Creaking Praxis BB

[highdraw]

Sorry goodboyr...you just administer a lot of bad advice including the two things you wrote above. Common sense is unfortunately uncommon as it turns out. Sorry if you feel I repeatedly correct you and nothing personal.
For example, your trolling is quite annoying but I try to focus on setting the record straight and not on your
ad hominem attacks above which is your compensation for being called out for being repeatedly wrong.
You do see that boysa agrees with me right?

[goodboyr]

Let's get this straight. I sometimes disagree with you, as others may do as well. But given this is a discussion forum that's OK. But you take it further and call stuff you disagree with trolling, etc. It is personal, because you are making it personal.

[highdraw]

No. You take things personally goodboyr. I don't. Your comments in your previous post are inexcusable.
Its selfish on your front to continue to sully this board with your personal attacks. So desist. I explained why you were wrong. Let's focus on technical discussion and try to not react to being corrected.

[boysa]

Alright guys, let's get back on topic...

Regarding epoxy, I think its biggest weakness is its biggest strength. You need to be able to remove a bottom bracket, and epoxy would make that problematic.

I pulled my Praxis unit last night, cleaned all surfaces, applied the loctite 609, then reinstalled everything. I timed this, along with several other maintenance projects, around a mandatory/forced/needed rest week, so it'll be late next week before I'm back on the road. I'll certainly follow up with what happens on my end once I have a chance to put it through its paces.

FWIW, I was surprised at how well the loctite covered the surfaces. I put it on the inside of the shell and on the sleeve of the bottom bracket, and a little certainly went a long way.

[Calnago]

Once again, you see fit to disparage anyone who disagrees. The op asked for opinions on epoxy. I gave mine. You disagree. Fine. But stop making it personal. And since the mods allow this to happen, I feel no obligation to keep my complaints private. You have a serious behavioural problem that got you banned from other forums, but apparently is fair game here.

+100

@Highpath: Since when is suggesting calling the manufacturer of a product you are working with "pointless advice". That should always be the first course of action, rather than just taking the word of some Theoretical Bubble Boy (yes, that would be you @Highbrow). While your technical knowledge is usually sound and pretty text book, I question how much experience you actually have on many of the things you give advice on, beyond the theory and asking who I'm quite sure has truly got to be your best friend in the whole world, Mr. Google. Earlier in this thread I asked you what I still consider to be a straightforward question. You eventually responded saying the question was far too broad, then proceeded on a long winded dissertation ending by saying you have worked on hundreds of bikes. When all I asked was how many bottom brackets you have actually removed that were installed with some sort of retaining compound and what was your experience in doing that. Specifics would be nice. Not sure why you felt that question was so broad that you couldn't answer it, but I just moved on because as you've proven here and in many other threads, engaging you is pointless. It's too bad, because you do have some good technical knowledge, but not so far above or arguably even equal to a number of posters on this forum that would warrant the high and mighty status that you believe you and only you are worthy of.
Apparently, you've been banned from other forums, and I know you've been banned from this forum before as well and witnessed why... for the same behavior as you now exhibit in this thread and others. Two things still puzzle me... 1) Why your posting privileges were reinstated, and 2), Why you haven't been banned again, except permanently this time.
I submit this with some trepidation, not because of its content, but because it will prolong this agony for one more post at least, I'm sure.

[rpenmanparker]

Alright guys, let's get back on topic...

Regarding epoxy, I think its biggest weakness is its biggest strength. You need to be able to remove a bottom bracket, and epoxy would make that problematic.

I pulled my Praxis unit last night, cleaned all surfaces, applied the loctite 609, then reinstalled everything. I timed this, along with several other maintenance projects, around a mandatory/forced/needed rest week, so it'll be late next week before I'm back on the road. I'll certainly follow up with what happens on my end once I have a chance to put it through its paces.

FWIW, I was surprised at how well the loctite covered the surfaces. I put it on the inside of the shell and on the sleeve of the bottom bracket, and a little certainly went a long way.

I know this is too late to help you, but I hope you used the corresponding Loctite primer with the 609. You can probably get away without it for a metal to metal bond, but it really does help. Also I have been advised to reassemble the crank to the BB while the 609 is still fluid in order for the crank spindle and preload to set and hold the BB alignment properly while the 609 cures.

[Attermann]

where do you get the primer? is it just called loctite primer?

[Squint]

Loctite 7649.

[boysa]

I did not use a primer since it was metal-metal. I also didn't re-attach the crank yet (two strikes against me, I guess), but I think there is so much pressure from the expanding collet it shouldn't matter. Of course, I may be doing this whole procedure again down the road.

To be honest, if it is even in the same condition as before I'm probably just leaving it be. I'll sort it out on the next frame.

[highdraw]

Alright guys, let's get back on topic...

