Bottom bracket failure?


I don’t do too much tech on here but it seems to go down well, my piece on the possibility of an electric SRAM group in particular proved popular. Today I’m interested by the variety of bottom bracket standards on the market because it’s something that seems fairly unique amongst consumer goods.

It’s common for industries to have various “standards” when it comes to technology, for example a Android smart phones or maybe those with Windows; a Blu-Ray disc or HD DVD. In times past VHS famously saw off Betamax and there are many more examples. But I don’t remember other industries offering so many options and above all, so many parts that won’t work together. Yet this is what the bike trade is doing with a variety of proprietary bottom bracket designs.

For a reminder, the bottom bracket is the axle between the cranks and a key component. It’s subject to a lot of force and for years there was not much to it, just some cups to screw into the frame to house the bearings and the axle between the cranks. It was ripe for a redesign.

But now there are so many standards. There’s BB30, PF30, BB90, Cervelo’s BBright, BC30, Zed2 and more, plus now there’s a new one called BB386EVO. What’s so confusing is two fold: first the ever changing nature of things, second a lack of compatibility between many of these systems.

Lessons from other industries
Other industries have seen differing standards competing for supremacy but often consumers had a binary choice like VHS or Betmax rather than the wide range of standards in the bike industry. And away from bikes the choice doesn’t affect other goods, for example you can still use an existing TV whether you have a Blu-Ray or HD DVD. You can call someone with a Nokia phone if you have an Apple iPhone. Yet bike frames and components have a bewildering choice of options and many don’t work together. Get one frame and many cranks won’t work with it.

Costs, complication and incompatibility
All this raises costs and confuses consumers, a recipe to keep consumers away. For example you might be in the market for a new frame… only to find you will need some new cranks as your current set won’t work thanks to a different BB standard. As a result, if the frame is already expensive then new cranks raise the cost even more… and so maybe you hold back. The frame builder loses a sale.

Similarly you might fancy some new cranks… but have an eye on replacing your frame in a year or two… so you don’t buy the cranks in case they’re redundant with the new frame. I do wonder if this potential expense has put off a lot of customers. In addition it means additional costs for retailers in terms of tools and training.

Engineers vs. sales
The new designs do offer benefits. Oversized axles and different bearings allow for better stiffness and reduced friction. But all the same nobody’s claimed “axle flex cost me a race“. As a result the costs involved of changing one element of the drivechain can potentially far outweigh any gains. In other words engineering benefits get negated by consumers who stay away and retailers shaking their heads.

The name doesn’t exactly roll of the tongue, it sounds like a reference number from a spare parts catalogue. I groaned when I heard about it but having looked into it, the benefits are that it offers a great deal of compatibility. Thanks to various kits a frame with a BB386EVO bottom bracket will be able to accept Sram’s GXP, Shimano and and more because it shares the same width. In other words this new standard will accept others. For me, this might have a winner.

I’m all for improvements but the variety of BB standards confuses customers and I wonder if it’s reducing sales. Incompatible frames and parts mean higher replacement costs, implying consumers will hold on to their existing frame or remain loyal to their current set up for longer. Small performance gains from better design come with wider costs.

The new BB386EVO standard is worth watching but for now it feels like the bike industry is unable to settle on a common standard or two then this will surely costing manufacturers, retailers and consumers alike.

25 thoughts on “Bottom bracket failure?”

  1. While innovation is good, some things just are not broken, and don’t need fixing.

    Something isn’t a “standard” until multiple parties adopt it, and put it to use. Prior to this it is probably more aptly named a specification. Even if the specification is open for others to adopt, if it isn’t in wide spread use, it has the same net affect as being proprietary.

    I believe the multiple “standards” harm the industry, and in turn the consumer, and it may not have anything to do with lost or delayed sales (which is a valid concern). Think about all of the R&D that the crank and frame makers have to go through. Either they have to back 1 horse (and hope they pick the winner), or they need to extend their platforms to be compatible with multiple “standards”. This doesn’t come cheap.

    Then at the distribution & retail levels, one needs to carry adequate inventory to serve anticipated demand. It is hard to achieve economies of scale, and to maintain viability if one has to maintain many different SKUs (stockable units), particularly if they go obsolete quickly. Since the bike business has fairly rapid turnovers of technology and turn over in model years (or at least in terms of what is popular), this is a losing proposition.

