In part 1 of this blog post, we looked at different bottom bracket types and at adapters. Part two will go a bit more in depth about the best location for bearings and installation techniques.
Bearing stance and bottom bracket stiffness
Imagine the bottom bracket area of your bike to be very similar to the transmission in a car. You can have the strongest engine and the widest tires with the most grip. As long as the parts connecting them are not as stiff as they should be, all that power is not going to result in maximum acceleration.
Bottom bracket stiffness is super important. Besides avoiding plastic and unnecessary parts, you want to look at a bottom bracket with a wide bearing stance. The closer the bearings are to the crank arms, the wider the base for your spindle to rest on. This translates in a stiff set up and speaking from our experience, a lot less wear on the bearings.
A clear demonstration of a narrow bottom bracket shell mated with a long crank spindle. All the adapter space is wasted real estate. Moving the bearings as far out as possible will increase stiffness and bearing life.
Installation and removal
This is something to consider for any press fit type bottom bracket. Threaded bottom brackets are installed with the appropriate tool and removed with the same.
Installing and removing threaded cups is done with the same tool.
Switch to anything pressed and information is all over the place: instructions range from using Loctite to epoxy to grease or nothing at all. In our opinion, you should think about removing a bottom bracket before installing it: anything glued into the frame is going to leave a residue, which needs to be removed before installing something new. In the case of epoxy, this could mean you spend the next twenty minutes toying with a box cutter or Dremel tool. Kogel Bearings prefers grease for installation. It helps the bottom bracket slide into place, helps to silence potential creaking points and can be cleaned with a rag after removal.
Any loctite or epoxy used in a bottom bracket is going to dry out and needs to be removed before the next installation. This can be a time consuming task.
While you are thinking about removing a bottom bracket, have a look on the inside of the cups. Press fit bottom brackets are often removed with a hammer and some sort of punch. Now look on the inside of your cup, is there something your tool can grip on and take a beating if the cups are tight in the frame?
In short, there are many things to consider for a quality bottom bracket:
- Type: threaded, press fit or threaded press fit, whichever fits best with your frame
- Materials and small parts: look for a high quality build with as few parts as possible
- Bearing stance and stiffness: look for bearings placed as far apart as possible
- Ease of installation and removal: how easy is it to get the bottom bracket in the frame and how easy is it to remove and prep the frame for the next bottom bracket
Notice how we did not speak about weight? If you follow all these steps (alu cups, wide stance, quality build), you will no doubt end up with a bottom bracket that is a handful of grams heavier than a plastic, narrow stance bottom bracket with adapters. In our eyes, there are only a few grams to be saved on a bottom bracket and if choosing those extra grams is going to help you transfer more of your watts to the road, they are well spent.
If you have any questions about Kogel Bearings, ball bearings in general or our Ball Bearing Adventures, please ask them either in the comments section below, one of our social media channels or by email via firstname.lastname@example.org. We will answer them in a highly professional, but not always scientific way. We do not shy away from many subjects. Please ask, we are here to answer.