Unable to Loosen K-Tech Fork Top Caps

[NotVeryCreative16]

I have K-Tech 20IDS carts installed on my 2015 FJ-09 and can’t for the life of me loosen the top caps with the spanner (https://www.ktechsuspensionusa.com/p-19860-k-tech-suspension-front-fork-tools.aspx). I’ve tried WD-40 and heat to no avail. I was going to try to use a piece of pipe as a cheater bar for more leverage, but on my last attempt, I chipped part of the top cap with the spanner so I thing k cheater bar is probably just going to make it worse. I’m not sure if I’m doing something wrong like the preload or rebound/compression should be set to a certain setting. I’m thinking I need to get one of these sockets: https://www.ktechsuspensionusa.com/Yamaha-FZ09-2015_p-19765-k-tech-suspension-front-fork-tools.aspx

 

Thoughts?

Edited May 18, 2023 by NotVeryCreative16

[betoney]

It might sound silly but with the fork still in the bike, have you fully loosened the top triple clamp pinch bolt before trying to turn the fork cap? 

Did you the install the K-Tech parts yourself? the fork caps don't need to be overly tight and you definitely shouldn't need heat or a cheater bar.

[NotVeryCreative16]

2 hours ago, betoney said:

It might sound silly but with the fork still in the bike, have you fully loosened the top triple clamp pinch bolt before trying to turn the fork cap? 

Did you the install the K-Tech parts yourself? the fork caps don't need to be overly tight and you definitely shouldn't need heat or a cheater bar.

It doesn’t sound silly because no, I didn’t loosen either pinch bolt. Maybe I’m an idiot, but I don’t understand why this would stop the fork cap from turning. I did install them myself but that was 2 years ago and I really don’t remember how tight I made them. I do know I tightened them with the same spanner that I’m trying to loosen them with though so it shouldn’t be this difficult. I’ll try it with the top pinch bolt loosened. I guess the compression is enough to stop the cap from turning? I appreciate the advice.

[skipperT]

Yes it is. @betoney has nailed it.  The upper triple clamp squeezes the caps of the cartridges. 

loosen each bolt (leave the lowers tight!) and it should spin right off. 

if it makes you feel better, you’re not the first person to do that. 🙂

-Skip
 

 

[NotVeryCreative16]

1 minute ago, skipperT said:

Yes it is. @betoney has nailed it.  The upper triple clamp squeezes the caps of the cartridges. 

loosen each bolt (leave the lowers tight!) and it should spin right off. 

if it makes you feel better, you’re not the first person to do that. 🙂

-Skip
 

 

Wow, I’m such an idiot lol. Makes sense I guess but it’s crazy that a pinch bolt tightened to 19 ft lbs is enough to make it impossible to spin the fork cap. Glad I asked before I completely stripped the thing trying!

[dazzler24]

4 hours ago, NotVeryCreative16 said:

Makes sense I guess but it’s crazy that a pinch bolt tightened to 19 ft lbs is enough to make it impossible to spin the fork cap.

Having said that, it's all that holds the front together while we pound our way down the road so I guess it's not hard to appreciate the clamping forces that must be exerted via those 4 clamp/s.  Also, while the bolt is torqued to 19 ft/lbs, the force applied by the ring of the clamp is significantly larger.  I'll leave those calculations to smarter folks than me to determine.

Anyway, good to know it all worked out for you. 👍

[dazzler24]

So, out of pure curiousity of what actually are the forces applied to a band I found this....

If I've understood this correctly (and I probably haven't!), the force applied to the clamp when the bolt is torqued to 19 ft/lbs is thus.....

2 x 3.4159 x 19 ft/lbs =~ 130 ft/lbs. 

No wonder you were unable to turn the cap!!

** Engineers - please confirm or alternatively feel free to deride me accordingly.

[NotVeryCreative16]

7 hours ago, dazzler24 said:

So, out of pure curiousity of what actually are the forces applied to a band I found this....

If I've understood this correctly (and I probably haven't!), the force applied to the clamp when the bolt is torqued to 19 ft/lbs is thus.....

2 x 3.4159 x 19 ft/lbs =~ 130 ft/lbs. 

No wonder you were unable to turn the cap!!

** Engineers - please confirm or alternatively feel free to deride me accordingly.

That’s very interesting. Makes total sense now that I think about it that way. With the pinch bolts loosened, it was comically easy to crack open the fork top caps. I appreciate the input from everyone as always.

[betoney]

12 minutes ago, NotVeryCreative16 said:

That’s very interesting. Makes total sense now that I think about it that way. With the pinch bolts loosened, it was comically easy to crack open the fork top caps. I appreciate the input from everyone as always.

Glad to hear that you got it sorted out. 😎