To follow up on Mark Hickey's question in the Disc/QR thread, I'm starting this thread to have a
separate thread just for riders to give observations about any kinds of evidence that can be seen on
the dropouts of forks used with front disc brakes. It seems to me it would be helpful to note
approximately how many miles the fork has been used with discs, just for benefit of those reading to
evaluate your observations. As far as I am concerned, I am open-minded about this problem. It seems
clear that a change in design is highly likely and probably rightly so. On the other hand, I'll
continue to ride with discs (I personally never intend to go back to previous brake designs on my
MTB) and will take the best precautions I can to see that the QR engagement is tight and secure. I
looked at my fork to see if I see signs of QR "wandering" on the dropout faces. I see no evidence on
the Marzocchi currently installed. All indentations from the QR are very sharp and precise, with no
sign of "wandering" or moving at all. That fork only has about 300 miles on it, however, so I looked
at the SID fork that had been on the bike several years, with the last 2000+ miles using Hayes disc
brakes and 6" rotors. The miles are almost all singletrack on very mountainous terrain, with plenty
of long (3-4 mile) downhills. I am not sure what to make of the SID dropouts. The marks on the
inside of the dropouts are as crisp and sharp as those on all surfaces of the Marzocchi dropouts.
However, the outer sides of the dropouts are less distinct. I don't see any signs of the QR sliding
up and down, but the little indentations are not as clear. This actually might be related to my roof
rack fork mount attachment points. I use a Yakima Steelhead fork mount, which I think does not have
quite as sharply defined indention ridges(?) as most QRs I have used. It might be that it has
smoothed out the dropout faces on the SID over time, and since the Marzocchi has not been used as
much, maybe it just has not had time to show this pattern. On the other hand, maybe the SID is
showing signs of movement of the QR. Since the QR nut cannot really move far even if it were loose,
we may not be able to tell much from this anyway?? Both the SID and the Marzocchi "lawyer lips"
contain the QR nuts so well that it cannot do much sliding around even when loose. I do not recall
ever having had a loose QR on the trail since using disc brakes. As for QR tightening issues, I use
a fork mount rack on the vehicle, so I have to put the front tire on fresh before every ride. (Kinda
glad about that, in light of recent events!) I also tend to tighten the QR pretty firmly as a matter
of practice, though I might be tightening it a bit stronger these days.
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Off to ride the mountains, Dale Heath To reply, poke out my eye.