Hub Parts & Service Guide

Updated: 6 October 2022

First, we would like to say thank you for choosing Strummer hubs to drive your bike forward. Our hubs should last you many years and accompany you through long rides. We would like to offer you this list for your convenience. If you feel this post is helpful, feel free to share this list to other users of Strummer hubs.

While we try to keep this list comprehensive, updated, and accurate, this list might contain historical information as we improve our product range. Please double check if possible before purchase. Feel free to contact us for further assistance if needed. If you found any mistakes in this list while, please contact us, we will fix this list as fast as we possibly can.

General Guidelines

  • Do not use thread-locking compound on any part of your hub(s).
  • Strummer classic mountain and road bike hubs are designed to work with 14 gauge spokes.
  • Riding conditions will determine how often cleaning and lubrication are needed.

O.L.D. & Diameter Conversion Using Adaptors / Conversion Kit

Strummer hub inner diameter and O.L.D. width can be converted/changed to fit different bike sizes by changing the end caps (also called adaptor), or by using conversion kits. Here are conversion kits that you can use to change your hub Over-Lock-Nut Dimension (O.L.D.).

Note: 5.2 mm is the inner diameter of the hub end caps.

Conversion(s) for HR-360 Centerlock 4-Pawls & HR-360 Centerlock Ratchet:

  • Front 12*100 mm → 5.2*100 mm : Use 5.2*100 mm for HR-360 
  • Rear 12*142 mm → 5.2*135 mm : Use 5.2*135 mm for HR-360
  • Rear 12*142 mm → 5.2*142 mm : Use 5.2*142 mm for HR-360

Conversion(s) for HM-280, HM-350, HM-380:

  • Front 5.2*100 mm → 12*100 mm : Use 12*100 mm for HM-350/HM-380/HM-650
  • Front 5.2*100 mm → 15*100 mm : Use 15*100 mm for HM-350/HM-380/HM-650
  • Front 5.2*100 mm → 15*110 mm : Use 15*100 mm for HM-350/HM-380/HM-650, then also use 100 to 110 mm hub adaptor
  • Rear 5.2*135 mm → 5.2*142 mm : Use 5.2*142 mm for HM-350/HM-380
  • Rear 5.2*135 mm → 12*142 mm : Use 12*142 mm for HM-350/HM-380
  • Rear 5.2*135 mm → 12*148 mm : Use 12*142 mm for HM-350/HM-380, then also use 142 to 148 mm hub adaptor

Freehub Body Conversion / Replacement

Strummer hubs can be converted to fit different cassette sprocket standards. This means that our hubs can fit different groupset preferences. Furthermore, if one day you decided to change your groupset, you just need to buy the right conversion kit for your hub. The following is Strummer freehub body compatibility list:

Conversion(s) for HM-280, HM-350, HM-350 Boost, HM-380, HM-380 Boost:

  • 6-Pawls 3T Hyperglide Compatible
  • 6-Pawls 3T XD Compatible
  • 6-Pawls 3T Microspline Compatible

Disc Brake Rotor Conversion

Strummer hubs came in several braking systems: rim brake (no disc brake), ISO 6-bolt disc brake, and centerlock compatible disc brake. For our who bought centerlock disc brake system, but wishes to use 6-bolt disc brake rotors, Strummer offers an adaptor that can be used to convert the hub into 6-bolt compatible. We also offer several colors to fit your bike/style.

Freehub Body Rubber Seals Replacement

Strummer rubber seals are reinforced to give it extra strength and durability. The reinforcement helps it to keep its' shape for longer periods of time. However, rubber does degrade over time. It is generally a good idea to check the seal when cleaning the hub. If the seal has degraded, please replace the rubber seal to prevent foreign elements that can degrade performance and longevity of the hub.

Our rubber seals are easy to install, just pull from one side and the other side consecutively. For installation, make sure rubber seal is aligned, then push it in by grabbing 2 different sides of the rubber seal.

