Dolan Pre Cursa / PreCursa / Track Champion

Yes, drilled the rear bridge with an electric hand drill and used a front brake to get the longer bolt and just used a nut to secure rather than an internal allen nut as felt it was safer making as small a hold as possible (plus you can drill straight through as hole size the same both sides so no awkward angles drilling from back of bridge)

doesn't drilling the rear bridge result in structural instability?