  2. I suspect tying customers in to one brand is the aim. If you already own a bike with BB30 and Shimano gears then buying a training bike with an incompatible bracket and campagnolo/SRAM gears would be not be favourable unless there were considerable gains which nobody is saying there is.

  3. There are a few chapters in Varian and Shapiro’s “Information Rules” ( ) on “cooperation and compatibility” and “how to wage a standards war”. It’s geared towards a discussion of “information goods” like software, movies, and the like, but the discussion is applicable to things like this as well. One of the better books on economics and business that I’ve ever read – I’d highly recommend it.

  4. The epidemic you’re describing is trans-component. Headsets came first and it spread easily to their bottom brackets, their bearing brethren. Now, of course, you have all kinds of seatpost/seatmast insanity, Cinelli’s new 35mm handlebars, and of course the occasional new saddle rail configurations.

    It’s nice that you get a tightly integrated package at the prices people are paying for carbon wonderbikes. At the same time, you should expect quite a few years of service from the bike. I wouldn’t dare drop $10k on a Cervelo R5ca frame, knowing it could very well become a white elephant before it’s ready to retire, or that I have to shell out five times as much as someone would pay for a commodity item.

  5. Touriste-Routier: that was my point, that the changes are costly for all… but as you say the team won’t back down.

    Anonymous: true, it does tie people in but this also keeps people away.

    David Welton: I’ll look it up. It’s an interesting business case study, sort of why I looked at it.

    Champs: headsets seemed to have settled on some other standards, plus you end to take forks and headsets with you. With you on the seatposts and as you say, it’s probably scaring away a lot of customers for Cervélo frames and other manufacturers.

  6. Inner Ring:

    A) BB386EVO may have the benefit of compatibility, but at the cost of the lower Q-Factor, which was one “the” benefits of BB30. Plus, are you not also losing out on the weight factor, since now the spindle is 30mm and standard width.

    B) As much as I hate needless obsolescence just for the sake of driving consumers back into the show-room, I at least accepted the idea that in 5 years, we would all be on BB30 bikes, and it would be the end of the story. Now however, you are playing a guessing game as to whether in 5 years time your BB is going to be a cycling curiosity.

  7. Remember when it was British, Italian, French and Swiss (and probably a few more, like JIS) threading? Eventually that got boiled down to just two but now the pendulum is swinging back again. The makers run the risk of creating things that will soon be obsolete but they’re after those who want the “newest-latest” (in the electronic biz they call these the early-adopters I believe, those who’ll pay a premium to be the first to have whatever is new, whether it’s actually an improvement or not) Betamax was/is a superior system vs VHS, but lost in the marketing wars. The BB axle stiffness issue is laughable, as you point out, NOBODY ever lost a race because their BB axle somehow wasted their power. A component maker told me (very quietly) once that their test-riders would ALWAYS come back and tell them, “oh yes, this new X is way stiffer/better riding/more efficient/etc. than the old X”….unless they didn’t TELL them anything about that…then they noticed no difference. It was all in the power of suggestion and the marketers of all these BB designs know it full-well. It’s all short-term market-think, how many of these “flavor of the month” designer/marketers of Chinese-made frames will even be in business in a few years? So many of these carbon bikes look identical if you strip the paint and decals off and so many of them are made by the same few Chinese factories, marketing demands that the designer/marketers create some special “quality” of theirs vs the others in order to drive sales. They don’t really care what (if anything) you do with it after you’ve purchased it..but they work darn hard to make sure you know when it’s obsolete and time to get another one if you want to be up there in the “newest-latest” competition with your friends and neighbors! Sadly, much of the modern bike biz is driven solely by passion for profit vs passion for CYCLING.

  8. ColoradoGoat, there isn’t actually any meaningful improvement in Q-factor with most (perhaps all) BB30 cranks. The “improvement” being pushed with BB30 is improved heel clearance (which Cannondale and FSA are calling “W-factor” or something like that). Heel clearance!? When was heel clearance an issue? Like you, my understanding was that Q-factor was improved with BB30, and that was the major reason that I liked it. Having looked into it, it appears that this is not actually the case.

    Some kind of new crank standard is certainly welcome, but the deluge of new designs isn’t doing much good. Most of them are not intended to be “standards” at all, but proprietary designs to lock consumers into a brand. BB30 is the only one that’s being seriously pushed as a new universal standard, and the only one seeing significant adoption across multiple manufacturers.

    I’m leaving out GXP, Hollowtech and other technologies based on the old 68mm threading standard because there is considerably more interchangeability with these designs.

