Joined: Jan 2010
Posts: 9,830
Likes: 1,807
From: Northern California
Bikes: Cheltenham-Pedersen racer, Boulder F/S Paris-Roubaix, Varsity racer, '52 Christophe, '62 Continental, '92 Merckx, '75 Limongi, '76 Presto, '72 Gitane SC, '71 Schwinn SS, etc.
If the bike is a "rider", then a dent doesn't mean very much as long as it doesn't cause rust, especially on a lighter frame made from thinner steel.
On a collector's bike with original paint, the first significant/noticeable dent might drop the bike's value by perhaps 25% or so.