TKJava

Recently I was fairly laid up with knee surgery so I had the opportunity to watch too many YouTube videos and found this guy Hambini who makes custom BB's. He has many videos that show how poorly bikes are made and to such sloppy tolerances. I have a Canyon that I purchased mid-summer of 2019 that I absolutely love. Hambini does a video of how poorly Canyon frames are made and he's also trashing Orbea, Cervelo, Specialized and Cannondale. Does anyone find this information to be of value? Would a bike that met such strict tolerances be so expensive that we could not buy it? How does one know (really know) if their frames have voids in them or have oval bottom bracket holes etc. Are there frames that have been made to higher standards and how would you know? You can't go to a Trek website and under "specs" find something like bottom bracket hole round to within 0.000001mm and are parallel to within 0.0001 mm etc. etc. The same would go for all parts on your bike? Are we wasting our money or in order to afford a bike that costs $4K we need to put up with 1 out of 10 bikes being a total lemon? If you walk into a LBS today and look at Cannondales or Cervelo's I guarantee the salesperson is going to tell you that the frame is the best, why because every other bike manufacturer puts the same components on it e.g. Shimano Ultegra/Durace or SRAM Red etc. the only differentiation is the frame

HillRider

Given sufficiently precise measuring tools I suppose you can determine out-of-round and out-of-parallel dimensions that you can claim are excessive. Hambini has the financial incentive (he sells custom bottom brackets) to make that claim. However expensive, or even fairly low priced, bicycles frequently failing does not seem to be a major problem and most owners never have a problem despite these claimed poor tolerances. He seems to have a solution in search of a real problem.

​​​​​​If you expect NASA level tolerances I guess you have to expect to pay NASA level prices.

DaveSSS 

With bicycle frames made by the thousands, there's bound to be some that have BBs that are not made accurately enough to perform adequately and there are some BB standards that are poorly conceived, with many early bearing failures being the result, like BB30. Finding those few frames made with bearing bores badly out of alignment does not say anything about the percentage of frames that may exhibit this problem, only that some exist.

Videos can be found showing frames with the bearing bores that are greatly oversized, but those bikes were ridden for a long time with the problem ignored.

Bonzo Banana

When you look at what he recommends it's pretty much actual manufacturers, Look, Time, Giant etc and the bikes he criticises are pretty much full importers or brands who basically have assembly plants and don't manufacture any parts. I've been saying Quest Composites are a mediocre manufacturer of CF for some time and so its no surprise in his recent video he shows how rubbish Canyon CF frames are made by Quest Composites. However I think Canyon may still be using Giant as their OEM supplier for aluminium frames. At the end of the day if you are buying a brand who doesn't manufacture themselves and are reliant on other factories and keep changing those factories to get the best price quality will vary. I'm happy to buy cheaper bikes from importers but if I'm paying serious money for a bike I would go for an actual manufacturer. What difference does it make to me if a company spends huge amounts on marketing and sponsoring sporting events I just want the best value product for my cash. When you look at the component brands he recommends many of those are actual manufacturers and those he disses are those that pretty much get their products made for them. Fully controlling the quality process inhouse with your own factory seems to be the main reason they offer better quality. Of course for the end consumer it takes a little bit of research to find out which brands are actual manufacturers and which are really just importers.Companies like Shimano manufacture many of their parts but at entry level prices often use low end factories, Tourney etc. Hambini puts Shimano in the middle. SRAM who manufacture far less of their own parts and rely on other factories far more he rates far lower in fact it seems the engineering quality of SRAM is as poor as he suggest with many engineering faults either caused by SRAM themselves or the factory contracted to do the manufacturing.

I'm not keen on Hambini's language but I genuinely believe the criticisms are completely honest and fair and he is not alone in his criticisms of many brands. I remember reading on a forum a Canyon CF bike that pretty broke on the first ride and was clearly very poorly manufactured. I don't believe Canyon scans every frame in fact I believe they are a completely dishonest company who manipulates their customers and never lets the truth get in the way of a sale. There are some German companies based on great engineering and others that piggyback on that reputation who don't merit it and Canyon would be a good example of that.

cyccommute 

How close is “close enough”. Does a bottom bracket need to be within ±1 nanometer? Consider that there are a billion nanometers in a meter. I question anyone’s ability to measure something within ±1 nanometer. I question someone’s ability to measure something within the 0.01 micrometer. The first is 3x1^-9 inchs for the metrically challenged.

That’s not even NASA level tolerances. To put it in a way that people might understand, a human hair is 75,000 nanometers in diameter. The relationship between that hair and a nanometer is similar to the relationship between a mile and an inch. There are 63,360 inches in a mile. Now, imagine that you have a yard stick and try to measure ±1” in that mile.

TakingMyTime

I gave up worrying about ball bearing tolerances a long time ago. Get the right size for the job and install. There are a million other things to worry about on a bike before I start worrying that my bearing are the "best" money can buy.

