Bottom Bracket Design and Friction Tests

[@mikehall6608]

As a mechanical engineer with more brains than money (hopefully that's the case, if not then god help me), this is the kind of content I tune-in for 🤓

[@robertmcfadyen9156]

Shimano BB93 threaded is my recommendation .

[@reginaldscot165]

I remember making a very similar video to this some time ago. I remember pointing to my titanium BB shell and saying “I don’t need Hambini BB (overpriced boutique bottom bracket) because their is nothing wrong with my BB shell.” And “a fancy BB won’t fix a bad frame.” I was criticised for my logical argument and told by some that I can’t have an opinion this subject as I’m not an engineer. Nice to have a real engineer back up my argument almost word for word. 😂👍🏻

[@edrn1842]

All 3 of my bikes have Shimano BBs. 2 of them threaded, 1 pressfit. The pressfit one is still the original stock one from 2016 and going strong at 44,000km. And this is through South East Asian weather and humidity too. I've ridden the bike through proper monsoons and have had to replace my headset & wheel bearings on more than 1 occasion, but the BB remains smooth as silk. In fact, I think the cranks may have spun smoother with time! Long live Shimano BBs!!

[@jaro6985]

Yes as the seals wear in the friction will reduce. I agree Shimano are great for the price with a good seal design. Though we usually get around 8,000km here in PNW before they rust out, constantly riding in the rain.

[@beckers2287]

Finally somebody is talking sense about the fantastic Shimano press fit BBs.

[@TraceVelo]

Dude, great video. I've always been a massive fan of threaded bbs like BSA and T47, but after this I might be a pressfit convert 😅. Also the design of those bearing seals on the Shimano press fit bbs, mental...

[@denis_roy_7]

Merci!

[@lukasseitz8294]

In regards to the GD&T, it is quite common to use position tolerance only, since it combines concentricity and perpendicularity/parallelity into a single, common tolerance zone.

[@PeakTorque]

Correct!

[@pauldamian2988]

I might also use A-B combined datums (where one bore is A and the other is B) so you can hold a true position tolerance on EACH. Pretty typical in engineering drawings for shafts and housings. I only wandered down in the comments to make the same statement Luka made... CHEERS! As always great stuff Peaks!

[@basengelblik5199]

Fabulous video. Was considering T47 for a custom Titanium frame, but decided on pressfit now and I am modelling my own labyrinth seal cup for it. Thanks man.

[@johnkasza2315]

Finally, a voice of reason! The money that has gone to ceramic speed, promoted by"cycling youtube channels" as an upgrade is so stupid....Dura ace is built for professional bike racing in the rain...seals with grease that will last years with almost zero maintenance..i can buy 8 duraace bb for 1 little beaver boy BB....

[@robertmcfadyen9156]

The friction level is slightly higher than that of Ceramic Speed or some HSC ceramic bearings . It is all about trade - offs .

[@lilfinesse]

@@robertmcfadyen9156 how do you know?

[@robertmcfadyen9156]

​@@lilfinesse An automotive engineer I know had done some accelerometer testing in his laboratory .

[@tettychristina962]

'03 Lemond Ti frame, threaded BB(Ultegra) lasted 21yrs...

[@robertmcfadyen9156]

I can relate to this .

[@OldDavo1950]

My 1983 Steel Bob Jackson with a Stronglite BB spins and spins. Agree it all about how the BB is made.

[@lenolenoleno]

Such a good vid. Love the deep dive into the brilliance of the less sexy bike parts.

[@trykpaa]

Absolutely agree. Worst thing about threaded solutions is that no 2 BB apparently use the same damn tool - I literally have a box full. For PF I have 1 tool. I have had issues related to frames and poor factory install, but generally prefer PF. My 2018 Trek is still on its factory Shimano BB after >20000km.

[@jaro6985]

PF installation and removal tools are more expensive. There are also multiple PF standards, so saying you just need one tool is disingenuous. You'd only need one BB installation tool if you used one model of threaded BB as well.