Regarding epoxy, I think its biggest weakness is its biggest strength. You need to be able to remove a bottom bracket, and epoxy would make that problematic.

I pulled my Praxis unit last night, cleaned all surfaces, applied the loctite 609, then reinstalled everything. I timed this, along with several other maintenance projects, around a mandatory/forced/needed rest week, so it'll be late next week before I'm back on the road. I'll certainly follow up with what happens on my end once I have a chance to put it through its paces.

FWIW, I was surprised at how well the loctite covered the surfaces. I put it on the inside of the shell and on the sleeve of the bottom bracket, and a little certainly went a long way.

I know this is too late to help you, but I hope you used the corresponding Loctite primer with the 609. You can probably get away without it for a metal to metal bond, but it really does help. Also I have been advised to reassemble the crank to the BB while the 609 is still fluid in order for the crank spindle and preload to set and hold the BB alignment properly while the 609 cures.

Hi Robert,
I wonder who gave you that good advice?
As it turns out, it is less applicable with Praxis compared to the BB you chose for your new Chinese uber light build because you purchased a 'decoupled' Press Fit, separate halves PF30 solution which should continue to be dead quiet because you used Loctite. With Praxis, threading it together unitizes the halves for better bearing co-axiality and hence in boysa's case, immediately assembling the crank to a freshly applied Loctited BB is less critical. No doubt that will make sense to you...and boysa, hopefully this should give you peace of mind...you're good.

I hate to say it but the design flaw of Praxis is being exposed on forums like this. Creaks are showing up in spite of vigilant adherence to their recommended installation practices and hence the search for solution.
If one takes a moment to dissect the design, its pretty clear what is going on. The NDS of Praxis is in effect, BB30 for BB30 framesets and PF30 for PF30 framesets...simple press fit where the sleeve can rattle if tolerances don't agree say with rider power. What does the industry do to quiet press fit? They Loctite it. And yet, Praxis doesn't spec Loctite for their sleeve installation. That's why calling them is silly. They have a flawed design based upon their installation practices that will creak under certain (not all) installations based upon their specification for installation. Smart guys understand this and are perhaps reluctant to throw out the baby with the bathwater and totally toss Praxis to the curb because they see the virtue in the design. Loctite will quiet it. So aside from the trolling on this great forum from guys whose elevator doesn't go to the top floor which has distracted conversation, OliverRB the OP, PhD Robert, boysa, Squirt, Atterman, Rick who contributed great advice, treetops and many others following this thread with interest and participating in earnest, I believe you appreciate the gist of discussion and may even benefit. Praxis is a clever solution albeit as with many designs, imperfect under certain conditions. It would be even more clever had they engineered it to have less asymmetry in terms of internal stresses across the sleeve by making it uniformly expanding versus only one side. But this would have made the product more complex, expensive and perhaps even slightly heavier. Guys just keep in mind there are other viable candidates to Praxis out there depending on whether you have BB30 or PF30. So keep the faith with Press Fit. If you own Praxis, you should be good with Loctite especially with a BB30 frameset. But even with Loctite if you have PF30, the Praxis design WILL be challenged on the NDS as is standard PF30 with non integrated bearing solutions and there are better alternatives to Praxis. Robert, your cheap BB solution for PF30 for example is probably more robust than Praxis for creaking. With BB30 however which is alloy on alloy for both sides of the BB, Loctite WILL tame it.
I look forward to your findings guys...

PS: Robert on the epoxy front, consider what Specialized spec's for gluing their Delrin bushings to 46mm ID virgin carbon BB shell...its a low shear strength epoxy by design intent...for serviceability. They spec 3M DP-420 2 part epoxy. This allows getting it apart and isn't the stuff on the shelf of Home Depot FWIW.

Their product spec below:

[rpenmanparker]

More good info or maybe just good info again.

[Trkorb]

Update time!

Yesterday morning I fitted my Praxis BB to my CAAD10 with Loctite 609 (no primer), I immediately fitted the crank after the BB was installed and left the system for about 10 hours.

Went out for a 50km spin yesterday evening, and also a 10km commute this morning.

Creak free! I suspect it will stay like that as long as the Loctite has set correctly and does not pump itself out of contact.

Thanks for all your help guys!

In other news my shoe is squeaking...

[treetrees]

OliverRB, what did you do for cable guide on the bottom of the bb shell as the praxis bb interfered with the guide . I had to oval one of the holes when I used the praxis bb .

[treetrees]

On a separate note I just noticed that the bearing on the nd side feels rough ( wheels mfg outboard ) it's only had 50 miles use

[Trkorb]

I'm not sure I know exactly what you mean, on my CAAD the cable guide runs externally, with a small retaining clip that sits inside the BB shell (I think!) It didn't interfere with installation - I didn't even really think about it!