What Are The BEST And WORST Bottom Brackets | Expert’s Opinion And Deep Dive

[@gcntech]

What's your experience with bottom brackets? Have you found the perfect one?

[@layton3503]

They tend to creak

[@davidadamus177]

My square taper ones have lasted the longest, though hollowtech 2 is pretty nice also. Don't have enough miles on my press fit (3,500) to comment on longevity, but so far it's dead quiet

[@DumpsterBuddhaGames]

I once bought larger cranks/chain ring to gear a single speed mountain bike up to be a good commuter bike. Bought cranks with square tapper because that's all that I knew existed, just to find out my bottom bracket had some star shape. Anyways I bought a new bb and it rides good now. Thanks for all the details!

[@fancitickler]

Used three bikes with the Hollowtech crank assembly (hub gears btw). Two failed at the crank arm bolts as the splines had started to wear. So changed it to a Sturmey archer BB and crank assembly with a basic square drive and spline. The Hollowtech crank (IMO) would be much better if the crank arm bolts (M6) were bigger or the bolts and crank arms were case hardened. However in the defence of Hollowtech it did take a few years before the crank arm splines started to wear out.

[@DoyleShadduck]

I’ve had excellent success with the press fit sealed setups. I see no compelling reason to change. I should add that I’ve always run them on aluminum higher end frames, but can’t speak to other materials such as steel or carbon fiber.

[@turboplopp]

This is the tech content I like. Not about shiny things to buy but real world engineering challenges. Well done!

[@gcntech]

There are also shining things with great engineering behind them 😃

[@SirBrass]

​@@gcntech yeah, but we want to hear more about advances in the actually affordable trickle down tech. Like more about microshift, improvements in mechanical 105, etc. Di2 & etap are so far out of most of our budgets that it isn't funny.

[@james-p]

Calvin getting real: "Birmingham Small Arms, or BSA..." The man knows his history. The dude's a gem. He's one of those guys who's "forgotten more about bike repair than you and I will ever know." I find his instructional vids invaluable. Park Tool is lucky to have him. Great show, thanks for this!

[@keirfarnum6811]

Totally agree. He’s the mechanic’s mechanic. Nobody works on my bike but me, but I would trust Calvin.

[@krug123]

Or “bits stuck allover” as we used to call it.

[@TalkToMeGooose]

I really hope Calvin lives forever. Just love listening to him. It’s nice that he brings his kid to work as well.

[@mplsmark222]

Just ran into him on Saturday, out for a Global Fat Bike day ride. Going strong and the same friendly beanpole we all know. He is a wealth of knowledge and a fantastic teacher and mechanic.

[@GREENGARDENSMOKERZ]

- New Bottom Bracket: 16€ - Tools for Changing Bottom Bracket 40€ - notice that the creaking noise comes from the loose derailleur hanger: priceless

[@Ober1kenobi]

It's always the seatpost for me 😂

[@independentthought3390]

@@Ober1kenobi Many, many years ago, on a mountain bike I sold back in 2019, creaking noises were driving me crazy. I replaced or took apart and re-lubed many components, including the Hollowtech II bottom bracket. Nothing helped. It turned out it was the seatpost, which I never even considered for some reason.

[@andreasr6632]

@@independentthought3390 👍 been down that spiral myself. Started putting assembly paste everywhere ever since.

[@LawrenceMacMacster]

I've been chasing a creak for 12 months. Yes it was the f*cking hanger, of course

[@yutehube4468]

It's more likely to come from your saddle rails. - New Seatpost: 40€ That didn't fit it so... - New saddle: 80€ HURR HURR HURR I GOT TOP COMMENT.

[@throx]

Calvin having an old-school mike in a vice clamp is just gold.

[@stephensaines7100]

Being an audio tech, I immediately noticed that. His mike is a 'hand-held' one though, not 'old-school'.

[@mikesmith2864]

Famous cartoon posted in our bike shop: "There are 15 BB standards; let's create a new universal one." One year later, " There are 16 BB standards."

[@gcntech]

It seems like a step backward has been taken 😂

[@gavgams]

Ha. Ha very droll 😅

[@joelv4495]

Stolen from an xkcd comic.

[@MrGoodaches]

The bike industry likes standards, that’s why there are so many standards to choose from.

[@scottvalone3368]

@@MrGoodachesI don't think the bicycle industry knows what the word standard means.

[@MudguardFan]

Who’d have thought 30 mins on bottom brackets could be so interesting. Thanks 👍

[@gcntech]

When you like bike, you unconsciously like everything about them

[@MiguelAugusto1982]

it went by so fast!

