Now that you're well-versed in crank removal, it's time to take the surgery one step deeper and remove and replace your bottom- bracket bearing cups. You need to do this to overhaul the crank-spindle bearings, replace the spindle, or replace the crankset. To service the bottom bracket bearings of a normal, three-piece crankset, you must remove the bearing cup on the left side.
Working on bottom brackets requires special tools. It is also very useful to have a small magnet on hand to help with pulling the slippery ball bearings out of the cavity, but it is only a help, not a necessity. Start by using the correct tool to loosen the bottom bracket's lock nut.
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.
Since our post on Installing bottom brackets like a bossit only seems fair that we write up instruction on how to safely remove a pressed in bottom bracket. The main goal is to remove the bottom bracket with minimal amount of damage to the cups, while making sure we do not destroy the bearings by hammering away on the seals or inner race. All Kogel Bearings cups are designed with a lip on the inside that is meant to take a punch and protect the bearings. Depending on the design restrictions of each setup, this lip is more or less prominent.
A Shimano Hollowtech bottom bracket may have a shell made of metal or tough plastic. Shinamo Hollowtech bottom bracket s need a special ring spanner that fits into splines and allows each side to be screwed in and out. Push the ring spanner onto the external splines on the left side of the Shimano Hollowtech bottom bracket.
This article will discuss the removal and installation of the common cartridge bottom brackets of the three-piece cranksets. Most cartridge bottom brackets are held by retaining rings or cups on either side. See Adjustable-Type Bottom Brackets.
Nowadays, bottom brackets have disposable sealed cartridge bearings and, as frames have got beefier, bearings have increased in diameter to allow for lighter, stiffer chainsets using larger axles. And so goes the irresistible march of technological progress. However, while a traditional bottom bracket sits inside the frame and includes the axle in a single unit, Hollowtech bearings sit outside the frame and the axle is integrated into the crank.
Time Required. Bottom bracket broken and can't ride your bike? This guide will walk you through how to remove the bottom bracket, how to grease the threads of the new bottom bracket, and then how to reinstall the bottom bracket.
This is a simple home-made tool to remove a bottom bracket that refuses to budge. So simple, I'd be surprised if somebody else hasn't already come up with this. But, I can't find it on the internet, so made this myself.
By justin loretz. The humble bottom bracket BB gets subjected to some of the most intense and punishing conditions of any system on the bike. High loads are continuously channelled through rotational motion onto the bearings, which take the full brunt of both bodyweight and muscle power. Servicing will rarely involve actually repairing the BB itself.