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Finally good engineering stuff without marketing shit

I really enjoyed this video! I looked forward to it for a week and I learned a bit as well. Thanks for all your efforts! . Heres a little practical info (my opinions and experiences) Ive learned just playing around with bicycles, vehicles and machinery for a few years. Traditionally, bicycle hubs,headsets and bottom brackets were all cup and cone, loose ball type angular contact bearings. They have been proven, tried and true over many decades. The fact that Shimano, Campy and Chris King and just a few others still use angular contact tells you something. These are the only brands Ive seen and experienced consistently true high quality in, along with Phil Wood(cartridges). The FACT that mostly all other brands, even high end blingy stuff, uses cheap radial contact cartridge bearings tells us something else. Most radial contact bearings used in bicycle parts are in actuality designed for electric motors which spin at thousands of rpm. These are even specced with a lesser amount of grease for thermal expansion. Not exactly ideal for a bicycle application!! (Phil Wood specs his own fully greased bearings) I have to totally disagree with Hambini about the difficulty of servicing cup and cone bearings. I serviced them as a child!! I can service a cup and cone component in 20 minutes or less! They require simple inexpensive tools such as cone wrenches. Loose balls are available in any hardware store! Sure they’re messier. Getting adjustment perfect DOES require practice and PATIENCE! But you CAN make them perfect! They CAN be adjusted for preload AND WEAR!! Have we become this lazy, impatient and or mechanically inept? (Job security for me, HAHA) Are we so pressed for time, were willing to sacrifice perfection? Especially those who seek high performance, longevity and low friction!!!Our bicycles roll on bearings! If you want them to perform at their best, they require extra love and care. Radial cartridge bearings, on the other hand, CANNOT be adjusted for preload or wear. Good operation is solely dependent upon QUALITY manufacturing!! Once they are used they wear, (even the high quality ones) they get looser, you must tolerate wear until its bad enough to need replacement! That looseness, that we must tolerate, leads to faster wear and potential damage. Furthermore, a cartridge bearing depends solely on a EXTREMELY precise fitment into the hole in which its pressed and the components they mate with. . If that hole or components are not machined to a VERY EXACT TOLERANCE, even the very best cartridges available will wear out prematurely and or perform in less than an optimum manner. Cup and cone/ angular contact does not suffer these issues!! Press fitting bearings into their housings require tolerances in tenths of thousandths of an inch! As set forth in a machinery handbook, a common engineering and machinist’s reference. We see all the problems with press fit BB bearings!! What would make anyone believe quality is any less shoddy on all the other aspects of primarily Asian made bicycles? Ive messed around with bicycles, autos and machinery for 50 years. Im not an engineer. I cant and wont argue theory. Out of all due respect, Ive had so many young engineers and programmers tell me ‘In theory this should work!’ , LOL!! I have practical, DIRTY, hands on experience to offer. Ive been a machinist and mechanical inspector for many years. Ive machined and installed bearings in aircraft and spacecraft. I build wheels and wrench on bikes in my retirement. I own and love Shimano, Campy and Chris King bearing components. None of this stuff is new at all. I buy quality and MAINTAIN IT FOR LONG LIFE! Im a long distance randonneur and bike packer mostly. Im not concerned with highest performance or lowest rolling resistance.All of my stuff has been ridden hard, abused, on and offroad in all weathers. Ive raced endurance type events. My Chris King stuff is 16-35 years old. ALL on the original bearings they came with!! Some of my Shimano and Campy stuff is even older and still working great! Because its maintained like EVERYTHING ELSE needs to be! Remember,NOTHING lasts forever! My stuff has hundreds of thousands of miles on it! In comparison, someone gave me a set of White Industry track hubs. These require new bearings AT LEAST every other year!! I like them just because they’re shiny and built into beautiful wheels!! I wouldnt say the WI hubs are bad, but for what people pay, they should be much better!! Ive overhauled most ‘high end’ hubs on the market and most use cheap off the shelf Chinese radial contact bearings. They are simply there for the bottom line, not because they are a superior spec, plain and simple!

Race surfaces are always doomed to fail before the balls due purely to the overall surface area offered up for wear and tear. It must be noted that 'cup and cone' bearings, due to their serviceability, can be maintained to easily last 20-30 years which is a figure that 'cartridge' bearings can only dream of. A 'cone' will fail before a 'cup' due again to the surface area offered up for wear and tear. It must be noted that in this regard Shimano have always offered replacement cones for their hubs which, thus, further contributes to that 20-30 year lifespan.

