Originally Posted by
aliasfox
I’ll have to double check where the stem clamps to the steerer - I don’t remember taking note of that when I reinstalled.
If that ‘seam’ is really a compression-crushed steerer, that’s a bit of a bummer. I’ve tweaked my position a few times:
- Most of my riding has been done on a 100mm stem, with 10mm of spacers below the stem (and 10mm above)
- Swapped the 100mm for a 110mm a few rides ago, same spacer configuration
- Dropped the stem by 5mm after my last ride (15mm on top, 5mm below), and the front end play bugged me enough to disassemble and discover the irregularity.
Understanding the weaknesses of carbon steerers and that the bottom stem bolt is likely below the compression nut inside the steerer, I’ve always used a torque wrench after each adjustment, doing my best not to go past 5nm.
I cannot tell from your photo whether one section of the steerer is crushed. As
13ollocks said, the glossier segment seems to be too low to correspond to your description of your stem setup.
Many regular expander plugs are barely long enough for a regular stem (just under 40 mm height) with a 3-5 mm spacer installed above. I understand that is why excessive steerer length must be cut, i.e., to let the expander plug reach low enough within the steerer and past the lower stem bolt to properly support the stem. Having ridden mostly with a 10 mm spacer above the stem all this time, the compression force exerted by your lower stem bolt may not have been counteracted by the expander plug. Why not try a longer expansion plug? For example:
Specialized Extended Expander Plug For Carbon Steerer Tubes (1-1/8") (Alloy) - Performance Bicycle (performancebike.com)