[@BestKiteboardingOfficial]

Praxis bb in a Chinese frame from planet x, 8 years young, popped seals, flushed and regreased twice. About 50,000 miles on it

[@rickrichardson1141]

That Framework from what I can see is fire

[@CatManDoSocial]

Great stuff, Alex. Thanks. Yes, please more of this.

[@abhimawa1]

Thank you PT for the explanation. Well put out. 👍 👍.

[@nayeemrahman8219]

Regarding your giant's BB, I understand what you really meant. I have a giant fathom from 2017. It still runs well with the stock Shimano PF 92 BB. In my case, my frame is Aluminum and I had to clean & regreased that BB twice without removing it from the frame. It was due to water ingestion (first after 5 years on factory grease) from rainy day riding. The tolerance of giant's frame both alloy and carbon seems fine to me. I also had that weird feeling when looking at those tiny bearing balls. the awkward part is when I check to see the bearing play, after 7 yrs it develops significant play also a jittery feel to it suggesting a quick change. but after installation and properly preloading the bearings it all went away. Even there is no sign of bearing being over tightened. May be i am loosing one or two watts because of it but since it's a Mtb I am astonished to see the sturdiness of shimano BB. Even the Bike has gone through some moderate crashes in this 7 years.

[@clp91009]

I agree 100%. The Shimano PF BB86 plastic bottom brackets are excellent. On one of my bikes I swapped in a metal bb with ceramic bearings. Guess what, I just put a Shimano bb back in after experiencing various issues. And at such a reasonable price I just throw a new one in every year as part of maintenance.

[@dakalla]

I have a relatively cheap "first components" t47 bottom bracket with fully sealed bearings that spins better than any ceramic speed video i saw till now. If i "let it fall" from the top it will swing around 20 times back and forth due to the weight unbalance of the left and right crank arms. It is all about perfect alignment. "Standert Erdgeschoss" stainless steel frame with T47 BB. However on my bmc teammachine slr01 with pf86 dura ace BB, it will max spin 3 times around when i give it a good push.

[@paulgrimshaw8334]

Good video, more for the level of thinking that goes into the analysis. Far too many online reviews equate price and quality, rather than looking at the finer points of design and engineering tradeoffs.

[@PeakTorque]

@@paulgrimshaw8334 thank you

[@CharlieCarbsandCycling]

sponsored by Lidl. Lad's made it!

[@asmaco1]

I'm quite happy for Lidl's headquarters being very near to me. They finance a lot of educational projects and also research institutions, which the state could never equip so well. And now they extend into cycle sports as a team sponsor and also as main sponsor for the "Deutschland Tour". Of course, thank you for this very informative video, bringing the discussion down to facts.

[@PeakTorque]

I wish! Lidl bakery section got me like a fat kid at Christmas

[@zygmuntthecacaokakistocrat6589]

Is that Hambini banging on your window and saying rude words?

[@RichChh]

😂

[@ebikescrapper3925]

Hambini will draw rude pictures on his windows with his crayons.

[@Elbrunosh]

😂😂😂😂😂

[@cup_and_cone]

He couldn't make it, his bearings went out halfway there.

[@PeakTorque]

What this test shows is that metal/one piece designs absolutely do provide a stiffer system and low drag in extreme cases. But how much the BB shell (frame deflects) can only be tested in a frame

[@crack0n]

When I installed a bsa68 Shimano BB back in 2016 I thought that I might try a ceramic BB when the Shimano is worn out...Now its 2024 with 50k km later its still running fine 😂.

[@adamchambers7502]

That bottom bracket test , they shouldn't be using a grub screw to fix it aswell as that will induce a bend in the nylon.

[@robinrai4973]

I like the plastic Shimano bbs simply because they’re not very daunting to install or remove compared to some other press fits, that was the main reason why I preferred threaded bbs until I got a bike that used pf

[@mcveyj]

Love this. Long live PF86.

[@stijndeklerk]

I'd agree the Bikone test was specifically designed to simulate deflection of the alignment in the BB cups. Otherwise there is no purpose for the 10kg weight in the centre & the design choice to clamp only one end.. Regarding your comment about ease of pressfit replacement. That's not my experience. I'm choosing to use a screw together "pressfit" BB in the hope not to write off a frame when the time comes to replace the BB. I have a bike with a Bikone BB & its not coming out. If you try their BB do it on a surplus frame..

