Noisy BB

Page may contain affiliate links. Please see terms for details.

Tojo

Über Member
I agree with Yellow Saddle here, I think that press fit BB's were invented by the industry for the industry for ease of manufacture.
They have introduced something to suit themselves and tried to replace threaded BB's that have been the norm and WORK perfectly well whether Italian or British thread from cup and cone to cartridge to hollow tech.
I recently had to replace a press fit for a friend on a Giant TCR which had creaking problems from new as he took it back within two weeks, the dealer solved the problem.....only for me to find out how when it totally failed...They had taken it out and replaced it, yes but had glued it in, not with tread lock but with strong glue... obviously to save having to redo it as they knew it would be back if they hadn't....We know they are Sh*te but you've got to deal what your dealt with....not that I agree with the dealer gluing it in and leaving the problem to the next mechanic who has to remove it and replace it...........which was me and it was a total fecking nightmare....:banghead::cursing:
 
OP
OP
ozboz

ozboz

Guru
Location
Richmond ,Surrey
This is a bit hard ti get your head around , after checking on on other sites , the compaints go back four years about these
Bb30's , so there has been plenty of time to sort it out you would think , or just stop using them ,
I took it in last night , he was going on about wet weather , which i expected , anyway I call him later , no doubt it will be quiet whan I get it back , but how long for is anybodys , I have read that there are ways to fix it by having other parts fitted , is this the case ?
Got to be worth it ,
 
U

User6179

Guest
This is a bit hard ti get your head around , after checking on on other sites , the compaints go back four years about these
Bb30's , so there has been plenty of time to sort it out you would think , or just stop using them ,
I took it in last night , he was going on about wet weather , which i expected , anyway I call him later , no doubt it will be quiet whan I get it back , but how long for is anybodys , I have read that there are ways to fix it by having other parts fitted , is this the case ?
Got to be worth it ,

What BB is it ? , you said hollowtech crankset but they dont work with BB30 ?
 
Location
Loch side.
This is a bit hard ti get your head around , after checking on on other sites , the compaints go back four years about these
Bb30's , so there has been plenty of time to sort it out you would think , or just stop using them ,
I took it in last night , he was going on about wet weather , which i expected , anyway I call him later , no doubt it will be quiet whan I get it back , but how long for is anybodys , I have read that there are ways to fix it by having other parts fitted , is this the case ?
Got to be worth it ,
It is all the weight weenies' fault.
The problem started the minute people started to weigh bikes and use that number as the primary decision-maker when buying a new bike. The mantra is that lightest is best.
Press-fit BBs are a result of making frames lighter. The move to carbon has eliminated the possibility of screw-in BBs. Yes, screw-in sleeves are sometimes used but customers vote with their scales - the sleeve cost a whole 68 grams and they cannot afford it.
I've written an extensive history of the BB previously on this forum but I can't find it now.

To understand what happens when a crank turns in a BB you have to get your head around the concept of precession. You can look it up on Wikipedia or such but don't expect to understand BBs immediately even if you understand precession. I'll try and explain. Make an O with your thumb and forefinger on your left hand. Now (rudely so) stick your index finger from your right hand in the O. Turn it backwards and forwards to simulate BB axle rotation. Now visualise that rotation as being imperfect in that it is weighted at one end only by your foot and the crank lever. Now, not only does the BB axle turn perfectly on its own axial centre line, it also rotates the centre line itself. If you forcefully do this with your finger you'll notice that the O ovalises or at least, distorts in the direction of wher your foot is pulling the crank around the circle. You can in fact ignore the actual rotation and just focus on the rotating oval. In other words, no need to turn your index finger anymore, just move it around the circle like a motorcyclist on the wall of death.

Now imagine this happening to a BB. The thin carbon shell distorts all the time. It ovalises ever so slightly as the crank moves round and round. This movement causes fretting between the plastic BB bearing cup and the carbon shell. The two surfaces don't slide smoothly against each other (especially once dirt gets into the grease in there (which shouldn't be there but that's another story) but do stick-slip movements. Each slip produces a crack. You know what it sounds like, I don't have to tell you.

You may say that the same happens with screw-ins and yes, of course it does and often you can hear them too. However, the precession on a screw-in is designed to tighten the BB as you pedal. Not by friction between the crank, bearing and BB races but by precession. To visualise this, go back to your finger experiment. Now imagine that both your index finger and the inside of the O is threaded. Imagine what happens if your finger runs around the now-threaded wall-of-death. Yes, it follows the thread direction. By cleverly designing the thread direction you can get the BB to self-tighten in use. That helps a lot. It isn't a perfect design, but it helps a lot.

A perfect design would have been a BB without reverse thread on the one side - just like Italian BBs, but with a tapered shoulder on the BB cup and a corresponding taper in the BB shell. Just like a car's wheel nut. Wheel nuts don't need reverse threads to stay in. The taper does the trick and prevents relative movement between wheel and nut. An of course runs silent.

