What is generally referred to as a "loose hub" indicates some service is required. Normally the sign of a loose hub is movement felt at the wheel or possibly indicated by a slight rattle sound while moving the front of the bike.
The looseness or lack of bearing preload is indicated by some lateral left to right movement at the wheel notably felt at the rim. A loose hub is not good for the longevity of your hub / wheel because it means the bearings are not optimally positioned and that inaccuracy can cause misaligned wear, it is also potentially a cycling hazard as your wheel doesn't track as well. It's good practice to periodically check and address as needed.
The basic steps needed are
1. Checking for looseness (play and wobble).
2. Accessing the adjusting clamp.
3. Adjusting the bearing preload to remove looseness.
4. Securing it all back together.
Check the wheel for movement (lateral play)
1. Hold the rim (not tire) between your fingers using one hand (use the other hand to steady the fork, frame or handlebars), apply a firm side to side force at the rim, sense for any motion that feels like its' a wobble from the hub.
2. If you feel any side to side motion / wobble, you will need to adjust the hub to remove it. We call this adjusting the preload on the bearings. Riding with loose bearings will long term damage your hub / wheel and could be potentially a safety hazard.
There are two main mechanisms of adjusting the preload and these depend on what wheels / hubs you have, so make sure you identify with the images and follow the correct steps below.
Adjusting the preload on the rear hub and most disc front hubs
Before starting work - scroll down and identify the hubs with the photos to ensure they have similar mechanical features for adjusting. (for reference the following photos show a R45 Hub with 12mm thru axles)
Rear Hub
1. With the bicycle secure (in a stand or having your friend hold it) ensure the wheel is correct in place and the Thru axle or QR skewer is tight and proper.
2. Locate the adjustment clamp (Rear hub: non drive side near the axle. Front hub drive side)
Note: there will be a small set screw / bolt and a small hole next to it. Please note part is photographed separate below for instruction and clarity.
3. Depending on your hub model you will need either a Torx T10 or a 2.5mm Hex key.
4. Loosen the set bolt by turning counter clockwise (the bolt stops the clamp from coming lose )
5. With the bolt loose you can now rotate the clamp.
Clockwise tightens the clamp and applies more pressure on the bearings removing the loose feel. The clamp is threaded and tightens the bearings and it may feel stiff to turn so we included a "helper hole" where you can insert your tool and use to rotate the clamp much easier.
6. The clamp should be rotated around so it is firm to but you do not have to apply excessive pressure. On a scale of 1-10 about a 6. Note: Having the clamp on the tight side is much better than loose and will not affect the speed of the wheel.
7. You can check the wheel at any time to see if you have eliminated the wobble.
8. When satisfied with the adjustment, simply tighten down the set bolt to 1.1 Nm which is firm but not excessive to risk stripping the bolt.
Front Hub
The procedure is very similar to above. the main difference being that the adjustment is completed on the drive side of the hub.
Here are the photo steps for the FRONT WHEEL:
1. Ensure the thru axle is tight in the fork.
2. Loosen the set bolt counter clockwise (the bolt stops the clamp from coming undone) Note: the adjuster clamp is on the non drive side.
3. With the bolt loose you can rotate the clamp.
Clockwise tightens the clamp and applies more pressure on the bearings removing the loose feel. The clamp is threaded and tightens the bearings and it may feel stiff to turn so we included a "helper hole" where you can insert your tool and use to rotate the clamp much easier.
4. You can check the wheel at any time to see if you have eliminated the wobble.
5. When satisfied with the adjustment, simply tighten down the set bolt to around 1.1Nm which is firm but not excessive to risk stripping the bolt.
Front Hub (Non Disc) - Quick release hub only
1. Check for wobble / lateral play using the method shown above. Remove the wheel from the bike, remove the quick release skewer.
2. Using two 5mm hex wrenches in either side of the hub, turn both counter clockwise respectively to unlock the axle. Note: sometimes with corrosion the axle ends can be difficult to unlock. Tip : place one of the 5mm wrenches in a bench vice.
2. The axle ends should unscrew leaving the adjusting cone nut exposed. The adjustment cone has 4 notches. Shown below in silver.
3. Using your hand or for more precise adjustment use the Chris King cone adjustment tool - tight down (clockwise) the adjusting cone. Advance adjusting cone until it just contacts bearing, then back off approximately 1/16 turn (this allows for axle compression while under skewer clamp pressure).
4. On a rare occasion, if you need assistance rotating the adjusting cone, place a 5mm tool in the opposite side to hold the axle.
4. Apply a small amount of grease to the threads and install the axle ends.
5. Tighten using a 5mm wrench to 12.4Nm
6. Place the wheel back in the fork and check the rotation and the lateral play.
For more information, details can also be found under your specific hub instruction in the manuals here: LINK