Loctite for threaded BB shells

[Colinmclelland]

My Praxxis M30 T47 threaded BB has started to creak. (I think - it's unproven but it's the prime candidate)

Other forums say the answer is to re-assemble with Loctite 609. Which has a high rotational strength but low shear strength so you can disassemble things. Except unthreading things would be rotational wouldn't it? You can't just use a bearing puller.

I created a fixed gear bike using a standard hub and high strength Loctite when I was at uni (I know, but I was young! - and tight) so I know strong is strong. I'd prefer to use the right one! Does it just want a threadlocker?

I like that I'm asking the interweb to verify the interweb, but the Salon has standards.

[Chik]

No experience with the BB in question, but a few thoughts nonetheless.

It's probably worth confirming the source of the noise before getting too deep into the BB question?

I think it's generally not ideal to resort to thread locker for bits where one would normally use grease or otherwise not use thread locker.

Furthermore, even if the BB turns out to be the source of the noise, it may not be the threaded interface. Of course, you wouldn't know unless you try to eliminate possible sources, but a friend of mine had the issue with a British-threaded King BB with a Sram chainset. After he had two shops look at it, it was still there. We first did an exhaustive check on other possible sources, including cracks in the frame because his particular make is known to suffer cracks in the weld. Then, I had a look at the BB. Cleaned and degreased everything, re-lubed everything and reassembled. I even measured the BB shell to see if one or both sides might be out of round but couldn't find any fault.

He had a protracted email exchange with King, and in the end, they admitted that it was a common problem when paired with Sram chainsets. They didn't reveal the actual source of the noise, but I'm guessing that there is a tolerance issue related to the spacers required for Sram. Anyway, he went back to a Sram BB, installed with grease on the thread as was the King BB, and the noise went away.

(He gave me the King BB and the grease injector tool after that. I discovered that there were bearing seals missing or damaged, probably as a result of one of the shops mishandling it, but that couldn't have been the source of the noise.)

We all love a bit of creak, don't we? Not.

[Drew]

I am a big fan of Vibra Tite for these types of applications. https://www.vibra-tite.com/threadloc...-3-threadmate/

That said, I doubt the threads are the source of the creak, unless they are coming loose... ie, you can remove by hand. I had a MTB with a creaky BB once, and the BB was so loose that I didn’t need tools to unthread it!

Loctite is a tough one... to use it correctly, it requires very clean surfaces, and will also require cleaning/tapping upon each subsequent R&R. Vibra-tite doesn’t do that.

[andrew flowers]

I’d check the nds bearing. Due to the captured nature of that bearing with the m30 system (big gxp) they wear super fast if the bb dimensions are not perfect

[kdawg]

My T47 is silent but I’ve had a few threaded BBs creak - mainly after wet weather. I’ve always just removed it, cleaned the threads and shell, greased both and the spindle and reassembled. I put it down to moisture or contaminants getting in there and that has solved it.

Loctite, especially a strong one feels like a mistake.

[thollandpe]

Make sure your bottom bracket shell has a hole to let water out. Because if you ride in the wet, water does find its way around your seatpost. And probably into the BB.

I’ve quieted a whole lotta BB creaks with a No. 21 drill bit.

[Gattonero]

My Praxxis M30 T47 threaded BB has started to creak. (I think - it's unproven but it's the prime candidate)

Other forums say the answer is to re-assemble with Loctite 609. Which has a high rotational strength but low shear strength so you can disassemble things. Except unthreading things would be rotational wouldn't it? You can't just use a bearing puller.

I created a fixed gear bike using a standard hub and high strength Loctite when I was at uni (I know, but I was young! - and tight) so I know strong is strong. I'd prefer to use the right one! Does it just want a threadlocker?

I like that I'm asking the interweb to verify the interweb, but the Salon has standards.

That s a bit generic, you are not saying what cranks are you using?
That adapter, IIRC is flanged so it's not going to run away. Copper grease or another tenacious compound will make a good work provided the assembly is sound in the first place: too may BB shells are machined a tad over, which makes easy to install the cups but it's poor once they get in use. In such case, you'd need a "filler" compound like Loctite 603 or 638, they work best when left to cure for as long as you can (I'm talking day).
I assume you already checked your pedal cleats, the chainring bolts, the saddle clamp, the wheel skewers/T.A.s, and all that?

[Colinmclelland]

I thought you could only use the Praxxis cranks given the varying bearing IDs. Whatever, I'm using Praxis cranks! And to be more accurate it's more of a clunk than a creak. Haven't started proper investigations but I know it's not the cleats or the thru axles...

I'll have a proper dig around this week. Thanks to Rich I now have the tools to attack it!

I ride my commuter regardless of the rain, but this bike has really only seen nice weather so it shouldn't (which is different to isn't!) be water in the BB. I'd never heard of Vibra-Tite...

[Calgary_George]

From personal experience, it is worth verifying that your pedals are adequately tight to the crank arm... they too can creak annoyingly.

[Colinmclelland]

Mmm....if I were a suspicious man, I would be wondering why they polished a part but anodised the rest.

E5F97D16-E9F5-4405-951E-1A46E029159B.jpeg

I’m not sure of the solution, but I’m guessing I’ve found the cause...although I don’t know the cause of the cause

[mack_turtle]

I always use Loctite 242 for threaded BBs. per Barnett. anti-seize is good in some applications as well.

