Space between steering head bearing cap and stem.

[Doug.]

Hello. Re. above .
On my road bike I have spacers between the frame head bearing cap and the bottom of the handle bar stem of 3 c.m.
My hybrid the spacers are of 4 c.m.
Both cycles are of carbon fibre frame and forks construction (if that makes a difference ? )
I have been told(?) that the above gaps are too great and may effect the steering at speed.
May I ask for readers advise and opinion concerning the maximum gap.
Thank you.
Doug.

 

[black'n'yellow]

I wouldn't go above 30mm of spacers on a carbon steerer. However, if your steerer is aluminium, it is less of an issue. Either way, the issue is not steering-related - whoever told you that needs to be put right.

 

[Ian H]

Here's some information specific to carbon or alloy steerers: http://cdn.specialized.com/OA_MEDIA/pdf/manuals/08_Fork_Installation_Guide_r2.pdf

 

[PpPete]

I've ridden a lot of miles with (mostly) 3 cm of spacers below the stem. Was told by a very reputable and knowledgeable bike shop (in whom I have very great faith) that this was the max they recommended. It is an aluminium steerer tube on a carbon fork.
Other folks (notably Chris Juden - Technical Officer of the CTC) are very worried indeed about fatigue life of aluminum steerer tubes.

I can imagine that more spacers would potentially increase the leverage on the steerer (and thus potentially reduce the fatigue life) but I cannot for the life of me see how the height of spacers will have any effect on the steering at speed (unless it breaks completely)

 

[festival]

40mm max is the general accepted limit.
Steering, no, there is are other issues that affect steering.

 

[Doug.]

Thank you all very much.
Yours
Doug.
The Specialized link is very interesting , and useful !