One23 Ceramic/Carbon external bottom bracket

The One23 Ceramic/Carbon is a trick Shimano compatible bottom bracket that is sure to spruce up your drivetrain.

A quick spin of the pedals with this model installed and I was quite simply blown away (sad, I know)! There is noticeably less friction than with my usual Shimano XT BB installed; the smoothness approached that of a quality ISIS style bottom bracket.

The issue with outboard bottom brackets in general, is that the seals have to be quite tight to prevent dirt ingress, a major problem with their exposed position on the bike. Most of the friction in outboard BBs comes from seal drag and not from the bearing/race interface. Given the One23's silky smooth performance, I was afraid that durability may have been compromised by using slacker seals. As such, I stuck the One23 onto my mountain bike in the hope that I could properly test its durability in a shorter space of time.

The bedding-in period was short with the One23 working flawlessly until, with around 500km off-road km logged, it developed a creak. A quick re-grease of the threads and contact surfaces, and it was back to business as usual. Since then, the One23 has stood up to multiple wet and muddy races without complaint, and continues to perform beyond my expectations. I see no reason why it could not survive many thousands of kilometres on the road, its intended environment.

One benefit of all that ceramic and carbon goodness is that the One23 weighs in at a feathery 100g. Compared to the usual plastic sleeve, the carbon one found on the One23 just looks plain awesome - although that's kind of pointless, since it's hidden in the frame! The alloy cups do require a bit more care when tightening, but that is the price you pay to achieve the light weight.

Some will scoff at the £130 price tag and as ever it's the law of diminishing returns. One23 offer another model with the same ceramic bearings but with less nicely finished cups and an alloy sleeve... for a whopping £50 less. Whilst we don't have info on the weight difference, it can't be that much, so that would probably be the one we'd look at if it was our own money. The £130 price tag means it's quite a bit more expensive than a Chris King BB or a Hope ceramic one, though still a good bit less than SRAM's top-end model. We've got no issues with the performance though, it was excellent throughout.

Verdict

The One23 Ceramic/Carbon bottom bracket is a very high quality piece of kit. The smoothness and lack of friction is excellent, and it appears to come without a durability penalty. Whether a bottom bracket will ever be worth £130 is ultimately a personal decision, and we'd be more tempted by the cheaper option without the Carbon sleeve.