BEST ENGINEER ON KZfaq !

“The headset bearings will never do 1 revolution in their entire life” Sam Pilgrim has entered the chat

Stoked to see you putting out so much great content recently Hambini. Looking forward to the new bike reveal.

I love my old Campy Record hubs with 9 ball bearings and a cone. I overhaul them a few times a year....still super smooth...bought new in 1988 on Mavic MA40 rims

You're the man, simply explained what's it all about.

Your technical terminology is very easy to understand. LOL Another great video

Great quick overview of bicycle bearings.

Learnt so much about bearings! brilliant detail and explanations, keep it up hambini👍

ඔබගේ පැහැදිලි කිරීමට ස්තුතියි.

This vlog was easy to understand, thanks!

Informative and entertaining as usual. Thank you.

Great info, thanks for the video. Not a cyclist, but still very widely applicable and well presented information. Cheers.

I love when you get two or more bearing books out. Looking forward to this one!

Another very helpful and informative video - thanks!

Thank You for an excellent explanation of ball bearings. You gave a great overview, but as you know it can get very complicated when the bearings are designed for a very specific use. In the last century, pre-2000, cartridge bearings in hubs and bottom bracket had contact seals and you could feel the drag and feel a wobble after extended use. High quality cup and cone bearings when properly adjusted felt lower in friction and with regular service gave great life. Campy used to sell replacement cups, cones and bearings(grade 25). You might want to explain bearing grades and how that affects bearing performance.

Best techo description of a bearing that I've heard. I've also used that same techo description. Good informative video that youtube suggested to me and because it was good and well presented I'll have a gander out your other videos and potentially/probably subscribe.

Technical term it's f#cked !! Hahaha

Thanks habini Nice video explaining the difference between the bearings👍🏻

Interesting, down to earth and educational. What's not to like? Thank you

Demystified that nicely. Thanks!

Good video for anyone looking to understand basics of deep groove ball besring vs up and one. Cyclists would love this. Tks.

Just gets better and better!

I thought this was really clear. (Very neutral for Hambini too!). I'm sure I am not the only person who runs destroyed cup/cone angular contact bearings with a little bit of excess play (bottom bracket especially) because I don't have a spare bottom bracket spindle. I wish I new better what causes the damage to the cones. It doesn't seem to matter what I do with bearing adjustment, the cones always show pitting first. One of the great things about radial bearings is that there is no preload setting to worry about. So for sure they will wear out, but at least you are unlikely to damage them during the initial installation.

I replace the bearings in my Race Face BSA BB with Enduro SS angular contact bearings. I put them in the Race Face cups. Right off they were smoother and after 4 months they are working smoothly. I did pop the crank out to see if there were signs of spinning in the cups as I just pressed them in, and there was non. So a $63 upgrade to a 2 year old BB. I'm happy.

Very good explanation of bearing makeup uses

Awesome, thank you for an excellent explanation. 👌🙏

Very nice. Thanks you for your knowledge

Hey Sachin! Huge fan from Seattle. Could you please discus lubrication at length? I'd love to know what kind of grease I ought to put in my bearings and how much. Thanks!

I have a large bearing like that from an old mining town. So much fun to play with. That plus my Chris King R45 with cutouts, I can play with myself all day long!

Great video thank you for sharing. Would you recommend ceramic bearings in a 1/8 buggy?the stock steel bearings keep going bad in my wheel hubs. They offer aluminum wheel hubs that might help the bearings from flexing around corners which would possibly help save bearings from wearing out. What are your thoughts? 1/8 scale arrma talion truggy 6s running on 4s most of time. Fast eddy bearings or jims bearings offer ceramic kits. I thought about searching each size separately to see cost. Thanks for your time

I know he's speaking English but this sounds like one of those classes I dropped illicitly in high school. lol Na, seriously - this is good stuff! Kudos to you sir and thanks for the valued information!

Thank you for the great video.

I think that cup and cone is easier to maintain and cheaper. Simpler tools to dismantle correctly. The only importent thing is to to tighten the cone just right. For this you need to secure the axle at one end to be able to gently adjust with cone spanners. It's not hard and once set up perfectly I think they perform better because there are less contacting surfaces compared to most cartridge designs and less friction. They clearly perform better in wheels that I have set up. I don't think cartridge bearings on wheels is a techical improvement at all and I think this is why Shimano and Campagnola didn't change to cartridges.

great explanation

Great presentation

Looking forward to this.

