This is a story more about materials and design than products, specifically, but it ends with an addition to their lineup. Enduro’s XD-15 material is considered a “super stainless” because it has a much higher nitrogen content, which helps make the metal more homogenous. So you end up with far less pitting and much more even wear regardless of the type of bearings rolling around in there.

They’ve used that material for years and years, but only in the angular contact bottom brackets that have a 45° angle, which require proper bearing preload to work properly. That means they’re really aimed at the rider that’s willing to spend the extra time setting up their gear, because without the right preload tension, they won’t work as well or last as long.

Enduro Bearings explains the angle of angular contact bearings with new XD-15 degree bottom brackets

The bearing races are curved to follow the roundness of the balls inside. These are 45º races, a number that’s an average of the angle throughout the curve.

Now, they’ve added the XD-15 race material to their 15° Angular Contact and true radial contact bearing bottom brackets. Yes, that means there’s an XD-15 15º, which can be confusing, so just remember that the XD-15 BB’s mean you’re getting the better metal inside.

Both the new 15º and radial bearings offer much easier set up since they don’t require preloading to work properly. During installation of the cranks, most of us like to crank them down pretty tight so they won’t come loose during riding. So, most every bottom bracket ends up with some side load, even if it’s one with radial bearings that don’t need any preload. Enduro says, because of this, their 15° bearing BBs will offer a little smoother performance than using a true radial bearing since they can handle that side load better and will last longer when run under such tension. As such, they’ll only offering complete bottom brackets with the 45º and 15º angular contact bearings. The radial bearings will be available separately if that’s what you really want, and you can pop them into the BB shell yourself.

Enduro Bearings explains the angle of angular contact bearings with new XD-15 degree bottom brackets

Enduro Bearings’ XD-15 bottom brackets will be available for pretty much any crank and frame standard you have, check their website for a complete list to find the fit you need. Retail pricing depends on the model – The Enduro Bearings Corsa BB is 45° and runs $299, and the Pro BB is 15° for $249.


  1. Dinger on

    Anybody remember the 7700 series Dura-Ace BB? That was angular contact bearings for side-load, roller bearings for main load. I thought it was the best BB ever designed. What’s old is new again.

  2. JustSomeGuy on

    That looks suspiciously like a cup and cone bearing. You know, like the ones that Campy and Shimano still use in hubs and essentially last forever because they tolerate misalignment well and can handle loads from any direction.

  3. Crash Bandicoot on

    A lot of money considering my 16 dollar SM-BB52 has been on my hard tail for 2 years, thousands of miles, many power washes/wet weather commutes, snow, Ice, and salt and yet is still silent and smooth


COMMENT HERE: (For best results, log in through Wordpress or your social media account. Anonymous/fake email comments may be unapproved or deleted. ALL first-time commenter's posts are held for moderation. Check our Comment Policy for full details.)

This site uses Akismet to reduce spam. Learn how your comment data is processed.