Which loctite product should I use for press fit joint between fork crown and steerer

PB Forum :: Mechanics' Lounge
Which loctite product should I use for press fit joint between fork crown and steerer
Previous Page | Next Page
Author Message
Posted: Jun 5, 2020 at 10:09 Quote
I have received advice suggesting I use loctite to mend a click which is likely to be coming from the press fit joins in the CSU unit of my fox 34 fork. I have looked quite deeply into which loctite product to use and loctite green 290 seems to be advised. Does anyone know of a reason why I should use a different one and how is it meant to be applied?
Cheers Edward

Posted: Jun 5, 2020 at 11:51 Quote
290 is a threadlocker right? I think you need more of a retaining compound here.

Loctite has a few of those. They all start with a 6 if that helps. How does this help if the crown and steerer are already pressed into each other though?

Posted: Jun 5, 2020 at 12:36 Quote
Will1848 wrote:
290 is a threadlocker right? I think you need more of a retaining compound here.

Loctite has a few of those. They all start with a 6 if that helps. How does this help if the crown and steerer are already pressed into each other though?

I've heard that there cam be a problem with the aluminium of the crown oxidizing unevenly, I read about it in this article:
http://blueliquidlabs.com/suspension/article-two/#:~:text=So%20oxide%20begins%20to%20form,of%20the%20stanchions%20and%20crown.
Cheers for the advice on the loctite, glad I was corrected cos it's not too cheap to buy

Posted: Jun 5, 2020 at 13:02 Quote
To solve problem you need to disassemble CSU (steerer tube and stanchions out of crown), clean, apply Loctite 648 or 603 and repress everything back.....(this can't be done at home).

Posted: Jun 6, 2020 at 3:14 Quote
Andrazzz wrote:
To solve problem you need to disassemble CSU (steerer tube and stanchions out of crown), clean, apply Loctite 648 or 603 and repress everything back.....(this can't be done at home).

I've heard that using 290 means that it can get into the gaps without taking the press fit apart, it's a less reliable method but the only one available to me since I can't take apart the press fit

Posted: Jun 6, 2020 at 12:12 Quote
Loctite 638 is what you want, its wicking and anaeoribic so seeps into gaps and cures over 24 hours in an airless environment. Its made for small gaps 0mm - 0.25mm, cylindrical press fittings within 24 hours you'll have a 50% strength bond and it'll take a week before its 100%.

Just flip the bike upside down, clean, dry, brush and apply around stantion/crown and crown/steerer then come back in 24 hours and wipe off any excess. It wont go hard on the surface so dont worry too much about stantions and making a hash of it.

Posted: Jun 6, 2020 at 13:44 Quote
AerialAtom wrote:
Loctite 638 is what you want, its wicking and anaeoribic so seeps into gaps and cures over 24 hours in an airless environment. Its made for small gaps 0mm - 0.25mm, cylindrical press fittings within 24 hours you'll have a 50% strength bond and it'll take a week before its 100%.

Just flip the bike upside down, clean, dry, brush and apply around stantion/crown and crown/steerer then come back in 24 hours and wipe off any excess. It wont go hard on the surface so dont worry too much about stantions and making a hash of it.

Thanks for advice just got some 609 earlier this evening, I think its similar to 638 but with a lower viscosity? Hopefully I haven't gone and bought the wrong stuff, another guy on a different page recommended 609, I'm guessing it's down to preference or is there an important difference

Posted: Jun 6, 2020 at 13:50 Quote
We're on two threads here but for the sake of it, 609 doesn't handle surface contaminants as well as 638 to my knowledge and the fittings in question are old and difficult to clean where the loctite needs to work

Posted: Jun 6, 2020 at 14:06 Quote
AerialAtom wrote:
We're on two threads here but for the sake of it, 609 doesn't handle surface contaminants as well as 638 to my knowledge and the fittings in question are old and difficult to clean where the loctite needs to work

I'll just stick to this thread then, think it sounds like I should use 638, worth the extra £10 to get a better job done
Cheers for your help

Posted: Jun 6, 2020 at 14:28 Quote
Just had a proper look, 609 advises using an activator and has half the sheer strength of 638. 609 fills gaps up to 0.15mm whereas 638 does up to 0.25mm and is oil resistant wheres 609 isnt.

To be honest, I wouldn't be surprised if a lot of times people have tried to fix it with 609 and it hasn't worked because they havent used an activator

609 will get into gaps easier due to the lower viscosity but I think that's only relevant if you're on limited time restrictions as 638 will still fill the gaps. 609 gets to 100% cure strength in a couple of hours whereas 638 takes 24 hours.

That's on steel, aluminium is 50% at 24 hours, 75% at 72 hours and 100% at about a week.

Previous Page | Next Page

 
Your subscriptions
no posts

Copyright © 2000 - 2020. Pinkbike.com. All rights reserved.
dv56 0.005484
Mobile Version of Website