Ask the Expert: James Huang on Bottom Brackets

StrangelyBrown

I have an aluminium frame with a BB30 BB and and Apex chainset. The chainset appears to have jammed into the bearings (which are good quality SKF), and nothing I do will shift it. I've even tried resting the BB shell on wood and smacking the splined end with a hammer, as hard as I dare.

Any suggestions on how I could try to shift it without damaging the frame?

Cheers

Caader

Hi,

I've purchased a Specialized Tarmac SL4 frameset and want to fit an Ultegra crankset. Do I need buy any additional bb converters such as praxis or will the supplied bearings and cups support this installation. Secondly, which would be your preferred BB Setup for this match. Thanks

angryasian

brettjmcc wrote:

James, the thing is it is not metal to metal. The Rotor BB is metal, but the bottom bracket area is just a carbon shell.

Rotor suggest using 641 in their installation, but I thought this was for metal to metal installation, or would it work on metal/carbon fits too without potentially damaging resins in the frame? Thanks once again

angryasian wrote:

brettjmcc wrote:

Can you advise the best way to install a Rotor 4130 (BB86 but for UBB30 axle) into a carbon shell frame such as a BMC GF01? I am thinking of just pressing in and using carbon paste, as the BB shells are metal

For metal-on-metal interfaces like that, I like to use a mild sleeve retaining compound such as Loctite 609. It cures quickly, lasts seemingly forever, prevents corrosion, and is still easy to remove if/when needed. You could certainly use friction paste (or grease) but it's unlikely to be a good long-term solution.

Sorry, you threw me off in your original post when you said the "BB shells are metal". Sleeve retaining compounds are supposed to be safe in carbon composites but the initial prep work is even more important so as to ensure a proper bond.

angryasian

BR_Gregor wrote:

One question that was emailed to us from a BR reader with limited internet access this week (Eric Foster – this is for you):

"What kind of FSA cranks and bottom bracket do I need for a Kestrel Talon 105 Road Bike? I'm lost, please help me."

Sorry, but I'm going to need a little more information on this one. What year is the bike? Can you post a picture of the bottom bracket area please?

angryasian

BR_Gregor wrote:

Also two questions from the promo posts that were asked on those threads and haven't been rolled over into this one:

1) 'Why the hell do manufacturers continue to fit press fit bottom brackets to mountain bikes? It's a stupid idea and no one wants them.'

2) 'Why do they continue to fit press fit bottom brackets to non-carbon bikes?'

I continue to hold the opinion that the *concept* of press-fit bottom brackets is sound. It's not that the idea is stupid; it's just that the execution has been done so haphazardly that press-fit BBs now have an irreparably damaged reputation. At least in theory, press-fit BB systems save weight and allow frame designers more flexibility. They also allow companies to tout their frames as being lighter, too, so many companies continue to use them. While I've seen plenty of examples where press-fit was done poorly, I've also seen plenty where it was done very well.

Non-carbon bikes can reap similar benefits as carbon ones, such as increased frame design flexibility. There's no weight to be saved in the frame itself but there's usually some weight saved in that you no longer need big, chunky cups. Wider press-fit shells also allow for wider chainstay spacing (which is good for gaining more mud clearance in cyclocross, for example), while oversized PF/BB30 ones offer more weld area for bigger adjoining tubes.

angryasian

StrangelyBrown wrote:

I have an aluminium frame with a BB30 BB and and Apex chainset. The chainset appears to have jammed into the bearings (which are good quality SKF), and nothing I do will shift it. I've even tried resting the BB shell on wood and smacking the splined end with a hammer, as hard as I dare.

Any suggestions on how I could try to shift it without damaging the frame?

Cheers

Something isn't making sense here as SRAM doesn't offer the Apex crankset (sorry, I'm American!) with an oversized BB30 spindle. My guess is that you have some sort of adapter setup in your frame that has apparently broken loose. What kind of bike is it?