[andrew flowers]

That’s isn’t polished, that is worn from irregular bearing contact.

Something is out of alignment, and the m30 (basically big gxp) has no way to compensate. That shelf sits up against the bearing, and any irregularity in spindle rotation goes through the nds bearing. Loctite will not fix this issue. I’d look into facing the bb shell, and if all else fails switching to a crank with floating preload (ie shimano hollowtech 2).

Love or hate him hambini has good videos on this subject

[thollandpe]

I agree with Andrew that the silver part is wear, not polish. However, I don't think it's from the left side bearing being misaligned.

How is that silver patch oriented with the left crank? Say the crank is at 6 o'clock. And that the only work patch on that surface? And how far around does it extend (again, o'clocks would be helpful)?

[andrew flowers]

I agree with Andrew that the silver part is wear, not polish. However, I don't think it's from the left side bearing being misaligned.

How is that silver patch oriented with the left crank? Say the crank is at 6 o'clock. And that the only work patch on that surface? And how far around does it extend (again, o'clocks would be helpful)?

I didn’t say the nds bearing was misaligned. Due to the step down (30 to 28mm) the nds bearing cannot float lateral input as well as the drive side bearing can. I have no idea what part is misaligned, but the effect is always wear to the nds spindle/bearing. Gxp forces unequal load across your drive and non drive bearings due to the design. Again, I am explaining this poorly on my phone, and implore you to check out hambini’s videos on the subject.

[thollandpe]

Regardless, I don't think bearing misalignment is going to leave that kind of a mark on the rotating part. I'd guess that the face of the left crank isn't square, or the washer between the crank and the bearing isn't flat.

Aside: my tandem ate a few GXP bottom brackets and that's why I am done with drive side/non-drive side (DS/NDS) terminology. The front (captain's) crank has the drive on the left, but the BB cup marked "drive side" goes on the right. And yes, that BB fixes the spindle axially on the right side, which is opposite their normal BB. Thankfully it's English threaded so hard to screw up as long as you get front and rear right, er correct. Rear (stoker) BB is their standard arrangement that fixes the spindle axially on the left.

PS: that bare aluminum part is now a good suspect for creaking. The bare aluminum will not take long to form an oxide after you stop riding. The oxide is brittle and takes up a larger volume. When you start riding again it will creak as you apply pressure and break up that layer of oxide. Grease will not keep the oxide from forming because you'll just squeeze it out. Green Loctite might (cylindrical retaining compound) but it will make servicing it a beeyotch.

[j44ke]

Mmm....if I were a suspicious man, I would be wondering why they polished a part but anodised the rest.

E5F97D16-E9F5-4405-951E-1A46E029159B.jpeg

I’m not sure of the solution, but I’m guessing I’ve found the cause...although I don’t know the cause of the cause

Bad or worn wavy washer maybe. Or the wavy washer just isn't taking up enough space to prevent movement. Which could be then that the BB shell narrower than spec.

In the photo, the NDS crank arm would point in the same direction as the worn area, i.e. crank arm at 12 o'clock. So wear occurs at base of downward force on the NDS.

Worn wavy washer (I know - they aren't supposed to happen but...) means pivot point is at the wavy washer and thus the moon rise wear mark at the edge of the spindle.

Just a guess.

[Colinmclelland]

Thanks all. Firstly apologies, i was trying sarcasm. I know the worn bit isn't polished, not least because it was all anodised when I fitted it.

Watched the Hambini vid. I confess I didn't know Praxis has adopted that design. If I had, they would have been on my avoid list too! Never mind

I have a nice set of Lightning cranks on a bike that is now my sons, but they are silent on that bike. Based on Rich's experience that might be down to luck as much as my genius. I don't want to pinch them and have them creak.

I might just talk to EBAY about some Shimano ones...I bought the Praxis cranks because i thought the Shimano and Campy ones were hideous, but I seem to have become desensitized.

but since you asked - the wear is not quite aligned with the crank. If the crank is 12 o'clock, the wear is centred more around 11 o'clock. I guess suggesting against all the odds that my totally awesome power is not delivered uniformly in the pedaling stroke.

Thanks for the thoughts. I think the solution is avoid GXP type designs in the first place. Birthday recently. Older and wiser.

[Gattonero]

A T47 shell is only useful if you have a native BB30 (or 30mm spindle) chainset with cables/hoses running internal. To fit a/ mm spindle chainset on this shell, it's overkill and you'll have to use an adapter.

I'd take the words of mr. Hambini with a heap spoon of salt (a pinch only won't do), bear in mind he seems to like Zipp wheels ('nuff said)

[watchcwgo]

One thing I would check is to make sure you have the correct drive side spacer, make sure it’s not too thick. I see gxp and m30 setups installed wrong all the time by having too many spacers on the drive side which prevents the nds arm from capturing the inner race of the bearing completely. The left arm is then held on completely by the tension of the 8mm bolt. The wavy washer on the drive side shouldn’t be flattened. You can usually tell right away when you are removing the crank arm of a bad setup because it softly loosens right after you apply torque and doesn’t have that hard breakaway feel.