Originally Posted by
hueyhoolihan
what i don't understand is why engineers haven't gravitated completely to the same design for all the axle/bearing(s) interfaces on a bike. hub, bb, and steering. all do or could have sealed bearings, pressed into an aluminum or steel housing. we just happen to call the axle a steerer on a fork and a spindle on a BB instead of an axle as it is called on a hub. the forces involved are similar and determined mostly by the weight of the rider and bike.
A good question, but it's because a different company makes the BB, and hub, and headset each. Each wants a certain style or standard to support its own marketing/engineering (hard to tell apart these days). Standardization allows a company with no R&D to come in and dominate (MKS to Campy in the 80s; Shimano(okay, this is a stretch) to Suntour/Campy in the 90s; carbon OEMs today) on cost.
Frankly, people today have no idea how much more standard and easy things are today compared to any point in the past. Thread gauges were a necessary evil only 10 years ago as you never knew which OEM would adopt which standard (English, French, Swiss, Italian). Shimano successfully standardized much of the drivetrain tech, as did the Taiwanese for frames and forks. Not too long ago parts had as many as 6 check-boxes on a package each for a different threading and/or width.