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Need help on installing compression plug in carbon steerer, please.

11K views 3 replies 2 participants last post by  Mount Dora Cycles 
#1 ·
I picked up a fork with a carbon-fiber steer tube/crown. I know it needs a compression plug. The fork came with an FSA compression plug. I wanted to know the amount of torque for the inner plug and proper installation depth. No joy on finding documentation online.

Questions:

1) What is the proper torque that needs to be applied to the inner compression plug?
2) What is the optimal depth for the compression plug?
3) Anything else I should know/do?

I found a .pdf with Reynolds system, but it doesn't quite apply. If you know of an FSA "guide", please point the way.

I would appreciate any help.

Cheers.
 
#2 ·
Depth should be around 5/8"
Does your plug have the two bolts or just the one?
A good rule to follow is, expander just tight enough so it does not slip and top cap
just enough to remove play from headset.

If you need EXACT torque settings, I believe it's 70in.lb. for the expander and 22in.lb.
for the top cap.
 
#3 ·
Mount Dora Cycles said:
Depth should be around 5/8"
Does your plug have the two bolts or just the one?
A good rule to follow is, expander just tight enough so it does not slip and top cap
just enough to remove play from headset.

If you need EXACT torque settings, I believe it's 70in.lb. for the expander and 22in.lb.
for the top cap.
Thank you. If I understand what you're asking, the plug is a 2-bolt version--one for the expander and one for the top cap. I read that the expander also serves to "balance" the crushing force of the stem in order to protect the carbon steerer.

As far as I know, the stem bolts are usually torqued to 4.5 to 5 nm. I did see citings of ~70 in-lb. for the plug, which translates to ~7.9 nm. I was concerned that it would be too much. Based on your confirmation, I presume it is okay...
 
#4 ·
If it feels like your forcing it, stop. I usually just use 2 fingers to snug it as tight as my 2 fingers can. I've heard people say you can save weight by removing the expander after the stem is installed. I cannot tell you enough how important is it to keep the expander nut installed on carbon forks as it aids in the crushing force of the stem. Not so important on alloy or steel steer tubes.
 
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