[@lbx5359]

This is the type of content I love. Nerdy, specific, and instructive. Make more of these mechanic/maintenance videos and less of these marginal gains "this company claims their bike to be stiffer, lighter and more areo for the 10th year in a row!". The bottom bracket is now essential in my choice of bike. I've had a press-fit BB on a bike, hated the fact I couldn't service it properly myself. Now all my bikes are BSA, and I wouldn't even consider anything else than BSA or T47.

[@irfuel]

Or you get a pressfit one that you only need to install one time, and where you can service the bearings.

[@markusseppala6547]

The unwritten law of creaks is when you start to listen and pinpoint where it's coming from it suddenly gets quiet.

[@ghowell13]

❤😂 Every. Single. Time.

[@dashd0t]

i think this may be because you shift your weight to a different part of the bike

[@saikat0511]

You shift your weight to check, meaning it's likely it's your seatpost rather than bb. Stand up while pedaling, if it still creaks it's your BB or cranks.

[@jonathanzappala]

Just like trying to find out which smoke alarm needs a battery, it’s always the one in the other room haha.

[@gcntech]

It’s as if the sound knows we’re looking for it 😆

[@user-cx2bk6pm2f]

Those two are just the nicest kind of people.

[@ghowell13]

In blaming the bottom bracket for creaking. I watched a guy at the BMX races chase a BB creak for 3 weekends. It was on a carbon framed V2 SpeedCo. He bought it used, (I saw it sell, and missed out buying it myself, loved that bike as built) He never serviced it in the 3 years he had owned it. I kept telli g him it wasnt the BB, it was something else. He kept tightening the BB. IT WAS THE CHAIN RING BOLTS. Iended up taking the bike home for a week and servicing it over the course of the week, for the next weekend before they left for Nationals, along with 4 of the son's bikes and his wifes bikes.

[@Crampion]

❤ Calvin. His lazy brake pistons video saved my cycling life.

[@williamsylvia3962]

Thanks for doing this episode and confirming that bottom bracket standards are just as confusing as I thought they were 😂. I really like it when you guys talk tech stuff with Calvin and Truman. Great stuff!

[@10ktube]

We aren't accepting that companies selling 5000 dollar bike frames can't make a circle are we?

[@klarkolofsson]

Correct!

[@markg0410]

Your comment would make Hambini proud.

[@zygmuntthecacaokakistocrat6589]

@@markg0410 Hambini is a fake and a fraud.

[@micgalovic]

CF bikes are light and aero but otherwise garbage (literal garbage because of it) when it comes to tolerancing and position of features. When you get all the forces on the BB.. RIP.

[@JulianKent]

Remember when anything made from carbon fibre was considered exotic and expensive, reserved for pros and the masts on luxury yachts? We now get complete carbon bikes with electronic shifting for under $3000 including inflation... and then we complain that some carbon moulded part isn't perfectly round. We are so lucky.

[@audiophiladelphi]

By far the most informative piece I've seen on bottom brackets...

[@petersauer94]

I can remember when crank arms were held on to the bottom bracket spindle with cotter pins/bolts with a nut you tighten 😮

[@rkentwenger5095]

Yeah, those were awful -- if the cotter pins got really stuck you were in a world of hurt...

[@Slogfester]

Painful memories of cottered pins. 'Micro adjustment' consisted of hitting them harder with a hammer!

[@IOSARBX]

GCN Tech, nice content it was really good

[@EverettWilson]

Still blows my mind that bike manufacturers won't ream and face their frames.

[@kalijasin]

They also don’t flex-hone the head tube, seat tube, and bottom bracket shell.

[@BeyondLumination]

Watching too much Hambini eh?

[@EverettWilson]

@@BeyondLumination His videos aren't my cup of tea at all, but he's 100% right about that.

[@JulianKent]

How about just using a plastic BB?

[@DanGRoberts]

Love these guys, could listen to them all day. Great video.

[@51im]

I think the main problem with most new press fit systems is that the mating face isn't flush or has paint left on it by the manufacturer. Then the soft paint compresses or wears which leaves the BB with free play between it and the frame.

[@WCIIIReiniger]

That is why I will most likely get the bottom bracket tube of my brand new Surly Straggler reamed and faced, when it arrives the next few days.

[@SignorLuigi]

Dealt with out of round press fit bottom bracket shells on carbon frames for too long. My most recent bike is titanium with a T47 threaded bottom bracket. Total and uncompromised bliss! 🙌🙌🙌 Never going back.

[@goodcompanycoffee]

Timely video. I’m into the rabbit hole of BBS right now after a new bike with a diff interface.

