Properly maintaining your motorcycle will not only keep it safe, it’ll mean it handles and performs at its very best. Being able to do some – or even all – of the work yourself can save you money and give you the satisfaction of getting even closer to your bike…
If the seals are in good condition around your bike’s wheel axles, the bearings should be fairly well protected. Keep the wheels clean, but don’t get too close with a pressure washer, which can blow the grease out of the bearings, especially if they’re an open design, like on the left side of my 1999 Kawasaki ZX-6R’s rear.
Open bearings can sometimes be accessed with the wheel out – if you can see the balls, make sure you keep them packed with grease; I use Corrosion Block from the makers of ACF-50, but there are lots of other suitable products available that meet or exceed the requirements of the NLGI (National Lubricating Grease Institute) for GC-LB. GC denotes use in wheel bearings on vehicles under mild to severe duty with the highest temperature ranges, while LB relates to a vehicle chassis and its components under mild to severe duty, which can be exposed to water and other contaminants (there are also GA and GB, as well as LA classifications for less severe environments).
A set of wheel bearings and seals can be bought from Wemoto
Your motorcycle’s wheel bearings can last for 100,000 miles or more if they’re looked after but blowing the grease out or riding through deep water can shorten their life, as can heavy impacts caused by off-road riding, wheelies etc.
Bearings with sealed faces should require no maintenance, but open-cage designs can be worn out after just a couple of years of use if they’re poorly maintained; the ones in this 18,000 mile ZX-6R’s rear wheel have had it.
Poorly maintained bearings can sometimes be obvious
Worn bearing can result in vague handling, but don’t wait until you notice that! With the wheel off the ground, check that it spins freely (don’t confuse the brake pads licking with bearing noise).
Next grip the top and bottom of the tire (you might have to hold the spokes of alloy wheels or the inside of the rim if there’s a fender in the way) then try rocking the wheel back and forth. Turn the wheel a little then do it again until you’ve rotated it a full 180°. Be sure that the bike itself isn’t moving, but if you feel any knock or slight movement at all, it’s a sign that the bearings are worn.
Always replace all of the bearings in a wheel, not just the ones you think might be worn. You should also change the seals as you’ll need to prize them out to get at the bearings, and they’re clearly not doing a great job of keeping water out as it is…
Fortunately complete kits are available from UK motorcycle parts specialist Wemoto, with a set including dust seals for the front wheel of a 1999 ZX-6R costing just £15.60, and for the rear wheel only £24.00.
This article isn’t intended to be all you need to change the wheel bearings on any motorcycle. I’m basing it on my 1999 Kawasaki ZX-6R, but your bike will have its own unique needs, so I thoroughly recommend buying a Haynes workshop manual first. My hope is that this will give you the confidence to take on the job for yourself, but only with a workshop guide specific to your machine will you have the correct procedure. Remember that Bennetts customers can save a massive 40% on Haynes manuals at Bennetts Rewards. You’ll also need the following…
Popping bearings in the freezer before fitting might make the slightly easier to fit
The bearings on my bike’s front wheel looked and felt fine, while whose on the rear wheel were getting pretty nasty. Both wheels require generally the same technique, with the rear usually being slightly more involved and carrying more bearings.
It’s debatable whether it makes much difference, but putting your new bearings in the freezer over-night can potentially make them a little easier to drift into the wheel – take them out just before you fit them.
Step 1: Remove the wheel
Once you’ve taken the wheel out (remember it’s always much easier if you remove the caliper(s) first), lay the wheel down on two lengths of wood that support the rim but keep the brake disc off the ground – this will protect the rim and the disc when you start hammering.
If you’re working on the rear wheel, as I am, pull the sprocket carrier off (being careful not to have it stick then break free to bash you in the face). Watch for any cush rubbers or spacers that might fall out. We’ll worry about the bearing in the sprocket carrier later, so put that to one side.
Step 2: Remove dust seals and circlips
On the rear, there’ll likely only be a dust seal on the opposite side to the sprocket carrier but remove any that are covering the bearings; you’ll be able to prize these out with a flat-bladed screwdriver.
With the seals out, wipe any grease away and check carefully for any circlips; there’s one under the seal on the ZX-6R; using circlip pliers, carefully remove it and put it somewhere safe as you’ll need it again.
Step 3: Drift the first bearing out
Making sure the rim of the wheel is sat evenly on the lengths of wood, and the disc or face of the wheel isn’t touching the ground, place a long drift down through the wheel until you reach the inner ring of the bearing on the bottom. It’s really important that your drift has a good, straight face so it doesn’t roll off the edge – you need it to catch in order to release the bearing enough for the spacer to move more. If it’s not flat on the end, grind it.
You want the drift to be pushed tight against the inside edge of the top bearing, so that it’s forcing into the opposite side of the bearing you’re hitting; don’t try driving straight down.