[@PeakTorque]

Interesting. Have you got a proper threaded extractor? Not a hammer and park tool prong

[@stijndeklerk]

@@PeakTorque Interesting. I didn't know threaded tools existed. I've just ordered the one "Rides of Japan" uses in his video from 5-7-2020. That looks much more civilized. Thx for the suggestion!

[@michaelmechex]

Thank you. I've also been banging my head against a wall telling people that a well machined press fit is the obvious best choice and actually, threaded bb is the one that is flawed by design. I always get arguments from people who think they know better. Often their argument is 'well bike brands tried press fit and went back' and they're right. I wonder what those brands were thinking, I bet it's either 'this lot is too ignorant to educate, just give them what they want' or 'fixing this mistake would include admitting that we have pinched a few pennies on frames that cost thousands and it significantly decreased their quality, let's not do that' 😂

[@adamchambers7502]

it probably matters more for road cyclists, but i am almost exclusivley a mountain biker these days so to me, i dont need perfectly aligned bb cups that press fit allows because they are going to move and warp every time i huck to flat or jump (105kgs weight 6 ft 25 blob of a person) threaded works best for a lot of people i assume like me, because i can chuck a load of grease on the threads and get the cup out easily in a years time in 5 mins to thro another 20 odd quid hollowtech bb in. I very much doubt i would notice the extra pinch casued by misalignment. ive 2 kids and time to ride about once a week if even . 5 years ago ai was riding 5 days a week and in the top physical fitness of my life...maybe then id appreciate some free'er moving cranks on long arduous 6k ft elevation rides. but when youre cranking out climbs on mtb rough terrain, there are far bigger efficiency gains to be had elsewhere in technique id say vs the bb

[@xzcion]

Similar boat. Threaded works well enough for who it's for, i.e. me. (Can't deny press fit would be the better solution when done well.)

[@Hysterically-Inaccurate]

@@michaelmechex I get your point @adamchambers7502 and for the most part I agree but the benefits are not limited to just spinning friction. Threaded bearings sit outboard of the bb shell whereas PF sits inside. Cranks are a set width so for a PF BB shell you'd have a wider shell, which when coupled with your MTB 1x drivetrain means you can space the chainstays out more and run a wider tyre. Also you don't have the threads taking up the ID of the BB shell on a PF which would leave room for a bigger OD axle (albeit with different bearings) of just a bigger bearing so if you're a big guy, hucking to flat, that's a benefit too. Like you say though, you prefer the tooling for threaded so there's lots of benefits to both systems.

[@bamicus9342]

Thank you for saving us all money, and all you do to expose the crap bike biz. Got a new Time frame and DA BB. Last frame was a TCR SL and the Ultegra BB lasted about a year though. LBS put in a wheels manufacturing, and it works well so far but 4 times the cost.

[@Hysterically-Inaccurate]

Nice video, bb86 or whatever it's called (Shimano press fit) is my fav too. The other benefit is you can have a wider BB shell which is a good for your bearings and b good for tyre clearance. Can't get my head around why anyone prefers threaded!😂

[@zdravo4]

Big like for T shirt 👍😍

[@swites]

Yep my shimano press fit BB86 has done 29.5k on my bike I bought in 2017 and still spins like new.

[@billyshakespeare17]

2013 Cannondale Lefty, BB30. 2 bearings in the shell, nothing else. Have changed the bearings twice. SRAM OEM bearings are around 25 USD. Thanks to a shell within tolerances.

[@adriansmith5446]

Got that Dura-ace bb, fitted to a Cube Attain GTC, in 2016. Earlier this year, I replaced the chainset, anticipating a neccesary bb replacement. A tiny bit of 'graunch' on the nds bearing, and I mean tiny. The ds bearing was smooth as silk. This bike is used year round, through Scottish Winters, and encounters the kind of conditions that resulted in the rear hub bearings seizing. Quite remarkable. When, eventually, the bb needs replaced(after another 8 years 😂), it'll be the same again please. Oh, and it's run completely silently, as it still does, with zero play, since day 1.

