Threadless Steerer Question
 

Admitting I'm somewhat new to threadless steerers, a question I have:

This pic shows the top of the steerer tube on my alloy 2026 (not one with Future Shock) Diverge once the steerer cap's been removed:

https://cimg3.ibsrv.net/gimg/bikefor...ab5aacaacb.jpg

Am I safe in assuming that the 9nm / 80n in.lb. is for that central, threaded bit into which the stem cap bolt screws?

Seems absurd to infer it to mean the stem cap bolt should be torqued to 9nm, when maybe 4 or 5 would be enough, if its purpose is simply to preload the bearings in the headset until the stem's clamp bolts have been torqued?

I want to mount a longer than 80mm stock stem's why I'm asking.

Yes, that is the spec for the expander plug.

Thanks for confirming!

I would also add that I never use torque specs when tightening the Top Cap since it's better just to tighten to get the proper bearing preload feel. Should be just tight enough to rotate freely but without any play and while tightening the cap have the stem clamped just tight enough so it can move on the steerer freely without being so loose that it's a sloppy fit. Once you get the proper preload with the cap, tighten the stem clamp and your top cap's job is done and its bolt just needs to be snug, no gorilla force needed to keep it in place.

Backing up what Crankycrank is explaining for the top cap. I used to tighten the preset with cap with too much torque. It negatively affects the steering, and causes premature wear on the bearings. Once it is set properly, and the stem to steer tube bolts are tightened to correct specs, the top cap is simply aesthetic.

One wants the expander/pressure plug's tightness to be greater than the top caps. Otherwise when turning the top cap bolt the plug could turn with it and move about within the steerer ID. I get far less concerned about absolute torque levels than I do with the relative interactions the various parts have and how their tightnesses work with each other. Andy.

Crankycrank & Delbiker1 your comments are exactly what I was looking for when I authored this thread yesterday. What you indicate as being your practice is what I'll adopt for my own. Being new to threadless, it hadn't dawned on me that there'd be an expansion plug inside the steerer tube, as is commonplace with threaded steerers.

Initially I began searching for the cause of a 'click' I could hear while standing at rest with my front brake applied then pushing hard against the handlebar. I thought perhaps it was from a maladjusted headset, when in fact it turned out to be the front disc brake's pads moving ever so slightly against their retaining pins. Seems inconsequential enough of an annoyance unless and until I learn otherwise.

It was a star nut when threadless first came out, then they came out with carbon steer tubes.

Try turning the fork 90* and then with the ft brake locked rock the bike fore and aft again. This will position the disks and pads to see no rotational forces when testing the headset adjustment. Andy.

Yes, that ought to be a good test; put the front axle in line with the frame's long axis! Thanks!

When I was messing about with this bike yesterday, after mounting a longer stem than the one it came with, I eventually could see a little bit of motion of the front pads when they were held in contact with the front disc. The motion was timed to accompany the slight clicking I'd been hearing, that I thought could be from the headset not being properly tight.

No movement was felt at my fingertips when I had them bridging the seam between the fork bridge and the bottom bearing housing end of the headset tube.

I'm pretty certain now the noise was the pads shifting slightly in the caliper, moving with the disc while being restrained by their cotter pins.