More importantly, what makes you think the crankset is "jammed" into the bearings? And are you referring to the driveside or non-driveside? Keep in mind that SRAM GXP cranksets use a stepped spindle on the non-driveside, which butts up against the inner race of that bearing.

angryasian

Caader wrote:

Hi,

I've purchased a Specialized Tarmac SL4 frameset and want to fit an Ultegra crankset. Do I need buy any additional bb converters such as praxis or will the supplied bearings and cups support this installation. Secondly, which would be your preferred BB Setup for this match. Thanks

If I remember correctly, Specialized usually includes with its Tarmac framesets parts to install either 30mm or 24mm-diameter crankset spindles. That said, the cups are plastic and don't fit as well as I'd like, and I really don't like using additional adapters to make one standard fit into another. More parts equals more interfaces equals more potential for creaking.

Assuming your budget will allow, I'd strongly recommend getting a Praxis conversion bottom bracket. It's very well made, exceptionally well designed, and is absolutely rock solid. There's currently nothing else on the market like it.

Peddle Up!

I have a Trek Madone 5.2 a couple of years old. I seem to get through BB bearings like there's no tomorrow. Granted I'm a big rider, but it's ridiculous. My local bike shop has sourced some better grade ones (evidently the Trek standard are about the minimum standard you can buy!). What really annoys me is that if I spin the crank I only get half a revolution before it stops. My Trek 7300 hybrid goes on and on after a gentle push.

Any thoughts?

angryasian

Peddle Up! wrote:

I have a Trek Madone 5.2 a couple of years old. I seem to get through BB bearings like there's no tomorrow. Granted I'm a big rider, but it's ridiculous. My local bike shop has sourced some better grade ones (evidently the Trek standard are about the minimum standard you can buy!). What really annoys me is that if I spin the crank I only get half a revolution before it stops. My Trek 7300 hybrid goes on and on after a gentle push.

Any thoughts?

What exactly is the issue you're having with the bearings? Are they corroding or do they just feel rough?

Assuming you aren't constantly riding in wet weather, you definitely shouldn't be going through bearings quickly down there. I don't recall the ones Trek uses stock in its BB90 bottom brackets to be particularly low-quality, and given the relatively light-contact sealing, I don't see many that spin poorly, either.

Those bearings are almost definitely radial-type cartridges, which are rather sensitive to side loading. If you're using a Shimano crankset, make sure your shop isn't overly tightening the preload cap upon installation - it just needs to be snug.

Barring that, consider switching to angular contact bearing cartridges. They're far more tolerant of side loading and slight frame dimension irregularities. If you're having issues with corrosion, consider ponying up for a set of Enduro XD-15 ceramic angular cartridges, too. They're unquestionably expensive but I had one tester commute five days a week on an XD-15-equipped bottom bracket through an entire Colorado winter and there were ZERO signs of wear. If that's not impressive enough, consider that I also removed all of the bearing seals, too, so everything was fully exposed.

Harrybear1

Hi i am running FSA gossamer on my ridley cyclocross bike. i imagine they use this as stock to cut down on not using full shimano ultegra. my question is, is it possible to use my ultegra stages power crank with this fsa bottom bracket? or will i have to swap out for a shimano bottom bracket and crankset? can the bottom brackets be swapped?

any help in saving me money would be great!!

thanks!

StrangelyBrown

angryasian wrote:

StrangelyBrown wrote:

I have an aluminium frame with a BB30 BB and and Apex chainset. The chainset appears to have jammed into the bearings (which are good quality SKF), and nothing I do will shift it. I've even tried resting the BB shell on wood and smacking the splined end with a hammer, as hard as I dare.

Any suggestions on how I could try to shift it without damaging the frame?

Cheers

Something isn't making sense here as SRAM doesn't offer the Apex crankset (sorry, I'm American!) with an oversized BB30 spindle. My guess is that you have some sort of adapter setup in your frame that has apparently broken loose. What kind of bike is it?

