What Are Bottom Bracket Bearings?
The bearings are the part
that enables rotation. The bearings can either screwed or pressed into the BB,
which are referred to has threaded and press-fit respectively. The threaded
variety are more common, with the most common variant being BSA or the English
threaded bottom bracket standard. There is also a less common Italian threaded version.
Press-fit bearings came
about with the rise in popularity of carbon frames. Since you cannot cut threads
into carbon fibre, an alternative means of seating bearings was needed. The solution
was to literally press them into the frame. There are benefits to this method,
including more freedom for designers, and stiffer and lighter frames. However, this
method gave rise to a multitude of different standards, incompatible with each
other.
How to Install Your Bearings
As the name implies,
threaded bearings are screwed into the frame; this is a relatively
straight-forward process. Press-fit bearings need to be pressed into the frame
with special tools that squashes them in from either side. While threaded
variants will require specific tools, the process is generally simpler.
Bear With Me
Bearing maintenance
should be a somewhat regular activity, at least on a seasonal basis. The signs
it might need some attention are creaking, a gritty feeling when pedalling, and
play in the cranks. A little bit of grease can go a long way.
Replacing Your Bearings
When it does come time to replace your bearings, you’ll need to check
the manufacturer’s specifications to see what bearings or cups you need. Unfortunately,
there’s quite a wide variety so you need to be sure you’re getting the right
part.
