Sleeve in Serotta Colorado III seat tube

[Frank]

While admiring the beauty of the 2001 Colorado III frameset I have, I noticed it looked like it has a sleeve in the seat tube. This sleeve measures about 5cm deep from the top of the seat tube, is slotted in the rear like the frame to cinch down on the seatpost, and has 3 about 1cm round cutouts on both sides and front.

Is this sleeve there so the what looks like oversize tubing will accept a 27.2 seatpost?

Why the 3 holes?

Thanks,

Frank

[Brian Smith]

Is this sleeve there so the what looks like oversize tubing will accept a 27.2 seatpost?
Frank

Yes.

Why the 3 holes?
Frank

for gas venting, oh wait no, WEIGHT REDUCTION! :)

[dave thompson]

for gas venting, oh wait no, WEIGHT REDUCTION! :)
Brian, you're a baaad boy!