To The Point: Understanding Bottom Brackets

Mar 17, 2014 at 21:05
Mar 17, 2014
by Mike Kazimer  
 
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Bottom brackets might not be the most exciting part of a bike, but without them you'd be stuck pushing around a high tech scooter. In this edition of To The Point we sort through an alphabet soup of acronyms and abbreviations to take a brief look at the numerous 'standards' on the market today.




What exactly is a bottom bracket?


A threaded bottom bracket shell.
A bottom bracket is the assembly that allows a bicycle's crank arms to rotate. The bottom bracket sits in the part of a frame called the bottom bracket shell, which is located where the down tube, seat tube and chain stays meet. Depending on the configuration, a bottom bracket can either be a self contained unit made up of a spindle that rotates on a set of bearings, or if the spindle is affixed to one of the crank arms, the bottom bracket would consist only of a set of bearings. The bottom bracket is either threaded or pressed into the frame depending on the standard that is used.



What are the main types of bottom brackets currently being used for mountain bikes?

These days the most common options are the traditional threaded style, with either external or internal bearings, and two variations on the press fit theme, the PF30 and the BB92. The BB30 and Trek's proprietary BB90 system are also used, but not as extensively as the other styles. The BB30 and BB90 use bearings that sit directly in the bottom bracket shell, while the PF30 and BB92's bearing are housed in a retainer that is pressed into the shell.


Many downhill bikes use a threaded 83mm bottom bracket shell combined with 150mm rear hub spacing, although both SRAM and Shimano now offer press fit options that can be used with the wider rear hub spacing.


What's the difference between a BB30 and a PF30?

Both standards are designed to use a crank arm spindle with a 30mm diameter (hence the '30' in the name), but with a BB30 set up the bearings sit directly in the frame, and with a PF30 the bearings are housed in a nylon or aluminum retainer that gets pressed into the frame. Tolerances need to be tighter with a BB30, making this a more expensive system to manufacture. BB30 was originally developed by Cannondale in 2000, but they have since made the dimensions and technical drawing available to any company who would like to use the BB30 standard. To make things more confusing, several companies are now offering cranks with 30mm spindles that work with the BB92 standard – by using a bearing without a retaining cup, an inner race that's wide enough to accommodate the larger spindle can be used.


Race Face Next SL
Race Face's Next SL cranks use a 30mm spindle diameter, but the company offers a bearing that allows them to be compatible with a BB92 bottom bracket shell.


So then what's a BB92?

The BB92 standard, also known as Shimano Press Fit, uses a bearing housed in a nylon or aluminum cup that is pressed into a bottom bracket shell that measures 92mm wide. This standard is designed around the 24mm spindle diameter used by Shimano. Because the bearings are housed inside the shell, the spacing remains the same as it would be with an external bearing configuration, which means a wider spindle length is not necessary for riders switching from a 68/73mm threaded shell to a BB92 set up.


What are the advantages of a press fit bottom bracket?

For the consumer, the benefits aren't immediately apparent, and some manufacturers like Santa Cruz have resisted the press-fit trend, stating that the disadvantages outweigh the advantages. For manufacturers, doing away with a threaded shell saves time and money, especially when constructing a frame out of carbon fiber. It is much easier to create a smooth, circular opening rather than cutting threads or installing a threaded sleeve into a frame. Using a wider bottom bracket shell also allows for more real estate to work with when trying to stiffen up the rear end of a bike. For instance, Kona's new Process series of bikes uses a BB92 in order to gain the clearance necessary for the bike's wide chain stays.

What are the disadvantages of a press fit bottom bracket?

The most common complaint regarding press fit bottom brackets has to do with noise. If the tolerances are not tight enough, hard pedaling can cause the cups to shift slightly, causing an annoying creak with each pedal stroke, especially if contaminants have managed to make their way between the cups and the bottom bracket shell. Careful installation and the use of Loctite or a sleeve retaining agent helps to mitigate any problems, but this issue does seem to be more common with press fit style bottom brackets compared to the traditional threaded style. Frame damage can also occur if a bearing is pressed in improperly - again, using the correct tools during bearing intsallation and removal is the key to avoiding any issues.


What does the future hold? Why isn't there one standard?

It's unlikely there will ever be one standard, but press fit does seem to be gaining traction, especially as carbon fiber frames grow in popularity. The major drivetrain players, Shimano and SRAM, are each pursuing their own standard, with Shimano supporting the BB92 and SRAM the PF30. Only time will tell if one will prevail, but for the near future there will continue to be multiple 'standards.'
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219 Comments

  • + 195
 stupid bottom brackets! I just want one that plays metal music and is only compatible with 26 inch wheels. Oh and it can't cost more then 2 dollars
  • + 85
 2 dollars!!! wow what do you want me to do? sell my kidneys? this sport is becoming to expensive! I'm taking up curdling!
  • + 171
 ^^ mix milk with orange juice in your mouth, thats the secret to curdling
  • + 19
 not a fan of BB30 as metal bearings sitting in a metal BB shell = creaks and clicks, and damage to the frame itself if the bearing fails over time (seen this too many times coming into the workshop). even when bearings are fitted using anti-seize, over time it always get flushed out by water / contaminants and then its creaking again

Trek also seem to use a system where the metal bearings sit directly into a moulded carbon fibre cup that is part of the BB shell, which is not ideal as the bearings are a loose fit (we have pressed them in using hand pressure) and I have seen these cups become damaged, writing off the frame !

prefer the hybrid systems like PF30 as the bearing is isolated from the frame BB by the bearing being installed into a nylon cup. Any damage to the bearing does not damage the frame itself. As long as the cup is installed properly using DP420 and bearings installed into the cups using gap-seal loctite, and then good smear of anti seize on the bearings before crankset is installed, its not a problematic setup

I'd always prefer the English ISO threaded BB shell any day though Wink
  • + 33
 What is the difference btw a BB, a BB69 and a BBW?
  • + 31
 I try to stay away from BBW, I prefer BBC personally (no homo)
  • + 1
 You know what? I just can't wait for them to release an Enduro-specific bottom bracket that will make Enduro-ing much more awesome and epic! #Enduro
  • - 25
flag Tnp128 (Mar 18, 2014 at 7:18) (Below Threshold)
 BBW is short for Big Breasted Women
  • + 3
 If they come out with a frame, component or wheel that plays metal, I'll buy it. Just blare despised icon at me and we're good.