More importantly, what makes you think the crankset is "jammed" into the bearings? And are you referring to the driveside or non-driveside? Keep in mind that SRAM GXP cranksets use a stepped spindle on the non-driveside, which butts up against the inner race of that bearing.

Good point James - I was typing on auto pilot. The groupset is Apex, but the crankset (as it's you) is an FSA Gossamer. I think it's jammed because when I remove the non-drive side crank the crankset should just slide out, but it's jammed solid. I cannot shift it at all - not even slightly. I can only think that the spindle has jammed into the bearinggs - no idea if drive or non-drive side. I'm happy to sacrifice the bearings and/or the crank if I have to, but I don't want to damage the frame. I've taken it out many times before.

I'd appreciate any suggestions. I suppose at least it's not creaking.

angryasian

Harrybear1 wrote:

Hi i am running FSA gossamer on my ridley cyclocross bike. i imagine they use this as stock to cut down on not using full shimano ultegra. my question is, is it possible to use my ultegra stages power crank with this fsa bottom bracket? or will i have to swap out for a shimano bottom bracket and crankset? can the bottom brackets be swapped?

any help in saving me money would be great!!

thanks!

Unfortunately, that Shimano Ultegra/Stages arm definitely will not fit on your FSA spindle. Assuming you're talking about the MegaExo version of the Gossamer and not the BB/PF30 variant, though, you should at least be able to use the same bottom bracket.

angryasian

StrangelyBrown wrote:

angryasian wrote:

StrangelyBrown wrote:

I have an aluminium frame with a BB30 BB and and Apex chainset. The chainset appears to have jammed into the bearings (which are good quality SKF), and nothing I do will shift it. I've even tried resting the BB shell on wood and smacking the splined end with a hammer, as hard as I dare.

Any suggestions on how I could try to shift it without damaging the frame?

Cheers

Something isn't making sense here as SRAM doesn't offer the Apex crankset (sorry, I'm American!) with an oversized BB30 spindle. My guess is that you have some sort of adapter setup in your frame that has apparently broken loose. What kind of bike is it?

More importantly, what makes you think the crankset is "jammed" into the bearings? And are you referring to the driveside or non-driveside? Keep in mind that SRAM GXP cranksets use a stepped spindle on the non-driveside, which butts up against the inner race of that bearing.

Good point James - I was typing on auto pilot. The groupset is Apex, but the crankset (as it's you) is an FSA Gossamer. I think it's jammed because when I remove the non-drive side crank the crankset should just slide out, but it's jammed solid. I cannot shift it at all - not even slightly. I can only think that the spindle has jammed into the bearinggs - no idea if drive or non-drive side. I'm happy to sacrifice the bearings and/or the crank if I have to, but I don't want to damage the frame. I've taken it out many times before.

I'd appreciate any suggestions. I suppose at least it's not creaking.

If you've previously removed this crankset without any issues in the past, then yes, I'd probably agree with you that something is stuck. It's not likely to be anything mechanical, though, but rather some level of corrosion. If it's a true BB30 bottom bracket (and not a PF30 one), that chromoly spindle rides directly on the inner bearing races and it's entirely possible that that metal-on-metal interface has chemically bonded to some degree.

My suggestion would be to use some penetrating oil on both sides of the bottom bracket at the spindle and let it sit for a day or two, reapplying as necessary - and then have at it with a (soft faced!) hammer. Unless the spindle pops out very quickly, you'll almost certainly have to replace the bearings afterward.

BR_Gregor

angryasian wrote:

BR_Gregor wrote:

One question that was emailed to us from a BR reader with limited internet access this week (Eric Foster – this is for you):

"What kind of FSA cranks and bottom bracket do I need for a Kestrel Talon 105 Road Bike? I'm lost, please help me."