[@ghowell13]

May the lord bless you and keep you on your journey. Last I wend down that rabbit hole, I nearly went crazy. I collect bikes, and have no less than 6 different standards. Some are the same standard, but 2 different sizes😂

[@ianlopez4541]

One of the best shows. Loved the depth of info. Thank you!

[@frankalexander4125]

I love nerdy out on all the different intricacies of all the different parts of the bike. You guys are making great videos. Keep up the amazing content. I always look forward to your new videos.

[@Andrew_smart100]

Tell Me your a cyclist without telling me your a cyclist- I just watched a 30’minte video on bottom brackets, and enjoyed it

[@topher.m]

TLDR : BSA/English is still the best. 30 years on.

[@markg0410]

I am currently waiting on two frames from Braun in Holland. I specifically chose that manufacturer for four reasons: a traditional top tube, external cable routing, rim brakes, and a BSA BB. In my opinion, BB should have threads.

[@yohansharp3040]

@@markg0410 yeah BB with threads are so much better

[@pastelink6767]

I think T47 takes that title now. Similar but bigger so more easily accommodates larger axles and bearings.

[@fatrobdouble]

"30 years on?" The modern 1 3/8x 24tpi BB shell with drive-side reverse threads has been around for over a century. (BSA used RH threads on both sides and a few different thread dimensions prior to that...) Shit, even Birmingham Small Arms, the firm often credited with the ISO/BSC bb standard) sold their bicycle division close to 70 years ago. I agree that the BSC is probably the best standard overall, due largely to the design but also to its ubiquity. t47 is essentially the same shit but bigger, allowing for larger-diameter spindles, larger bearings, etc...and is therefore likely "better" head to head, but with the vast majority of bikes made in the past century having the smaller BSC shell, the t47 is, as of yet, very limited.

[@hoiyyhonho1978]

​@pastelink6767 T47 exists only because of trying to retroactively correct another BB standard, and not because it tried to make any innovation.

[@andygolborne5747]

Quality nerdy stuff! Calvin is a true cycle super hero. I stick with best Shimano I can afford at the time.

[@Frostbiker]

As a layperson I felt this was a fair assessment of a controversial subject. Thanks to Ollie for soldiering through his cold, too.

[@Cycle.every.day.]

T47 seems to be the future , it's pretty much just an over-sized bsa-english like we all knew for years but allows modern chunkier axles.

[@countspokeula539]

Reliant on clean, properly chased threads and facing. Press-fit is superior in every way.

[@凸Bebo凸]

@@countspokeula539 T47i doesn't need any facing. It literally screws all the way into the frame just like Square Taper does and doesn't rest on the BB shell. As far as chased threads goes, that helps with everything not just T47.

[@markusseppala6547]

Yeah and the bigger shell is stiffer

[@wagj16]

T47 vs BSA 68 what are the diferences?

[@凸Bebo凸]

@@wagj16 Bearings spin better, supports large axles. Overall not much of an upgrade over Square Taper unless you are a friction / bearing nerd.

[@donball370]

Alex, Ollie great conversation with Calvin & Truman. So good to hear the Tech talk with no Bike marketing "flexing" spin. Threaded BB rules ... just need a few less standards 😂

[@louchedecay7922]

Best GCN video I've seen. I'd love to see more collaboration and deep dives into the technical side of cycling.

[@jameslee-pevenhull5087]

Was designed in Small Heath, Birmingham. The MOST important factor is the cups MUST be parallel and have a single centreline. Any misalignment is probably the threads or sleeves in the frame not correct. When a new bike is purchased, the groupset documentation should be included. On buying a used bike, research and download the specification sheets. I'm restoring a 1944 Sun gent's bike. Bottom Bracket is still in there. Smooth as silk. I have a 1939 B.S.A. Sports. B/B is original, never been out. Instead of tack welding, try Theadlock or PTFE tape.

[@jdmcdorce876]

When I hear the term “bottom bracket standards” used, I don’t know whether to laugh or cry. Of the six bicycles I maintain, three have BSA bottom bracket interfaces, two have PF30, and one has a square taper. Between what is currently on the bikes and what is in my parts drawers, there are five different axle interfaces: Shimano (24/24), SRAM Dub (29/29), M24 (24/22), M30 (30/28), and whatever you want to call the square taper. In both cases these are a small fraction of what is actually out on the market. It would be nice to have a “standard standard” (or even narrow it down to a standard screw-in and a standard press-fit and converge on standard axle size), but until then we are left to whatever the frame manufacturers and component manufacturers think is best. As somewhat alluded to in the video, my opinion is that if the bottom bracket interface in the frame is dimensionally off, merely throwing a “premium” bottom bracket in it isn’t going to fix the issue. This begs the question how many “bottom bracket” issues are actually interface issues that merely swapping the bottom bracket isn’t going to fix?

