"Tom Nakashima" <[email hidden]> wrote in message news:...
Quoted message said:
<[email hidden]> wrote in message
news:[email hidden]...Tom Nakashima said:Quoted message said:>> Since switching to swiveling head bearings (Shimano) I haven't
>> had dimples in the races (indexed steering) from fretting damage.Quoted message said:Quoted message said:> On the subject dimpling with ball bearings in headsets, will small
> diameter balls prolong the races? I know I need to switch over to
> the swiveling head bearings someday.Quoted message said:Quoted message said:I don't know which effect is greater, contact pressure or ball
rotation. However, larger bearing balls have usually been the
better course even though the number of balls for a given circle
decreases with increasing ball size. I'm still using the angular
contact pre-loaded cartridge bearings I had before converting to
threadless. That required boring out the threads and putting a
conical seat in the upper bearing mount to receive the centering
cone. It looks like a typical threaded head bearing.Quoted message said:I remember you telling me this, but was meaning to ask you about the
conical cone angle, how did you get the right conical cone angle in
the seat? Or is angle not critical? Also aren't the seats
hardened?Quoted message said:Quoted message said:No hardening, all parts are aluminum. The centering cone is a one
slot split ring with a 60° angle so that when it is pushed in axially,
it clamps the steertube and centers the upper bearing cup. I
saw no reason to buy a new head-set and had my old one modified.http://en.wikipedia.org/wiki/Image:Threadless-bicycle-headset.jpg
Quoted message said:Quoted message said:Jobst Brandt
Thanks for the link and the description, I can see it now.
As for the steering column, Dale Saso recommended cutting the original
and brazing a short tube to fit over, and then adding a 1.00" dia. tube to
extend. Making an extension to the steering column to accommodate
swiveling bearing headset instad of just brazing on a whole new steering
column.
Your comments on the extension?
-tom
Sorry I messed up.
Still an extension, but a short piece to be brazed in the ID of the original
steering column once it had been cut. Then add a piece of 1" tube to make
the extension to accommodate the swiveling bearing headset.
What this does it eliminate a new paint job.
-tom