11 speed 11-34 cassette on Campagnolo

Discuss light weight issues concerning road bikes & parts.
alcatraz
Posts: 3020
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Wolf tooth + racing. That is just an insane idea.

Just fit the largest cassette and derailleur your shifter can support and try to live with that. 52/36 and 11-32t is pretty damn close to the range you're trying to achieve and you don't get delayed shifts from the rear derailleur.

Admittedly a 52/36 won't shift as crisp as a 53/39 but I guess you don't shift the front much during racing (or at all?).

by Weenie


Yoln
Posts: 134
Joined: Thu Nov 14, 2019 10:26 pm

by Yoln

Why that about the wolfTooth?

DaveS
Posts: 2888
Joined: Fri Mar 24, 2006 1:26 pm

by DaveS

Nothing wrong with a wolf tooth, since campy installs a similar device on the chorus RD, to clear a 34T sprocket, but without a 72.5mm cage length, it won't wrap 39T. That's OK, if you're running a 53/39, but not a 16T difference at the crank.

I suppose that some people setup their bikes so they won't wrap the big/big, but it's risky.

Yoln
Posts: 134
Joined: Thu Nov 14, 2019 10:26 pm

by Yoln

DaveS wrote:
Mon Nov 18, 2019 2:54 pm
I suppose that some people setup their bikes so they won't wrap the big/big, but it's risky.
I know how inattentive I might be once I get tired, I would never do that :)

CrankyCarbon
Posts: 91
Joined: Tue Aug 13, 2019 1:15 pm

by CrankyCarbon

I'm curious on the diameter of the 34 tooth cog?

I run 2015 11 speed with 11/12x32 with the Medium Rear der on two bikes one with 52x36 and 53x39.
There's not much space to allow the chain to engage between the upper pulley and the largest cog (B adjuster spacing). The rear mech shifts back quite a distance for clearance compared to the newer longer body design of the 12 and Shimano's newer stuff. I guess some B adjustment may help that but I'd have to check.

The shifting up there is slow compared to the rest of the range too. So I can check the diameter variance and get back to you on any potential clearance problem after I take a look.

Yoln
Posts: 134
Joined: Thu Nov 14, 2019 10:26 pm

by Yoln

Yes please, I would appreciate that a lot! Thanks

Yoln
Posts: 134
Joined: Thu Nov 14, 2019 10:26 pm

by Yoln

alcatraz wrote:
Mon Nov 18, 2019 12:27 am
Wolf tooth + racing. That is just an insane idea.
Why exactly would you say that?

alcatraz
Posts: 3020
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Yoln wrote:
Tue Nov 19, 2019 1:38 pm
alcatraz wrote:
Mon Nov 18, 2019 12:27 am
Wolf tooth + racing. That is just an insane idea.
Why exactly would you say that?
The derailleur is distanced from the cassette. It increases the chance of poor shifting.

Racing requires reliable dependable gear more than saving a watt or two and we know how important saving watts are.

DaveS
Posts: 2888
Joined: Fri Mar 24, 2006 1:26 pm

by DaveS

The shifting on the new Chorus 12 is the best I've ever experienced. No need to worry about poor shifting.

CrankyCarbon
Posts: 91
Joined: Tue Aug 13, 2019 1:15 pm

by CrankyCarbon

The space difference from 32 to 34 is 1cm/10mm as shown here
RulerMeasure1.jpg
Looking at the spacing on the rear der is shown here
Ruler2.jpg
Here's the 32 tooth on a 39 chainring, 2018 Chorus HO Rear Der Medium Cage
Chorus32x39.jpg
And the 32 on a 36 chainring, 2018 Record HO Rear Der Medium Cage. Shorter chain, so tensioned higher with rear der pulled forward rotating the top a bit more
Record32x36_1linkshort.jpg
Last edited by CrankyCarbon on Wed Nov 20, 2019 2:50 pm, edited 4 times in total.

CrankyCarbon
Posts: 91
Joined: Tue Aug 13, 2019 1:15 pm

by CrankyCarbon

it looks to me that there is not enough room for a 34 tooth cog on a normal setup with a Medium Cage 2018 11spd Rear Derailleur (Chorus / Record shown).
I pushed the rear der all the way back (no picture) and there was "barely" room for a 34tooth engagement but that would require your dropout adj screw and B adj screw to be setup to do that for all the cogs. Shortening the chain gives more room due to the top of the der cage being rotated more. So technically it could barely fit.

FYI, many around here use the entire cog set and never get out of their 53 or 52, or 50 (for the more tourist types) so I frequently see large chainring and large cog (Campy, SRAM and Shimano).

I only go up to the top 3 cogs when I'm in my small chainring as I don't like the "grinding I sense" from the chain angle coming off of the top of the large cogs to the large chainring.

FYI, you'll see more chain tension on the 36 picture as the setup is 1 link shorter than normal. I found it to shift faster and there's less overall chain bounce with an 11 v12 ( I have both 11x32 and 12x32 cassettes) but you can't use the large chainring on the large cog. I mention this as it does rotate the top of the rear der which can add a little more clearance up there. But you'll may have to compensate your riding style/shifting around it.

alcatraz
Posts: 3020
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

The lowest gap possible is achieved when there is no noise when shifting between the two largest cogs on the cassette.

To achieve that you need a few millimeters (maybe 3-5) more clearance than noiseless in the 1st cog alone.

The lower the clearance, the better the shifting, so I say to just lower it until the noise starts and bring it back up a notch. Keep shifting between 1st and 2nd. Try both chainrings too.

Yoln
Posts: 134
Joined: Thu Nov 14, 2019 10:26 pm

by Yoln

Thank you all. After giving it some thought I think I'll stick to the 32, maybe with a 52-36 instead of my 53-39, I'll have to try how I like the 52 for racing...

duende
Posts: 46
Joined: Sun Jan 11, 2015 9:07 am

by duende

Fwiw,

I'm running Record 11 with a shimano 11-34 in the back and 34/50 up front. Works flawlessly. No Wolftooth required

by Weenie


alcatraz
Posts: 3020
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Depends on the length of the derailleur hanger. Trek bikes have relatively long hangers. Other bikes might not have that and could grind the big cog with B-screw all the way in.

Ideally you wanna use a cassette close to what the derailleur was intended for.

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