Hey Hambini, thanks for another masterclass. What do you think about Coombe pedals? I am currently using Speedplay Zero system, because of walkable cleats and better cornering clearance (riding fixed gear crits) and precise adjustability, tho even under my 59kg their bearings go shite quite fast. I also wonder if Speedplay bearings (I bet quality of those are not far from zipp's lol) can be replaced with something better.

In practice, my impression is that the guys using Shimano wheels or the more expensive Campagnolo (or Fulcrum) wheels with cup and cone bearings seem to have VERY little trouble with them. The modern ones are very easy to adjust with the wheel in place, and they seem to need very little maintenance. Campagnolo's cup and cone hubs have been the exact same design since the 1999 model Record hub that introduced the aluminium spindle and moved to 5/32" bearing balls, 15 per side, both front and rear. The hub shells are different wheel to wheel, for marketing purposes, but internally the only difference is that some wheels use ceramic balls, and some also ceramic bearing surfaces. These parts are all interchangeable. In 18 years of regular use, I never had any issues with these hubs. I never had to replace any parts. Meanwhile, my buddies seem to be busy getting new sets of cuntish shitbag bearings for their (insert brand here) wheels.

Hi there. Great work, keep it up! I have a question. Since I cant upgrade the bearings in the Shimano pressfit bb-s, is there any benefits of upgrading my cheapo bb BB-RS500-PB to SM-BB92-41B?

Thanks, again learned something.

Excellent explanation! I'm doing a conversion on a giant drill press that I have to turn it into a light milling machine. The bearings that are in there are deep groove (6204Z and 6201Z), but a drill press mostly has axial load. A mill, though, will mostly have radial. In that case, am I better off replacing these with angular contact bearings (especially if I might still want to drill with it)? Preferably single or double row?

Interesting as usual 👍

Looking forward to this: cartridge bearings seem to be the norm on modern higher-end bikes, but I still chose to build mine using both. Going to be a good Saturday. :)

Excellent explanation. For clarity of younger viewers it would have been useful to show a proper cup-and -cone wheel bearing (say). I don't think any manufacturer still use cup and cone bottom bracket bearings. I think the reason Campagnolo and Shimano still use cup and cone bearings is that they can be adjusted for wear and give minimum friction due to being cage-less. I'm guessing that to accurately machine and grind the cup and cone in bearing quality steel and then assemble and adjust them would be more labor intensive and more expensive than banging in a couple of preparatory ball races in. Some National Time Trail champions I was lucky enough to ride with as a Junior, (in the early 1960's) used to polish their wheel bearings every week. They also polished their chains usually on a Saturday afternoon while watching sport on the BBC's Grandstand. They assembled the bearings dry in order to get the adjustment with just a hint of shake, then lubricate them with 3-in-one light machine oil. And as a keen youngster I did the same. Riding out on a silent Sunday morning you could hear each unloaded ball drop into place. That is if you could hear them above the rasp of your tubulars at 130 psi pressure on the tarmac. Happy days. Only criticism is I don't like the superfluous swearing.

Great one! Perhaps a little extra fact about probably Sweden's largest industrial pride, SKF, could be worth noting: "Assar Gabrielsson, SKF sales manager and Björn Prytz, Managing Director of SKF were the founders of Volvo AB in 1926. In the beginning, the company functioned as a subsidiary automobile company within the SKF group. SKF funded the production run of the first thousand cars, built at Hisingen in Gothenburg, beginning in 1927. SKF used one of the company's trademarked names: AB Volvo, which derives from the Latin "I roll", with its obvious connotations of bearings in motion."

I actually enjoy doing my cup and cone hubs. My biggest question is what bearings to get Chrome Steel, Carbon Steel or Stainless Steel or Ceramic Ball Bearings Si3N4 Silicon Nitride vs ZrO2 Zirconium Oxide. I have plenty of Chrome Steel G25 but thinking there is a better option what is your view?

Good information, thank you. I have a concern with trying to convert a 6304 to a sealed tapered roller bearing. Is this possible? I can't seem to find the correct bearing online if it exists.

So factory set up with my 2017 Cannondale CAAD12 has a PF BB30, 4000 miles In the first year, and I’ve had it serviced twice for the dreaded CREAK, needs a third now. I don’t wash the bike, but do wipe it down, so the bearings are rarely subjected to water. Very hilly/mountainous area where we ride. I’m contemplating switching out to a Chris King BB that is angular contact. Reviews are good in terms of solving the creak. Will I notice the friction then in terms of watts? How much more likely then will service and/or replacement be needed? Stick with radial? Go Angular? Better Hambini BB solution?

