How to Adjust and Repack a Cup and Cone Hub: A Step-by-Step Guide

Servicing a cup and cone bicycle hub is one of the most rewarding maintenance tasks you can perform at home. Unlike sealed cartridge bearing hubs, which must be pressed out and replaced when worn, cup and cone hubs are fully adjustable, highly durable, and designed to be serviced indefinitely. By learning how to properly disassemble, clean, regrease, and adjust these hubs, you can keep your wheels rolling smoothly, prevent expensive damage, and improve your overall riding experience.

A cup and cone system consists of loose steel ball bearings rolling between a curved race integrated into the hub shell (the cup) and an adjustable threaded race on the axle (the cone). This design handles both radial loads and lateral cornering forces exceptionally well. However, because the system is not completely sealed, water and road grit will eventually find their way inside, turning the grease into an abrasive paste that can quickly destroy the polished metal surfaces. Regular maintenance is key to preventing this wear.

Tools and Materials Needed for Hub Maintenance

To safely service a loose-ball hub without damaging its components, you will need a few specialized tools alongside standard workshop supplies. The most critical items are cone wrenches, which are thin, stamped steel wrenches designed to fit into the narrow flat spots on the hub’s adjustable cones. Standard open-end wrenches are too thick and will prevent you from holding the cone while tightening the outer locknut. You will typically need a pair of cone wrenches in sizes ranging from 13mm to 17mm, with 15mm being the most common for front hubs and 15mm or 16mm for rear hubs.

You will also need a standard adjustable wrench or a socket set to loosen the outer locknuts, which are usually 15mm or 17mm. For rear wheels, you must remove the cassette or freewheel to gain access to the axle flats on the drive side. This requires a cassette lockring tool, a chain whip, or a specific freewheel remover tool, along with a large adjustable wrench.

Consumables are equally important for a successful repack. You will need a high-quality, bicycle-specific grease that offers excellent water resistance and shear stability. Avoid generic household lubricants, which lack the viscosity needed to protect low-speed, high-pressure bicycle bearings. A dedicated bicycle degreaser, a clean workspace, lint-free rags, and small containers to organize your parts will complete your setup.

Step 1: Disassembling the Cup and Cone Hub

Start by removing the wheel from your bicycle. If your wheel uses a quick-release skewer, slide it completely out of the axle, taking care not to lose the two small, conical springs on either end. For bolt-on axles, remove the outer axle nuts and washers. Place the wheel flat on your workbench with the non-drive side facing upward. It is generally best to perform all disassembly and adjustment from the non-drive side, leaving the drive-side locknut and cone locked firmly in their original positions on the axle. This preserves the overall axle spacing and wheel centering relative to your bicycle frame.

Place your cone wrench onto the flat sections of the non-drive-side adjustable cone. Next, place your standard wrench or socket onto the outer locknut on the same side. While holding the cone wrench completely still to prevent the cone from turning, turn the outer locknut counterclockwise to loosen it. Once the locknut is loose, unscrew it completely and set it aside. Remove any washers or spacers that sit between the locknut and the cone, making a careful mental note or taking a photo of their exact order and orientation.

Slowly unscrew the adjustable cone from the axle. As the cone backs off, the loose ball bearings inside the hub shell will become exposed. Carefully slide the axle out of the hub shell from the opposite side. Be prepared for some of the ball bearings to fall out during this step. To prevent losing them, work over a clean tray or a light-colored rag that will catch any runaway bearings.

Using a small magnetic pick-up tool, a flathead screwdriver coated in a dab of grease, or your fingers, extract all the ball bearings from both sides of the hub. Count the bearings as you remove them to ensure you have not missed any. It is absolutely critical to keep the bearings from the drive side separate from those on the non-drive side. Even if they appear identical, the bearings on each side have worn in match with their respective cup and cone races. Mixing them can lead to uneven wear and premature hub failure during reassembly.

Step 2: Cleaning and Inspecting the Bearings and Races

Once all components are removed, place them into a small container filled with bicycle-specific degreaser. Use a clean brush to scrub away all traces of old, dirty grease, dirt, and metal particles from the axle threads, locknuts, spacers, and individual ball bearings. Wipe the parts completely dry with a lint-free rag. Next, spray some degreaser onto a clean rag and thoroughly wipe out the cup races inside the hub shell. You must remove every trace of old lubricant to perform an accurate inspection.

Inspect the cleaned components under a bright light. Examine the polished, curved surfaces of the adjustable cones and the cup races inside the hub shell. A healthy race should look like a continuous, highly polished, mirror-like track. Look closely for any signs of pitting, which appear as small, dark craters, rough grey patches, or deep scratches. Run a fingernail or the tip of a ballpoint pen along the wear track; if you feel any clicks, catches, or rough spots, the metal surface has begun to fatigue and fail.

Examine the individual ball bearings as well. They should be completely spherical and have a bright, reflective, mirror-like finish. If any of the balls look dull, grey, pitted, or misshapen, they must be replaced. Fortunately, loose ball bearings are inexpensive and widely available. If you find any damage on the adjustable cones, you must source matching replacement cones. However, if the cup races inside the hub shell are deeply pitted or gouged, the hub shell itself is ruined. Because these cups are usually integrated into the hub, severe cup damage means you must replace the entire hub or the wheel itself.

