Are you talking about chain stay length, from bottom bracket to skewer? I just measured my 2009 P2C and it's 380mm, I have been using eTap for about half a season. What problems are you running into? I found the front DR is a pain in the ass to dial in (small to big ring shifting) where the chain either doesn't jump or falls off. I've been able to get it setup though.

What did you do to dial in the front derailleur? I have the same issue.

I have had eTap on a 2012 P3 for at least half a year now...no issues at all...my LBS did advise me that using the top cog in cassette would be noisy...but I have never had a chain drop...nor any problem shifting the FD...there is a little shim that needs to be placed in between the FD and the frame...it keeps it stable when it is called to shift...maybe that is the problem you guys are seeing...do you have the shim(spacer) utilized for the FD?

Yes, the shim is installed. I have triple checked the install against the SRAM instructional video and everything appears to be set up correctly. Also, one more note.....the bike shifts great while on my stand but out on the road under tension it attempts to shift but never quite makes it onto the big ring. Maybe I should adjust it on my stand so that it overshoots the big cog a little and maybe that setting would be perfect out on the road. However, something about that logic annoys me a little.

A few hours of adjusting... I found some posts on the internet (mostly road cycling forums) with people also mentioning FD adjustments being a pain, they didn't mention Cervelo specifically either. For me what helped was adjusting the height, the top of my largest tooth is lined up with the BOTTOM of the height marker. I found that when I lined it up right in the middle of the marker I couldn't get the shifting right.

Also turning the pedals by hand was "different" when on the road or trainer so I did all my adjustments on the trainer. I haven't had a chain drop in about a month (last time I set it up) so we will see...

Thanks for the advice. I'll set up my FD using the trainer as well since this will mimic road conditions better than my stand.

Perhaps this guide can be helpful?
https://sram-cdn-pull-zone-gsdesign.netdna-ssl.com/...t_spec_2017_road.pdf

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Anne Barnes
ABBikefit, Ltd
FIST/SICI/FIST DOWN DEEP
X/Y Coordinator
abbikefit@gmail.com

Thanks, hadn't seen that document before... Perhaps those 20mm are the source of my front DR headaches. Maybe another reason for a new bike...

Is this with all bikes or just this model Cervelo? Just wondering because I was thinking about putting it on my 2008 P3C.

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Let food be thy medicine...

I would look up or measure your chain stay length. The new P2's are listed as 399mm vs the older P2's at 380mm.

Yes, the rear chain stay or center of bottom bracket/crankset to the center of the rear axle/spindle is 380mm. I'm running a 50x34 with a 11-28cassette. The new Cervelo's (2014 and newer) all have 399mm chain stay lengths. The Big to Big won't stay on front big and shifting from front small to big doesn't work unless you have it in the middle of the rear cassette giving me more chain length to make the jump. What Sram is saying, is that the overall chain length(on a chain stay less than 405mm) is too short to operate properly.

I guess I am just lucky...but I have it on an "old" and a "new" P3...have never dropped a chain...have never had any kind of shifting problem...maybe my LBS is better than most...I am careful to stay out of/or be gentle with the biggest cog...but I mostly rode that way before I went to eTap as well...

Did you replace chainrings when you installed eTap? When I had trouble getting into the big ring it was due to wear on that ring.

I have a 53x39 up front which probably gives me a little more wiggle room due to slightly longer chain length... I guess try to do most of your front shifting while in the middle of the cassette block...

Everything is new and I shouldn't have to see where I am on the rear cassette to be able to shift from small to big on front.

I have 53/39 as well...so maybe that is why I have had no trouble...but I have never missed a shift up front...and have not checked which cog I was in before I shifted the front...I love eTap...from what I have experienced so far...I don't see myself ever giving shimano another go...and I am really happy with how SRAM controls their distribution compared to shimano...I love being able to support my LBS

I had this problem and squeezed the front derailleur side plates together to narrow it up to the width of a Dura Ace front derailleur that worked perfect. It now shifts big to small and back without issues. The chain still does not stay on the big cog when on the big chain ring but that's minor.

This sounds incredibly scary to me... That said, did you just use a pair of pliers?

Yes, with a rag to not scratch the metal. Yes scary since it's an expensive part. But it wasn't working so really had nothing to lose.