Ball Bearings are Confusing


Note to self: don’t write a blog about ball bearings in bike parts, it’s a bloody nightmare. In fact it would be a mammoth task for anyone to precisely evaluate the amount and size of ball bearings for each component over the years. To be honest, the ball bearing question is downright confusing, and information isn’t really that forthcoming on all the different types and variances within parts. First off, there are 4 different sizes of ball bearings used for bike parts: 5/32″, 1/8″, 3/16″ and 1/4″. Oh, and some Shimano pedals even use 3/32″ size balls. Now, to show how confusing it can be, just look at Campagnolo’s headset ball bearings entry in Sutherland’s Handbook For Bicycle Mechanics: 4th Edition: 

Nuovo Record, pre-1985: 22 balls, 3/16″ size.

Gran Sport, pre-1985: 25 balls, 5/32″ size.

So, two headsets of the same era, from the same brand, hold different amounts and different sizes of balls. And this is just the start of it.


Two Different Sized Ball Bearings





Forget numbers for a minute. And different grades of balls?? Yeah, no let’s move on. What about sizes? Would a layman be able to tell the difference between a 5/32″ ball and a 3/16″? Referring to my Sutherland’s again, it states that the difference in mm is thus:

  • 5/32″ balls are 3.97mm
  • 3/16″ balls are 4.76mm


  • 1/8″ balls are 3.18mm
  • 1/4″ balls are 6.35mm


I can infer that 1/8″ balls are therefore the smallest, even with my lack of mathematical nouse. However, I’m not even sure you could confidently identify a 5/32″ ball just by looking at it. In other words, when a person opens up the races of their headset, it’s not going to be clear if the balls inside are 5/32″ or 3/16″. I wonder why there has to be two different sizes of balls for very similar sized races, but I’m no engineer.


A Headset Race




If you’ve ever dropped ball bearings while servicing a headset, then you’ll know how frustrating it is to find them once they’ve clattered about the floor. Chances are, you’ll lose one or two forever, as they bounce so far and hide themselves in the most bizarre places. It easily happens; you are carefully loosening the threaded top race of the headset, when click click click..a few of the little blighters have escaped and dropped away. I’ll be making a video of how to avoid this one the next few days. Nevertheless, once the bearings have escaped their long held captivity, you may very well be wondering how many you require to put the headset back together again.


Loose Bearings Guide:


Sutherland’s has a chart for all the different variations of headset ball bearings used, so there’s no basic standard for vintage headsets. The ball bearings will either be 5/32″ or 3/16″ size, and the number can range from 22 balls to 25. I think for vintage French bikes, most balls will be 5/32″, but there will be exceptions. The general rule is, pack the balls evenly next to each other, and leave space for one. Unsurprisingly, Campagnolo have all kinds of variances, but so do Shimano, Ofmega and Stronglight; there seems there was no clear or set formula that these brands were working to. Here is a Stronglight headset I recently filled:

  • The Bike: 1981 Peugeot PFN10 
  • Stronglight Headset
  • 5/32 size, Loose Ball Bearings
  • Upper Race: 23 Balls ( Space for one more ball )
  • Lower Race: 23 Balls ( Space for one more ball )


Lower Race Bearings


  • The Bike: 1982 Peugeot PFN10 
  • Stronglight P3 Headset
  • 5/32 size, Loose Ball Bearings
  • Upper Race: 25 Balls ( Space for one more ball )
  • Lower Race: 25 Balls ( Space for one more ball )


Loose Headset Bearings 1982 Peugeot PFN 10


Caged Bearings Guide

I actually prefer to use loose ball bearings, rather than caged ones, even though I see the very practical reason of keeping small metal balls imprisoned in a cage. Doesn’t having a much larger number of balls mean that the headset will effectively be a better performing mechanical device? It seems to me it would, though I just cleaned up a caged headset from a 1981 French bike, and the headset was as smooth as silk..