Step 3: Regreasing and Reassembling the Hub

If your cups, cones, and bearings pass inspection, you are ready to begin reassembly. Start by applying a generous, continuous bead of fresh bicycle bearing grease directly into the cup races on both sides of the hub shell. Do not be sparse with the grease; any excess will simply squeeze out and can be wiped away later. The grease serves two vital purposes: it lubricates the moving parts to minimize friction, and it acts as a physical barrier that prevents water, mud, and road grit from entering the bearing assembly.

Carefully press the clean ball bearings back into the grease-filled cup races. The thick, tacky consistency of the fresh grease will act like glue, holding the individual balls securely in place so they do not fall out when you move the hub. Ensure that you place the exact same number of bearings back into each side. Do not crowd the race; there should be a tiny gap between the balls, allowing them to roll freely without binding against one another.

Gently slide the axle back through the hub shell from the drive side, taking care not to dislodge any of the bearings as the axle passes through. Once the axle is in place, thread the non-drive-side adjustable cone back onto the axle by hand. Always start threading by hand to prevent cross-threading, which can permanently ruin the fine threads on your axle. Spin the cone down until it gently contacts the ball bearings.

Slide any spacers or washers back onto the axle in the exact order they were removed. Finally, thread the outer locknut onto the axle. At this stage, leave the locknut finger-tight, as you will need to perform precise micro-adjustments to achieve the correct bearing preload.

Step 4: Adjusting the Bearing Preload to Eliminate Play

Adjusting the bearing preload is the most critical and delicate part of the entire process. The goal is to find the precise balance where the axle spins completely freely with zero friction, yet has absolutely no lateral (side-to-side) play. If the adjustment is too loose, the wheel will wobble, which causes unstable handling, uneven tire wear, and accelerated damage to the bearing races from impact loads. If the adjustment is too tight, the bearings will bind, creating massive friction that slows you down and rapidly crushes the bearings and races.

To begin the adjustment, thread the adjustable cone down until it lightly bottoms out against the ball bearings, then back it off approximately one-eighth to one-quarter of a turn. Hold the adjustable cone completely still using your cone wrench. With your other hand, use a standard wrench to tighten the outer locknut firmly against the cone. Tightening the locknut jams it against the cone, locking the cone’s position on the axle threads.

Now, test your adjustment. Hold the exposed ends of the axle in your fingertips and spin the wheel. The rotation should feel exceptionally smooth, consistent, and completely free of any rough, grinding, or “notchy” sensations. Next, try to physically wiggle the axle back and forth relative to the wheel rim. There should be no perceptible lateral play. If you feel a distinct clicking or rocking sensation, the adjustment is too loose. If the axle feels stiff or rough to turn, the adjustment is too tight.

Optimal adjustment almost always requires an iterative process of micro-adjustments. If the hub is too loose, loosen the locknut, turn the adjustable cone clockwise by a tiny fraction of a turn (often just a few degrees), and retighten the locknut. If the hub is too tight, loosen the locknut, back the cone off counterclockwise slightly, and lock it down again. Repeat this process patiently until you eliminate all play while maintaining a completely smooth spin.

Step 5: Final Verification and Troubleshooting

Once you are satisfied with the bench adjustment, you must perform a final verification that accounts for the clamping force of your bicycle’s frame or fork. If your bicycle uses a quick-release skewer, the clamping mechanism exerts a massive amount of compressive force on the hollow axle. This force actually compresses the axle slightly, which pushes the cones closer together. Consequently, a hub that feels absolutely perfect on the workbench will often bind and feel rough once it is clamped tightly into the bicycle’s dropouts.

To compensate for this compression, you should intentionally adjust the hub on the bench so that there is a microscopic, barely perceptible amount of lateral play. When you slide the quick-release skewer back through the axle and clamp the wheel firmly into the frame or fork dropouts, this clamping force should compress the axle just enough to eliminate that tiny remaining play, leaving you with an optimally adjusted, smooth-rolling wheel.

After clamping the wheel into the frame, perform a final check. Grab the tire near the brake calipers or frame stays and try to wiggle it side-to-side. You should feel absolutely no play. Spin the wheel and watch how it comes to a stop; an optimally adjusted wheel will gently oscillate back and forth at the very end of its spin, pulled by the weight of the valve stem, rather than stopping abruptly. Finally, wipe away any excess grease that squeezed out of the hub during reassembly, and apply a very light film of grease to the outer edges of any rubber dust seals to help repel water.

Frequently Asked Questions (FAQ)

How often should I repack my cup and cone hub?

The ideal maintenance interval depends heavily on your riding environment and mileage. For bicycles ridden primarily in dry, clean road conditions, repacking the hubs once a year or every 3,000 to 5,000 kilometers is generally sufficient to prevent wear. However, if you frequently ride in wet weather, tackle muddy off-road trails, or commute through winter road salt, water and grit will bypass the hub seals much faster. In these demanding conditions, you should inspect and repack your hubs every few months, or immediately after any deep water crossings where the hubs may have been submerged.

Can I use automotive grease for bicycle hub bearings?

While high-quality automotive grease, such as marine grease or wheel bearing grease, will technically lubricate the bearings and offer excellent water resistance, it is generally not ideal for bicycle hubs. Automotive greases are formulated for high-temperature, high-speed, and high-load environments that a bicycle simply never experiences. Because of this, they have a much higher viscosity, which creates noticeable rotational drag (viscous drag) in low-torque bicycle bearings. Using a dedicated, bicycle-specific grease ensures your bearings receive the correct level of protection and water resistance while allowing your wheels to spin with the absolute minimum amount of resistance.