D1 frame

[cdsdorset]

I have been asked to enquire.
Anyone with a D1 is the frame top tube totally straight or does it have a slightly dip?
The frame in question has a slight dip in the top tube but no apparent corresponding obvious make/kinks anywhere else to suggest that the frame has been bent at anytime.

[JulianS]

Should be straight. See the diagrams below.

Probably had a shunt.

[cdsdorset]

Thanks for that.