This illustration from the Haynes manual explains how to position your drift
Using solid blows, start driving the bearing out, working one side, then the opposite side, then 90° around, opposite to that and so on until the bearing falls out of the wheel, likely followed by the spacer.
The spacer will likely fall out with the first bearing
Step 4: Drift the other bearing out
Now flip the wheel over, making sure it’s secure on the lengths of wood before repeating the process on the other bearing.
Once they’re both out, check the wheels for any damage while giving the bearing seats a good clean – get any dirt out with a screwdriver or pick, and be sure to clean the groove for the circlip too.
An old spindle can help get a damaged bearing out
Expert tip: What if my bearings have collapsed?
If your bike’s bearings are so shot that the inner race has collapsed, you might not have any area to drive the remaining outer race out if it’s flush against a face. Nick Nomikos, owner and MoT tester at The Two Wheel Centre in Harpenden says that all is not lost:
“If you can get hold of an old wheel spindle with a flared end that’ll fit through, you can use this to get behind the shell of the bearing.”
Push the edge of the old spindle against the bearing (note that there isn’t a bearing here; we’re just showing how to lever it).
“Ask a mate to use a tyre lever to force the edge down against the back of the bearing while you strike it from the other end; you should be able to get the bearing to start moving away – once it’s crept, it’ll just get easier until it’s free. If you’re struggling, try warming the surrounding rim carefully with an electric hot air gun; remember, you need to heat the part that you want to expand.”
Step 5: Fit the first new bearing
Before fitting the new bearings, find a socket that’s large enough to only press on the outer edge of them, but will just fit into the wheel (remember that the outer races might be different sizes). If you don’t have a suitable socket, you could grind the outer edge of the old bearings down, so they’ll drop in and out of the wheel.
If the bearings you’re fitting don’t have a dust seal covering the balls, pack them with grease on both sides.
At least one side of the wheel will have a lip that determines the depth of the bearing; find this then place the wheel on the lengths of wood with the lip on the top.
Now take your new bearing and lay it onto the top of the opening (if it drops in, you’ve got the wrong size, or your wheel is knackered!). I lay another piece of wood on top of the bearing, then hammer it down until it’s flush with the edge of the rim, making sure it goes in absolutely straight. To prevent damage to the new bearing, you could also use the old bearing laid directly on top then hammer this, but only ever hammer the outer edge. Also make sure you don’t keep driving the new bearing all the way down as you’ll get the old one stuck in there too (unless it’s been ground down).
Once the bearing is flush with the wheel face, hit your socket (or ground-down old bearing) with a wooden mallet or wood and hammer to drive the bearing to the bottom of the recess; you’ll hear the tone of your hammering change as it hits the bottom.
You could use a drift, moving around the edge of the bearing as you go, but you must make sure you ONLY strike the outer edge. Again though, make sure you’re driving the bearings in straight.
On the ZX-6R, this was the same bearing that required a circlip, so with the groove completely visible, pop in the new circlip and rotate it a little to make sure it’s fully seated.
Don’t forget the spacer!
Step 5: Fit the new bearing to the other side
Now flip the wheel over, making sure it’s sat safely on the lengths of wood before popping in the spacer (don’t forget!). Repeat the process above to fit the second bearing, seating it against the spacer.
Don’t keep hammering once the inner race of the bearing contacts the spacer or you risk damaging it. If the spacer is slightly offset, just knock it to the side with the drift until it lines up; you might find it easiest to poke it into line with the axle before finishing.
Step 6: Fit the new seals
On the front wheel, you’ll likely have one seal to fit on each side; pack the backs (the open side) of the seal with grease and wipe it around the inside and outside edges. If the new bearings are an open design, also pack some more grease in if you can.
The new seals should just press in by hand – at the most, you might need to tap them in with a piece of wood laid over them, but fingers should be enough. Make sure the seals go in with the open side against the bearing.
Having to drive the bearing out using the inner race is where things could go wrong – if the bearing collapses, see the expert tip above
Step 7: Replace the bearings in the sprocket carrier
If you’re replacing the bearings on a rear wheel, chances are there’s at least one in the sprocket carrier too. The process is just the same as on the rest of the bearings, so keep an eye out for a circlip here, as well as any spacers.
And that’s it. Now just refit the wheels and check everything is fully secured and safe before riding. Make sure there’s no grease or oil on the brake disc or pads, and triple-check your work before congratulating yourself on a job well done and money saved.
If you can’t do this job yourself, your dealer will be happy to take the work on. While prices will vary, Nick Nomikos, owner and MoT tester at The Two Wheel Centre in Harpenden says he’d charge labour of £24 per loose wheel to replace the bearings, or £33 if the wheels are still on the bike.