My big question hasn‘t been answered by this presentation, that is: Is it better to use an angular contact bearing in a Bottom bracket than a radial one? Like Wheels manufacturing is promoting it? When i understood correctly, the AC bearing produces more friction - but can take axial loads better. So more friction is bad in the BB. But what about the axial load? How much axial load gets the BB, or in other words, what are the angles of load applied to the crank spindle and thus the bearings and what is their typical direction? Would have liked those questions to be answered. Strange to me that a „BB specialist“ like you are excluding especially this very important part?

Hi everybody, I have some experience to share with you. I hope in doing so maybe I can help the good and mechanically sound products not to disappear entirely from the market, which currently seems to be the trend. Actually I understand this is a hopeless endeavor but at least I’m doing what I can... Mr Hambini, in the end I have treat for you. :) I was working as a bike messenger in Stockholm Sweden for 7 years (but this was 10 years ago). This job really deals a lot of punishment to the bike, probably much more than most people would think. The first few years I trashed several bikes and especially a lot of wheels. Then I learned what works. This is my experience: Bear in mind, because of my professional history I might be overly focused on reliability, over characteristics needed for competition. However I want my bikes to be as fast as possible, just without sacrificing functionality. What works and is price competitive, is older Shimano LX, XT, XTR or similar quality race standard (105, Ultegra or DA). It has to be quality above Deore and it has to be steel or titanium axle 9/10mm. Unfortunately when Shimano introduced aluminium axles, they made the bearing balls smaller and thus decreased bearing life by more than 90% (I'm not exaggerating!). I could also detect fatigue damage on the aluminium axles, on steel or titanium axles I never saw that. Sadly, almost all of these good solid hubs seem to be discontinued. And for what, saving a few grams? What also works very well is Phil Wood hubs, if you can stand the weight and price. The Phil hub has very long lasting cartridge bearings that can be replaced and the hub itself will last FOREVER! They are absolutely bomb proof. I think in the aftermath of a nuclear war, mutant cockroaches will somehow move around on Phil Wood hubs… To summarize, my tip for long lasting hubs in demanding conditions, is above Shimano for gears and Phil Wood for high end SS/fixed. Beware though, to get good value out of older Shimano you have to have some knowledge about setup and maintenance, this is crucial. Factory build wheels might work for racing but not for messaging. I’ve tried a couple, and they both failed to scraps after only a couple of salty winter months. Carefully hand build wheels with 32 or 36 J bend spokes is the only wheels I trust. Finally for BB, square taper is the most long lasting and generally reliable BB standard. It is also very available and adaptable for chain line or clearance issues. Integrated systems might be stiffer and lighter but for hardwearing all weather workhorse bikes they are just no good. And I would never even try the press fit systems, for me they just scream trouble! So mr Hambini, if you actually red through all of my text. Maybe you with your great mechanical understanding and engineering skills could be inspired to make an in depth analysis on one or two square taper BB’s compared to modern integrated systems. To my knowledge the best cheap square taper BB option would be Shimano UN55 and the best high end option a Phil Wood BB. These BB’s are also very well known in this realm of the bike community. That would certainly be very interesting for the likes of me and I think a lot of touring people and hardcore commuters. Even if you did a three hour video on it I’d be sitting like glued to the computer sucking up knowledge. Maybe you’ll also see the light and then increase your business with some intelligently made square taper BB’s. :) Cheers everyone! /deswhip

I think this will be intresting for the review of how bearings designed for radial load vs axial load will "stack up" to each other. When and where is a good time to use each, and examples in the real world of larger environments and possibly smaller.

Hi Hambini in a roll down test same bike and rider and tyres etc how much faster are one type of bearings over another . Have you got a long hill handy and a stopwatch handy? I have seen tests for tyre pressure done this way to prove a point cheers .

If only a manufacturer would sell a bike that addressed all of the factors you discuss. Seems like most bikes do one element well and another terribly. Looking forward to seeing where you spent your money.

What do you think about the SKF MTRX bearings? Sounds like the same idea as oilite bushes, lubricant suspended in porous material. What about servicing? Throw away when bad?