@shemphoward bbw is a fantastic thing involving boobs and butts. Get bikes involved and you have a great time Wink
  • + 8
 METAL! Amon Amarth to channel your inner viking on those brutal slog-fests, Slayer when you're slayin berms, Aborted when you wreck, some Agalloch or Gojira when you're communing with nature, Suffocation when you're bustin out a climb and can't breathe.. I'd pay 2 bucks for that in a heartbeat!
  • + 1
 See it needs to use the same technology of the wind up music boxes. Makes sense to me
  • + 1
 Bbc over bbw...you might be a Homo, lol Origin and Blut Aus Nord for the win!!!
  • + 0
 I am a homo and do prefer BBC.
  • + 2
 they forgot to mention than bb92 is the same as American BMX bb
  • + 3
 WTFfff is going on
  • + 10
 Pinkbike in a nutshell…. Thats whats going on.
  • - 4
flag snoopy24777 (Mar 19, 2014 at 18:27) (Below Threshold)
 just to clarify with previous comments BBW does NOT mean big breasted woman but Bros Before Women
  • + 7
 I though bbw was big beautiful woman
  • + 7
 nope^ it can also mean beverian butt whip
  • + 62
 Im glad you guys got to the bottom of this!
  • + 50
 I was certainly im-pressed by the author's knowledge
  • + 29
 You mean the (bottom) of this!
  • + 10
 {bottom}
  • + 9
 [bottom]
  • + 3
 (bottom)
  • + 3
 bottom>
  • + 2
 bottom>
  • + 29
 @conv3rt

there is unfortunately, more to this topic than covered in the article itself Frown

we have threaded shells:

English ISO
Italian

we have press fit shells:

BB30
PF30
PF86
PF92
OSBB
BB90
BB92
BB95
BB386EVO
BBright

I work as a bike mechanic and have to know about all this nonsense when a bike comes in for "repair" and the customer says "I need a new BB?"
  • + 6
 @hampsteadbandit and what about US BB? Spanish BB? Mid BB?
  • + 8
 @Auxx those are all BMX standards, less common in most shops unless the shop does have a wide selection of them.

And I hear you @hampsteadbandit, same god damn story for me. The worse is when a customer walks in WITHOUT his bike and wants to buy a BB, "Okay, what standard?" "Eeeeeeh... Standard standard, you know for a regular bike..." hahaha.

And don't forget French threaded shells found on old Peugeot's and other bikes from about 30-40 years ago. And Euro BB's too.
  • + 1
 @Auxx

of course you are right!

the BMX bottom bracket standards exist, but I don't get to work on BMX anymore so don't really figure on my radar...
  • + 1
 @Alex-Mtl

we don't really see French anymore, or many Italian (sometimes on high-end steel road frames)

"Euro BB" is same as English ISO (BSA) threaded (1.37 in x 24 TPI)
  • + 4
 @ Hampsteadbandit You're right, I just had to deal with two old Peugeot's this summer and discovered the old standard at the same time, but I had never seen any before that.
  • + 1
 @Alex-Mtl

its one of those rare oddities you will see from time to time, but perhaps less than once a year even in a super busy workshop
  • + 2
 the best part is if someone brings a crank and a frame with diffrent standards and asks if this can be fitted.
  • + 1
 @hampsteadbandit dirt/street frames comes with BMX BBs. Like Commencal Absulut CrMo comes with Spanish (discontinued model now, but still), Dartmoor Cody comes with Spanish too. I've never seen an US BB on an MTB, but Spanish and Mid are pretty common.
  • + 1
 @auxx the old dmr frames come with a us bb
  • + 1
 @Auxx

yeah I am aware of the bmx BB (I spent years riding BMX and my last frame had Mid-Size BB, and previous had Spanish BB)

unfortunately don't get DJ or BMX into our workshops any more (for the last few seasons) so just don't seem them much Frown
  • + 1
 And now there's BB30A as Canondale continue to be arse holes
  • + 34
 I understand the press fit to a degree with carbon. However, press fit for metal frames is just a step backwards in tech IMO. If manufactures need to go wider, fine. But keep the threads for metal frames. Growing up with BMX, we constantly had to deal with poor tolerances with frames (loose or too tight), noise, tight bearings, etc with the old press fits. Threaded euro BB's made things so much more polished and simple for BMX frames once they were implemented.
  • - 22
flag deeeight Plus (Mar 17, 2014 at 22:11) (Below Threshold)
 You do realize that press fit bottom brackets are essentially the exact same technology as is used in headset cups, the majority of which are pressed into frames right?
  • + 19
 Absolutely. However, a headset cup goes thru different types of loads (primarily thrust) on a regular basis than a BB. Even they can get creaky at times. I am fine for wider tolerances. Just seems press is easier to get wrong. Again, my opinion after 28 years of riding & countless bike builds
  • + 13
 Deeeight, sorry, but you are wrong. There is a huge and fundamental difference. On a bottom bracket, the forces are perpendicular to the axis of the bracket, making the tolerances much more important. For a headset, the force is parallel and therefore automatically spread evenly around the shell.
  • + 2
 this is stupid ... e13 has bigger bearings for it's hive dh crank and a larger cup that threads in the 35 mm "standard" shell ... why can't sram make threaded cups for the 30 mm spindle? that would solve a lot of problems ...
  • + 12
 Simple, press fit bb's are cheaper to make (no threading required) , meaning that the manufacture gets more $$$$ from their 10k bikes, and then you need to buy a bb press ( if you like wrenching on your bike) , and ultimately it is easy to mess up the bb thus leading you to buy another 10k bike = more profit.
  • + 4
 Threaded all the way. Press fit have plastic cups & are generally shit. Try explaining to a customer why their press fit BB in their expensive frame never appears to last very long. Easy to work with but that doesn't always make things better.
  • + 6
 bman33: My sentiments exactly. Press fit bb's f*cking suck. Press fit is another cost saving measure by the made-in-china bike industry. And idiots who say a headset is the same thing as a bb have no f*cking clue what they are talking about. Thank god some companies like yeti, knolly, and others are still using threaded.
  • - 6
flag deeeight Plus (Mar 18, 2014 at 7:09) (Below Threshold)
 Right right... you whiners on a web forum know more than engineers with degrees and apparently do so without even a basic understanding of physics. With headsets, the loads aren't just coming parallel to the bearings... they also have to deal with perpendicular forces since every frontal impact the fork and wheel takes tries to leverage the steerer tube against the top and bottom headset cups.

And while "insulting" the made-in-china industry... where exactly do you get off thinking chinese made carbon frames are poorly made?
  • + 0
 @bman33.... you do realize that most BMX manufactures have gone back to a pressfit BB, right? Spanish and mid BB's are pretty much the norm now except for some race bike manufactures that still use the euro style threaded BB.... just sayin'
  • + 3
 I know most street/DJ bikes are press. My experience is just with race bikes. Either way, I just see press as a backwards step. Again, my opinion. It's seems a more precise fit. Maybe the manufacturers of the frames and the BB have tighter tolerances now. I just remember dealing with massive sizing/tolerance issues on the frames and some BB's as well as the creaks and noises. You can also install a threaded BB with a $20 tool instead of a press. (or 2x4 and hammer as many 12 years did back in the 80's Ha!).
  • + 16
 Yes, deeeight, bman33 (and others here) do realize that press-fit BBs are the same tech as headsets. That's exactly why it's a step backward. Decades ago, headsets and bottom brackets both had cups pressed into their respective tubes. Then BBs started being threaded. Less noise, easier installation, no hammers. Now they're going back to press-in. Hence, a step backward. Creaking is back again, installation/removal is a pain in the ass again, and hammers are used once again, which customers who spend thousands of $$ on their bikes just LOVE to watch while we mechanics work on their bikes for them, let me tell you...

