The scab board as seen in the pics is tapered in order to, maybe, get some flex. I dont think that’s really needed, but its a good concept.
Its birch, and is simply bolted right on through the original board.
If you look close at final product shot, It has an extender/filler piece integral on the scab to add some cm’s of length to the original 154cm making it 160?
I epoxied all exposed wood including the scab board with no cloth, just the resin.
End result? Totally awesome and rock solid. Bit heavy. Packs in luggage real easy. The perfect travel companion, LW use, plus tandem rides.
So far, no signs of stress whatsoever.
Not even from the passenger