[@MAGAmaniac1000]

Every time I see a bike build and they install the crank and have to whack it in with a mallet it kills me! Then they don’t gap the crank sufficiently and do a spin. The crank rotates 3 x 4 revolutions with ceramic BB I just cry😂

[@alansheard553]

Im no mechanical engineer but i do understand structures, on that test they are effectively creating a beam supported on its end, a load applied to the other end will make it deflect. As you point out the insertion of the different material bb's will alter its stiffness. This will result in differential deflection between them all and subsequently the alignment of the BB, the exact problem that bike manufacturers should be tryi g to eliminate. In a bike the BB is supported at both ends aswell.

[@borano2031]

True. I couldn´t believe it when I first saw the splines of the T-47. Rgr

[@TypeVertigo]

I can attest to the longevity of the Dura-Ace SM-BB91-41 bottom bracket. The bottom bracket itself was fine after eight or more years of riding in Southeast Asia. Any minimal creaking I was getting was more because of dirty water getting onto the crank spindle, and as such, easily cleaned and dealt with. Bike in question is a 2014 Giant TCX in 6011A aluminum, with a very slightly undersized BB86 shell.

[@hockysa]

this is an awesome video. would love to hear thoughts on BSA bottom brackets especially SRAM vs Shimano bearing sizes

[@PeakTorque]

The shimano BSA has almost identical sealing layout as the pf86 version consequently lasts a very long time

[@hockysa]

@@PeakTorque well that's sorted buying a shimano BB right now.

[@christiancooper2342]

The Shimano pressfit BB86 BBs are the unsung heroes of the current bike industry in these days of high price mediocre quality boutique parts. Cheap, light and available everywhere. I've had 2 Canyon Ultimates since 2014 and am on my 3rd BB. First BB didn't fail as the frame was wrote off in a crash after a couple of years. The 2nd BB in the new frame lasted from 2017 til last year - 1 side stated to feel slightly rough so I replaced it. Cheap, easy to replace and will be good for the next 4 or 5 years.

[@Rose.Of.Hizaki]

As someone who also has a bike from 2016 and still using the same shimano BB despite putting absolute thousands of miles through it. I can breath a squeaky sigh of relief.

[@Hard_Work_Is_Rewarding]

Engeneering question: how short of a stem is too short? (No spacers at the top and please don't tell me that the steering tube needs to extend past the stem clamp) Let's say I have a standard 40mm high two bolt stem, the center of the top bolt is around 10-11mm from the top, and around 6mm to the top part of the top bolt. The general recommendation to fit the top cap will be 2-3mm gap between the top edge of the stem and the top of the steerer (more exact, top of the expander plug as its top is often has some thickness). But what if you made a mistake and cut it at say 4, 5, 6 mm below? When is the border line where you need to throw away the fork or to fit an expander plug with a thick top?

[@eva-kr8pf]

I’ve kind of run on the notion that outside of a track bike or a tt bike, it makes sense for me to use a Shimano BB. It’s simply a good value buy. And I’m not necessarily having to squeak the fraction of a watt or bit of stiffness

[@igglebert3261]

Thanks for this detailed explanation. My local bike mech always told me to stick with Duraace BBs but I had to try boutique 🙄 Any thoughts on why a Shimano axle corroded around one bearing? Under 9 months old, NTN bearings. I would've thought some water exposure is expected!

[@schmerol]

5:10 idk maybe my english isnt good enough but i don't understand why you say there is no concentricity advice, since the geometrical tolerance (again, no idea if this is propper english😂) clearly references A (radial surface of right side ⌀41mm)

[@PeakTorque]

@@schmerol yep its sort of covered in the hole position tolerance. You are correct 👍

[@aloispaulus8327]

Nice one !

[@harkat16]

All the lidl clips have really nice mic audio. Cheers

[@joules2936]

I have Merida road bike with Shimano PF86. 10 years old and still original BB. So depressing people shitting on press fit BB idea as a whole instead of frame manufacturers inability to align two correctly sized holes.

