SEAT STAY BRIDGE DETAIL
Four
different style of seatstay bridge, evolved over the life of the company
;
Mid
1930's to 1948 |
Straight
Only |
|
A
Simple tubular bridge with flanged (swaged) ends and an internal
support for the brake mounting bolt. This support was a small
additional piece of tubing, fitted to prevent the bridge from
collapsing when the brake was fitted and tightened up.
|
1949
- 1951 |
Curved
Only (Ver.1) |
|
Again
a simple tubular bridge with an internal support for the brake
mounting bolt. This change introduced the curved shape that remained
unchanged for a long number of years, however the ends were not
flanged but simply mitred to fit the seat stays. |
1952
- ? (Approx. 1954) |
Curved
with Brake Support (Ver.2) |
|
The
first change, was the extension of the internal bridge support
by 3/16" outwith the bridge towards the front of the frame. This
was introduced to provide better support to the brake assembly
and to prevent it from pivoting under hard braking. It is not
unusual to find frames without this support having the bolt hole
enlarged / opened out |
?
Approx. 1954 - 1980 |
Curved
with Brake Support & Strengthening Pieces (Ver.3) |
|
The
final change made was by the addition of diamond shaped strengthening
pieces. these were brazed to the seat stay's and to the bridge. |
Both the straight and curved bridges including the version with the
strengthening plates, can be found without a brake bolt hole. This applied
to some path frames and all pure track frames where there was no requirement
for a rear brake, hence a plain bridge was used.
Where a frame has been modified by an owner to allow a rear brake to
be fitted, the hole will generally not have the small internal support,
used to prevent the tube from collapsing. If you can see the open edges
of the bridge tube through the bolt hole, this has probably been the
case.
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Copyright © 1999-2003 R.Reid Last Updated
Thursday, 16-Oct-2003 17:33
hrs.
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