Sachs & SRAM 2-3-5-7 speed Internally Geared Hub bearing retainer sizes

Since the early sixties Sachs (and later SRAM) used some common sizes of ball bearing retainers for several gear hub models' shells and drivers, plus some special sizes for specific hubs where required due to the mechanical design of those models. Over the span of several decades, these retainers had different part numbers and physical appearances. This page shows which gear hubs use which retainers and the cross compatibility between certain hub models.

A visual representation of the sizes used for everything between the 515 to the Automatix:

Sachs and SRAM 2-3-5-7 speed Internally Geared Hub bearing retainer sizes
Download PDF version of the bearing retainer size document

The data grouped by hub compatibility:

DiameterPart numbersFits
Ø26.5mm 7/32" balls0576 102 000,
Star 0103-348,
S 2048,
Y33R90210		Inner driver bearing for the following models: 515/415, H3111, T3, Duomatic, Automatic, Automatix, i-Motion 3
Ø27.8mm 7/32" balls0576 301 000,
Star 0103-251		Inner driver bearing for the following models: Pentasport/P5, Super7/S7
Ø40.7mm 3/16" balls0576 103 000,
0576 103 100,
Star 0103-245,
S 1020		Hub shell right side: 515/415
Ø45.2mm 3/16" balls0576 001 000,
0576 104 000,
0576 104 100,
0576 104 200,
Star 0103-246,
Star 0103-248,
S 2049		Hub shell both sides for the following models: H3111, T3, Duomatic, Automatic
Hub shell left side for the following models: 515/415, Pentasport/P5, Super7/S7, Automatix, i-Motion 3
Ø53.7mm 3/16" balls65 0376 003 000Hub shell right side: Automatix, i-Motion 3, SRAM Torpedo Singlespeed
Ø56.3mm 3/16" balls0576 300 000,
Star 0103-252,
MPT 0576300		Hub shell right side: Pentasport/P5
Ø59.9mm 3/16" balls0376 102 000,
Star 0103-253,
MPT 0376102		Hub shell right side: Super7/S7
Please note: The ballring/cage diameters are average measurements done by me, other data sources' measurements might differ somewhat, and different historical versions of the retainers may be +/- 0.3mm compared to what is listed above.

If the Ø26.5mm or Ø27.8mm size ball bearing retainer is unavailable, loose 7/32" balls can be used instead.

Inch / millimeter conversion table for common ball sizes measured in fractional inches:

InchesMillimetersCommon bicycle uses
1/8"3.18 mmPedals
5/32"3.97 mmHeadsets
3/16"4.76 mmFront hubs, gear hub shells
7/32"5.56 mmGear hub drivers
1/4"6.35 mmRear hubs
Tags: bicycle, torpedo
Page last updated 2026-03-22 10:43. Some rights reserved (CC by 3.0)