That's the perfect world. Unfortunately weight weenies define perfection with a scale and consumers lap it up. Also, our addiction to legacy mistakes and reluctance to revolutionize designs doesn't help either.

Edit: reading your post again, I see you assume the problem is a BB30 one. Although BB30 is super terrible - mostly for other reasons, the problem exists with standard Hollowtech pressfit BBs as well.
 
Last edited:
OP
OP
ozboz

ozboz

Guru
Location
Richmond ,Surrey
It is aBB30 set up ,, Weight Weenies ? , are they the cycle producers / designers , race team. riders or the paying public ?
Ive seen this term mentione elsewhere ,
any way I picked it up ,he said there was an element of dirt / grit in there , so its been serviced ,
I will go for a 30 miler or so at weekend and see ,
But , Its hard to work out how anything got into the bearing after 150 ish miles ,
I take it that the forces of peddaling esp the downward stroke are stressing the CF shell and it is distorting , which in turn is bound to cause problems,
 
Weight Weenies ?
I think it's a term from the 80s, with people doing anything to get the weight of the bike down.

weight-5.jpg


I take it that the forces of peddaling esp the downward stroke are stressing the CF shell and it is distorting , which in turn is bound to cause problems,

My newly replaced bb is doing the same in it's allow frame, so don't blame the CF.
 
Location
Loch side.
QUOTE="jefmcg, post: 4686871, member: 14860"]I think it's a term from the 80s, with people doing anything to get the weight of the bike down.

View attachment 338283



My newly replaced bb is doing the same in it's allow frame, so don't blame the CF.[/QUOTE]
Yup, you're right. It is a breed of cyclists who make purchasing decisions based primarily on weight. They can recite the weight of each and every component, including aluminium headset top caps (they replace them with plastic ones) and valve caps. I kid you not.
However, what you pictured above is the work of another cult. It is called Drillium. Plenty of examples online. Drillium is quite an art when practiced right and I do think there's a bit of tongue-in-cheek in it. Weight-weenieness on the other hand is just naff.

Drillium.jpg
 

gbb

Legendary Member
Location
Peterborough
It is aBB30 set up ,, Weight Weenies ? , are they the cycle producers / designers , race team. riders or the paying public ?
Ive seen this term mentione elsewhere ,
any way I picked it up ,he said there was an element of dirt / grit in there , so its been serviced ,
I will go for a 30 miler or so at weekend and see ,
But , Its hard to work out how anything got into the bearing after 150 ish miles ,
I take it that the forces of peddaling esp the downward stroke are stressing the CF shell and it is distorting , which in turn is bound to cause problems,
If it's the shell that's causing the problem, that's poor frame design surely ?
 
What BB is it ? , you said hollowtech crankset but they dont work with BB30 ?
It does with an adapter such as THIS :okay:

I have read that there are ways to fix it by having other parts fitted , is this the case ?
I fixed my Cannodale CAAD10 BB30 issues by fitting THIS adapter* and a Hollowtech II chainset, and never had an issue since. So if you like the bike sell your chainset, throw the press fit $hite in the bin, fit this and then cycle happy :okay:

*Note - they do say to consider this to be a non-reversible fix, (particularly in a CF frame), but why on earth anyone in their right mind would ever want to go back to press fit is beyond me anyway :crazy:
 
OP
OP
ozboz

ozboz

Guru
Location
Richmond ,Surrey
It does with an adapter such as THIS :okay:


I fixed my Cannodale CAAD10 BB30 issues by fitting THIS adapter* and a Hollowtech II chainset, and never had an issue since. So if you like the bike sell your chainset, throw the press fit $hite in the bin, fit this and then cycle happy :okay:

*Note - they do say to consider this to be a non-reversible fix, (particularly in a CF frame), but why on earth anyone in their right mind would ever want to go back to press fit is beyond me anyway :crazy:

Definatly love the bike !!
Ive done about 30 mile today all around London , so its had plenty of welly !!
But thanks for info , if it persists, then its all change !!
 

Ajax Bay

Guru
Location
East Devon
I've written an extensive history of the BB previously on this forum but I can't find it now.
@Yellow Saddle said last autumn:
"It is a design issue, hardly at all a fitment or component (bearing) problem. The BB has a very chequered history and I'll quickly recap.
First we had cotter pin. Cotters were problematic but were eventually replaced by the square taper, which was brilliant. It allowed lightweight aluminium cranks to be securely fastened to steel crank spindles without any problems of precession and lash, both problems with the cotter. (Note that I'm referring to a British cotter, not American cotter).

