Sizing Help for Cervelo RS

[rinconryder]

My current ride is a stock 55 Moots. Fits like a glove and I will continue to ride it but I also want something with a taller head tube for longer days and a Di2 project where I am going to have Calfee drill the frame (found a good deal on a used RS). I am torn between the 54 and 56 sizing of the Cervelo.

here is the link to the Moots Geometry

http://moots.com/our-bike/road/vamoots-cr/geometry/

here is the Cervelo geometry

73 Degree Seattube Angle
Size Wheel Size Head Tube Angle BB Drop Top Tube Head Tube Length Front Center Rear Center Stand Over Height Stack Reach Rake
XS 650c 72° 40 515 175 555 410 732 520 355 40
51 700c 71° 68 532 140 588 410 742 531 369 53
54 700c 72° 68 546 160 590 410 764 555 376 49
56 700c 73° 68 565 180 593 410 787 579 388 43
58 700c 73° 68 580 200 608 410 805 599 397 43
61 700c 73° 68 592 220 620 410 816 618 403 43


The 56.5 TT concerns me a little but I ride the Moots with a 120 or 130 stem (I have been comfortable with either depending on what group I have on it). I am 5'10" with a 30 pant leg inseam, so torso long.


Any input would be greatly appreciated. Thank you!

[tv_vt]

A little bit of an aside, but noticed in Velonews online that Cervelo has discontinued the RS. Was just a brief comment in the article about the R3 frames being used in P-R.

With the tweaking of the geometry of the R3 frames in the last few years, there wasn't much difference between them except for the price and different strength carbon.

Re: frame choice - Moots has a non-integrated head tube, RS has integrated head tube - yes? Makes HT comparisons a little apple to oranges. Measure your Moots HT including headset to get similar length for a non integrated, more or less.

Also, what angle stem are you using on the Moots? -17*, -10*, -6* or 0* (73*, 80*, 84*, 90*)? Changing that angle gives you more options with whatever you end up with.

[Dave]

The head tube length on the Moots would be around 170, depending on the exact headerst stack height. The 54cm Cervelo would be 175mm with a 15mm headset top section and the 56cm would be 195mm.

As for the reach, the 54cm would be significantly shorter - nearly 2cm. The 56cm would be about 5mm longer, with proper correction for the difference in the STA.