  • The Bike: Pecchio 1980
  • Unbranded French Headset
  • Caged Ball Bearings
  • Size: 5/32″
  • Number: 16


A Caged Ball Bearings Headset



Bottom Brackets


Bottom bracket bearings are bigger than headset ball bearings, and are normally 1/4″ in size, though vintage Campagnolo Super Record cups take the smaller 3/16″ size. Safe to say, the number of balls in each cup is 11.  The last thing you want is to service your bottom bracket and put it all back together, only to find one little bearing sitting on the table. Sometimes they can go missing in the cloth you are using to clean them, or be overlooked by sheer overconfidence. Don’t believe your own hype that you won’t lose any of the buggers.


Loose Ball Bearing Guide

  • The Bike: 1979 Mercier
  • Stronglight Competition Bottom Bracket
  • Size: 1/4″ Inch Balls
  • Number: 11
  • 22 in Total ( For Both Cups )



The Adjustable Cup


Caged Ball Bearings Guide


  • The Bike: 1980 Motobecane C2
  • Unbranded Bottom Bracket
  • Size: 1/4 Inch Balls
  • Number: 7
  • 14 Caged Balls ( In Both Cups )


Heavily Greased Caged Bearings




The confined space of a hub means that working with wheel bearings can be a finicky business. The races which they roll on are much smaller than bottom bracket cups, and the balls can easily fall out as you try and get to them. Servicing the front hub, with its small balls and bearings, can be a frustrating process. The front hubs of vintage bikes use 3/16″ balls, but the rear hubs mostly use the larger 1/4″ inch size, which are the same as for the bottom bracket. There are normally 9 in the rear, as in the case of this Taiwanese brand below:


  • The Hubs: 1983 Sovos Hubs
  • Type: Low Flange
  • Ball Bearings Size: 3/16″ for Front Hub
  • Number: 10 Each Side
  • Ball Bearings Size: 1/4″ for Rear Hub
  • Number: 9 Each Side


Rear Hub Bearings



  • The Hubs: 1975 Normandy Hubs
  • Type: High Flange
  • Ball Bearings Size: 3/16″ for Front Hub
  • Number: 10 Each Side
  • Ball Bearings Size: 1/4″ for Rear Hub
  • Number: 9 Each Side


Normandy High Flange Rear



  • The Hub: 1976 Atom Front Hub
  • Type: Low Flange
  • Ball Bearings Size: 3/16″ for Front Hub
  • Number: 10 One Side
  • Number: 9 Other Side
  • Total: 19


Atom Front Hub




  • The Hub: 1985 Maillard Helicomatic Rear
  • Type: Low flange
  • Ball Bearings Size: 3/16
  • Number: 13 on Both Sides




Maillard Helicomatic Rear







I opened up three pedals last week, and each had a different ball bearings set up to each other. What’s more, there seems to be little information online about the variances of ball bearings in these components. Unlike the equal number of bearings in the races of headsets and in the cups of bottom brackets, the two races of a pedal bearings can hold different numbers and different sizes of bearings. One race may contain 5/32 size balls, the other may hold the smaller 1/8″ balls. There is not therefore, no standard amount of bearings in pedals, and they can vary according to the brand and their age. The inside bearings of a pedal is on the side of the pedal which is nearest the crank, and the outside bearings are held in the race furthest away from the crank.


  • The Pedals: Lyotard 460D
  • Size: 5/32
  • Outside Bearing: 10
  • Inside Bearing: 11
  • Total: 22


Lyotard Ball Bearings


  • The Pedals: Rewax ( French Threaded )
  • Year: 1981
  • Outside Bearing: 11, 5/32″ Balls
  • Inside Bearing: 14, 1/8″ Balls
  • Total: 25


Rewax Pedal


  • The Pedals: Sifem ( French Threaded )
  • Year: 1982
  • Outside Bearing: 10, 5/32″ Balls
  • Inside Bearing: 14, 1/8″ Balls
  • Total: 24



Some of the balls from the three pedals





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