Replacement End Caps for Disc Hubs

Instructions:

To replace the front end caps, simply pull off the caps you are removing, and push on the end caps you need, making sure not to pinch the o-ring that surrounds the end cap.

Fidelity M Disc & R36 Disc Rear hubs: The Fidelity M Disc hubs have a serial number that starts with Y41 (or Y42 for Boost). Current generation R36 Disc rear hubs have serial numbers that start with 4S3, and older R36 Disc hubs start with 4SC. For example, your serial number would be something like ####-Y41MR-#### for a Fidelity M Disc rear hub. You can find the serial number on the rear hub flange, near the freehub body. On these hub systems, the pawls are on the freehub itself. The rear end caps simply pull off. If you aren't able to do this by hand, you may want to use a vise grip and axle vise, or a tool such as the Unior Hub Genie. Simply pull off the end caps you want to replace, and push on the replacement caps. NOTE: This is also how you would remove the freehub body. If you do remove the freehub, make sure that the spacer between the freehub's bearings and the hub body's bearings remains in place when you reassemble. Otherwise the freehub body will bind when you try to spin it.

Fidelity R30 Centerlock Disc Rear hubs: The Fidelity R30 Centerlock Disc hubs have a serial number that starts with Y35. You can find the serial number on the rear hub flange, near the freehub body. These 30T hub systems have the pawls in the hub body. To replace the rear axle, you'll need to insert two 5mm Allen wrenches (QR) or use two 17mm cone wrenches (12mm rear thru axle) to loosen and remove the existing axle. Unthread the cap on the non-drive side, and remove the entire axle. This is also how you would remove the freehub body. If you do remove the freehub -- make sure that the spacer between the freehub's bearings and the hub body's bearings remains in place when you reassemble. Otherwise the freehub body will bind when you try to spin it.

Insert the replacement axle, and tighten down to 6nm, as printed on the axle caps. Again, make sure the replacement axle passes through the spacer that sits between the freehub body bearings and the bearings in the hub shell.