Great ! That is what I was looking for... Thanks for the explanation ! But one question still remains: orientation to mount angular bearings. I think the right way to mount it is the same orientation like shimano's cup and cone, right ? But I won't risk to "break" the bearing when removing it ? I mean, to remove it, I'll have to push it from the center (in to out). This force won't risk to dismantle the bearing itself ? Thanks !

Quesetion about the cages. For old style cup and cones, I was always taught to replace cages with loose bearings for increased efficiency. What is the issue with contact? Do you recommend cages for nonsealed cup and cone bearings?

Thank you, I understood this much better..... So a cup and cone bearings for my headset and bottom bracket and a cartridge bearing for everything else? Only had to play it back once!

Not particularly bike related but in pairing up angular contact bearing in say a machine spindle application, these bearings are mounted in various ways, i.e back to back, or face to face or a mixed triple etc. You've explained clearly that an acb is best used to deal with axial load and it does so by transfering forces occurring down the length of a shaft and therefore the bearing's inner race, through preload balls, and into the bearing's outter race and housing.....phew! But I have a drilling machine (think expensive drill press) that was given to me in pieces. It has paired angular contact bearings for the bottom of it's spindle. Now of course in this application, considering that an operator would necessarily be applying a heavy axial load via a lever upon the spindle, axial load is the main focus. But, if you wish to drill a nice 'round' hole, then radial accuracy must run a close second. So my question is, how are these bearings best paired? As I see it, if they are paired back to back in order to counter axial loads both down and up the spindle, the preload shims would need to be placed at opposite ends the paired bearings. But to my mind, the most support is being offered over the shotest length of spindle with a back to back arrangement and I therefore question how this would benefit radial accuracy? On the other hand, mounting the bearings face to face with preload shims between would 'seem', (once again to my mind) to offer a little more radial support by increasing the distance between the outter races? Then of course I could be over thinking because I just don't actually 'know', and perhaps the best option in this application is to ignore axial force up the spindle because load is low withdrawing a drill out of material, and don't worry about radial load....just because, and pair the bearings from the bottom of the spindle, face to back, with preload shims placed between and on top of the upper most bearing, thus both bearings then addressing axial force applied down the spindle only??? Have I even got the concept right? Forgive the pun, but as you can see, the pairing of acb's has me spinning in circles 😮

There was a lack of perspective here on the hertzian stress involved. You said the angular have less stress, but does it matter? Bicycle bottom brackets don't see very much load I don't think compared to their rating, so the stress would be relatively low. Radial bearings become angular bearings when preloaded, so the matter to be decided is if it is worth it to endure the lower sealing ability and higher drag vs the lower stress and possibly longer race life, but I'd like to see the numbers. It seems to me that bearings fail in this application because of contamination and/or corrosion so sealing would be a priority.

I know this is an older video, but if i got this right. IF I buy a pair of 7808 bearings and i want to but them in my bottom bracket, are they directional? i mean due to the construction of the bearings there is basically a right and a left one?

Speaking of Shimano sticking with "old" style bearings. What do you think about some bike companies using threaded bbs instead of press fit? As always great vid

Do you actually make BSA bottom brackets? I have read some teams at TDF (i think bora) went back to BSA bottom brackets.

Is there available an angular contact bearing from a reputable manufacturer that would fit in a standard 30mm ID bottom bracket (30x42x7)? I've searched near and far and all I've come up with is the 7806C from NTN but it isn't sealed, and the Enduro offering.

I used to have shimano cup and cone and they always spun smoothly and lasted a long time. I adjusted often to keep play at bay. As mentioned often the preload is terrible on cup and cone.

I have a guy that rides his mountain bike hard and frequently wears out his rear hubs. I would assume the fact he launches his bike a lot creates bearing issues, but would moving him to an angular contact bearing help with premature failure due to the heavy axial loads being put on a mtn rear hub? Otherwise, is it a 6 of one type situation?

What are your thoughts on the new SKF MTRX bearings? I am mostly interested in bearings that last in wet and muddy conditions.

Nice video. I know a decent amount about bearings ....... and I learned something here. sub'd

I know this is an older video. But for bmx racing would you recommend a bearing with fewer but bigger balls or more smalller balls?

Great presentation very easy to understand and great analogy's! In the future could you give us your thoughts on lubricants for chains specifically waxing vs. synthetic lubes! Again thank you for your time and explaining things to us!

@hambini what do you think to SKF MTRX solid oil bearings?

hi hambini! great show! what's your take on placing bearing (not just bike cartridges, but any industrial bearing) by hitting it with a metal hammer?

