Cervelo P4 size measurement and serial placement

Hi all - a friend is trying to work out which size her (purchased used) P4 is. Is the seat tube length still the best measurement? As for the serial number, anyone know where it would be on the frame?

Thanks in advance.

Best compare stack … http://mx.cervelo.com/media/docs/P4-Geometry-f35fee0f-fa0c-4cd9-8e91-366e608c51f0-0.pdf … the frame number should be on a sticker under the bottom bracket ore close …

Thanks - that’s helpful.

For most bikes - just measure the head tube and look up on the geo chart. It’s the easiest dimension to measure accurately and the options are usually fairly distinct between sizes.

Yup, happy with that - but the serial is proving very hard to find for some reason. The pal in question isn’t super familiar with frame angles/measurements but does now have the Cervelo spec sheet.

Serial probably under the brake cover. I didn’t pay much attention to that when I had mine.

Check the chain stay down side close to cassette … http://de.tinypic.com/view.php?pic=11ak8sh&s=6 … that should be a P4 serial number …