In the last few years more and more bikes have come with bottom bracket bearings that simply push into the frame. Here's how to get them out.
If your press-fit bottom bracket bearings have gotten worn or damaged by corrosion, you'll need to get them out. As the name suggests, these bearings are not held in place by threads in the frame, but are pushed into place and held by friction.
That sometimes doesn't work very well, and and press-fit bottom brackets have gained a reputation for creaking. To fix that, you can replace them and use a mild thread-locker to hold them in place, as long as you have an aluminium frame.
First you'll have to get them out, which is actually pretty straightforward as long as you have teh right tools.
Our guide below shows you what we believe is the best method to remove. We've included a threadless press-fit bottom bracket cups. We list of the tools and materials that you will need to complete the job and in some cases where you can buy them. If there are others that you prefer then feel free to let everybody know in the comments.
Tools & Materials
How to remove press-fit bottom bracket bearings
1 Remove the cranks You'll need to remove the cranks. With a SRAM crank that means undoing the 8mm Allen key bolt in the left hand (non drive side) crank arm. It unscrews anti-clockwise, so with the crank arm pointing towards the front of the bike you fit the Allen key so the handle points forward (as pictured above) and press down on the Allen key.
2 The bare axle With the crank arm released from the splined axle you'll be able to access the left hand bottom bracket cup. Before you can though there are a few small bits to remove.
3 Slide off any spacers Make a note of how many there are and what order the spacers need to go back in. It's always handy to have a sheet of paper on which you can place the little bits in the order and orientation in which you remove them. Taking photos with your phone as you disassemble the parts can often be handy too.
4 Take out the right hand crank Sometimes the right hand (drive side) crank and axle will just slide out. Other times the fit will be tight. In that case use a rubber or wooden mallet to give the exposed left hand axle stub a sharp tap. This will just break the friction fit and allow you to slide the drive side out. Remember you'll have to unship the chain for the crank to slide completely out.
5 The bare bottom bracket With the cranks now removed, there are only the dust caps on the bearings to remove before the action begins.
6 Remove dust caps With the spacers removed you can now remove any dust caps. These will fit directly next to the bearing seals. This Chris King model uses a BB30 to 24mm step down adaptor which doubles as a dust cap. Other models may use flatter, more traditional-looking dust covers.
7 Using the bearing remover It might not be immediately obvious how you use the Park Tool BBT-30.3. The metal hammer end is introduced through one side of the bottom bracket (you can start with either side). The head is wider than the hole in the bearing so you'll have to go at an angle, get the first side of the head in, as shown, then straighten up the tool and repeat to get the other side of the head inside the bearing.
8 Locate the tool against the bearing When you've got the tool inside the bottom bracket shell, position the head so that the steps cast into the head of the tool fit against the inside edges of the bearing. With the handle of the tool lined up dead centre of the bottom bracket shell, you should feel both sides of the tool head firmly seated on the backside of the bearing. The pic above is how it should look.
9 Fit the guide With the head seated against the far bearing, slide the blue plastic guide against the bearing facing you. This supports the tool shaft and keeps everything lined up while you hit the metal end of the tool's handle with a hammer. Sharp blows will dislodge the far bearing. Keep going with even blows. Hold the blue collar flush and you can't go wrong.
If you had to use anything else as a drift remember this. Only ever let the inner metal ring of the bearing take the force. The plastic shields and the outer case of the bearing must never be struck or you risk permanently damaging the bearing.
10 On the way out As the bearing starts to move, it'll creep out of the shell in a neat, uniform way. Here you can see the cup after three good hits. The first breaks the static fit, the second and third each produce just over a millimetre of movement. Keep going.
11 The bearing and cup The cup will pop right out. Have a hand ready to catch it.
12 Take out the second bearing The form for removing the other side is a reverse of the first, only you won't have to wiggle the tool head through a bearing, because you've just removed it. Remember to seat the tool properly on the inside face of the second bearing before you hit the tool, as you haven't got a direct guide to automatically ensure that it's square on.