Sorry, but I'm going to need a little more information on this one. What year is the bike? Can you post a picture of the bottom bracket area please?

[Apologies for the capitalisation: Eric's email]

ITS A 2014 NO PICTURE, BUT AFTER A WEEK OF RESEARCH I THINK I FINALLY DISCOVERED THAT IT IS A STANDARD ENGLISH THREADED B.B. IVE RIDDEN BIKES ALL MY LIFE BUT NEVER A DESCENT ROAD BIKE LIKE I HAVE NOW, AND IF YOU DONT KNOW CERTAIN THINGS, ITS KINDA HARD TO FIGURE OUT, WITH ALL THESE "STANDARD B.B'S", I MEAN I COULDN'T FIND ONE MANUFACTURER OR ANY WEBSITE THEY CAME RIGHT OUT AND SAID LOOK, THIS IS WHAT YOU GOT.

LOL.......BUT YEAH IM 98% SURE THAT IT IS A STANDARD ENGLISH THREADED SHELL, SO WHAT DOES THAT MEAN?
MANUFACTURES STILL DONT COME RIGHT OUT AND SAY THIS BB WILL FIT A STANDARD ENGLISH THREADED?

ANY ADVISE YOU CAN GIVE WILL BE APPRECIATED, IVE ALREADY RETURNED THE CRANKS AND GOT SOME NEW ONES ON THE WAY...THEY ARE FSA K-FORCE LIGHT 39-52 FROM BIKEWAGON SAYS THEY COME WITH A CERAMIC BB, WHAT DO YOU THINK,

THANKS

ERIC

Mathelo

James,

I'm trying to determine what BB I have before servicing or changing out. I'll need some tools but I'll need to know what I have before buying. It's creaking and I'd like to eliminate that noise.

My bike is a Felt Z2 purchased new in 2013. The drivetrain is all Ultegra Di2 but where the cranks attach to the axle there are FSA EE085 spacer / 24 reducers between the cranks and the frame.

I checked the Felt website for this frame and it seems to have a "machined threaded aluminum BB shell".

What do you think?

Louis

angryasian

BR_Gregor wrote:

angryasian wrote:

BR_Gregor wrote:

One question that was emailed to us from a BR reader with limited internet access this week (Eric Foster – this is for you):

"What kind of FSA cranks and bottom bracket do I need for a Kestrel Talon 105 Road Bike? I'm lost, please help me."

Sorry, but I'm going to need a little more information on this one. What year is the bike? Can you post a picture of the bottom bracket area please?

[Apologies for the capitalisation: Eric's email]

ITS A 2014 NO PICTURE, BUT AFTER A WEEK OF RESEARCH I THINK I FINALLY DISCOVERED THAT IT IS A STANDARD ENGLISH THREADED B.B. IVE RIDDEN BIKES ALL MY LIFE BUT NEVER A DESCENT ROAD BIKE LIKE I HAVE NOW, AND IF YOU DONT KNOW CERTAIN THINGS, ITS KINDA HARD TO FIGURE OUT, WITH ALL THESE "STANDARD B.B'S", I MEAN I COULDN'T FIND ONE MANUFACTURER OR ANY WEBSITE THEY CAME RIGHT OUT AND SAID LOOK, THIS IS WHAT YOU GOT.

LOL.......BUT YEAH IM 98% SURE THAT IT IS A STANDARD ENGLISH THREADED SHELL, SO WHAT DOES THAT MEAN?
MANUFACTURES STILL DONT COME RIGHT OUT AND SAY THIS BB WILL FIT A STANDARD ENGLISH THREADED?

ANY ADVISE YOU CAN GIVE WILL BE APPRECIATED, IVE ALREADY RETURNED THE CRANKS AND GOT SOME NEW ONES ON THE WAY...THEY ARE FSA K-FORCE LIGHT 39-52 FROM BIKEWAGON SAYS THEY COME WITH A CERAMIC BB, WHAT DO YOU THINK,

THANKS

ERIC

Hi Eric,

First off, this article might give you some good information for future reference: http://www.bikeradar.com/us/gear/article/complete-guide-to-bottom-brackets-36660/.

