I recently purchased a used Impec and have some worries it may be fake. I don't think it is but there are a couple of notes that have me thinking.
Signs that it may be fake:
It was hard to find any actual data on the weight, but I read that a module is around 1790g - frame, fork, headset, seatpost. Mine is around 175g more than this.
Some of the photos I've seen of these nodes look quite good where it looks like the nodes were painted separately from the tubes and then glued afterwards like: http://www.flickr.com/photos/54067629@N02/5226657731/
" onclick="window.open(this.href);return false;
Others I've seen look more like mine: http://veloaficionado.com/ride-like-a-robot-bmc-impec/
" onclick="window.open(this.href);return false; The nodes look like they're painted after the frame is assembled. You can see the paint edges around the nodes in some of the photos and there isn't a clear distinction between the two halves.
Signs that it is authentic:
Carbon weave is exact to all the photos I've seen of Impecs. There is a rectangle in between the chainstays near the BB that looks like an authentic SN starting with CH 01/12 (seems like build date) followed by a 2nd line with IP and a short sequence of numbers for the SN.
The seat tube node where the seat post clamps to is definitely a separate piece from the seat tubes. I can see where the seat tube gets cut and meets the node. Also, the seat tube and head tube appear to be solid pieces meaning I cant run my finger into the top tube from either of these tubes. I would expect a Chinese knock-off to be from a single mold rather than go through the trouble of tubes and nodes, but what do I know. Also it requires the proprietary seat post bolt (square that fits into the seatpost hole as well as the 4mm allen head).
The seat post weighs in a scant 175g which was quite surprising given its size and length.
Couple of other questions:
Are the cups that hold the headset bearings carbon or metal?
Anything else I should be looking for?