AnkleWork

That's jive. I hope you get more ride time (and less video time) soon.

tyrion

How many watts can you afford to waste? (Rhetorical question since Hambini's target market is watt-weanies.)

cyccommute 

I haven’t gone and read what Hambini has to say but what effect does the roundness of the bottom bracket (to a ridiculous standard) have on power output?

DOS

Probably nothing but he also is very critical of bicycle specific cartridge ebearings and advocates use of high end industrial bearings (nki skf) having found (according to him) that many bearings sold specifically for bike applications are watt sucking crap.

cyccommute 

I guess that’s to be expected from someone who gets wigged out about a nanometer.

AnkleWork

This is the way that con artists (big media, politicians) work. They pretend to have special knowledge of something you don't know about so they can create a false narrative, then tell you to do something you would not otherwise do.

Clue: nothing can be perfectly round. If you look closely enough you will always find eccentricity.

DaveSSS 

Hambini videos typically show frames with the two bearing bores misaligned enough for the cranks not to spin properly or maybe the bores so far off that the bearings are either loose or the bores so small that the bearing or cups can't be pressed into place. There is no implication that standard measuring equipment isn't adequate for the task. Any time you require a press fit, the tolerances have to be close. The old fashioned threaded BB is starting to look better all the time.

Several brands of aftermarket parts now have BBs that are intended to rescue frames with press fit problems. I bought my first frame with a BB86 bottom bracket, in July of 2018. It's worked OK so far. Hambini considers the BB86 to be a decent standard.

guy153

I think he has a point. If you're paying thousands for a frame that costs (according to Hambini) about $80 to make there should never be any issues with the accuracy of the BB and the HT. I think all it would take is for them to make them with the holes a bit undersized and then machine them to the final dimensions at an extra cost per frame of only a few tens of $.

tyrion

There are various kinds of BB misalignments and Hambini talks about their various friction costs. I'm not an engineer so I don't know how credible he is, but to me he sounds like he knows what he's talking about. I get the impression that he's getting these friction costs from some standardized engineering tables or formulas.

rccardr 

Bicycles do not require extreme tolerance precision in order to work just fine. The potential wattage loss in most cases is so minimal that even an expert rider would not be able to tell the difference, or see it in overall performance.

If your cranks spins easily, your chain is properly adjusted and lubricated, and your wheels spin effortlessly, you're good to go.

I've worked with high precision tolerances with other sports in racing situations where such exactitude is critical to winning or losing; bikes don't even come close unless perhaps at the professional racing/TT level.

As a side note, my Canyon Endurace CF is the only 'modern' bike in the collection, and right out of the box it's as fast (or faster) than any of the vintage bikes that get doted over. So, there's that.

alcjphil

OK, I am watching this thread and I can see that some people who have had experiences with some brands are feeling defensive because they have had a good experience with a particular frame. I understand. They may not have had a bad experience with the same product. Hambini deals with worse case scenarios. If one particular frameset is particularly bad, he will call them out. Press fit bottom brackets have to be very precise in order to work well. IT isn't just about whether the opening is circular, it is about whether one side of the frame bottom bracket lines up properly with the other side. This guy may step on some toes, but he is not afraid to say exactly what he means. I think that it is very telling that the companies that he flags as staying within the best specifications are the ones that have their own manufacturing facilities.

asgelle

You should read up on metrology. To paraphrase Robert Chung, just because you aren't able or can't imagine how to make a measurement, doesn't mean that others with skill can't.

Oh, and while NASA tolerances are quite sufficient for their application, they're hardly the strictest in use.

tyrion

The problem he's addressing is friction. Some people will pay hundreds of dollars to save a couple watts of friction.

Mad Honk 

So he is giving is opinion about a lot of parts and tolerances. I am familiar with the tolerances for 7000 rpm internal combustion racing engines. They are always within .005" or less. Now about nano-meters in measurements, most racing guys don't care about that. The ultimate performance is the answer. But if you could get to the nano-meter place it could make the parts run smoother, but it is more theoretical than practical. Smiles, MH

DOS

He is also not wrong that there are a lot of crappy bearings being sold as “bicycle bearings”. Which isn’t to say that one needs bearings that meet high speed industrial tolerances.

Racing Dan

Now THAT is a great question. Assuming a 1.1W additional bb loss, you can equate that to adding one pound to the bike, if you are doing 3000 ft an hour. So much for you UL, uber expensive race frame.

If the poor tolerances presented by hambini is true, its all a frigging joke, on behalf of the customer. And Im betting it is true. Theres a reason for binding and creaking BBs, and slipping seat posts ect. Its garbage manufacturing combined with the quest for ever lighter parts (because marketing). Plain and simple.

woodcraft

I like his videos on aerodynamic drag.

Just replaced a BB30 bearing with one that cost $.66, so I guess I'm not caring that much about super-precision bottom brackets.

cyccommute 

But it also doesn’t mean that you have to have unnecessary precision. Good enough is usually, well, good enough. There’s no need for ±1 nm tolerance in bicycling. There’s probably little need for ±1 no tolerance in any machine. It is probably even detrimental since there forces get weird at that small a distance.

asgelle

Nice dodge but completely irrelevant to you original claim, sorry “question,” that it can’t be measured.