I had a moment two weekends ago where I forgot about the two bikes on my roof rack and ploughed straight into a coach house (slow speed so not to bad on the damage).
The only really significant bit of damage was on my buddys steel hardtail which rotated on the rack arm, squashing the rack arm and taking all the paint of a small section of the bottom of the downtube.
It also dented the downtube near the bottom bracket. Do you think this will affect the strength of the frame?
FWIW,when my bike was a couple of rides old I had a stone flick up and dent the down tube, about 3″ up from the BB. This was a lightweight aluminium thing. The dent incident was around 6 years ago. I’ve only just retired that frame… Only time it ever crossed my mind was when I had the bike upside down – the only time I could see the dent.
edit – dent was around the did. of a 5p piece and probably about 1mm deep in the centre. Pretty much central to the lowest point of the tube diameter – hope that last bit makes sense!