  9. @grolby:

    Actually – heel clearance is an issue for some, who like me, rub their heels along the spindle during pedal strokes. This is both a waste of energy (friction in the pedal stroke) and damages the crank (carbon may be stiffer than all other materials for certain forces, but it is not a good material durability wise when your show heel rubs against it. While it just marks up the crank now, it will eventually damage the crank to the point of needing a replacement.

    My problem with BB386EVO is that it is not a solid advance in BB shell design as BB30 is. Its only advantage to me is compatibility with existing cranks rather than providing a new design meant to truly improve BB shells.

  10. @Larry T:

    I think this is something that will become a much bigger issue over the next decade. Carbon bikes have become so solid at the base level, that except for some rare exceptions, the difference between a budget frame such as Pedal Force vs. a Trek or Bianchi is tough to justify the price differential.

    The outsourcing really took off in the last 15 years, and the secret is out…almost all frames are manufactured by Giant, Merida or Kinesis. It used to be you paid for a bike designed and built by the manufacturer, and there were tangible differences in quality between a De Rosa steel frame and a lesser lugged bike (Fuji). But by trying to compete with lower labor costs, the main manufacturers have made it even more difficult to differential themselves, and some smaller players (Ritte, Pedal Force etc..) have jumped in with competitive frames.

    So how will Specialized, Cervelo differentiate themselves? Why of course…make proprietary design/technologies that they can market to differentiate, regardless of the benefit to the consumer.

  11. On the tech side, I’m still not seeing great engineering gains. Just small tweaks that help… but as we’re saying in the comments, a range of proprietary systems. When you ride it’s hard to tell of BB30 beats 386. The same is true in the workshop. Perhaps the biggest leap is from Look and their Zed2 where the cranks are one piece, meaning no bolts on the arms or axles?

  12. The rash of BB redesigns is a cure in search of a problem. While some flex must exist in some frames for some riders, when is the last time someone you know broke one? When is the last time someone truthfully decided to get a new frame because they just lost too much energy through their flexy BB? I have never had issues with BB flex from any kind I’ve ever tried and it is certainly not something to seek out when buying a new bike…other than I want to make sure the technology I buy is not so obscure that it is outdated quickly or not available for spare parts.

  13. Thank God for the UCI! Their new frame compliance scheme – as an adjunct to the wildly successful wheel compliance scheme – will ensure consumers of high tech cyclery – you and me – are kept fully informed about and protectedfrom the nasty commercial vagaries of the mean old bike makers.
    I can’t wait till the UCI protects us with a clothing compliance scheme.

  14. Whilst not strictly “axle flex”, I do have a hazy memory of a Campag SR Ti BB “costing a race“.
    Sketchy research reveals this as a best guess:
    (1) Type I was a hollow version of NR; bearing races were pressed-on steel (like the Ti SR pedals). An unfortunate incident involving Laurent Fignon, the 1982 Giro, and a bad fall while he was in the lead owing to a broken Ti axle resulted in a redesign:

  15. Ken: I still think things can be improved from the normal 68mm BSA… but outboard bearings go a long way to helping.

    sillyoldbugger: don’t go there, bringing the UCI into the mix would be lethal.

    diamondjim: yes. Fignon had a bad incident just like that when a neo pro and it cost him a one day race too, I hadn’t heard about the Giro.

  16. As someone who’s needed to replace a headset and a fork (different occasions) before, the varying standards of taper, bearing diameter, et al would have been a mess. Cane Creek, the company whose crappy, standard 1 1/8″ headset I replaced, can only respond by selling separate upper and lower assemblies.

    It’s doubtful manufacturers are aiming for proprietary lockin. Plenty of these systems have adapters for more common standards, while others like PF30 put a cost (ergo consumer) friendly spin on something else. A few others are pushing the envelope because they legitimately believe they can improve a system, whether that’s Chris King’s InSet, or an enormous bottom bracket that swallows the bearings and for a higher stiffness-to-weight ratio.

