REtrouble":1hqdjv0b said:
You don't think the chain stay bridge does anything for rigidity then?
I hope not …
My completely uneducated opinion (Guess

) is that it will do absolutely nowt for a vertical loading on the frame (with no wheel resistance both chain stays will be in even tension and both seat stays in even compression) and due to its closeness to the bb shell nowt / virtually nowt in a horizontal loading (how much twist would the frame have to see before there was appreciable amount of movement in the bridge area ?). Open for comments on the above and I am quite prepared to be corrected / shot down in flames …
What planted the seed was my mums orange from the same era – steel frame and no bridge. The final decision was made when looking at my friends steel Cotic – that has half a bridge to allow the fitment of a mud guard but it doesn’t connect the stays providing zero bracing.
Bear in mind that this bike wont be seeing the top of any mountains again (its going on slicks) so it should have quite an easy life
WD