Rear Wheel Alignment

On Wednesday, October 28, 2015 at 6:43:00 PM UTC-7, John B. wrote:
The new(old) bike frame that I am slowly rebuilding into a light road
bike, has horizontal, the opening facing forward, frame ends on the
rear triangle, as did many older bikes. Unfortunately the R.H.
adjusting screw is frozen in the frame end and so far efforts to
remove it have failed and I am afraid to get too aggressive as there
isn't that much metal available that one wants to take the chance of
drilling and having the drill go off center.

What I have been thinking about doing is, perhaps, braze a shim,
perhaps 1/8" - 1/4" thick into the R.H. frame end, to establish a
fixed position for the R.H. axle end, and use the L.H. adjustment
screw, which is not installed and the threaded hole is in good
condition, to align the wheel.

The problem is that if both the right and left hand screws are
installed than the rear axle can aligned and also can be moved forward
in the slot by about one inch so the question is whether this is a
critical measurement.

Moving the axle will of course vary the distance between the upper
derailer pulley and the free hub but riding the bike with its
originally install derailer and the wheel as far back in the frame end
as possible and other bikes using vertical drop outs that have had the
upper idler pulley at various distances from the free hub, seem to
indicate that the distance between the derailer pulley and the cogs is
not a critical factor (which is not to say that it can be completely
ignored).

In brief, attempting to remove the broken screw presents the
possibility of damage to the frame end while not removing it means
that the wheel will likely further away from the derailer then on the
usual vertical drop out frame end. So the question is, is this
meaningful?

Comments?

John - that is so common that it is no surprise.

http://www.ebay.com/itm/like/3912483...chn=ps&lpid=82

Be sure and remember that sometime around 1962 (??) they switched from 8 mm axles to 9 mm axles. Some of the old really fine bikes had rear dropouts so well made that the new axles have to be forced.