pushing Shimano r7000 gs rear derailleur with 50/34 up front

[eddief]

Shimano says it can handle 34 tooth cassette and I have easily installed with an 11-36. no Wolftooth, no nothing on my Domane. Shifts like it was meant to be. Now wondering if anyone has pushed it to handle a 40 tooth cassette and the results. I do not want to fiddle with a Wolftooth. If it won't work well on its own then won't go there.

[NHAero]

People have posted about making the Ultegra version, R8000GS, work with a 40T cassette cog. I tried it and it worked, but it works a lot better with the Wolftooth DM.

[dem]

Yup, works for me with an 11-40 XTR cassette. You just use up a lot of the "B" screw without the Link extender, so less than ideal wrap - higher cassette wear and it may skip gears when back pedaling (depends on frame geo, stay length, etc.)

Shimano-san generally knows what they're doing. If you want *perfect* you stay within Shimano's specs.. personally I am fine with 95% of shimano-san perfection..

[Dave]

Reading the manufacturer's info sheet will probably show a 39T wrap capacity. IF the chainstay length is just right, you might get 41-42T out of it.

With a 50/34 and an 11-36, you're already getting 41T of wrap. If you went to a 40T, most likely the upper pulley wouldn't clear and you'd be 4T beyond the RD's maximum wrap capacity.

If you make the chain 1 inch longer to wrap the big/big, the chain will hang loose in the little ring and several of the smallest cogs. A RD won't magically have more than 2-3T of extra wrap and that's only there to cover worst-case chainstay lengths.

[Look585]

It will most likely work fine, not *perfect* but very well. Borrow a 11-40 cassette and give it a whirl.

The Roadlink DM is better than the older "hanger drop extender" version. The DM replaces the linkage piece in the RD instead of just adding an extra piece to add drop.

[NHAero]

True, when I had the Ultegra Rd without the WT, my front was 40-28, so four fewer teeth of total differential than what the OP proposes.

I don't think total wrap is critical on my Litespeed because I've geared and set chainlne to use the large chainring almost as a 1X, and the small ring as a bailout, so don't find myself using that ring with the smaller half of the cassette.
I'm about to try a Dura Ace 9100 RD on my Firefly with a 46-34 in the front, and a 12-34 cassette, for a total of 34T of differential. The Shimano spec is 35T, but it's only rated to a 30T large cog, so will see if it works without fussing or aftermarket help. The Record 11 RD that I'm replacing shifted the 34T cog fine. Here I want to get most of the cassette with each chainring, so wrap matters more.

Originally Posted by Dave

Reading the manufacturer's info sheet will probably show a 39T wrap capacity. IF the chainstay length is just right, you might get 41-42T out it.

With a 50/34 and an 11-36, you're already getting 41T of wrap. If you went to a 40T, most likely the upper pulley wouldn't clear and you'd be 4T beyond the RD's maximum wrap capacity.

If you make the chain 1 inch longer to wrap the big/big, the chain will hang loose in the little ring and several of the smallest cogs. An RD won't magically have more than 2-3T of extra wrap and that's only there to cover worst-case chainstay lengths.

[eddief]

can handle 34 cassette. you might want to go down a level from DA for this reason.

Originally Posted by NHAero

True, when I had the Ultegra Rd without the WT, my front was 40-28, so four fewer teeth of total differential than what the OP proposes.

I don't think total wrap is critical on my Litespeed because I've geared and set chainlne to use the large chainring almost as a 1X, and the small ring as a bailout, so don't find myself using that ring with the smaller half of the cassette.
I'm about to try a Dura Ace 9100 RD on my Firefly with a 46-34 in the front, and a 12-34 cassette, for a total of 34T of differential. The Shimano spec is 35T, but it's only rated to a 30T large cog, so will see if it works without fussing or aftermarket help. The Record 11 RD that I'm replacing shifted the 34T cog fine. Here I want to get most of the cassette with each chainring, so wrap matters more.