btw, this raised an interesting point. I looked into comparisons of power using a power meter vs. Strava estimates. An example of what I found is here...

http://forum.slowtwitch.com/forum/Sl...tual_P4054650/

Some quotes:

"The estimated "power" in Strava is for entertainment purposes only."

"First to the OP, as everyone else has said, ignore the estimated power in Strava. I'm sure it can be occasionally close under the right conditions, but it is more often than not wildly inaccurate."

"I can understand the appeal of wanting to be able to use Strava to estimate power, but even under very specific conditions that’s just a foolish pursuit. Sorry, if you want power, you’re going to need to buy a power meter. Plain and simple."

So maybe you are getting over 250 watts, regardless of what Strava tells you.