New Cervelo California, the Rca

Discuss light weight issues concerning road bikes & parts.
Posts: 8
Joined: Fri Oct 26, 2012 1:08 am

by jsjenkins

There seems to be confusion about the R5ca seat tube angle (myself included). After careful measurements it looks like its a 71 degree seat tube, with 4mm of offset forward of BB center line.

I think it was a good decision going back to standard 73 deg seat tube with the Rca. I've had some difficulty getting the right fit with the R5ca with so much setback being forced on me..

by Weenie

Posts: 281
Joined: Fri Oct 21, 2005 4:08 am

by virenque

Got a geometry question, I ride a 49 SL4, does this mean I'd ride a 48 R5? but according to the geometry of both, the SL4 ha a 386mm reach while the R5 is 360mm

Posts: 408
Joined: Tue Jan 29, 2008 8:20 pm
Location: Denmark

by munk93

DamonRinard wrote:Hi virenque,

The Cervélo approach, sell what our pros race, was (and is) different: Instead of making the bikes the market wants, then fixing up some customs for our pros, we'd rather make the bikes our pros want, and then sell the same frames to the market. The other way doesn't make sense: we sponsor pro teams specifically so we can learn how to make better bikes. Why some companies don't incorporate those lessons into production bikes is a mystery to me.

I don't know if pros want this or not, but it seems a bit weird to me. Cervelo frames have a very "relaxed" geometri, when it comes to the bigger frames. It's the headtube I'm talking about here. :) A size 56 has a 17,3 cm headtube. while most other bikes is around 15,5 or less. And the 58 goes up to a ridiculous 19,9 cm. while others are around 17 cm. Off course every company should do it the way they think is the best. Cervelo don't have to do like anybody else. But...
Why are most pro's I see on Cervelos, using a -17 deg stem on the bigger frames, if the bikes are made for them, and not the average cyclist, who needs a lot more stackheight?
What about shortening the headtube in the bigger sizes. A 56 with a 16 cm headtube, and a 58, with maybe 17,4 and off course continueing in the even bigger sizes?
I'm no framebuilding expert, but I think it's safe to say that a shorter headtuber (which would also lead to a shorter toptube), would shave off more weight. And when the tubes gets shorter, there would be a bit less stress, and therefor the frame would be stiffer (I think :wink: ) But who am I to know. Cervelo got some pretty smart people working on this, so they are most likely right. I just think that it is very weird. And also it looks very stupid. :wink: I think the smaller (cervelo's 54 and under) looks great. And I think the geometri there, is perfect.

Shop Owner
Posts: 1980
Joined: Sat Jun 13, 2009 4:02 am
Location: NoVA/DC

by thisisatest

Only the head tube would be shorter. The top tube would be about the same size, depending on the preferred slope.
Extending the head tube places the headset bearings at the farthest ends, greatly increasing stiffness. As long as the preferred position can be achieved, it is the way to go.
I do think they went a little too far with it all. After all, all their bikes come with 40mm of spacers EXCEPT THE 61. The steerer tube is a typical 300mm, the max most forks are made with, and uncut it only fits 25 or 30. So they ought to cut down their head tubes at least 10mm to be true to their fit philosophy, or make a taller steerer for their 61s.

Posts: 571
Joined: Fri Jun 05, 2009 9:40 am
Location: Switzerland

by GT56

i think things went out of whack when cervelo increased the stack height of their largest size frame by 3 cm without adding a size to the number they had on offer, so they had to stretch the stack size jump going from size to size

(with most manufacturer, the indicated size closely matches the stack height, which imo is very practical)

all this to reduce the number of spacers that most weekend warriors (those that bring cervelos revenue) ran on their old geo cervelo's

the sad thing is, that viewing pictures of very many weekend warrior bikes of new geometry cervelos still show big spacer stacks, and those that need the reach have to run -17 degree stems, which imo looks ugly on a bike with a sloping top tube

User avatar
Posts: 7929
Joined: Wed Sep 26, 2007 1:57 pm
Location: San Francisco, CA

by djconnel


User avatar
Posts: 1513
Joined: Fri Apr 04, 2008 2:49 am
Location: Europe

by mythical

“I always find it amazing that a material can actually sell a product when it’s really the engineering that creates and dictates how well that material will behave or perform.” — Chuck Teixeira

Post Reply