rushbikes

Can anyone tell me if the Specialized Tarmac SL2 framesets were identical for both 2008 & 2009?

Also, to confirm what I've read in prior posts, the 2010 SL Pro uses the same mold as the 2009 SL2, but with a slightly lower grade carbon compression?

To anyone that's owned both the SL2 & SL3, is the difference very very noticeable?

umd

Yes, although there could have been internal differences I suppose. Also in 2009 there was a "team" version, which had a lower head tube and according some sources possibly a beefier bb shell.

Yes. The SL2 uses 11r and the Pro SL uses 10r, the same as the S-Works SL before the SL2. Also note that the Pro SL was unchanged from 2009 to 2010.

I don't have an SL3, but one of my teammates had an SL2 which he sold and got an SL3. He's a big guy (190-200ish) and complained of flexing in a sprint. I know smaller people who have ridden both and didn't notice much difference.