[@jeffreywilliams3646]

Much better audio on the GCN end than the last conversation with Park Tools. 👍

[@LukeGJPotter]

The previous episode's audio was, to uses BB terminology, egg-shaped and under-sized.

[@ShawnIsBatman]

If you enjoyed this discussion, you are a definitely a cycling geek....I LOVED it! I just completed a bb upgrade on my Pinarello Prince, I upgraded to an Enduro bb based on the brand reputation, reviews and lifetime warranty. So far, I am extremely satisfied. The one small issue (which this video addressed when talking about upgrades and parts not fitting perfectly) is that my new bb is slightly wider than my old bb. This necessitated the mechanic to do a front derailleur adjustment to get things to line-up correctly. On this new setup, I now have a little bit of a 'chain noise' when I am cross-chaining on the big ring to the largest cassette cog and to a lesser degree the second largest cassette cog. This cross-chaining noise did not exist on the original Shimano Ultegra bb. I realize that cross-chaining and riding in those gets is not the best, so this is not an issue which impacts me in a practical way, rather it is just an example of how the different sizes, standards, parts and manufacturers can have small variances which can complicate issues.

[@FuchsHorst]

On my 15+ years old hybrid steel bike I've a SRAM DualDrive hub/8 speed cassette combined with Shimano BSA bb, Rotor 24mm gravel spindle and crank arms with a chinese powermeter spider. And it works. Good old times.

[@DalstonVinyl]

I'm about to take my bottom bracket out at home, an externally threaded 44mm bb30 in an aluminium frame, a FSA unit...which should be a doddle with two, relatively inexpensive, tools...I do like modern BB designs, especially their longevity when correctly installed.

[@matt_acton-varian]

All hail Calvin. What a cycling encyclopedia. I have used vintage cottered, modern square taper, octalink and hollowtech BB's and all present their own challenges for maintenance, but a bike would be just an ornament without it. My one Pressfit BB has a BSA threaded sleeve insert for ease of maintenance. Paul from Mapdec Cycles has done several videos on pressfit BBs and their pitfalls, especially with poor manufacturing tolerances. One American brand is notorious for their PF sleeves being oval - being to tolerance on one axis but the perpendicular radius being .2mm or more too large.

[@MrKOenigma]

I once replaced the bottom bracket on my XC Bike after having a creak on left pedal downforce. It turned out was the saddle, running against the adjustment screw of the seatpost 😂😂❤❤

[@davidrobinson9507]

I learned a lot about bottom brackets, cranks, spindles, bearings etc in my many years as a bike mechanic. Ironically, the one time that I found the perfect bottom bracket set-up, was on my Titan Half-Track ( look them up!) It had a problematic double pinch system which tightened on the cartridge bearings. It constantly worked loose and although the bike itself was brilliant, the b.b. made it a nightmare for our shop, so I was given one for free and I rode it and raced it hard. Late eighties, early nineties. What I found worked finally, was a Mavic bottom bracket. It simply had two symmetrical lock rings, bevel- faced so they tightened in two ways; they drew together closer, and they forced the now permanently tightened down sides of the frame's shell to be incapable of moving, creaking, clicking, whatever. Those Mavic bevelled lock rings were big and beefy. You had two threaded sides to exactly line up your chainrings and the chain line. It was perfect perfect. Now when I say it was ironic, it's because this was the one bike that got stolen. Straight out of my Toronto classroom, while I was on lunch. The nervy thieves got one of the best bikes I ever owned. About three years later I saw some teenagers riding past and I recognized my bike, now spray painted bike theft black, and I watched my bike being enjoyed by a smiling 14 year old. I waved and smiled. I'll bet that bottom bracket is still working. Whatever happened to the perfect Mavic double sided threaded bottom bracket ? Cheers, Canadian fan.

[@DoyleShadduck]

I’ve been using press fit sealed since my early 90’s Klein Pinnacle came from the factory set up that way. It worked so well that for the first time I didn’t have any bb issues. I’ve always ridden aluminum frames so I can’t give any advice on how well it’d work with carbon frames. I raced all through the 90’s with different aluminum Klein’s and Trek’s and never once had any problems with the sealed bb’s, prior to that I did have periodic issues with different types of noise that let me know something down there needed attention. Usually just a tear down, inspection, cleaning and reassembly fixed my problem. I’m intrigued by the ceramic bearing idea, not sure if it’d make much of a difference though. I have run ceramic bearings on my downhill long boards and they are pretty fast compared with steel. I’m not sure they can be bought in a standard press fit bb bearing or not..anyone else have experience with ceramics?

