Cervelo 2017 product news

[Dez33]

While it isn’t something you can appreciate while riding, the placement of the inner chainring on the crankset is 0.4 millimeters closer to the centerline of the bike. This improves chainline and allows frame manufacturers to use shorter chainstays. Shimano specs now list 410 millimeters as its shortest recommended chainstays, down from 415mm when using 9000 series cranks.

http://www.bikeradar.com/road/gear/cate ... iew-50505/

I don't know why Cervelo (and Specialized) just didn't extend the chainstays by 5mm. Anything else isn't really fixing the chainline issue, it's just masking it.

[mrlobber]

My only guess would be, to continue praising the "handling" trait of the bikes?
On tight corners, I definitely feel some difference on two of my bikes who have similar stack & reach, while chainstays differ by 5mm. That doesn't mean that I would definitely prefer the one with shorter chainstays over the other, though.

[TiCass]

Extending the chainstays make the bike less "agile"... its not a good compromise for a race bike.

[AZK]

Sub optimal in what way?

What kind of sub optimal shifting issues would I be having with a regular crankset?

I would happily pay the price of having a bit of poor shifting from the second to last, to the last sprocket on the cassette, if it meant that I could transfer my Rotor inPower cranks straight over to the S3 disc from my current Cervelo.

Unless I'm missing something, I don't see why moving your Rotor inpower cranks over would be an issue, just use the appropriate NDS/DS spacers to get the chain line 100%


Even if you didn't get the spacing 100% the issue would only really occur when you cross chain.

[Dez33]

Extending the chainstays make the bike less "agile"... its not a good compromise for a race bike.

It makes the bike feel less lively or slightly less positive when turning into a corner, that doesn't translate to slower cornering. I don't hear people with Canyon's complaining about their bikes handling and Quintana does ok cornering.

Cervelo have chosen to keep the chainstays at 405mm and have a chainline issue, I think that's the wrong decision.

[euan]

Extending the chainstays make the bike less "agile"... its not a good compromise for a race bike.

You're right, a S3 is more of a race bike than say a Madone.

[Calnago]

...Cervelo have chosen to keep the chainstays at 405mm and have a chainline issue, I think that's the wrong decision.

I would agree with that, except they're dealing with the chain line issue in their own proprietary way. Where I take more exception is when I see the same chainstay length for all sizes it smells of nothing more than manufacturing cost savings. When I see the same short (405mm) chainstays on a size 48 frame as I see on a size 61, I just think well, they're not even taking into account where a 6'4" riders center of gravity might be versus a 5'3" rider. Even accounting for different seat tube angles between the sizes that makes no sense to me, except from a manufacturing cost point of view.

[Dez33]

...Cervelo have chosen to keep the chainstays at 405mm and have a chainline issue, I think that's the wrong decision.

I would agree with that, except they're dealing with the china line issue in their own proprietary way. Where I take more exception is when I see the same chainstay length for all sizes it smells of nothing more than manufacturing cost savings. When I see the same short (405mm) chainstays on a size 48 frame as I see on a size 61, I just think well, they're not even taking into account where a 6'4" riders center of gravity might be versus a 5'3" rider. Even accounting for different seat tube angles between the sizes that makes no sense to me, except from a manufacturing cost point of view.

Re bolded: Only partly dealing with it though, without the special crankset they need to be at 420, with it they need to be at 410 ... they are at 405 so still an issue.

The unbolded: absolutely agree.

[MoPho]

They're not going to say they're "unhappy" with the performance if that's what they're selling. I know how close some of these tolerances can need to be for "good performance". "Acceptable Performance" is what you get outside the specs and will often involve more trimming than you would otherwise have to do and/or noise at the outer limits which wouldn't be there if everything was totally within spec. For many, that probably wouldn't matter and they wouldn't know the difference.

I did a 60+ mile demo ride over varying terrain on the Giant and it shifted fantastically and I noticed no noises. Of course I know better than to cross chain from the small ring into the smallest cog (and have no need to either) so it is a non issue.





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[wingguy]

Re bolded: Only partly dealing with it though, without the special crankset they need to be at 420, with it they need to be at 410 ... they are at 405 so still an issue.

I think you're getting confused between cranks. He's talking about the FSA cranks designed specifically for the Cervelo and its 405 stays.

[Dez33]

Re bolded: Only partly dealing with it though, without the special crankset they need to be at 420, with it they need to be at 410 ... they are at 405 so still an issue.

I think you're getting confused between cranks. He's talking about the FSA cranks designed specifically for the Cervelo and its 405 stays.

Is it actually a special Cervelo design though? I can't see that on their site? Either way if the Shimano specs say 410mm then changing the position of the rings isn't going to fix anything if you have 405mm stays, it's just shifting the problem making it better in some gears and worse in others.

[spartan]

another proprietary c** up by cervelo. first bbright and now this.

the new dura-ace di2 and next years ultegra di2 do not allow you to use small chainring two smallest rear cogs. new giant tcr advanced disc have short chainstays no issues with shifting.

[tinozee]

Ew! I would rather use old drive train than lengthen chainstays

[srshaw]

I have a caad 12 disc with 405mm chain stays and didn't give any of this any thought. I did put a 2mm drive side spacer on my shimano 105 crank since the front mech was a little close to the seat tube. Seams to shift fine and run quietly enough. I don't generally run big big though. I wouldn't want any bigger feet though (I'm size , my heels are quite close to the chains stays.

[Mr.Gib]

another proprietary c** up by cervelo. first bbright and now this.

You forgot automatic disassembling R2.5 frames, self ejecting bottom bracket shells, collapsing front derailleur mounts, some bizarre geometry for smaller sizes, and time trial bikes that were incompatible with co-sponsor's disc wheels. While not intentionally proprietary...these items as a group are unique to Cervelo.