That's great news that your bike has a standard English threaded bottom bracket as you've got a wide range of options in terms of compatibility. As far as the FSA K-Force Light is concerned, anything labeled 'MegaExo' is designed to fit a threaded shell. You can also use the BB386EVO version provided you purchase the threaded cups to match.

Hope that helps!

angryasian

Mathelo wrote:

James,

I'm trying to determine what BB I have before servicing or changing out. I'll need some tools but I'll need to know what I have before buying. It's creaking and I'd like to eliminate that noise.

My bike is a Felt Z2 purchased new in 2013. The drivetrain is all Ultegra Di2 but where the cranks attach to the axle there are FSA EE085 spacer / 24 reducers between the cranks and the frame.

I checked the Felt website for this frame and it seems to have a "machined threaded aluminum BB shell".

What do you think?

Louis

Hi Louis,

I'm not sure where you saw "machined threaded aluminum BB shell" but Felt's web site shows that frame as using a BB30 shell: http://2013.feltracing.com/USA/2013/Road/Z-Series/Z2.aspx. Given that Felt hasn't used threaded shells in any of its higher-end road frames for some time now - plus the fact that your frame is equipped with 30-to-24mm reducers - I'm strongly inclined to believe your bike is BB30. Felt's web site lists that frame has having an aluminum BB30 shell at that but from my memory, I believe the site is incorrect and that frame uses Felt's proprietary carbon BB30 shell instead.

Either way, I'm very strongly against just stacking on additional spacers to adapt one BB standard to another as more interfaces just mean more potential for creaking and poor bearing alignment. Normally I would suggest getting a Praxis conversion bottom bracket but given the molded-in central spacer that Felt uses on its carbon BB30 frames (see http://www.praxiscycles.com/wp-content/uploads/PRAXIS-FRAME-GUIDE.pdf), that unfortunately isn't going to work for you.

There are other 'BB30 Outboard' bottom brackets that have a stepped-down center diameter instead of the Praxis' constant-diameter shape, though. Any BB30 Outboard bottom bracket will also carry the added benefits of wider bearing spacing (which should, at least in theory, provide better bearing life). I would personally go with one of the newer thread-together designs such as from Wheels Manufacturing (http://wheelsmfg.com/products/bottom-brackets/bb30-outboard/bb30-outboard-bottom-brackets.html) but given the unique configuration of your frame, you'll likely want to verify with either Felt and/or Wheels Manufacturing that it'll fit before you buy one.

BR_Gregor

Many thanks to James for answering all those! Hope you got your question answered. If not, feel free to add it to this thread, which I shall see if it gets bumped to the top of the posts and will chase up an answer for.

There'll be a new Q+A coming soon. Got something that you want to discuss with the BikeRadar team? Let us know: either here or by the feedback form on the main site, or even by email: gregor.macgregor@immediate.co.uk

BR_Gregor

Eric's answer, fwiw, James:

'YUP,

SURE DOES, THANKS FOR THE HELP, MAN!

ERIC'

Ziboul

Hi James!
Is it possible to replace a square taper BB (in my case: Shimano BB-UN26, 122mm spindle, 68mm width) with a Shimano Hollowtech II (in my case, i'd like to put a Shimano Hollowtech II Deore, Slx or XT BB)?
Thanks!
Ziboul

angryasian

Ziboul wrote:

Hi James!
Is it possible to replace a square taper BB (in my case: Shimano BB-UN26, 122mm spindle, 68mm width) with a Shimano Hollowtech II (in my case, i'd like to put a Shimano Hollowtech II Deore, Slx or XT BB)?
Thanks!
Ziboul

Yes, absolutely! It's a very straightforward swap. Just make sure to buy threaded bottom bracket cups to go with the crankarms and you'll be good to go. Those cups are designed to fit both 73mm and 68mm-wide threaded bottom bracket shells and all you'll need to do is install the correct number of spacers.

