mustang1

On Spec's web they write (for various model years):

2009 Allez
Specialized E5 aluminum, fully manipulated tubing, smooth weld compact race design, FACT carbon seatstays
2004 Tarmac S Works
Specialized compact design, E5 AEROTEC, fully double butted, heat-treated tubing
2003 Tarmac S Works
Specialized Compact design, E5 AEROTEC, fully double-butted, heat-treated tubing
2002 Tarmac S Works
E5 Superlight Alloy, Aerotec tubeset by , fully double butted, compact geometry frame

Any similarity in frame between new Allez and old Tarmac S-Works?
What does 'E5' mean?

grolby

The S-Works Tarmac from a few years back is a different beast from the S-Works E5 Aerotec - the Tarmac at that time was a half-carbon, half-aluminum frame, the E5 Aerotec is full aluminum.

I can only assume that "E5" is a Specialized buzzword for the material used, which is Columbus 7000-series aluminum. Allez E5 and the S-Works E5 share a material and a geometry, but the rest of the answer is probably right there in front of you; the Allez may not be double-butted and may not be heat-treated. I won't say that they aren't, since they're as likely to change their copy from year to year as anything else, but the frames are definitely not of identical quality, or the Allez would be a lot less expensive. Aluminum technology and the costs associated with it have probably not changed much in the last five years.

ETA: It's actually not clear if E5 is a material or a manufacturing (welding) process. I've assumed that the E5 Allez is also Columbus aluminum, but I don't actually know if this is true.

bike_forever

Specialized is a very innovative company among my top 2 favorites along with Trek. The E5 tubing sure feels good and I am seriously considering buying an older Specialized Allez Comp with a Columbus E5 Aerotec frame.

Bacciagalupe

In terms of functionality, a 2009 E5 Allez frame should be the same as a 2004 E5 Tarmac frame. Assuming both have had the same level of use.