5 Reasons Why Bottom Bracket Upgrades Are Often Pointless

Despite all the noise and hype, the reality is that bottom-bracket upgrades are a bit overrated, to put it mildly.

Below are 5 reasons why it’s not worth investing in a “superior bottom bracket” unless it’s part of a bigger upgrade.

1. High and Low-end Bottom Brackets Offer Similar Performance

If we take two bottom brackets, one from the high-end segment and another from the low-end, you will be hard-pressed to notice the difference between the two provided that each unit is in good working condition.

For example, my hardtail MTB has a basic Shimano square taper bottom bracket with 1000s of kilometers on it. I’ve also ridden a bicycle that had a bottom bracket with external bearings.

Did I feel a difference? Not really. (And I am not ashamed to say that.)

I am not saying there isn’t a difference. It’s just not noticeable enough to matter in a practical context.

Why is that?

The parameters that make a higher-end bottom bracket superior are not as tight to performance as one might think.

The main advantages of higher-end bottom brackets are:

  • Lighter weight (If your goal is to save weight, that’s helpful. But the weight of the bottom bracket doesn’t matter when it comes to the unit’s performance.)
  • Compatibility with higher-end cranks (This is a significant advantage but doesn’t equate to better performance of the bottom bracket itself.)
  • Greater durability (This is also a significant advantage but in this case, we are comparing working bottom brackets. So, the extra durability doesn’t matter in the short term.)

Ultimately, the main advantages of a higher-end bottom bracket don’t directly contribute to superior performance.

And if anybody tells you otherwise, remind them that champions like Eddie Merckx used bottom brackets (old-school square tapers) that would be considered a major downgrade today.

Would Eddie Merckx be faster with the latest bottom bracket?

For real. Ask yourself this question and answer honestly :).

Bottom line: As long as a bottom bracket is of acceptable quality and in decent condition, its performance is comparable to that of a higher-end model from a practical/perceivable perspective.

Higher-end bottom brackets offer advantages, but as long as the basic function of the bottom bracket unit (smooth rotation of the crank) is intact, switching to a high-end unit will not have a phenomenal if any effect on your performance.

2. Bottom Bracket Weight Savings Are Real But Also Inconsequential

A Hollowtech bottom bracket is about 3.4 times lighter than a square taper model. That’s nice if you’re trying to build the lightest possible bicycles out there, but when it comes to performance the weight savings are inconsequential because the bottom bracket is in the middle of the bicycle.

Saving weight at the front or rear has a real, maybe even evident, impact, but when the weight is situated in the middle, 150 grams are non-perceivable.

Remember that most of the rider’s weight is over the rear wheel and the bottom bracket shell. Therefore, the middle of the bike is a location that one can load heavily before feeling an effect.

For instance, I carry my folding lock on the seat tube. That lock weighs over 2lbs (I think), but I don’t really care. I can still perform a small bunny hop with my commuter bike.

However, if the weight was at the front or the rear, some technical movements would be a lot more difficult.

3. The Money Can Be Invested Elsewhere

Bottom brackets are not expensive (unless you go for a very exotic model), but if you don’t need a new one, the money can be invested in components and accessories that make a bigger difference.

For instance, you can get a small handlebar bag or a saddlebag. Once I began bike commuting some 5 years ago, I quickly found out that accessories such as bags and clothing could be a lot more important than minor upgrades as long as the bike is in working condition, of course.

Here’s a full list of small parts and accessories that you might get for the price of an average bottom bracket:

  • Handlebar bag
  • Saddlebag
  • Tool bottle
  • Multi-tool
  • Disc rotor
  • New gear/brake cables
  • Gear/brake cable housing
  • Brake-shifter
  • Shifter
  • Inner tubes
  • A Tire
  • A New Rim (if you use cheap ones)
  • A Bell
  • A Smartphone holder
  • New handlebars
  • Bike Poggies for the Winter

…you get the idea.

4. Zero Aesthetic Gains

The bottom bracket is practically an invisible bike part as 90% of it are in the frame; the cranks hide the remaining 10%.

Thus, a new bottom bracket won’t add a new style and freshness to your bike.

There’s one expectation, however. If you need the bottom bracket so that you can install a new set of crank and chainrings, the story changes because those are crucial for aesthetics.

Nothing beats the look of old-school cranks (IMO)

5. Extra Mechanical Work

Replacing a bottom bracket is a fairly straightforward process (if you have the right tools for your particular type), but at the end of the day, it’s a time and energy investment that can go elsewhere.

[Of course, this point doesn’t apply if your bike is already stripped for another repair/upgrade.]

If you want to upgrade from a square taper to Hollowtech, you will need the following tools:

  • Crank extractors (plus wrenches for them)
  • Bottom bracket socket
  • Hollowtech wrench
  • Allen keys

To be honest, it’s nice to invest in those tools because you will need them sooner or later when you have replace a worn bottom bracket.

(Tip: To check if your bottom bracket is worn, put the bike on a stand [or let it hang off a branch] and take the chain off. Then, spin the cranks with your hand slowly. If the cranks are rotating smoothly, there’s no noise and the bottom bracket doesn’t wobble, it’s all good. If not, service the bottom bracket (if possible) or replace it.

When Is a Bottom Bracket Upgrade Justified

I am not a bottom-bracket hater (haha).

I am a bike enthusiast and mechanic myself and realize their importance.

However, I would replace my bottom bracket only in the following cases:

  • I want to install new cranks on my bike and they aren’t compatible with my old bottom bracket.
  • The old bottom bracket is non-serviceable (sealed) and in bad condition (squeaking and rotating poorly)
  • The axle of the bottom bracket is bent or broken.

Note: In the last two cases, you can go for the same model you’re replacing if it’s available, of course.

Good luck my friend.

And thank you for visiting my website.

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