I'll consult a pro bike fitter regarding this but I thought I'd throw this out here. I recent bruised my tailbone on two 60-63 mile road rides two weeks apart. I mountain biked between those road rides several times with no issues. Both my road and mtb are pro-fitted and I have had no problema at all with either over the years. My road bike is super comfy and I did a century in Sept '15 with no issues. Now, I haven't been on the road bike much leading up to the recent 60-milers. Note, I'm a bit more stretched out on my road bike than the mtb due to the inherit diffs between the two kinds of bikes (mtbs are more upright and compact in the cockpit). I say this because I thought I might have been unconsciously sliding forward in the saddle to mimic the fit of the mtb. However, on my second ride I made sure to try and stay back on my sit bones. I still got bruised albeit not as bad. So what has gone awry? Has the saddle fatigued to a point so that it's supporting me differently? It's 4-5 years old…and like I said, I had no issues leading up to that century (40, 60, 75 mile rides prepping for it). Any points I should look into? Thanks.

Update: On a whim, I measured my saddle height and somehow (?) it was a cm too high! I have no idea how that could've occurred. I lowered it and will try the bike after my t-bone settles down.