"Then the weight weenies came around and questioned the solid BB axle and asked for something to be make lighter. Shimano responded with the Octalink BB. It fitted into existing BSA BB shells and thus didn't require a frame redesign. However, the enlarged axle required smaller bearings so that the assembly could fit into the limited space inside the BB shell. This reduced the bearing durability. Further, the advent of MTBing meant that people now jumped their bikes whilst standing on the cranks one foot forward, one 180degrees to the back. This put huge strain on the axle and the short Octalink spines could not provide enough stiffness and the flex inside the splines caused the crank bolt to unscrew on the one crank pointing backwards. Visualise this is the bolt head moving backwards with the flexing inside the crank eye but not returning with the backlash. This caused the shallow splines to strip. In addition to that problem, the splines were blind and assembly had to be very accurate, otherwise the spindle peeled pieces of spline and ruined the spline as the bolt is tightened. Then Shimano invented Octalink II without acknowledging the mistakes of what was not suddenly Octalilnk I. Octalink II solved the lash problem but not the bearing problem. Shimano even attempted to use roller bearings in its high-end Octalink cranks but these failed prematurely as well since roller bearings don't work well in grease where the grease is pushed away from the bearing and not returned as with a ball bearing.

"Then a repeat of the Betamax vs VHS story started. Shimano refused to license Octalink (or the Americans refused to buy a license) and a consortium of American companies then reverse engineered their own version of Ocatlilnk, called the ISIS spline. It had not 8 as in Shimano, but 9 splines and a different spline shape. This all to avoid patent licence fees. Octalink, Octalink I, Octalink II and ISIS is all rubbish.

"Shimano then decided that it will re-invent the BB again and came up with Hollowtech. This was a two-piece crank with a 24mm spindle and an externally mounted pair of bearings. The crank press-fit into the bearings, separated by a plastic spacer between crank and bearing race. The idea was to save weight, provide a stiff spindle by going oversize and create larger bearings but place them outside of the still-standard BB shell. Unfortunately the spindle was not stiff enough and the left hand bearing now fails prematurely because the spindle flexes on the left. Remember that torque is only transmitted through the spindle from the left crank, not the right. For a long time people through their left BB cup failed because a bike is laid down on its left side and water inside the BB was damaging the left bearing. However, it was the flexing spindle that pulls the sensitive deep groove bearing to run against the sides of its grooves and bind. Also astonishingly, the bearing balls were still too small for the job. Although the bearing diameter increased, the balls stayed small and they packed more of them in rather than bulk up the assembly a bit.

"A BB redesign was called for and national pride meddled with good design. Cannondale, Bullseye and some other American companies then perpetrated BB30. It had a large (30mm) spindle to prevent some of the flexing found in Hollowtech and to supposedly save the customer maintenance cost, fitted two standard industrial deep groove bearings directly into a redesigned oversized shell. This was a big mistake, especially in hindsight when frames were made from carbon. The BB shell on an aluminium bike is a fragile, highly stressed component. It is a little thin-shell transverse tube with four major welds connecting it to the top tube, seat tube and two chainstays. This welding distorts the shell. This happened with old BBs as well but now with BB30, the bearing was fitted directly into the shell by press-fit. Tolerances had to be very high if you don't want the bearing to bind because of out-of-roundness of the shell and, simultaneously you want the bearing to fit tight enough into the aluminium shell to not move and fret during hard pedaling. This is an impossible call. These bearings all move and creak. The Japanese had some wisdom in using a screw-in system and sticking with it. Further, the bearings in BB30 are not far enough outboard to prevent the aluminium crank spindle to not flex and cause lateral loading of the bearing. That's why it fails so quickly.
BB30 became an even worse idea when frames turned to carbon. Now the BB shell was too soft to accept a steel bearing directly and, cannot be machined even close enough to good enough tolerance in anyway. Out came another shell redesign and we got BB30 Presssfit. This called for the bearing to be housed in a plastic cup which is then pressed into the imperfect frame aperture. They creak like hell and wear the shell out in an oval shape. They are terrible.

"And that's where we are today. Weight weenies, poor engineering and national pride gave us a system that is worse than the 50 year old (guessing here) square taper. No-one admits it, few mechanics understand it and they're all looking for solutions such as warrantee replacements bearing glue and hope.

"The answer will only be found once we have a new design. Don't think BB-Right provides it either."
 
OP
OP
ozboz

ozboz

Guru
Location
Richmond ,Surrey
Well , now I know !
But it is even harder to understand now why the engineers / manufacturers have not sorted it ,
Its not hard to understand pro racing people demanding lighter components etc , but for those of us who want a bike that is going to be reliable and unproblematic ,
It is a let down , anyway , @smokeysmoo has provided a possible solution , so its not the end of the road ! Hopefully
 
Urgh, I'm a late comer to this revelation and just experienced problems resolving this cause of creak for the first time on my own bike. :thumbsdown: to weight weenies!
 
OP
OP
ozboz

ozboz

Guru
Location
Richmond ,Surrey
Its been ok up to now , he just fixed it , i am waiting for ride in a a storm , it was after a rodefir 3/4 of an hour in the pouring rain that I had the problem, so we will see , but there are mechs and then thereate proper mechs , but obv a design fault as pointed out by @Yellow Saddle ,
I do put a bead of grease around the collars to help prevent water getting in though
 
Top Bottom