  17. I remember Fignon’s broken BB spindle – it’s an example I use often when explaining titanium is NOT stronger than steel. This axle was pretty much a duplicate of a steel BB spindle made from a lighter, though inferior in strength material. I thought these special spindles were made for specific applications where the few grams saved justified the shorter lifespan and likely breakage. But just like a lot of SLS (stupid, lightweight shit) it failed. So yes, you could say someone’s race was lost — but not from his BB wasting his power due to flex or twist, which is the big claim of the oversize spindle proponents. The oversized spindles were certainly NOT the market’s answer to any rash of square-taper spindle failures. While they’ve certainly won the battle in the marketplace, I honestly can’t tell any difference when riding my bikes with old-fashioned, square-taper spindles vs the ones with oversized spindles and outboard bearings. And, as I wrote earlier, according to the component maker, neither could their test riders UNLESS they were made aware of the stiffness claims in advance. So much of this “performance” is in the rider’s head, not a lot different than the claims of Willy Voet on how much Richard Virenque thought his performance improved after Voet injected him with the special dope he’d long sought — despite the fact it was nothing more than salt water, according to Voet.

  18. Well Larry, through an odd set of circumstances, I’ve ridden the exact same bike with an old square taper aluminum crank (a late 80’s Shimano 105 crank, to be exact) and a SRAM Rival GXP crank, with oversized spindle and outboard bearings. The difference in stiffness is huge and extremely obvious; I doubt that any rider wouldn’t notice it. It turned out to be a much bigger difference than the stiffness of the frame itself (I had moved that 105 crank from an old steel bike to a stiff aluminum modern race frame). So it’s pretty clear that there’s a difference in stiffness.

    However. I’m not thinking much about how one bike feels stiffer or otherwise different from another when I’m riding my various bikes. I’m just riding. And I think that there’s good reason to be skeptical of claims that excess BB flex could cost a racer a win – in fact, there’s no evidence at all that any energy is lost to hysteresis due to frame flex. A frame is actually a very efficient spring, and it returns that energy to the road. Which doesn’t matter when racers and riders everywhere are convinced that more stiffness makes for a faster bike – the component and frame manufacturers are going to take advantage of beliefs like that, and they do.

    There is an important difference, though, between square-taper and outboard bearing cranks – they can be made lighter than the old square taper stuff, without compromising strength. In fact, they are probably stronger. That works for me. And stiff cranks feel good, irrespective of whether they are faster, so there’s that as well.

  19. Diamond Jim >
    the Laurent Fignon – BB axle disaster occurred in the 1982 Blois-Chaville race.
    it certainly cost him the race – Campagnolo later took out full page ad’s in L’Equipe explaining it was a damaged item – ie team mechanic error.

    In the late 90’s – Cees Beers of ADA Carbon was making BB axles for Rabobank team – which he then ‘fluted’ (side cut star profile) incredible engineering, and rigid.
    no exceptional weight penalty and the team used these for most races to the ignorance of their equipment supplier.
    Nowadays an immense amount of structural integrity of a carbon frame is created by the ever increasing dimensions between the BB – Down tube – Seat tube – Chainstays.

    The patent disuptes / and commercial advantages of these complex CAD designs will simply ensure the performance claims go upwards, as will the price…. meanwhile the BB will attain even more complex codes of description.

  20. Yes, I well remember my first ride with outboard bearings (XT on a mtb) I was amazed at the difference compared to in shell bearings and the smaller diameter taper or octaganal axle, got to have this on my road racing bike was my reaction. Once had a steel tapered axle snap on me during a race, on a steep climb (toe clips and straps days) leaving me dumped on the road pedal and crank still strapped to my foot.

  21. I am in a virgin year with a carbon Ritte…I love the bird bone bike.
    I truly feel like it wants to catch air.
    The BB30 has been sweet.
    With a 46 euro foot the chainstay clearance has been great.
    It would be great if the industry stays connected with standards.

  22. This is all made all the more interesting with Adam Haverstock of Praxis introducing the M35 BB standard for his own cranks – more info here:

    As you will read he claims his cranks are so stiff they make the BB the failure point, yet his M35 (the ’35’ meaning 35mm axle diameter) is compatible with both BB30 and PF30 options. I’m not claiming this will change anythng on it’s own, but if his cranks make the BB the weak point of that interface he must have some faith in BB/PF30 to make his setup compatible (to my mind at least).

    Interestingly, Baum were happiest (from an engineering and performance perspective) building my bike with PF30, but even then that nearly didn’t happen because nobody at SRAM could give Darren the information he needed when he was having trouble with a PF30 unit – if the companies themselves cannot understand their own ‘standards’ then who *is* supposed to be able to?!

  23. Interesting Rich, it’s as if strengthening one part shifts the “blame” onto other parts which then require redesign. Iterations later we’ll get there. My concern for the Praxis crank is that it’s still not universally compatible. No matter how good, shutting off large parts of the market don’t help.

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