[@davefeldman3740]

Klein did maybe the very best execution of the pressed bb. Smooth and quiet for YEARS.

[@IOSARBX]

GCN Tech, nice work, keep the videos coming

[@Xerp4Life]

GCN is back to it's best.

[@martinmartin400]

one of the best GCN TECH!! FACTS VS VISION

[@abhimawa1]

Good video. In the end it all comes back to quality manufacturing. That’s why some brands earn their reputation → consistently producing high quality products.

[@xGshikamaru]

Well, you kinda have wide versions of bottom brackets nowadays too. Back in the day it was often used depending on how many chainrings do you have (triple often needed a longer axle). Nowadays with gravel bikes having wider and wider tires you can get wider axles so there's enough tire clearance.

[@LovetheIPAs]

Great discussion!!! - super interesting and informative, and as others have posted, more tech videos like this, discussing hubs, spoke tension, etc.

[@JohnnyFYX]

On the topic of the T47 having a fine thread pitch: Size for size, a fine thread is stronger than a coarse thread. This is both in tension (because of the larger stress area) and shear (because of their larger minor diameter). Because of the smaller pitch, they also allow finer adjustments in applications that need such a feature. The fine thread pitch on the T47 BB was more of an engineering design choice for strength than a legacy design that was carried over from the BSA BB.

[@ErikBongers]

Recently ordered my first new BB. It's just for a dutch city bike. As a non-mechanic, it's new territory for me and I took days to step by step disassemble and reassemble that area of my bike. I didn't want to damage something as I rely on this bike daily. I had to buy the tools as I went along. Only when I was convinced that I had a BSA system did I dare to unscrew the drive side to measure the width. I'm now waiting for delivery of the new BB and I really hope I got the type and measurements right.

[@pentiuman]

I had a creak I'd hear only when pedaling, so I assumed it was my bottom bracket, which WAS loose when the bike came new from the store. So I changed to a Hollowtech BB. Problem solved? No, it still happened, so I thought it had to be my rear hub, which I took apart, and LOST a ball bearing! I put it back together w/ it missing, and still had a creak, so I thought it was the missing ball bearing, and measured and ordered new. They came, I took apart my rear hub (again) properly packed it with grease and 9 bearings each side. Put it back together, still had the creak! That's when I slowly turned the crank, while giving some resistance, and definitively figured out it's actually coming from my freewheel! Ordered one of those (a freewheel) tonight.

[@davids4610]

Most of this is over my head, but my '94 Cannondale R300 shimano BB has lasted thousands upon thousands of miles with no required maintenance. I've had to rebuild wheels, but that BB seems bulletproof

[@jfdomega7938]

That was a surprisingly very interesting video!👍🏻

[@rolandmg1]

BSA bottom brackets have always been simple to maintain and reliable but they used to wear out quickly. I’ve been using press fit for years and they do get a bad name but this is down to poor frame manufacturing and not the BB. I’ve had lots of issues with big brand frames where the machining tolerances are terrible which cause the creaking. But frames from companies like Look, Time are manufactured to such high tolerances the press fit BB’s work flawlessly. For the last few years I’ve been riding Ridley’s with BB86 and PF30 and cheap Shimano BB’s are silent and just don’t wear out and easily do 20K km’s including riding daily through a British winter. Great video.

[@klarkolofsson]

Square taper for all weather riding gets my vote.

[@independentthought3390]

It gets my vote too. I don't know why, but I never had to replace a square taper bottom bracket due to wear, or any kind of problems appearing. They are indestructible.

[@charlcoetzee93]

​@@independentthought3390Square taper is my go to, but I've definitely replaced a few worn ones

[@daniellarson3068]

I'm no bike mechanic, but I replaced my square taper bottom bracket on my old bike a few months ago with a new cartridge type. At that time I learned about all these different types of bottom brackets that have been developed for Carbon fiber frames. The square taper bottom bracket is yet another reason to keep your old steel bike.

[@kalijasin]

Square taper wrongly gets hated on by GCN and others.

[@OjStudios]

As a mechanic, gets my vote too. It's a weekly problem with "random noises" and none of these cases is square taper. Sometimes they need replacement too, but random problems is something they don't cause.

[@user-cx2bk6pm2f]

Oh hell yes, GCN. Please, sort through the fog of bottom brackets! I currently have pressfit, but hate that I need a press to do maintenance.

[@erickroeger1012]

I chased a creak around for months before I realized it was my knees.

[@KyleLanmon]

Love the mic in the work stand

[@51im]

I fitted a threaded cartridge square taper Shimano BB to my bike over 30 years ago and it's never had any problems.

