T
Tom Nakashima
Guest
"Tom Nakashima" <[email protected]> wrote in message news:...
>
> <[email protected]> wrote in message
> news:[email protected]...
> Tom Nakashima writes:
>
>>>>> Since switching to swiveling head bearings (Shimano) I haven't
>>>>> had dimples in the races (indexed steering) from fretting damage.
>
>>>> 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.
>
>>> 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.
>
>> 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?
>
>>>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
>
>>>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
>
> <[email protected]> wrote in message
> news:[email protected]...
> Tom Nakashima writes:
>
>>>>> Since switching to swiveling head bearings (Shimano) I haven't
>>>>> had dimples in the races (indexed steering) from fretting damage.
>
>>>> 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.
>
>>> 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.
>
>> 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?
>
>>>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
>
>>>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