Headsets are press-in for the majority, like you said, and guess what? A lot of them creak, they like to go in crooked if the tolerance between frame/cup is even the slightest bit too tight, just like PF BBs (even with a Park HS press), and removal is archaic using a hammer.

I, and many other mechanics I've talked to, would love internally threaded headtubes (like BBs) with cups that thread in just like external BB cups, using the same type of splined tool. (And how cool would it be to have your BB and headset cups match like that??). Easier, consistent installation/removal, and you know the cup is completely seated when installed. No more slightly settled (loose) headset after your first ride.

However, as this article points out with BBs, it would also be more expensive to manufacture the head tubes, as well as the headset cups. Oh well...

@cglasford: what makes the difference if bman33 didn't realize BMX manufacturers have gone back to pressfit BBs with Spanish and Mid? His points just resonate even more by adding in those 2 extra examples. Ever tried pressing bearings into a Mid or Spanish frame? You might get them in straight after the 6th or 7th try.
  • + 14
 This is why Santa Cruz doesn't use PF30:It is true that there are some slight weight savings available with the various pressfit bb designs (exact weight savings obviously vary depending on system, frame manufacturing techniques, and crank model), but we don't feel this small savings make up for the inconveniences. We are still able to make a frame that is lighter than most of our competitors (5.1 lbs), while still using a heavier bb system. There are a number of disadvantages that exist with press fit systems:1) Special installation and removal tools are required for these parts, including a headset press. This is not convenient for most home mechanics, and they are quite expensive. Traditional external BB's can be installed or removed with a simple $10 hand tool.2) "Permanently installed cups". Shimano doesn't recommend removing and re-installing their press in bb cups (as they may become damaged), so moving parts from bike to bike is no longer an option. http://techdocs.shimano.com/media/te...9830625426.pdf3) Creaking or shifting bb's can be common with these systems. Since the bearing is pressed into a cup, which is then pressed into the frame- it can be hard to get all of the press fits snug- without being too tight on the bearing or too loose in the frame.4) Reasonable tube sizes. One of the most commonly claimed advantages of a larger bb shell is the larger diameter downtube that goes with it. This may be an advantage on road bikes, where tubes can be increadibly thin and large for optimal stiffness. On a mountain bike, this area of the frame sees a lot of abuse from rocks and crashing, and needs to have a certain amount of wall thickness to survive actual use. Using what we consider a "safe" wall thickness and carbon layup, and a fairly typical tube diameter, we get an exceedingly stiff, light, durable product.
  • - 6
flag deeeight Plus (Mar 18, 2014 at 10:43) (Below Threshold)
 If mechanics are using hammers in bike shops, blame the shop owners for not spending money to upgrade the tools, not the manufacturers for specifying press fit BBs. A headset press is a tool all shops should own, and a headset press can also press bottom bracket cups perfectly. Park makes a whole series of presses that are even cheap enough for the average consumer. Anyone still using a hammer is just being lazy or cheap, or both. I've been installing headsets for 25 years...and my assemblies don't creak... if you know how to do it, you do it correctly...if you don't, you shouldn't be doing it all.
  • + 6
 If we used a larger downtube, we would either have a heavier frame (same wall thickness but larger diameter), or a less durable product (thinner walls and larger diameter).5) Chain clearance. Take a look at some of our competitors frames with press in bb shells. The down tube comes so close to the chainrings that many frames have chainsuck guards on the downtube! In our mind, the chain should be able to fall off on a mountain bike and not get jammed between your crank and thin-walled carbon downtube.6) Backwards compatibility: Many of our customers purchase a frame and build it up with their choice of parts, or parts from an old bike. By using a standard bb, we are compatible with everything without requiring confusing adaptors.7) Chainguide compatibility: While it may seem strange to talk about putting chainguides on a 100mm bike, it is becoming more common now with 10 speed drivetrains. Thread in bb's mean the frame is compatible with bb mount chainguides. We like versatility....Why did Shimano go with their current system (over say a BB30)?When Shimano originally released the external bearing two piece crankset back in '02 they determined that a 24mm diameter axle was the optimal for strength to weight ratio, stiffness and also minimising friction from the rotating BB bearings. It also allows them to use steel as an axle material without a weight penalty. A BB30 system requires an oversize axle to give stiffness but axle made of steel would be bring a weight penalty as it wouldn't be possible to make the steel thin enough to keep the weight down for this application. Shimano feels aluminium is an inferior BB axle material compared to steel. Shimano chooses to use steel on all its high end axles for durability and peace of mind.

Pressfit is inferior. Period.
  • - 16
flag deeeight Plus (Mar 18, 2014 at 10:49) (Below Threshold)
 yeah yeah, protour can copy & paste, but not actually understand...we all knew that already. Perhaps someone should tell Santa Cruz that Park tools offers a consumer series headset/bb cup press for 1/3 the price as their shop grade commercial tool. Perhaps someone with a BRAIN and common ingenuity should tell them that all it takes is $10 to BUILD your own such press.
  • + 1
 @ tmargeson: I guess my point is that they went back to it and everyone that I know that rides BMX is happy with it and would prefer spanish or mid bb... I as well do not mind pressfit. As deeight stated it isn't that difficult to install and 1 tool does both. Good deal there are options for both
  • + 14
 deeeight. You clearly know stuff. Ever think about not being a d*ck about it? People might agree with what you have to say if you skip the agro attitude. Thanks.
  • + 5
 Deeeight, take a look at the official Park (or any brand's) tools designed specifically to remove headset cups and press-fit BBs. They require a hammer. It's part of their design. Not the fault of the shop owner or mechanic for using a hammer.
  • + 12
 Damnit deeight, you interrupted my cut & paste.
  • + 4
 @deeeight You got me more then curious, how the heck do you get the old bearing (head or BB) out with out a hammer? please enlighten me!
  • - 2
 Why do bicyclists think that special rules apply all of a sudden to technology that's been used in aviation/motorsports for decades... or the ability to read and comprehend what someone writes without making up words that they didn't say...