If you use grease plus one or two winds of PTFE plumber's tape on the threads, that setup should stay creak-free for ages, too.

Hugh Evans

I have a 2005 Specialized Stumpjumper 120 - old I know but still going strong and I love it.

It has a Shimano ES-30 Octalink bottom bracket (the specs say it is 68mm shell, 118mm spindle and 50mm chainline). My local bike shop says that Octalink is now obsolete and harder and harder to obtain.

The bottom bracket is just starting to 'click' and I will probably need to replace it soon.

What are my options?

Thanks for your help.

Hugh

nicklouse

Learn how to change the BB yourself or change your LBS to one that does not just want to sell you new stuff.

http://www.chainreactioncycles.com/de/e ... -prod34653
And the better quality es51 are still readily available.

New BB from £11 if you have the tools.

Virgle

I have been trying ti figure out bottom brackets due to having to get a new on, The old is a BB-LP27
I measured from the end of the axles it says 111.5 and its 68 mm
I assume I need a 68 x 111mm, ok with that being said where the axle goes through right side its stamped mm 110
Can someone clarify what I need...

Thanks

Mathelo

angryasian wrote:

Mathelo wrote:

James,

I'm trying to determine what BB I have before servicing or changing out. I'll need some tools but I'll need to know what I have before buying. It's creaking and I'd like to eliminate that noise.

My bike is a Felt Z2 purchased new in 2013. The drivetrain is all Ultegra Di2 but where the cranks attach to the axle there are FSA EE085 spacer / 24 reducers between the cranks and the frame.

I checked the Felt website for this frame and it seems to have a "machined threaded aluminum BB shell".

What do you think?

Louis

Hi Louis,

I'm not sure where you saw "machined threaded aluminum BB shell" but Felt's web site shows that frame as using a BB30 shell: http://2013.feltracing.com/USA/2013/Road/Z-Series/Z2.aspx. Given that Felt hasn't used threaded shells in any of its higher-end road frames for some time now - plus the fact that your frame is equipped with 30-to-24mm reducers - I'm strongly inclined to believe your bike is BB30. Felt's web site lists that frame has having an aluminum BB30 shell at that but from my memory, I believe the site is incorrect and that frame uses Felt's proprietary carbon BB30 shell instead.

Either way, I'm very strongly against just stacking on additional spacers to adapt one BB standard to another as more interfaces just mean more potential for creaking and poor bearing alignment. Normally I would suggest getting a Praxis conversion bottom bracket but given the molded-in central spacer that Felt uses on its carbon BB30 frames (see http://www.praxiscycles.com/wp-content/uploads/PRAXIS-FRAME-GUIDE.pdf), that unfortunately isn't going to work for you.

There are other 'BB30 Outboard' bottom brackets that have a stepped-down center diameter instead of the Praxis' constant-diameter shape, though. Any BB30 Outboard bottom bracket will also carry the added benefits of wider bearing spacing (which should, at least in theory, provide better bearing life). I would personally go with one of the newer thread-together designs such as from Wheels Manufacturing (http://wheelsmfg.com/products/bottom-brackets/bb30-outboard/bb30-outboard-bottom-brackets.html) but given the unique configuration of your frame, you'll likely want to verify with either Felt and/or Wheels Manufacturing that it'll fit before you buy one.

Jim,

Somehow I missed this reply and now almost 2 years later I've come upon it. Thanks for the guidance but I think I was fortunate to have missed it. As it turns out, this frame does have a smooth aluminum shell with circlips for holding the bearings in place. I successfully used a Praxis conversion kit. All the creaking is gone in the BB is much stiffer.

Thanks!

Louis