Category: Bottom Brackets

Regrettably, selecting bike parts has become enormously complex in the last one or two decades; it has always been a complex topic from the start. There are numerous bottom bracket sizes and parts to attach your crankset to your frame.

BSA has become more popular, and square taper spindles appear to be here to stay, but Hollowtech II appears to be the most popular.

BSA size, and outboard bearing type are becoming more common, while press fit rather than bolt-on solutions have been used on road bikes for a long time.

It’s a complicated topic with a lot of proprietary standards that doesn’t play well with others. Road bike bottom brackets, such as square tapers, will fit MTBs, but you’ll have the wrong chainline, for example. If you are building a bike from scratch, choosing the correct parts can be a hit and miss. Some riders have headaches about chainlines, just because they incorrectly place washers in SRAM GXP / Shimano Hollowtech II bottom brackets – it’s very common. Sometimes, even removing old cranksets are a huge problem due to egzotic parts in vintage bikes, which you can’t even find a tool that fits it. Creaky cranksets are generally related to bottom bracket problems. There is lot to talk about bottom brackets!

shimano hollowtech ii bottom bracket cup

Bottom bracket creaking: reasons, fixes, don’ts

Creaks are super annoying, and I saw a lot of people complaining about bottom bracket creaking. However, bottom bracket creaks are rarely related with bottom brackets. There are lots of areas on a bike that can create those annoying creaks. Spotting the exact problem can be easy, or almost impossible, depending on the problem. To cure a problem, we have to ask the right questions first: why people automatically think it is the bottom bracket that creaks? Bacause people tend to think cranksets are not good enough for them. I’ ve seen a lot of people, who cannot sustain 100 watts for a few minutes, complaining about flexy frames or cranksets. Well, I don’t meant to harm your feelings, but you’ re not that strong to flex a frame or bend a fine crankset. That’s where pros or avid riders… Continue Reading Bottom bracket creaking: reasons, fixes, don’ts

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Bottom Bracket types and standards

Bottom bracket is simply what mates your frame and crankset together. Other then that, it’s far from being simple. There are millions of frame shells sizes that accepts bottom brackets, and also millions of bottom bracket types. You may come across many, many categorisation of bottom brackets. Like, press fit, outboard bearing, square taper, etc. Nomenclature is vast; yet it’s not really hard to determine what type of bottom bracket you have, or what you will need for replacement. I’ll follow a simpler categorization. Since a bottom bracket is fitted to your frame shell, it can be fitted in 3 ways: Either pressed (no threads on your frame shell) or, threaded inside, or threaded outside. What that means?  Modern bottom brackets like Shimano’s Hollowtech II, Sram’s GXP or DUB, have 2 exterior cups that is bolted outside your frame shell.… Continue Reading Bottom Bracket types and standards

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shimano sm bb51 hollowtech bottom bracket

Why and how Hollowtech II bottom brackets fail

On paper, Hollowtech II is a step forward to old 3-piece cranks. It’s lightweight, bottom brackets are easy to remove / replace, cranks are easier to pull out. Getting the Hollowtech II bottom bracket cups is very easy and foolproof thanks to sturdy tool; while “inboard” bottom brackets like the first Hollowtech, ISIS, or the classic, conventional threaded ones are harder to remove; because they tend to “fuse” with aluminium frames, where these threaded type bottom bracket bodies are steel. Galvanic corrosion due to two different metals touching together can also damage these parts, especially aluminium, in the long run. You can use copper grease to slow it down; but thats not a permanent way to stop it forever. Hollowtech II (or similar) cranks are also lighter due to simpler bottom brackets. There is a common misunderstanding that Hollowtech II… Continue Reading Why and how Hollowtech II bottom brackets fail

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