Max. spacer height

[kidamaro]

A friend and I were discussing carbon and aluminum stearer tubes and wondering if there were any limits to the length of the stearerr tube that sticks out of the head tube for carbon & aluminum stearer tubes. Anyone know of any guide lines. Thanks

[stevep]

determined by the manufacturer.
not all the same

[michael white]

generally they'll tell you that aluminum steerers can be stacked higher, like at least 3 cm or so.

they'll tell you that carbon steerers shouldn't be stacked higher than the equivalent of the tube diameter, or something.

seems like the manufacturers want to err on the side of safety; they don't want a steerer to fail and make them look bad.

in the real world, lots of cyclists stack their steerers much higher than the manufacturer's guidelines, with no ill effects. Steel can be stacked highest, then aluminum, then carbon. Or so it seems.

my .02$.

[Dave]

The recommended amount will vary depending on the brand LOOK provides 3cm of spacer and a 1.5cm top section with the integrated headset on a new frame. The headset top section provides no more support than a spacer, so the total is 4.5cm.

Alpha-Q provides a glue-in aluminum support tube the is not be be placed more than 8cm above the top of the headset bearing. That leaves 4cm for the headset top section and spacers, plus a typical 4cm tall stem.

I haven't read of any specifics for aluminum steering tubes. More than recommended for carbon looks pretty silly.