Rubber Seal Variant(s) Size Hub Compatibility
Big Rubber Seal (44) ODØ 45mm * IDØ 37.6mm * Thickness 1.9mm

HM-280, HM-350, HM-350 Boost, HM-380, HM-380 Boost, HM-650 Microspline, HM-650 Microspline Boost

HR-100 (6-Pawls), HR-200 (6-Pawls)
Small Rubber Seal (37) ODØ 39.5mm * IDØ 32.6mm * Thickness 3mm HR-10 (4-Pawls), HR-20 (4-Pawls), HR-10 Ratchet, HR-20 Ratchet, HR-360 Centerlock (4-Pawls), HR-360 Ratchet

Star Ratchets Upgrade / Replacement

When replacing and installing new star ratchets, make sure not to lose the inner spacer of the hub. The inner spacer is needed for precise engagement between the body of the hub and freehub body. Imperfect alignment might cause the hub to wear out faster and cause premature failure. This effects are especially more significant for hubs with pawl mechanism.

Star Ratchet Variant(s) Spec Hub Compatibility
36T Star Ratchet

36T star ratchet with regular springs

2 pcs each

 HR-10 Ratchet, HR-20 Ratchet, HR-360 Centerlock Ratchet.

Universal Compatibility
60T Star Ratchet

60T star ratchets with long springs

2 pcs each

HR-10 Ratchet, HR-20 Ratchet, HR-360 Centerlock Ratchet

Universal Compatibility, long spring can be cut shorter according to needs

Sealed Bearings Upgrade / Replacement

We offer two different bearing variants for service, replacement, or upgrade. Our hubs are assembled with sealed steel bearings when you get them. You can choose to get the same steel bearings for replacement, or you can also upgrade/change to ceramic bearings.

Please use the intended bearing variant for the right bearing boring bole. Incorrect usage/installation of bearings might cause poor alignment and affect performance.

Hub Variant(s) Front Hub Bearings (2 Pcs) Rear Hub Bearings (2 Pcs) Freehub Body Bearings (2/3 Pcs)

HM-280, HM-350, HM-350 Boost, HM-380

    18307-2RS (2 Pcs)

    6902-2RS (2 Pcs)
    6902-2RS (2 Pcs)

    HM-650 Microspline, HM-650 Microspline Boost

      18307-2RS (2 Pcs)

      6902-2RS (2 Pcs)

      		 6802-2RS (3 Pcs)
      HR-10 (4-Pawls)
        		 6802-2RS (2 Pcs)

        15267-2RS (1 Pcs)

        6802-2RS (1 Pcs)

        		 15267-2RS (2 Pcs)
        HR-20 (4-Pawls)
          		 6901-2RS (2 Pcs)

          15267-2RS (1 Pcs)

          6802-2RS (1 Pcs)
          15267-2RS (2 Pcs)

          HR-10 Ratchet, HR-100 (6-Pawls)

            		 6802-2RS (2 Pcs)

            6802-2RS (1 Pcs)

            6902-2RS (1 Pcs)

            		 6802-2RS (2 Pcs)

            HR-20 Rachet, HR-200 (6-Pawls)

              		 6901-2RS (2 Pcs)

              6802-2RS (1 Pcs)

              6902-2RS (1 Pcs)
              6802-2RS (2 Pcs)

              HR-360 Centerlock (4-Pawls), HR-360 Centerlock Ratchet
              6902-2RS (2 Pcs)

              6902-2RS (2 Pcs)
              15267-2RS (2 Pcs)

              The following are the measurements of each sealed bearing variants that Strummer offer(s):

              Bearing Variant(s) Inner Diameter Outer Diameter Thickness
              15267-2RS 15 mm 26 mm 7 mm
              18307-2RS 18 mm 30 mm 7 mm
              6001-2RS 12 mm 28 mm 8 mm
              6200-2RS 10 mm 30 mm 9 mm
              6202-2RS 15 mm 35 mm 11 mm
              6802-2RS 15 mm 24 mm 5 mm
              6803-2RS 17 mm 26 mm 5 mm
              6805-2RS 25 mm 37 mm 7 mm
              6806-2RS 30 mm 42 mm 7 mm
              6900-2RS 10 mm 22 mm 6 mm
              6901-2RS 12 mm 24 mm 6 mm
              6902-2RS 15 mm 28 mm 7 mm
              6903-2RS 17 mm 30 mm 7 mm