Yes a hammer is removed to take the cups/bearings out... they in fact make race hammers specific for this that can remove the bearing assembly properly without damage. But you don't use a hammer to install them, you use a proper press. Which is what I was describing doing. Of course why understand what I wrote when negative propping and/or bitching is easier.
  • + 0
 Press fit spreads the force on the frame outwards. The force from the bb is spread the most evenly and with the most surface area. With a threaded bb the force is pulled from side to side when the threads become a mechanical lock, thus creating a lot of weird stress areas. Im thinking I will deal with the noise for a stronger set up (when tolerances are correct). Oh wait ill just clean it and take care of it and not have a noise. Threaded makes more sense for most people as press fit require more bull shit to keep good but from a structural stand point press fit has the potential to be better.
  • + 1
 deeeight, actually propped you +

Anyway, we established the fact that a hammer is in deed need for the task of properly exchanging headsets as well as bottom brackets.
I just think is simply not an elegant nor smart solution for the exchange of a expendable part which is subject to wear.

In engineering you differentiate between nondetachable and detachable connections (excuse me if this is not the correct term, my engineering classes were held in German way back and i have no used or need this term since i moved to the states)
Pressing is considered a nondetachable connection method.
For a bearing, subject to wear you would not use this kind of installation in this place in aviation or motorsport for example.
Especially on a part that is supposed to be light weight and extremely thin walled this would be a no go considering the expected life time of bearing and surrounding part (frame) are not the same and the danger of permanently damaging components would be too big.
On carbon fiber you are facing excessive risks as it is nearly impossible to evaluate if the material got damaged throughout the mounting or dismounting but also on metal frames you face a problem as the softer frame material gets stretch out by the harder bearing on the first installment and you will not be able to reach the same strength in the connection anymore on the second BB you install on your alloy frame.
For this reason you can actually get a lot of automotive/engine parts in different tolerances meaning you install a bigger piece the second time around to maintain the strength of the connection.
I only guess here but i don't think we will be supplied different fitting BB's for second installation...

This leaves me only with the conclusion that using pres fit bearings is a bicycle only thing clearly saying "we don't care how your bike works in 2 years but we are happy to sell you a new one"
  • + 1
 Yes, basically it's the cheapening of the bike industry. Some companies care about their customers for the long term and use sound engineering principles, but most do not. Support the good companies, trash the bad ones publicly if you care. Or be a Specialized/Giant/big bike brand whore and pretend your Pressfit BB is superior. ... because the salesperson and marketing bs told you so.
  • + 6
 When I service a bike I remove the threaded BB & clean all the shit out, of which there is usually plenty. This is where all the water & grime that has entered your tubes ends up. This is not a problem if you can get it all out & degrease it all including the threads. You can't afford to remove a press fit & risk damaging it so the shit has to stay in there unless you are replacing the BB anyway. Again, calling your customer & telling them you have damaged their BB because you were trying to clean it out doesn't sound too good does it.
  • + 3
 hammers are not needed. get a bearing press and a bearing removal tool. one that grabs the actual bearing. Bike tool companies aren't the only ones out there you can get a bearing removal tool at any specialty tool store. if you have the correct tools you will never need to use a hammer Not saying press fit is better than threaded but it defiantly has some advantages. We don't use threaded headsets anymore...
  • + 3
 I like to do all my own wrenching. I have the tools for standard BBs. All this press-fit nonsense means extra expense for no real gains in performance and huge headaches, so much so in fact I'll never buy a frame with a press-fit unless I have no choice, until then it's a deal breaker.
  • + 1
 @JonJonM, oh I forgot, I could use a automotive bearing puller!
so i would not need to use my hammer to hit the Park tools split up tube from the top but can buy the expensive thing and damage my frame by pulling the integrated slide hammer... dammit bearing pullers have a part that is called hammer as well... what now?
magnetic magic remover?
Mr Clean spray makes the bearing go away! that's it! pft pft and gone...
  • + 2
 I know the OP says the pressfit is a step backwards in tech, but surely cycling is about performance?

I felt a HUGE difference when Giant when to press-fit BBs. I seriously could not believe that I would have even felt the difference, let alone that the difference when climbing and sprinting would be astounding. My legs told me that press-fit is superior, not marketing.

You guys can't say bad things about press-fit, when most of you, I'm sure, think the best type of wheel is a nicely built j-bend spoked wheel, even though they take a lot more time to build and maintain than a press-fit BB. And if you have all the wheel building tools, then I'm sure you are also the sort of person that will have all the BB tools as well. Engineers could make an indestructible wheel with terrible performance but you guys would be happy because you wouldn't have to maintain them. Mechanics don't get to decide what people ride, you just do the job you've been given and do it with a smile on your face. That's what it means to be a professional mechanic.

I've lost count of the bikes I've owned with press-fit BBs, but so far I have only had to replace one. Remember that days of ISIS BBs and square taper? I was changing those things on my bikes every other month.
  • + 5
 Press-fit: engineer's wet dream = mechanic's nightmare.
  • - 5
flag deeeight Plus (Mar 18, 2014 at 20:39) (Below Threshold)
 I haven't a problem with press-fit... follow the directions, use the proper lubricant for the assembly, use the proper tools... perfect assembly. Assemble a threaded bottom bracket incorrectly and it'll creak up a storm.
  • + 2
 I have swapped Sram and Shimano press-fit bottom brackets because I wanted to swap drivetrains between 2 bikes. I used a hammer and a big phat flat screwdriver. I still use those same brackets. Of course, I spent somewhat more time removing them like this than a mechanic would, but they still spin like a charm and I didn't spend a lot on tools or new components. I did buy a spare set of bbs because I could have damaged them, but they are now in the drawer waiting for the current ones to wear.

A friend of mine ruined a threaded bottom bracket and needed it to be threaded again. That will never happen with a pfbb.

This discussion could go on for days. Personally I don't give a single fvck about what bb is on my bike, as long as it spins and I don't need replacing it every 1000 miles Smile
  • + 1
 You can still f*ck a PFBB. Get the angle of the bearing slightly wrong and you can risk cracking your frame, which is a much bigger hassle than getting the threads cut again. I'm down for whatever, if my bike has a PFBB then so be it. I would prefer a threaded BB as they tend to last a bit longer and don't creak like a motherf*cker when properly installed. I'm a mechanic, so if I ever did get a PFBB then I can just go to my shop and use our tools so it's hassle free for me but I can understand why people who don't wrench for a living not liking the removal/install process.
  • + 1
 No... you can't... not with the proper tools... a deadblow mallet and a drunken brit hack maybe won't line up the cups right but the proper press tool and it'll line up perfectly. And given how most PFBBs have plastic or aluminium cups which aren't exactly super hard or strong, its basically impossible to crack the frame first unless you're using like a claw hammer to whail at the thing trying to hammer it in and you completely miss the cup on one swing.
  • - 1
 deeeight....we are simply like Christopher Columbus just trying to tell them that the world is actually round. I dont think they understand.
  • + 0
 KUNTHER... much like Columbus... believing to have found a better way to India...
  • + 2
 Only Columbus did some good for the world. You two swines are just talking about bottom bracket installation/removal. Yeh i see the resemblance.
  • + 1
 Columbus? This thread evolved to Columbus?

