No, not for bobsledding
This year there were a few track and field Olympics Athletes that was in the 2012 London games, one won medals in both 2012 and 2014. There are football and soccer players that are on the 2014 bobsled teams.
For the most part, bobsled is not a sport you grow up in, like skiing and skating. Athletes are regularly recruited in the 20's, so no, you are not too old.
You're never too old to anything and don't let anyone tell you otherwise. Go for it.
I'm about to turn twenty and am a division 1 caliber track athlete. On the USA bobsledding website, I looked at the combine requirements and my sprint times are competitive enough to match elite world drivers. However, I need to bulk a little and get stronger to meet the lifting requirements for national level bobsleigh.
Do you think it's possible or is it too late for a nineteen year old to pick up the sport?