You're right -- there may be more possibility there than I thought. I suppose this is because I'm always working from the non-greasy side of the bike. On the other hand -- is that a mini lock you're using? When I experimented again with mine, I couldn't get both chain stays without forming a very small vertical hole really close to the bike ... and directly below the seat which would then semi-block a vertical post -- not many secure posts that would work. Could form a good hole for a horizontal post, but those are really rare. Looks like I can get a fairly good vertical hole if I carefully thread from the non-drive side through just one of the chainstays.