We all know square taper is going the way of the dodo. Shimano stopped making their Un 72 / 73 bottom bracket, and replaced it with a crappier Un 52 then something called the DBBL BB -32, which stands for Dirty Belly Button Lint Bottom Bracket Negative 32. It’s made of unwashed button lint mixed with metal filings left over from making Tourney rear derailleurs. That leaves us with just a few square taper units that are worth purchasing. Let me list them on two fingers. This Stronglight unit, and the TA Axis. That’s it. But wait, what about Phil Wood? I’d rather run a DBBL BB -32. Better machining at 1/64th the cost. What about SKF? Stainless spindle, snappy snappy, even on gravel. What about White Industries? Same thing. If you are just road riding, probably fine, but this Stronglight will be good for at least 10,000 miles, and it’s 45 bucks. Chromoly spindle. Won’t snap, it’ll bend first. Have we seen snapped Stainless spindles? Yes.
Basically consider this Stronglight Bottom Bracket the heir apparent to the Un 72. It’s in the same price bracket, has decent bearings, isn’t light, isn’t heavy.
I have one gripe, no wait, two. One: it only comes in a 68mm shell, which is fine for older steel mtn bikes and most road / gravel bikes, but anti fine if you need to stick a BB in a late 90’s mountain bike. Two: it doesn’t come in purple.
Install any square taper bb the same way: Ideally into a faced and chased BB shell, with cleaned then lightly greased threads. Stick the non drive side in first, as far as you can screw it in by hand. That’s the guide cup, so you don’t cross thread the driveside threads with the weight of the bottom bracket. Grease the shoulder of the BB unit where the bottom bracket shell will touch the non drive cup. Install the driveside all the way in, snug it tight. Then snug down the non drive side. Lightly grease the spindle, and grease the crank bolts. Install the cranks to torque spec, voila, you are done. Check them again in 100 miles, they might need to be retorqued.