[@marcinstyle85]

Pressfit forever did so far 30tys km on my Giant propel with BB92 dura ace not a single problem 💪

[@Cynyr]

I'm hoping for a T47/BSA like setup that is basically just a short section of threads that is used to pull or push the press fit part in and out. All so that i don't need "special" tools to install or replace them. That said my cheap shimano BSA BB is now 5 or 6 years old, still works just like when i installed it.

[@feedbackzaloop]

Finally a T-shirt more wrinkled than Si Richardson's!

[@peterwillson1355]

Than Si Richardon's what?

[@kautzz]

omg I did not know this documentation exists (obviously it does). having a blast scrolling through it! thanks!

[@mf0u3021]

Toasted my Shimano pf bb last winter after 7 years and some deep puddles and not doing any maintenance on it. No hesitation to replace like for like.

[@Chris-iv2ud]

I heard from somewhere, that sram solution for bb86 to dub is to use outer cup of the bb as the outer race of the bearing, to an extend it fixs the small diameter of the bearing in this situation. Dont know if thats true or bs, seeking for your opinion😂

[@HarishChouhan]

I have under rotation marks on my old Sram Rival etap crankset. First it made sound on my new bike and now I moved it to my older bike and just getting fed up of the tick tick sound.

[@wsbygt]

I´m speaking as a ~1800Km\month rider who does his own maintenance: the experience of riding a near perfect Hambini BB, makes other bikes feel like crap. If you got the money and enjoy smooth and stiff pedalling just go for it. Even if you don´t race anymore... It´s worth it!

[@PeakTorque]

Like i said. There is a ford fiesta bottom bracket that will suffice, then you have your porsches. But i think a lot of people think they *need* a one piece bb.

[@wsbygt]

@@PeakTorque Totally agree and you can still enjoy a Ford Fiesta on a rainy day knowing that your safely sheltered Porsche is the best in the world..😀 Cheers!

[@GHinWI]

The (plastic) press-fit DUB BB has a similar sealing design I think and in my experience has been really long-lived.

[@troywillis9873]

I'm currently building a Winspace frame and I'm really hoping the T47 pays off in the long run as it's been a pain so far

[@bobbeeky81]

Another great video. Can you do a video on leaky disc brake calipers, why it happens, what can be done to prevent it and are some designs better than others. I've had no end of problems with Shimano calipers leaking, switched to hope and had a similar problem.

[@peglor]

The last Shimano generation that used pads that were mirrors of each other rather than the same pad on each side of the caliper are the only Shimano brakes I know of where leaking calipers is common - sadly it's also the last generation that didn't have the wandering bite point issues modern Shimano brakes suffer from. I'm pretty sure the wandering bite point was caused by Shimano changing the seals in the caliper to allow more seal roll as the pistons move, to increase the distance the pads retract on seal flex/roll when the lever is released, in an effort to reduce disk rub. I wonder if they were messing with the seal seat tolerances in the generation before, trying for the same effect (The servo-wave levers are ideal for creating lots of pad travel without sacrificing brake power), and went a little too far, leading to very slow leaks that contaminate the brakes over the course of a few days while the bike is unused. For the next generation they redesigned the seals to remove the leak, but created the wandering bite point issue. Either way, that's why I run Maguras now, after using every Shimano disk brake since their first generation 4 pot XTs (Which incidentally are still working 22 years later with nothing more than feeding pads when they wear out and adding a few drops of oil every few years, on a friend's bike)...

[@bobbeeky81]

Thanks for the in depth response. Very interesting. My issue is with a road bike, but you're right I am using the previous generation calipers (tried ultegra, 105 and grx - all leaked). Following your comment I've noticed some KZbinrs have fitted maguras to road bikes. That might be a solution. The leaking after a few days without use fits exactly with what I've experienced. 3 or 4 days without use and I come back to a squealing bike.

[@PeakTorque]

Wow interesting. Ive never had a shimano caliper leak, ive got 4 sets of road calipers and 3 pairs of mtb.