Columbus found some land he called India. Because he thought he was there. Instead, he found America; but he didn't know. Did it matter? Nope. He found land, the same as he would have found if he actually were in India. He met people and traded with them, the same he would have done if he made it to actual India.

So if you look at lands being bottom brackets and Columbus being a cyclist and the trading being riding, he had no idea what he got, but he managed to ride. Ok, this was a stupid comparison. My point is:

People should stop looking for differences within one same "category". Sure there are ceramic bearings and different weights, but a BB is a BB whether you slide it in or screw it on. If you manage to f*ck up your frame, it's you who were incompetent or not gentle enough. Stop blaming whatever else.
  • + 3
 Yeah I know, late to the game here. Never one to pass up shitting on stupidiotards though, here it is. That giant (sometimes 8" travel+) fvcking fork you load laterally with the radius of a 26"-27.5" wheel adding even more leverage to that pressed in headset is bearing down a hell of a lot more than your spindle does on your BB bearings. Big 180 drops with long forks that can tear the head tube right off a frame in under 3 months (yep I tore through that shit one after the other about 10 years ago along with fork steerers/stanchions) & most of the time the headsets stayed tight, unless the head tube stretched too which can't be remedied by a threaded up any better than a thicker tube. A press fit BB is no different than a typical hub with cartridge bearings. It's the same f*cking thing & no one ever has problems with hubs. A hub's a hub more or less. The two most forgotten about parts on a bicycle are cartridge bearing hubs & pressed headsets. EC headsets may give problems, but done right, bearings inside the tube, nah. There's no better way. Honestly how fvcking often does a headset or a hub ever give anyone any bearing related problems besides normal wear on bearings. Next to never! Less parts is more better. A threaded cup accomplishes nothing of value. It's another joint to creak, threads to cross (& they do & if they strip, you can't fix) & in case any of you dolts never took a look inside a pricey rebuildable threaded BB, the bearings press or slide fit into the fvcking cups you dumb shits! PF is forward, not backward. If it's not done right it may seem inferior (like EVs compared to IC cars) but the opposite is true for so many OBVIOUS reasons. :s
  • + 26
 Pressfit really isn't so bad, but if you make a trailbike with a pressfit only bb and NO ISCG TABS, you deserve to be shot at dawn. Seriously. Looking at you Pivot.
  • + 7
 Intense Carbine.... the reason I overlooked this bike when renewing my fun machine.
  • + 4
 Iscg tabs are soon a distant memory with the narrow-wide rings working so well. Chainguides are a fix to other components not doing their job correctly. Lets not cry when chaunguides become redundant, just bemoan that it took so long.
  • + 18
 I currently run a narrow-wide with a top guide (like many) AND a taco to avoid smashing my chainring and lower link of my VPP. No iscg is not the past if you want a taco. I do.
  • - 1
 EnduroManiac ever heard of a bashring? You only need a taco if you are using spiderless cranks eg new XX1.
I run a narrow-wide with top guide like you and a bashring. Thus negating the use of ISCG tabs.
  • + 7
 Not too hard to bend the spider and/or entire friggin crankarm. My vote is to keep ISCG tabs..not like they add anything more than a few measly grams.
  • + 7
 Seriously....narrow wide rings HELP retain your chain. Chain Devices KEEP YOUR CHAIN ON. Chain devices are not a thing of the past unless you really are very gentle with the bike. No skids, no pedaling in rock gardens, no hooking up on big gaps, no crashing, no dropping your back foot into corners. no fun basically
  • - 5
flag deeeight Plus (Mar 18, 2014 at 7:12) (Below Threshold)
 Having managed to pitch a chain enough to jam it into place between the ring and rollers, there is no perfect solution.
  • + 1
 SintraFreeride, if I wanna protect my lower ring with your bashring (yes i know that, I've had some in the past and found better solutions since) i'll have to use one the size of a 44 t at least... Not sure i'd find an upper chainguide fitting that and with a 32 or 34t, it might not be very efficient at keeping the chain on. But who knows?
  • + 6
 We don't give a **** if you want ISCG tabs any more than we care that you hate PF BBs. Non-ISCG is cheaper to manufacture. You'll take what we give you to take- and you'll like it. -The Bike Industry
  • + 2
 @deeeight If that happens with your chain guide you're probably not setting it up correctly.
  • + 1
 I wouldn't want to use a bash ring instead of a taco. Never add rotational weight when you don't need to. ISCG tabs are here to stay.
  • + 1
 @ gabriel-mission9 - you have obviously not used a narrow-wide ring. I was skeptic too until I got one now there is no going back.
@EnduroManiac - well if it works for you stick with it then. Personally I've been using a 32T front ring since the late 90s with a small bashing and have NEVER had any problems.
@dualsuspensivedave - seriously? you're gonna use the rotational weight argument against bashrings...
  • + 1
 Do you have a vpp style lower link to protect? I don't think so, 32t would be too small.
Now we don't all have the same needs and ideas, but those iscg tans don't hurt anyone so leave them on!
  • + 1
 I have obviously not used a narrow wide? Erm how is that obvious? Sorry but if you are pummeling through a rock garden whilst on the gas with no chain device your chain is coming off. Yes narrow wides help a huge amount. They do not eliminate chain offs. A well set up chain device does..
  • + 1
 Absolutely use the rotational weight argument. Makes the most difference. Hence a big reason why manufacturers are making direct mount chainrings. Have you ever tried using lighter cranks?

Pull your head out of the sand and realize iscg mounts are here to stay. Never even heard of someone even thinking that iscg mounts are on their way out.
  • + 20
 Love my threaded BB on my Santa Cruz bike. $10 wrench to remove and to install BB. Also, threaded BBs are super cheap and easy to replace/service. Santa Cruz is a cut above the rest, as usual.
  • + 8
 Knolly too!
  • + 3
 Liteville and Nicolai seem to stick to the same (proven) principle. Santa Cruz has something to say about threaded and press-fit BB's on their site, aswell as a nice article about "standards", fun and interesting to read. Nice to see they stick to some principles and have a sense of humor too.

Those cheap Deore/LX BB's aren't much good sadly, but what do you expect for 9 euros. I had one rust and seize up after two weeks of use, with good conditions... XT/XTR ones seem to be a bit better. But good excuse to buy one from Hope, they are a bit dearer, but so much better. Still runs smooth after 7-8k km's. Nice piece of kit, sealed cartridge bearings (which can be replaced, they offer a tool for it), very good fit and finish, selection of colors.
  • + 1
 i agree with @erik2k10 says, i prefer threaded BB because of it easy to replace/service
  • + 16
 I've been a bike tech for a few years now, and I can say most bottom brackets are a pain in the ass. Although threaded ones like shimano, are a bit less of a pain in the ass.
  • + 3
 So, as far as it comes to pain and bb shells... What about a pro tip for removing truvativ howitzer bb shells, kind sir?
I got the tool from truvativ, drowned the f*ckers in wd40 and they still wont come out?