[@paulpenfold2352]

I thought square taper shimano BB's were awful. The non-drive caps were made of plastic and the bearings inside the after-market ones lasted all of about six months. And if you took the crank off too many times, the end bits would lose friction. I can't believe I persisted with internal BBs for as long as I did, just so I could tell myself I had a perfect chainline. Mad.

[@michaelhayward7572]

You had a fake copy. A lot about especially Ebay/Amazon. Genuine Shimano should last years or a minimum of10,000 miles in all weather conditioms.​@@paulpenfold2352

[@51im]

@@paulpenfold2352 that's probably the model that I replaced with a slightly better model only a few £ more for much better quality. It's been faultless never needed to remove it and have only changed cranks once to slightly shorter ones about 10 years ago

[@galootlovestools]

@@paulpenfold2352 Shimano made higher end square taper bottom brackets with metal cups. If you remove the cranks you need to torque them properly when reinstalling them. Without a torque wrench you are likely to under tighten them, leading to loosening later on. Properly installed, they are bombproof until the bearings wear out. Easy to replace and no creaking. White Industries still makes premium square taper bottom brackets from steel or titanium for about $150 and up.

[@ebikescrapper3925]

Go for UN71 or UN91 if it fits. You can still buy high end square taper bottom brackets from other manufacturers.

[@joelperegrinefilms3475]

No mention of Q-factor being set in stone other than a comment about the lack of adjustability of the chain line. The ability to adjust the Q-factor will be a “new” thing to improve performance at some point in the future, much like shorter cranks are now. A square taper bb can narrow your stance more than 15mm to make possible bio mechanical gains and perfect chain lines for 1X conversions.

[@Bukester72]

This is a really great and detailed overview. Thanks!

[@andrewchutchins]

Love the in depth info - thanks! :)

[@Josh.Straughn]

Timely video sort of I just had to change my BB for the first time. Took me ages to figure out what i needed to buy for a replacement.

[@paronetti6192]

I'm just waiting to see what the 5 year old has to say about this

[@gazzas28]

Probably his is the best and everybody else's is rubbish.

[@mboretzki]

I guess there was not much said that he could complain about. Especially when it comes to ceramic bearings, what they are made for and how to tune steel bearings. You must be insane to buy ceramic bearings 🙈

[@shawnsmith7009]

He’s busy with his hairdresser

[@_Zane__]

I dont think there are bad BB's, it's only as good as the bike it's installed into

[@BeerSougion]

@@mboretzkiI think it was pretty fair in the critique on the bike industry lacking standards and precision. For an industry that raised prices to 15.000 euro’s for a very fancy bike they should have invested in precision tooling.

[@clp91009]

Good video really enjoyed it. I would like to have heard them discuss 1 piece press fit options like those from bb infinite or hambini. I think they are probably the best design for BB86/92.

[@countspokeula539]

They can be detrimental to the frame. You want some movement to be possible, the spindle and preload does the job of keeping things stiff.

[@clp91009]

@@countspokeula539 Thanks. I’ve been running the standard Shinano pressfit SM-BB92-41B. I’ve changed it once or twice over the years. It’s never creaked or given me any problems. Maybe I’ve been lucky with my frame, but I haven’t felt the pain others have with press fit.

[@jbarner13]

In terms of coarse vs fine threading, there is a case to me made for having a taller thread profile, as the BSA standard was created for steel cups in a steel BB shell, but most modern BBs use aluminum for both. However, "coarse" is a relative term, and a 1-3/8" diameter bolt with a coarse thread would be 6 TPI, while a standard fine thread for that diameter would be 10 TPI, in the US. Actually, once you get to 1" and above, most fasteners just go with 8 TPI, while those below 1" have coarse and fine standards. I don't think anyone is suggesting that BB threads be that coarse. A different issue is that the helix angle increases as the pitch decreases, so a coarser thread must be tightened to a greater torque, all other factors being equal. Also, the rocking action of pedaling is what loosens up threaded BB cups, and this problem is exacerbated as clearance increases. Since coarser threads have a taller profile and correspondingly increased clearance, one wonders if this might also be an issue.

[@charlesblithfield6182]

I think the old threaded square taper BB is given a lot of untoward slagging. It’s simple, it works, it’s easy to install/integrate with a crankset and maintain and it’s cheap. Shimano BB-UN101 and the like. I have one on a bike that’s 30 years old that I still ride and have ridden A LOT and it still spins with little friction and it’s never given me any problems.