[@peglor]

@@bobbeeky81 It is a little suspicious that every single set of brakes from every brand you've tried is leaking though. Just as a sanity check, try assembling the brake with tissue paper between the brake pads and the pistons and a cable tie or rubber band pulling on the lever for a day or two and see if you can see any oil on the tissue to be really sure the brake is leaking. If squealing brakes is the symptom of the leak, it's possible that something is contaminating your disks while the bike is parked without you realising. Do you have any children or pets, park the bike somewhere that anything oily would exist as s mist or spray or store anything oily that could contact the bike without you realising (Including other bikes). The generation of Shimano brakes that leaked predates Shimano making hydraulic disks road brakes - unless you count the one they did in 1969 that predates MTBs. I saw it on the Shimano's centenary celebration website. The other innovation in this one was that it used one lever and some cunning valving to actuate front and rear brakes without locking the rear on hard stops. See the Power Brake, item 8 on the list here - link broken to make it less likely that KZbin will arbitrarily delete it: shimano.com/en/100th/history/products/

[@bobbeeky81]

Thanks for the responses. I'm pretty sure it isn't something else contaminating the pads. The bike is in the garage and there's not much through traffic. I wondered if it was a temperature thing, as it appears to coincide with big temperature changes, but that might just be my imagination. I've also not ruled out user error, but I can't for the life of me think what I'm doing or not doing to cause this. Do people regularly clean their pistons to prevent grit being dragged back through the seals when the pistons retract. I did split the calipers once and when i pressed on the piston it sounded like grit was behind it. Cheers

[@fieldlab4]

What does showing off your rook have to do with bottom brackets?

[@4466ssss4]

My InfiniteBB is just dead after 3 years on an undersized (and I think misaligned) Cannondale PF30A. I'm checking with the Cannondale warranty and if it does not work, I will try to enlarge the hole myself following Hambini nasty tutorial.

[@bamicus9342]

Did you say go straight in with no compound, grease, etc?

[@lordkambing810]

best BB for me is pressfit shimano duraace, better than those metal thread-together ceramic stuff

[@glennoc8585]

One of my first disc road frames that i still have has a Bsa 68 aluminium shell into the carbon frame. The facing was perfect and so is the alignment. I ran a standard shimano bb set for over 250000 kms. The frame is chinese direct from 2016. Is that white plastic ptfe i wonder

[@bierowns]

What are your thoughts, if going for durability, on using xtr pf bb over da? You can just replace the spacer tube to match the inner size between bearings

[@DnDMF]

PT, always educational. Side question: everyone says that plastic BB should be installed dry. Does the manual you have says anything about it? Because Shimano's manuals say nothing about it - they just don't mention grease. Would you put grease if the shell is undersized?

[@jaro6985]

Since its a plastic material, clean and dry is generally the way to go. That is what Shimano intends. If the shell were oversized, then a retaining compound might help.

[@PeakTorque]

Ive always used grease because i end up taking these things in and out very often for groupset swaps and testing different parts etc. Never had a problem with grease.

[@DnDMF]

@@jaro6985 that's what Shimano insinuates but it is never clear in the manual, which is very detailed. In threaded bb there is a clear mention for grease. So I wonder if they think it's a case by case scenario.

[@DnDMF]

@@PeakTorque I always thought that a thin layer of grease wouldn't hurt. The bb won't spin inside the shell because of it. But maybe I am missing something.

[@jaro6985]

@@DnDMF It would still reduce the friction force holding it in place. In reality probably most of the grease gets pushed out so the difference would be minimal, not nearly enough to spin. But imagine an extreme example of using grease to install your MTB grips. It can make a difference in that case. For threaded BB you want the grease so the threads don't get stuck together, if the threads were plastic, you wouldn't need to use it.

[@jamespotts8372]

I’ve got an Emonda SLR frame that I, probably incorrectly, assumed could exhibit a performance gain from a Hambini BB. I was going to install it myself, but after watching this video, I’m questioning whether it’s a good idea. If the Trek dealer does the installation, then I’m supposing there’s no way they could deny a warranty claim. Of course, they could say his BBs are shite instead. Any suggestion about how to best approach the next step in this process?

[@benjaminnickolls3159]

my canyon's BB is so out that I snapped a screw-in two piece bb. Frame is getting warrantied fo sho.