Thanks. Smile
  • + 8
 My pro tip is explosives and a rail gun. Can't see what could possibly go wrong.
  • + 2
 Make sure you know which way the threads go, then engage impact driver.
  • + 2
 They both thread towards the front wheel. Put your bb tool on there, get a long pipe big enough to fit over the bb tool arm, give it hell. Leverage is your friend.
  • + 2
 Grab that bitch tool at the very end and yank !!! Haha of course making sure you're yanking in the right direction. It should say on the bb. Plus grease next time so it doesn't stick like a wanker again.
  • + 2
 m.youtube.com/watch?v=sGkdgrjzopI

Check out this vid. It should help and hopefully after seeing it you'll recognize exactly what you're taking out. Also make sure you let the Wd40 sit in over night if it's giving you troubles before you try anything crazy. And as I said before, grease before re installing!!!! So when servicing that wont happen again. If all else fails, if you go to your lbs and ask them specifically to remove your bb and nothing else. They will likely do it for free.
  • + 2
 Thanks for the tips, i will give it another try.
  • + 12
 Call me stupid, but I am still confused...
  • + 8
 Me 2….

One day I need to actually fit and unfit each design so i can understand WTF everyone talks about. Until i do it manually I'm screwed!
  • + 3
 Ok... you're stupid.

You did ask. ;-)
  • + 3
 i tried reading it twice between the bb30 and the pf30.. i got so lost.
  • + 8
 just kiss, nothing wrong with threaded BB's; all this press fit stuff is stupid. Atleast SC had the brains to use a bb for it's bullit pivot. THAT was smart, refining and simplifying things. What's next? lets suddenly make headsets threaded for freaking reason other than to sell more things.
  • + 5
 ISIS ,Octalink, X drive, GXP . All of these types are splined . None of these types are compatible. Now we have 68 mil. 74 mil 83 mil. and 200 mil. lengths.
How bout we throw in press fit cups. Why? Its cheap to make frames that way.
Oh lets make oversize axels and squeeze in tiny bearings. Wait it only fits in press fit cups! Brilliant!
  • + 6
 Cause we didn't go to outboard bearings in the first place in order to get rid of the awful bearing life of ISIS and square taper BBs, because of their bearings being tiny, right? I'm not usually one to hate on new tech, but all in all, I'm pretty non-enthused about press-fit BBs.
  • - 1
 Shimano went to outboard bearings because it let them return to using JUST ball bearings in their BB assemblies, in a proper size to support the spindle loads, and it also sped up assembly only having splines on one end of the BB spindle to deal with. The Octalink BBs that they used before used a combination of roller/needle bearings and tiny ball bearings, were costlier to produce and took longer to assemble. Pretty much any major "bearing" change in bicycles the last 25 years has been done to speed assembly and cut costs for manufacturers, not to specifically benefit consumers. That's why we all have threadless fork steerer tubes on our bikes now. Practically everyone else copied shimano's move to external bearings because they all learned their lessons after the ISIS debacle that its better to just copy the best than try and invent the worst.
  • + 2
 Threaded BBs come in 68, 70, 73, 83, and 100mm. At least you got one right...
  • + 0
 They make a 70 mil? oh I got the 68 and the 83..........That would be two correct.
I hope you feel all warm and fuzzy inside correcting me.
  • + 2
 I do, I do. Thanks. Smile

68 is standard road Euro and some hardtail MTBs. 70 is Italian road (also a different thread pitch and shell diameter). 73 is standard MTB on most full suspension and some hardtails. 83 is DH and FR. 100 is fat bike.
  • + 0
 100 was actually originally DH/FR bikes about the same time that 150mm hubs came along, it was simply adopted for fat bikes as a matter of convenience as it allowed for still wider rear hub spacing (170mm and now 190mm) to support wider rims and even fatter tires.
  • + 1
 Shimano made a 100 mill bb for the Saint crank. What is a fat bike?
I believe the wide BB is to make for a straighter chain line on bikes with wide rear hubs
Yes there are free ride bikes with 100 mm BB,s
  • + 1
 I can't find any documentation regarding a 100mm Saint BB.

But a fat bike uses 170mm spaced rear hub to help accommodate 3.5-4.0" wide tires on super wide rims. Therefore a 100mm BB is necessary.
  • + 1
 I don't have the Saint BB but I do have a Truvativ ISIS GigaPipe team bottom bracket in 100mm which I used on my Salsa Mukluk until I upgraded to Raceface Turbine cranks this winter.
  • + 5
 I have a shimano pressfit bb on my AM bike, the tools for changing the bb were expensive and hard to come by, but i needed them because the problem is the sealing, eventually the bearings almost seize, you can regrease them up to a certain point but then it must be replaced, i`ve changed bb once a year. For comparison, on my hardtail which i have used both for trail riding and commuting the threaded slx bb is still as smooth now as when i installed it almost 5 years ago.
  • + 4
 Much as I enjoy PinkBike (and fully appreciate the fact that it's free) I find these types of articles frustrating. They seem almost lazy in that they only scratch the service.

Below is BikeRadars (also free) effort which I found much more informative.

I love you Pink Bike but if your gonna do something, do it justice, make it useful those who are new or don't know much about the topic. Peace ya'll.

www.bikeradar.com/gear/article/complete-guide-to-bottom-brackets-36660

Yeah you've probably covered
  • + 2
 Oh, and no offence Mike!
  • + 1
 wow, that one looks setup a lot better than this article.. i tried reading the difference between a pf30 and a bb30 and still dont know what the difference is.

oh well...?
  • + 2
 As long as the industry keeps shi**ing all these different "standards" on us you may never know jumpman Smile
  • + 1
 lol. i know, right?!
  • + 6
 BB30's and all that pressed shits SUCKS!!!! Theres no problems with threads, placing and removing BB's, I hate when the only solution to remove things comes with a hammer.
  • + 6
 Pink bike should post more of this kinda of stuff so that people who don't really know about bike parts can actually learn something instead of "PROTOTYPE" frame and such.
  • + 5
 All the manufacturers try to find the way to save money for built a frame, but the final price are still growing up. The new standard :
BB30
PF30 ecc. ecc....
are not a advantages for the rider,.........
  • + 2
 Are we voting on this? Does anyone in the industry give a sh!t about our typed opinions? Threaded BB is my vote. Works well, easy to fix. Don't screw with it. PF offers little or no advantage while managing to be a pain in the .....
  • + 2
 They failed to mention that the new press fit bbs coming out now come with an inner shell with threads in the middle thus reducing creaking and allowing better installation.
www.hopetech.com/page.aspx?itemID=SPG528
"Press fit BB
Following the success of our PF41 bb we've now expanded the range to include PF46/PF30 BB's. Our unique system of aluminium cups and screwed together centre tube ensures precise and secure fitting into most frames, eliminating the usual problems of press fit bottom brackets becoming loose over time."
  • + 1
 That is an expensive aftermarket bb that no company will likely spec. There is no advantage to it over threaded bb's, and I don't think it would necessarily eliminate all the problems.
  • + 1
 I was saying it would be better than standard pressfit not necassarily better than current external threaded bbs
  • + 2
 I recently installed a bb30 on my Cannondale and I actually managed it fairly easily, which is rare for me. Bit of wood, rubber hammer, done. I felt like a caveman that was about to destroy a thing from the future, but it all went together nicely. My next task is shortening brake hoses, I've only got two tools, a hammer and the multitool I got free with an old copy of MBUK. Wish me luck.
  • + 2
 Yeah - it's only messing with brakes! Nothing could go wrong with that, eh? :-)

