Cervélo 2015 lineup

Discuss light weight issues concerning road bikes & parts.
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justkeepedaling
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by justkeepedaling

What do you mean laid back seat tube angles? 73 degrees is the most traditional of seat tube angles. There's absolutely NOTHING about that that warrants such criticism

maquisard
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by maquisard

Zero setback posts are lighter! This is weighweenies after all. The only problem comes is that if the seat tube angle is more laid back like Cervélo and the rider needs negative seatback. There in they have a problem... or a saddle clamped at the very back of the rails.

by Weenie


wingguy
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by wingguy

maquisard wrote:Zero setback posts are lighter! This is weighweenies after all. The only problem comes is that if the seat tube angle is more laid back like Cervélo and the rider needs negative seatback. There in they have a problem... or a saddle clamped at the very back of the rails.


More laid back than what? In the larger sizes (where setback is proportionally less correctible with saddle rail movement) Cervelos are pretty much the steepest thing out there.

In the smaller sizes 73d and a 25mm setback might be a bit far, but that's what 0 offset is for.

eric
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by eric

TheRoadrunner wrote:
Also, I would be careful on using ETT to compare different brands. Because some brands measure ETT differently, so effective comparison may not be possible.


A much bigger problem with ETT is that it does not take seat tube angle into account. A bike with a 72 degree STA will require the saddle to be farther forward on the post to get it in the same position as a frame with the same ETT but a 73 degree STA. Slacker STA subtracts from published ETT, steeper STA adds to it. The effect is greater with the more seat post you have sticking out.

This is why people have started using reach instead of ETT. Reach is relative to the BB.

KWalker
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by KWalker

a 73 degree STA in my size would require a 0 offset post. The Cervelo STA measurement is weird as it seems that they do not measure from the same point on the BB and in practice seats end up needing less offset. There was a thread about it on here once that I cannot find. Either way, I'm not going to buy a bike for that much cash that I don't like the looks of. My modded offset post isn't much heavier than a 0 offset option and I don't want to run a -17 or -21 stem to get the stack correct.

Cervelo size 56 stack: 380
Cannondale size 56 stack: 557
Cervelo size 56 reach: 387
Cannondale size 56 reach: 394

So considering I run a 130mm -6 stem on my Supersix, I'd need something more aggro than a -17 and it to be a 140 for the Cervelo to work. I can't think of another brand in a size 56 that would require that. Even the tall headtube'd Tarmac is 570 stack and has more reach. It also has a true 73.5 STA
Last edited by KWalker on Thu Aug 21, 2014 8:33 pm, edited 1 time in total.
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wingguy
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by wingguy

Hey, if it doesn't work for you then it doesn't work for you - but that doesn't make it bad.

Whichever way you slice it, a slammed 130mm -17 on an Evo is not common, and Cervelo are quite up front about why they didn't design their bikes to accomodate that positioning.

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djconnel
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by djconnel

KWalker: check your stack-reach numbers. There's typos.

On the geometry measurement: I think on the R5 and RCa it looks conventional:

Image

The R5Ca, on the other hand, was trying to be clever:

Image

72 deg but move the whole thing forward of BB which creates an effective saddle height dependent seat tube angle.

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53x12
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by 53x12

djconnel wrote:What bike is better than the R5, other than issues of specific geometry?



I think I would throw the Felt F FRD against the R5. F FRD frame is $1000 cheaper and should come in lighter.
"Marginal gains are the only gains when all that's left to gain is in the margins."

KWalker
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by KWalker

wingguy wrote:Hey, if it doesn't work for you then it doesn't work for you - but that doesn't make it bad.

Whichever way you slice it, a slammed 130mm -17 on an Evo is not common, and Cervelo are quite up front about why they didn't design their bikes to accomodate that positioning.


Its actually very common to see -17 stems on Evos- go check the gallery on this forum. I typed wrong, I use a -6 not a -12. Cannondale's geo seems to work so that a rider is often on the cusp or could ride 2 or more sizes. Reach wise I could go all the way up to a 60 and be fine since reach doesn't increase much, but stack does.

And great for Cervelo, but they definitely miss out on a market with that thought process.
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djconnel
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by djconnel

My present Fuji SL/1 is probably one size too small, but I went small because it was lighter. What I gave up in that deal was longer trail, which makes for inferior handling.

On that frame I have a +6 degree 11 cm stem (it used to be lower but I wasn't getting a lower position with the lower bars, just straining more to reach the bars). In the following plot I take that as a baseline I take the stack-reach of the Fuji SL/1, project out for the 11 cm stem at 6 degrees relative to the 71 deg HTA, establishing x,y coordinates. Then from there, using HTA's from Cervelo, I project back for +6, -6, and -17 deg stems using the HTA's of 48, 51, and 54 cm R5's, using 9, 10, 11, 12, and 13 cm stems. This gives the points shown.

For points falling above the stack-reach of a given frame size, that says I'd need spacers to get to my Fuji SL/1 position with that stem set-up. That's fine. And what I see is for the 48 cm Cervelo, I'd need a 13 cm +6 deg stem (too small). For the 51 cm Cervelo, the -6 deg stem would need to be around 11.5 cm. For the 54 cm stem, a -17 deg stem @ 10 cm gets me close.

Image

I also see what stems would be required for the Cannondale and the Trek Madone H1 (although the HTAs aren't correct for those frames).

Why did I do this? A local shop has some R5 demo bikes, size 48 and 54 (not 51). I have always wanted to ride one of these, so I'll give it a spin (okay -- I'll try to recapture a Strava KOM I held for a painfully brief 2 days...) . The 54 is the better bet, but likely they won't have the -17 deg stem.

tranzformer
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by tranzformer

djconnel, you asked what frame is better than the R5 and I might have to agree with the mention of the Felt F FRD. Awesome frame and very underrated. I also think for a mid tier bike, the 2015 F3 can't be beat. But for a top end frame, that F FRD is a great option.

uraqt
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by uraqt

I think from a technical point of view the R5 with it's aero benefits is just a little better than the Felt F FRD.

tranzformer
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by tranzformer

^ depends what you want out of a frame. Could be argued that the lighter F FRD and a better stiffness to weight is better than the R5 from a technical point of view.

mjduct
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by mjduct

R5 aero? Are you thinking of the S5? (I own a 2011 R5 and aerodynamics are not its #1 selling point)


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headwind816
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by headwind816

The R-series squoval shaping adds some degree of aero compared to regular round tubes. Cervelo in no way calls it an aero bike, that title is for their S-series.

by Weenie


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