[@tongpocalypse]

Tried to convert a pressfit BB to an aftermarket thread-though version. Maybe my BB shell isn't round or maybe the two faces aren't inline, but it was binding as it threaded together in the middle. Well, the removal tool ended up stripping the BB and now it's threaded together via the spindle and I'm unable to remove it from the frame 🤣

[@goodoleme747]

Squared tapered

[@daniellarson3068]

It seems like a lot of stuff on new bikes isn't better. Those square taper work a long time - and then you fix them to work another long time.

[@billeterk]

Cotter pins were annoying though.

[@gcntech]

🔲

[@robertjmillerma1059]

Great post, thank you 👏👏👏

[@swites]

I got a creak in my bike when off the saddle up a hill so just assumed it was my BB as could swear that's where the noise was coming from. Took the threaded BB cups off multiple times, cleaned/greased the threads, then tried locktite but to no avail. Gave up but the problem was solved when I changed the front wheel for another training wheel a few months later. Turns out creak was caused when my old cycle computer fell off its bracket(as I'd forgotten to put it on properly) into the front spokes down a hill at 70kph, exploding into pieces. Spokes nipples etc must have got a little damaged causing the creak when off the saddle when the front wheel flexed! Good lesson how creaks can come from an area you least expect.

[@tobya5381]

Timely! I'm just about to go out to yhe garage and see if i managed to order the right size BB for my bikepacking bike. 😅

[@pbanders]

Three bikes (Scotts) with BB86 press-in Shimano BB's. According to Strava, 67,000 miles between all three. Never had the slightest issue with noise or wear. Replaced one because I read that the updated version had lower friction, other two are original and working fine to this day. I weigh 66 to 69 kg. YMMV.

[@BroccoliLand]

Dang. GCN and Park Tool collab I never thought it existed.

[@edwardallan197]

I have never had problems with old cup/cone bottom brackets. If BBshell machined square, fixed cup seated tight, good grease, small preload and lockring tight. Spoke creaks far more common, from under-toned wheels. They creak at tbe tension cross. ❤

[@oheso]

Two things in my experience that weren't a bottom bracket: a loose water bottle cage, and a tire pump that wasn't sitting flush against the seat tube, allowing the crank arm to strike it.

[@ebikescrapper3925]

Shimano UN91 and UN71 square taper last for ages.

[@Xerp4Life]

Haven't changed the bb in my 90's Ti MTB, it's a UN71.

[@sghound]

settled the ceramic debate right thurr

[@RadCJ33]

24:55 - thanks for saying it. It is such a frustrating example of how the bicycle industry gets to standards.

[@yosacfc]

Great episode 👏

[@michaelmiller6180]

I realize I’m a bike nerd, because this was fascinating.

[@cassiowiemes]

I have a 386 for 2 years and it never make any noise, but the T47 with 28.99 axe is the ultimate.

[@meadows408]

A 3 piece screw together bb from VO was a perfect solution to a stripped out bb on an old Trek 770. Someone had tried to tack weld the regular bsa bracket and it wasn't holding.

[@georgeskinner2474]

Great show, more like this please!

[@kevinpower5880]

I bought my bikes for the whole bike and didnt think about bottom bracket. Both (Scott & Wilier) have pressfit with no issues. Creaking that has occurred came from the pedals and derrailier hanger.

[@adventure_scapes5039]

watching the part about ceramic bearings what if we use the chain wax method for the steel bearings instead of ceramic/grease? 🤔🤔

[@swites]

Done 28,000km on my BB86 pressfit BB. No creaks, no issues. Bought a new one at 20k but haven't needed it yet. I'm assuming a well made BB shell in my frame. My other bike has threaded BB that has done a similar mileage. The advantage being one can easily be replaced by a home mechanic with just a simple and inexpensive tool.

[@mkrj2576]

Been wrenching and riding mtb for over thirty years. Many loose and creaky threaded BBs over the years. Never have I had problem with a PF.

[@AnotherMrLizard]

Never had a problem in 30 years with any poorly sized bb shells? Pf itself isn’t necessarily an issue but improperly sized frames are, bsa is much better imo.