Joking aside I love the fact that 90% of bike maintainance can be done at home with a few tools and the willing. Best of luck (I hope you have a bleed kit!)...
  • + 2
 If you remove the pads and squeeze the lever so the pistons come in (not too far in) then you should be able to do it without bleeding…for Shimano at least. What else is there? Just need a razor blade, those yellow blocks and a vise and you're golden.
  • + 2
 I definitely feel a little odd using a rubber mallet to finish the installation of BB bearings on a carbon Trek road bike.
  • + 1
 Gusset make a pf30 shell to Shimano 24mm crank adaptor bbs.

here is my quick compatabilty chart for you guys:

threaded bb, square taper, isis, octalink, bmx euro, Shimano external ( fsa,raceface ect..) sram gxp threaded, raceface next sl, e-13 30mm

bb92, Shimano 24 ( raceface, fsa ect..) sram gxp, raceface next sl, e-13 30mm

bb30, sram bb 30 cranks (i think m-part make bb92 adaptors)

pf30, sram bb30 cranks, raceface next sl, e-13 30mm, and Shimano,fsa,raceface 24mm with gusset pf30/pf92 adaptor bb.
  • + 1
 I know i missed one or two so feel free to add to this
  • + 1
 I know this is irrelevant but my lbs don't seem to have any ideas on this so does anyone have a suggestion as to how to fix a bottom bracket shell? I have an old steel frame which I want to make a singe speed out of yet the edge of the bb shell is slightly bent in. Thoughts as to unbending it?
  • + 1
 Bent or deformed? No idea to what extend and how thick the shell is, so an educated guess here, but you could try and face it, chase or cut the threads afterwards.

Which incidently is quite ontopic. Much of the problems with threaded BB's stem from not properly faced shells (parallel), causes early wear and the thread being not clean enough or not cut properly.
  • + 1
 Find a suitable donor frame, fire up the oxy/welder and go nuts?
  • + 1
 we nowadays see more and more brands that use bushings instead of ball bearings for suspension pivots.. am I the only one wanting to experiment with BB bushings?weight reduction and stiffer as the stiffler! or maybe those tolerances are too expensive for mass production? anyone?
  • + 1
 PLEASE just stick to threaded. Make it bigger if you like, just stick to theaded. Pressfit is a stupid idea. I have lost count how many times my friend has changed his cannondale pressfit BB bearings.
My threaded Chris King is doing awesome however.
On that note-Chris King-could you please make a BSA30 Bottom bracket so I can by a raceface next sl crank?
  • + 2
 Shimano pressfit over here on SLX cranks- 2 years of beatdown, problem free (knock on wood) the nylon sleeve seems a stroke of genius. Smoothe as rubbing honey onto Keira Knightley.
  • + 3
 Buy, buy, buy!!! Buy this new standard! Buy pressfit! Buy everything, then you'll be safe!! This sucks! Threaded BB's FTW! Kudos to Santa Cruz for not being stupid.
  • + 3
 Funny how new stuff is designed not to last as long as old. that way can sell more product just like all big companies
why make it last longer?
  • + 2
 not funny, sad is the word...
  • + 2
 Yes it is sad, but that is how big business works The only way to change this is for people not to buy their products
  • + 2
 Internal bb 3 bearing 2 on drive side 1 on non drive bomb proof cheap . I've moved my Isis bb from frame to frame year after year 0 issued ... No school like the old school .. Oh and I can get cranks and bb for $75
  • + 1
 Should add, that the BB92 standard also applies to GXP (SRAM and Truvativ) cranks. However, they have a spindle that is 24mm diameter at the drive side and 22mm at the non-drive side. Thus, BBs for GXP use a bearing with a smaller inner diameter (to match the 22mm) on the non-drive side.
  • + 1
 Some indie companies make BBs that are identical on the drive side (24mm) but differ on the non-drive. In other words, if you buy one for GXP and one for SHimano you have the same drive side assembly on each, but a different non-drive side. Wheels Manufacturing is a company that does this. Some other companies use adapters that you insert to a Shimano assembly to reduce it from 24mm to 22mm. Hope does this. They only make a Shimano BB, and sell SRAM adapter rings. I have this setup, and it is golden. Some, however, complain that using adapters gives rise to creak.
  • + 4
 They lost me with that first question...
  • + 2
 I still don't know what a BB is.
  • + 1
 Don't worry surplus parts hang around for years and you can usually get what you need off the web just make sure you buy the correct part for your frame and do your homework its not that hard
  • + 3
 I took out my BB and put a small branch through. Decided pedalling was outdated.
  • + 1
 I like carrots
  • + 1
 this Idiot I know 'press fitted', loosely using the technical term because he just hammered it in like a nail, a threaded BB into a threaded frame... needless to say he is not an expert thinker let alone an expert mechanic.
  • + 0
 I would like to see someone build a frame with a rohloff or alfine type of gearbox ( although I see both kind of overbuilt, or too heavy) into the bottom bracket so the heaviest parts of the bike are centered and low. Maybe 5 or six gears only for dh?
I like zerode's approach but the alfine hub is too heavy to sit so high. Maybe putting it in the bottom bracket.
  • + 0
 I haven't followed tech stuff in the MTB world for a long time. They've never really known what they're doing. Not surprised that there's multiple standards. There always is. PF 30 is better because it has the bigger spindle. I don't get why there'd be problems with noise. The best way to do it is to press a bearing into each side of the frame, or 2 per side if you really wanna get tough, with a spacer in between that goes over the spindle, then the arms go on over the spindle, butting up against the inner race of the bearings on each side & clamping to the spindle with no less than 2 pinch bolts.

This is basically how my clean, simple, no-name brand front hub works (fork legs obviously in place of crank arms) & it works flawlessly. I've pounded the shit out of it for over 10 years. It's survived multiple fork failures, multiple frame failures, it's never maintained & it never makes a peep. It's not that hard people. Design it right, build it right & you won't have any problems. I've had plenty of squeaks & creaks with threaded BB's. You're still pressing a bearing into something with a threaded design & it's another part that can cause problems. The more parts you throw in to a system where they're not needed, the more likely you are to have problems. Fewer, bigger parts are always going to be better than a greater number of smaller ones to accomplish the same task.

