !
  • manglier
    manglier Posts: 1,211
    Ti is softer than stainless, Rockwell value is only around 36 and you really need over 60. If you want expensive go ceramic.
  • Vino'sGhost
    Vino'sGhost Posts: 4,129
    You want 52100 steel balls.

    yep the ball of the masses

    theres loads of toss written about bike bearings and hard chrome bearings like that are all you need. not those high carbon steel bits of shite in cheap sealed bearings that rust if theres ever a cloud and def not ceramic bearings.
  • Vino'sGhost
    Vino'sGhost Posts: 4,129
    although Triathletes might want Stellite steel because its very expensive and sounds like it belongs in Enve deep section wheels.

    "Stellite saves you 17watts over a ceramic bearing wheel" "this is 27 seconds in a 40K time trial or 2.5 minutes in an Iron Man.

    "this super high performance bearing is an investment"
  • cycleclinic
    cycleclinic Posts: 6,865
    The best balls are grade 10 chrome 52100. Why shimano, DT Swiss e.t.c use stainless balls in there bearings is beyond me. Those companies can specify what they want to a bearing company. Because stainless sounds better they pick stainless. There is no engineering reason to do this.

    The grease is key to making chrome steel ball last.nit all greases are equal. -wheel building and other stuff.
  • sextoke1
    sextoke1 Posts: 133
    Thanks for a good discussion on the use of stainless steel bearings. In a nutshell, they offer no advantage due to the fact that you can not harden stainless. Keep up the good work.