Location of Compression Plug in CF Fork Steerer

So, my son left the steerer on his CF forks uncut, and it projects quite a way above the stem. Without getting in to the whole issue of whether he'll be impaled (he won't), it strikes me that this might over-stress the CF steerer because the compression plug is above where the stem clamps, so the stem is clamping around a void rather than a compression plug. He's going to cut the steerer, but I was wondering if anyone had heard of problems not using a compression plug or placing it above where the stem clamps.

-- Jay Beattie.

On 2/13/2017 6:18 PM, jbeattie wrote:
So, my son left the steerer on his CF forks uncut, and it projects quite a way above the stem. Without getting in to the whole issue of whether he'll be impaled (he won't), it strikes me that this might over-stress the CF steerer because the compression plug is above where the stem clamps, so the stem is clamping around a void rather than a compression plug. He's going to cut the steerer, but I was wondering if anyone had heard of problems not using a compression plug or placing it above where the stem clamps.

-- Jay Beattie.


A bicycle technical query? On RBT?

I don't think it matters (although aesthetics might) because
the usual carbon fork plugs only grip enough to provide the
bearing adjustment. There's no structural improvement with
modern plugs IMHO.

Older epoxy-in chunky models probably did reinforce the
columns but I haven't seen one in many years.

But do have him call the fork maker's tech line.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Tuesday, February 14, 2017 at 2:49:37 AM UTC+1, AMuzi wrote:
On 2/13/2017 6:18 PM, jbeattie wrote:
So, my son left the steerer on his CF forks uncut, and it projects quite a way above the stem. Without getting in to the whole issue of whether he'll be impaled (he won't), it strikes me that this might over-stress the CF steerer because the compression plug is above where the stem clamps, so the stem is clamping around a void rather than a compression plug. He's going to cut the steerer, but I was wondering if anyone had heard of problems not using a compression plug or placing it above where the stem clamps.

-- Jay Beattie.


A bicycle technical query? On RBT?

I don't think it matters (although aesthetics might) because
the usual carbon fork plugs only grip enough to provide the
bearing adjustment. There's no structural improvement with
modern plugs IMHO.

Older epoxy-in chunky models probably did reinforce the
columns but I haven't seen one in many years.

But do have him call the fork maker's tech line.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

I agree. Modern fork plugs with O rings don't add strength, so it doesn't matter. Use carbon paste and torque the stem to spec (4-5 Nm). I once put a cut piece of carbon steerer in a vise and it takes a lot of force to delaminate the carbon layers.

Lou