Understanding bottom bracket issues. And why the standards are here to stay.

 

The good old bottom bracket, the silent work horse, hidden deep down inside the bicycle. Well, silent is referring to the ideal world in this case. With the explosion of bottom bracket and crank standards we have witnessed in the last decade, the bottom bracket has turned into a bike part that seems to be in constant need of attention. Today I will try to find out what led to this situation and if there is a light at the end of the tunnel.

Bottom Brackets have always had their problems

Many times in magazines, articles or forum posts we read that the bottom brackets of today are too confusing, and that is absolutely true. As a former shop owner, I always dreaded the moment when a customer walked into the shop with a random crank and frame in hand. I know I lost 20 minutes at that point: first determine the standard of the frame,  then the crank, then try to find the right pieces to fit them in a huge online ordering system.

But has this ever been different? Way back when bottom brackets were still called ‘square taper’, there was Shimano which would not fit with Campagnolo. There was Italian or English and in none of those cases a road BB would fit on a mountain bike. And then there was chain line: I found the right bottom bracket, but need a 118mm instead of a 113mm to keep my crank arms from jamming into the frame.

Like modern day bottom brackets, internal spindles developed over  time.
Like modern day bottom brackets, internal spindles developed over time.

Pushing the boundaries of bicycle development

After square taper we were ‘blessed’ with ISIS , Octalink, hollow tech II, Ultra Torque, BB30, GXP Power torque and Over Torque. And that is only on cranks! Frames spun out of control in a very similar way with a dozen press fit variations: BB30, PressFit30, PressFit without 30 which is also known as BB86 unless it is on a mountain bike, then it is called BB92 but it might measure 92.5 or 89.5 millimeter depending on the brand.

You lost me somewhere in there? I don’t blame you. Trying to fit a crank and frame seems about as easy as predicting the Euro/Dollar conversion rate for the next month.

Bottom braket standards can be confusing and overwhelming.
Bottom braket standards can be confusing and overwhelming.

The reason for this is that bicycle manufacturers are constantly looking for stiffer and lighter frame constructions. Sometimes this involves true innovations, sometimes it involves innovating for the sake of changing things for the new model year. Heck, one of the biggest players in the industry has used ‘Innovate or die’ as an advertising slogan for years.

Diversification of the bicycle industry

Another trend I have seen in the bicycle industry is a constant diversification. The village bike shop that does everything on two wheels has long vanished. Nowadays there are specialized shops for commuters, road bikes and mountain bikes.

Looking at the car industry, this development has gone much further. It is close to impossible to drive your Dodge into a BMW dealer for an oil change or to replace a light bulb, leave alone if something has gone off in the electronics. This is the auto industry’s way of making sure that the car they sold at low margin will keep coming back to the dealer for expensive service visits.

Along this path, almost every major frame designer is trying to integrate proprietary parts that can only be bought through their dealer network. It is not possible for a Trek dealer to order spare parts for a Specialized frame or Roval wheels.

How can we fix all these bottom bracket fitting problems?

I see a few solutions. The most obvious one is to always buy a complete bicycle from a brand. For the lifespan of the bike you will be replacing parts from the same manufacturers as the one that came in the catalogue. This is a good solution, unless you did not like a certain part that came on the standard build. What if you love your new cross country racing rig, but the brakes came from a brand that is notorious for quality issues? It also takes all the fun out of customizing your bike or completely building it part for part from the ground up.

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Downlad the kogel bottom bracket chart here, to make your life a bit easier.

As for bottom brackets, at Kogel Bearings we see a future in smaller boutique brands that have the ability to do small production runs and be quick to act when new fit issues arise. We pride ourselves in fitting any crank and any frame without adapters. Similar solutions are available from other brands for chain rings and setting up mountain bikes with a non-proprietary 1X drive train.

As long as the bicycle industry runs on creative people and small-time entrepreneurs, you will always be able to find a solution for your problems. It might take a bit of digging, though.

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