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One23 Ceramic/Carbon external bottom bracket



Super smooth and lightweight bottom bracket, but you're paying a big premium for Carbon you'll never see...

At every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.

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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.


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.

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Make and model: One23 Ceramic/Carbon external bottom bracket

Size tested: 68mm

Tell us what the product is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?

Intended for those who are looking for additional performance gains and have the cash to do so.

Tell us some more about the technical aspects of the product?

Ceramic Bearing Bottom Bracket

68mm Road specific

Carbon Centre/Red anodised cup

Shimano Compatible

Rate the product for quality of construction:

My fears over the seals proved unfounded; they have done their job. The alloy cups require a bit more care when wrenching than some stouter, but heavier, alternatives.

Rate the product for performance:

In use, the One23 performs brilliantly; it's light and silky smooth.

Rate the product for durability:

It has survived plenty of messy off-road rides and continues to perform like new. On the road, it should last even longer.

Rate the product for weight, if applicable:

There aren't many lighter bottom brackets out there

Rate the product for value:

£130 is a lot, and a £50 hike for a carbon sleeve seems a bit much.

Did you enjoy using the product? Yes

Would you consider buying the product? I would opt for the alloy sleeved version

Would you recommend the product to a friend? Yes

Overall rating: 7/10

About the tester

Age: 20  Height: 190cm  Weight: 70kg

I usually ride: Giant TCR Advanced 2  My best bike is: Canyon Ultimate CF7

I've been riding for: Under 5 years  I ride: Every day  I would class myself as: Expert

I regularly do the following types of riding: road racing, sportives, mtb,

For 5 years, racing was my life and I went all the way from a newbie bonking after 40 miles, to a full-timer plying my trade on the Belgian kermesse scene. Unfortunately, the pro dream wasn't meant to be and these days, you're more likely to find me bimbling about country lanes and sleeping in a bush on the side of the road.

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