If you really wanna clamp down on loose fits then it's simple, make a shell that clamps the bearings with pinch bolts. I can't imagine why that would ever be necessary though. :/
  • + 1
 I honestly don't care much about BB size, but I certainly care about a noisey BB. Pressfit sounds like its more likely to have a noisey BB than the a threaded cup, and for that reason alone I'll avoid Pressfit.
  • + 3
 I'm still using square taper bottom brackets. Some are 20years old and still mint.
  • + 1
 You're obviously not doing the type of riding that makes JIS obsolete in terms of reliability then. Because I have destroyed more than my fair share of square taper BBs in the past.
  • + 3
 I'm just starting with the jumping. We'll see how it goes.
  • + 4
 All I want is something that spins, how complicated is that.
  • + 1
 Spins smoothly and does not make any noise.
  • + 2
 This is the shiz, stiff, solid, creak free

praxiscycles.com/conversion-bb
  • + 2
 But heavier than a threaded set up with no real advantages.
  • + 2
 Good info for all the press fit lovers, haters, and ri-tardz...though I doubt the latter will read the article
  • + 1
 I don't get why is that difficult to find some plans with the masures of the standards, it can be really annoying trying to find the actual measurements of BB's.
  • + 1
 not an easy solution but, at the end we can cut that press-fit BB as a DIY with someone who knows how to and also with the required tool. this is my plan momently....
  • + 1
 I've had Mid and Spanish bb's die on me after a month of creaking Hell. It kind of feels good to hammer the bearings out when you're angry (while listening to metal).
  • + 1
 I'd like to thank the designers and manufacturers of whatever bottom brackets are on my bikes. I have not had to think about them much in many years of riding.
  • + 3
 threaded external all day long.
  • + 3
 I just want mine to be enduro specific and cost loads
  • + 2
 For the love of all that is holy in the world....PLEASE
  • + 4
 PLEASE bike manufactures stop with pressfit. PLEASE. I have a 73mm BB with a square taper bearing set I put in 8 years ago on my steel hard tail. I learned to pedal kick on it. I ride it in all weather. I have NEVER SERVICED IT AT ALL. It spins buttery smooth -- good as new. It cost $18. PLEASE. PLEASE.....
  • - 3
 All that is "holy" in the world? Nothing is "holy" in the world. Holy is something that only exists in the imaginations of stupid people.

Speaking of, that BB that you've had for 8 years that you learned to pedal kick on, yeah I learned to pedal kick on them too. I used to snap those shitty spindles left & right. They used to creak & squeak & they are complete shit. The BMX industry is the only one that's ever known how to do this shit right. Finally it looks like the MTB world has figured out that fewer parts, bigger spindles, bigger bearings & splines with pinch bolts are the right way to do this. Just because you ride like a lady & can get by for 8 years with a piece of shit that was intended for a different purpose in a different time doesn't mean that piece of shit is acceptable to everyone else now. It wasn't even adequate for some of us back then.
  • + 0
 What I want to know is if I have a PF shimano Zee 104.5mm crank. How would I be able to change my crank or crank arms? Can anyone help me out?
  • - 1
 There is no such thing as a PF Shimano crank. Shimano only makes one spindle type.
  • + 1
 The BB is 104.5 with ZEE with a Zee crank. I want to know what other types of cranks I put on this BB.
  • + 1
 If a Shimano crank fits on the BB then you can run any crank set that uses a non-tapered 24mm spindle. Which is basically Shimano and Race Face. Might be FSA as well but I am not sure.
  • + 1
 Ok. So lets say I want to buy a Raceface SIXC crank set. Does it matter what BB comes with it?
  • + 1
 Shimano BBs will fit Race Face cranks, and Race Face BBs will fit Shimano cranks. The only Race Face crank that will not work on a Shimano BB is the Next crank because it uses a 30mm spindle. Basically which BB you use will depend on your frame, not your crank.
  • + 1
 So it doesn't matter what BB I have my bike?
  • + 1
 That's not what I said at all.

It would help a lot if I knew what frame you were wanting to put the cranks on. What type of BB does your frame have right now?
  • + 1
 Sorry man! It's a 2014 Carbon Operator. It's a Zee crank. It's a Shimano Press Fit 104.5mm
  • + 1
 Well then it kinda depends on how long the spindle is on your Zee cranks. If it's the same spindle length as the ones that are designed for the 83mm BB shell then you can get the Race Face SixC cranks designed for the same BB width.
  • + 1
 How would I be able to do that?
  • + 1
 With a tape measure.
  • + 1
 Sorry, I'm stupid. Do I measure the eye to eye of the crank arms?
  • + 1
 Measure the width of the spindle.
  • + 1
 The Spindle is what houses the BB correct?
  • + 1
 The spindle is the part that is attached to the crank arm. It goes through the BB.
  • + 1
 Ok Perfect. I will measure that tonight and get back to you. Thanks!
  • + 1
 Seraph you must have about of patience with customers, impressive.
  • + 1
 You mean a lot of patience? lol!
  • + 3
 Thats pretty helpful
  • + 1
 I have a ISIS crank brothers bb, 5years and still going. ISIS bb's suck but not the crank bro's best so far for ISIS
  • + 1
 almost a good article, needs more pics to really be an effective guide though
  • + 1
 I came across this video that helped me out tipsperformance.com/how-to-remove-and-install-sram-crankset
  • + 1
 Gotta love it when there's more info in the comments than in the orignal article...
  • + 0
 I get that wider can be stiffer but can't they just make a 92mm bb that's threaded (for an internal bearing as an external would be too wide).
  • + 1
 they could but that would defeat the purpose of having a wider bb and thus helping frame designer make shorter and stiffer chainstays eg for 29iners.
  • + 1
 How would a 92mm wide press-in differ from a 92mm thread-in other than how the bearing is physically retained?
  • + 2
 Sorry misread your initial post. Thought you had said external rather than internal. Thus the only difference would be easy of manufacturing as mentioned in this article, frame manufacturing that is,
Personally I think they stick to external bb (in order to keep bearing size large) or create a bigger bb eg like FSA tried to do a few years back with the mega tech bb.
  • + 1
 Yeah a larger diameter wouldn't be a bad thing. Like you said, you could then have bigger bearings, and could also have larger diameter spindles.
  • + 1
 Who's answering these questions? The author/pinkbike personnel?
  • + 1
 Absolutely
  • + 1
 Have a Chris King PF 30 for almost a year, no play, no creaks.
  • + 1
 I have a 83mm threaded Hope bottom bracket, and have no issues.
  • + 2
 Isis bb
  • + 2
 Usual hollowtech ll FTW
  • + 0
 This is why I only buy BB's at the LBS.
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