[@Skooteh]

It would be interesting if someone did a 1-piece metal BB with plastic caps where it presses into the frame. I figure that would give you the strict alignment & rigidity of solid BBs and be able to accommodate the worst of the wonky bottom bracket shells. Also, copying shimanos labyrinth seals would be prudent. Come to think of it, that sounds a lot like a shimano square taper BB...

[@AndyDutton]

Is the superior seal design on the DA present on the XTR part?

[@timtaylor9590]

My bb90 still going strong, carbon bb with bearings.

[@mircozelle]

would love a video about currently available square taper bbs. i read bad things about the shimano options and would like to know if those are true.

[@peglor]

If you can get a UN-72 square taper and ride a road bike, it'll probably outlast your knees. The big thing that move people away from them was that the axles snap when given hard off road or trials bike use, which is why the Octalink and ISIS splined BB's were devised. The bigger axle meant less room for bearings though, so they didn't take mileage anything like as well. Moving the bearings outside the BB, Shimano Hollowtech II style, allowed decent sized bearings and a big hollow axle, and came in a decent bit lighter, but they still don't last as well as square taper BBs.

[@invisiblescout6335]

You hqve convinced me. Unfortunately, shimano don't recognize any standard other than bsa, ita and pf86

[@tednruth453]

Have you got the trainers to match the t-shirt?

[@PeakTorque]

Sadly no. They didnt have my size

[@morneauh]

Time frame, Rotor Ceramic Bottom Bracket. Tropical climate, 1000km bearings are finish... I replaced them with NTN, but now I need to fit top cap so there is no more weatherproofing as the Rotor rubber seal doesn't fit with the top cap. Any reliable solution for a PF46?

[@Cycle.every.day.]

Some of those really spinny bb's have have play , i'd rather have a good seal.

[@feedbackzaloop]

play/preload and seals are two separate things. You can have one of, both or neither

[@danieletognozzi7641]

I still wonder why most cassette bodies don´t seal the outer bearing properly with a similar design. Campa does not even have internal sealing, only a sealing ring on the outer part of the industrial bearing. Really bizarre and disfunctional to have some ceramic bearings in your hub if you have some exposed bearings in your cassette body.

[@williamshakespeare5646]

it's not that we are not subscribed, we're just not always logged in.

[@n.m.5723]

BB71 an Unsung Hero? you mean creak, creak, creak. Went through 1 a year in a giant frame, ever so slightly misaligned frame which would start creaking. Fixed it with a Hambini BB, which is a fix for such frame issues. Even the new BB71 had more drag I can feel, and see with spin test. Worth the money imo.

[@PeakTorque]

@@n.m.5723 sounds like that frame was undersized or misaligned

[@Yamaha_Bolt]

I asked my LBS to install a Dura-Ace BB in place of my wheels manufacturing because I have premature witness marks on the axle that are different left vs right. The mechanic said it can't be done b/c my Orbea Orca uses a 386EVO. Is there no way to do this with reducers? Would they impact the performance of the Dura-Ace BB? Thank you.

[@sbccbc7471]

There are no adaptors for BB86 BBs to fit in a BB386EVO frame.

[@TypeVertigo]

BB386EVO essentially marries BB30's 30 mm crank spindle and 46 mm BB shell inner diameter with the rest of BB86's shell spec. Unfortunately, no Shimano bottom bracket will work with a 30 mm crank spindle, and none of them will press-fit into a 46 mm hole (a Shimano bottom bracket will just fall in, as it's 41 mm). That's your problem right there.

[@Yamaha_Bolt]

@@TypeVertigo my Ultegra spindle is 24mm, before I upgraded this bike to 12sp Di2 and changed the BB to a WheelsMan it had a BB that looked very much like the Shimano BB, i.e. plastic cups, but I did notice that it had an adapter to reduce the size of the shell before pressing in the BB cup. What I don't like about the WheelsMan is the bearing inner race is metal and makes direct contact with the axle, and that's creating a 360 witness mark on the non-drive side and a 180 degree witness mark on the drive side. I had no such marks on the 105 crankset with the plastic BB. I've already had to change the bearings on the WheelsMan after only 13000km, less than 1 year of use.

[@owensnicholas]

I don’t have press-fit frames. Does the sealing on Shimano BSA bottom brackets work in a similar way?