I've always been surprised no one uses a tapered cartridge bearing in a BB. Decades ago, Bullseye had a combination BB that used a needle bearing. There have been tapered needle bearing headsets. Angular contact can potentially be loaded up with more ball bearings, depending on if the radial bearing has a notch for loading. Can you talk about how bearings are assembled, why there is a limit on number of balls, and if notches are used? Cup and cone bearings, *good ones* like old campy bearings can use *much larger* balls and races than cartridge. If cup and cone bearings are made to the same standards and hardness of cartridge bearings, they are every bit as good. The cage also keeps the balls from accumulating all on one side so the *bearing actually comes apart!*

Thanks for another well thought out and presented tutorial. Can you persuade Shimano to sell full service kits for the axial bearings? I don't understood the point of just replacing the cone, balls and axle (which is what they seem to sell) as the cup always looks as worn as the cone.

excellent - thank you

It's too good info video 🙏

Nicely explained Hambini. Could you discuss the aircaft spec "stepped bearings" which Whyte mtb bikes use on their suspension frames with the spacer washers in the assembley housing. loving the the techinal nomencalture of what a F#cked bearing is.

Another Saturday night of science! Nerds unite!

Hambini, would you say that bigger balled bearings (angular, cup&cone) have greater longevity than smaller balled bearings? Or is that too broad a statement? Anyway, thank you for quality content, I found it easy to follow and understand!

3:25 the exception is that most of the cheap bikes comes with the cup and cone stuff. At the lower end, which is the mass of the bikes are cup&cone.

How can you tell which side is the "face" and which side is the "back" ? - it seems i get a different answer from everyone i ask- is the back the side with the wide inner race lip? Or the wide outer race lip?

On 12:26, where you resolving force to axial+radial. Did you mean the force from the spokes, or force, that wheel under different conditions (turning, etc) may produce? Because resting wheel will not put any force on bearings, except the weight of the wheel. For vertically resting wheel this will be only radial force.

@Hambini, I've asked this before, this time I promise I'll remember. What kind of pencil do you use here?

Thanks Hambini, this was great! Over the years I've serviced lots of kids bikes and found that often the wheel cup and cone bearings are poorly set up from new, almost always over tightened. I've often wondered if the bearings are somewhat ruined almost immediately. A clean, re-grease and correct adjustment improves them significantly but I do wonder if the components were actually manufactured well, or whether it is just poor assembly of reasonably good parts.

Would love to see you do a video on Disc vs Rim brakes, from an aero perspective.

What wheels use the best bearings from the factory?

Is it true that radial cartridge bearings will also have the tiniest bit of play because the balls need a bit of float in the groove? I have Paul hubs with the enduro 61902 bearings in them and they had tiny play from the start (on the bike) and was told that’s the reason.

Is the lack of Roller bearings in bikes also a cost issue or is it more the difficulty of adjusting the correct amount of preload? I'm mainly thing about headsets.

Do you think oil filled polymer bearings like SKF MTRX will extend the life of the bearing when used in environments where risk of contamination is high? I'm thinking mountain biking in wet and muddy conditions.

Besides the ball bearing tolerance of the better bearings, NTN, etc are the cages, races, etc better than a common Enduro bearing?

Waiting !!!!!

At 12:16 you have two blue arrows showing force being applied to the upper part of the vbearings. Shouldn' these arrows be pointing at the lower part of the bearings? When weight (of the bike and rider) is applied from above, it's the lower part of the circle of the bearing that hold the weight up.

What do you think of the Zipp 454 wheels? Maybe a good video topic analyzing the wheels.

Would AC or DG be better for bicycle pivots on a full suspension bike?

In my orifice we have a never ending debate about preload for dg bb... SKF guidelines are somewhat arbitrary on the subject and empirical. In bike hubs we often see dg bb just locked on the inner races by tube spacers/shoulders with no preload. I guess this is to satisfy the people that say 'they spin up well' and are baffled by a spinning wheel with no load. I prefer hubs with angular contact or dg bb with some preload function. What's your view? The last set of tune hubs i bought, come with a selection of 100 micron shims to set preload. Nice touch.

Do you think there is an argument for using angular contact bearings on mountain bike wheels given the greater axial loads?

Is it worth to by grade 10 ball bearings for higher end wheels like shimano 105 , ultegra or even for the lower end ? Or stick with weldtite which is grade 1000 clearly rubbish. If the answer is yes where should I buy them ? Stainless or high carbon steel ?