[@markmyra-cn7rd]

Most creaking from pedaling the bicycle, comes from the pedal threads requiring grease. However, the press fit bearings and the use of aluminum as the interference fit system for holding steel outer race cassett bearings will always have the potential for being noisy. Interference fit, is potentially suspect, simply by virtue of the design. And is a design that can wear just because of maintenance. A knocking noise is more common from the bb cups moving in the bb shell. The newer designs will have new issues. I remember when cinelli introduced the 1R handlebar stems in the late 70s. It had a reputation for creaking and not holding the bars securely. In fact,,, all the issues were a result of poor installation. I have used them for years. No noise and they dont move im a 225 lb track sprinter that has actually snapped a Campagnolo crank arm and broke about 10 frames because i could leg squat about 600 lbs. And lets face it. Bikes are generally built for much lighter riders. So if something is going to make noise? I will find it. 40 years of being a bicycle mechanic helps with diagnostic acumen. If you have any knowledge of the aerospace industry, design, materials and manufacturing should understand how the consumer products trickle down happens. On a certain level, the aerospace type technology adapted to the new bicycles, Is old and boring. What about foam core, titanium and carbon Kevlar composite? Well,,, foam core was something Bert Rutan was doing a long time ago. It was a good gig being a bicycle mechanic. But i would never work in the bicycle industry ever again. Because it's simply managing itself into the ground. And all the hyper expensive bicycles? Are kinda crappy.

[@qaefaeqf]

Got one of those obsolete cups and cones squared tapered bottom bracket on my old mtb, it has been stored 20 years until I've decided to get back into cycling (that I completely abandoned after childhood), I've upgraded the crankset but it has a weird chainline so I've ordered a new one with a Shimano Hollowtech II (quite surprised they make it for the rare Italian thread), hopefully this one integrates well in my bike

[@nerigarcia7116]

12:00 I had a loose rear derailleur screw that was ticking, the sound traveled through my frame and I could swear it was the bottom bracket. Even took it to a shop and it took them awhile to figure it out. They always say the bottom bracket is most likely the last place to find a creak. Most of the time it's me knees and back that I hear.

[@Silidons91]

I've almost scratched the fancy BB itch, then I remembered I've never had a bad shimano bottom bracket, and they cost like $20. Tens of thousands of miles zero issues ever...

[@biscuitdingus]

Worst bb I’ve used was a hope bsa 30mm threaded one for their evo crankset. It needed spacers, and that with the already shallow insertion depth made it far too flexible in the shell. Became creak city and started uneven wear on the spindle. Switched to a HTII crankset and bb and have had no problems.

[@jonathanbenn2241]

I love my Shimano square taper cartridge BBs. One has 35,000 miles, still going.

[@paulwillis8504]

The video is absolutely fascinating, however I still understand stuff-all about bottom brackets! 😉

[@Xerp4Life]

HTII, BSA and standard industrial bearings with good grease works for me. Hope's simple Bottom Bracket Tool, 2-piece HTT178 makes fitting new bearings a breeze.

[@jarretgosbee7717]

I have an FSA mega evo 386. 30mm spindle. BSA threaded. Spring pre-load. I still think it's the best bottom bracket out there.

[@jbarner13]

Glad to hear them correct that statement that a premium, ceramic-bearing BB can make a "big" difference in performance. I think the ideal application for a ceramic BB would be when ceramic balls are matched with stainless steel races strictly for corrosion resistance for Joe the Commuter, providing they could get the cost down below $30. Yeah, right that. I wonder how many ceramic BBs have bearings with seals on both sides? If I saw that, I would know that it's all about marketing and profit margin, as there is no need for a contact seal on the inside. The fastest-spinning bearings on a bike are the jockey wheels and they are going under 500 RPM at 90 RPM cadence with a 52t chainring and 11-tooth jockeys. Hardly high speed, and the move to larger jockeys has reduced this even more.

[@irfuel]

The best part about the CeramicSpeed bottom bracket bearings is that they are made to be serviced, so you can easily remove all the dirt inside, relube, close and have a new BB bearing. The fact it is ceramic doesn't really add a lot (except for $$$ to the price). They even sell service kits with grease and new seals. About jockey wheels: a lot of jockey wheels don't even have bearings. Check Shimano 105 and SRAM GX jockey wheels. They just use a bushing.

[@jbarner13]

@@irfuel Campagnolo used ball bearings in their jockey wheels from 1950 to '64, and Huret copied this in 1958, keeping them all the way into the early 1980s. Suntour was the first I know of to use cartridge bearing jockey wheels, though the Bullseye aftermarket ones were the first of that style in 1973. Jockey wheels take a very light load, and a bushing style is cheaper to produce and works well when kept lubricated.

[@jellyfishsalad5926]

Nice one. Love a good bit of bike nerdery.

[@gcntech]

Then you’re in the right place.

[@firesurfer]

The essence of the problem is force exerted at 90 degrees to the parts. A headset can be press fit because the force is inline with the parts. I think bb can be pressfit if there is enough material to resist the forces, and all the parts are properly machined. BB are not a suitable location for pressfit in a carbon fiber frame. Was that a Hambini bb being held up?

[@edwardallan197]

I have used thread tape or mild lock compound. If thread standards leave a bit too much play.