[@PeakTorque]

Yes almost exactly the same.

[@RICHARD.WRIGHT1]

You did'nt mention your 5yr old friend who's married to a hairdresser.

[@81antiloop]

Whats the difference between the ultegra vs rhe duraace version ? Weather proofing and alight design changes?

[@TypeVertigo]

The Dura-Ace version has the unusually longer/wider inner race, which is the foundation of that bottom bracket's labyrinth seals and lip seal combo. Also mentioned: the Dura-Ace version has slightly smaller diameter ball bearings, so you're trading better designed sealing for a slightly lower load rating. In the real world though, you're still getting a very long-lived bottom bracket as long as your frame's got a good BB shell.

[@tobycolin6271]

I run Shimano press fit in my winter cx bike, hambini bb30 to Shimano converting in my canondale synapse and Shimano threaded bbs in classic bikes square ore hollowtech. depending on age. For me the preload system on hollow tech is superior to all other brands. They all run fine but all of my bikes are between 1972 and 2012

[@swagdamgus]

I have a bike with a Shimano UN51 square taper bb that still spins well, not sure how lol

[@fritspas]

I saw the thumbnail of this video and really wondered why the rook would be better than the queen

[@HYP3RK1NECT]

Ese es el que tengo puesto en mi bicicleta de ruta. El 71-41B

[@pgn666]

is there "plastic" Shimano stle BB for 46mm shell and 24mm cranks ?

[@PeakTorque]

No. Sadly

[@lovenottheworld5723]

When frames were all made out of metal all the bottom brackets were good. Is it a problem with manufacturing or is it a manufactured problem.

[@bbarber6845]

Damn, anyone check on Hambini? He might not be happy.

[@edmundhodgson2572]

I love shimano press fit, the perfect solution along with their preload system. Everything else is second rate.

[@croccofanto]

should one grese the plastic cups going inside a carbon shell?

[@Antoine_Frs]

Shimano says not to use grease or anything else. I think I’ve heard on PT or Mapdec’s channel that if your frame is really undersized and you can’t ream it for some reason, then a specific grease which is not agressive on the plastic BB can help to press it in.

[@GHinWI]

Bicycling needs an industry standards organization analogous to SAE.

[@ΘάνατοςΧορτοφάγος]

You changed my mind on threaded to pressfit. 👌

[@elbatch]

Going from the bog standard Shimano bb of my Giant to the crappy Cervélo one (bbright ?) for next year's team bike and I already know I WILL have some problems. Fun fact : I've never heard louder bb creaks than from a colnago v4rs T47. Then Pogi says you need the special team sponsor 300€ bb and it truly baffles me when it's just crappy bike

[@Miraflores1990]

Who did that test?

[@WstalSprzedKompa]

These Enduro bearings from the beginning of the video are NOT full contact seal! Enduro states so but they are not. Check it.

[@JamesSmith-qs4hx]

Make Bottom brackets Great Again.

[@RichChh]

Make frames great again. BB's are fine.

[@JamesSmith-qs4hx]

@RichChh Happy MAGAday Rich..😀

[@antoinedoinell]

i like fancy bb's and all but if i'm running shimano cranks i'm running a shimano bb. don't care enough to deal with fit kits and washers for something that costs 8-10 times more.

[@sbccbc7471]

You hardly need to use shims when pairing a Shimano Hollowtech II crankset with any Shimano-spec aftermarket BB.

[@antoinedoinell]

@@sbccbc7471 you don't need anything else then what's provided with shimano and that's the point. i was talking about if i were to run an aftermarket bb.

[@sbccbc7471]

@@antoinedoinell And I was talking about what you actually do when you pair such a BB with a Shimano Hollowtech II crankset. I'm now on a Wheels Manufacturing BB and I never needed to use the shims that came with it.

[@antoinedoinell]

@@sbccbc7471 very cool. I'm not against fancy bb's. I like chris king stuff and their warranty is top. however, i've had an XT bb i got for 24.99 on sale. I ride my mtb all year/all weather. i live in a rainforest with lots of puddles and mud. 3 years + and still spins smooth. I've had to replace chainrings before the bb. you can't beat that for the price.