Big Cassette (11-34) on road bike - any thoughts / experiences

On both my 2x11 bikes I worked up to 36-12t on the rears, playing around with fronts until settling on 36/46 (old cross) rings. Can't remember if I needed a long cage rear for the Force22 or the Ultegra, but both work well without further mods, even though 36t exceeds the recommended capacities.  I built up the cassettes as 36/32/28/25/22/19/17/15/14/13/12 or very similar.

The upshift from 36 to 46t up front is smoother than to the original 50t rings in both cases...perhaps the 36/46 are designed with accomodating ramps as a set? Since I don't race down hills (yet...but I'm a senior), the 48:12 ratio is just fine, and the 1:1 gets me just up my steepest hills.

Hope this helps.

Ern/Boston

I've got an 11-36 SRAM cassette on my CX bike with a single 40 ring upfront.

Using an Ultegra RX rear mech with RS685 shifters.

The shifting is ok, if a bit squishy and vague. But that's partly because of the RS685 shifters which have never felt crisp.

Used a wolf tooth on 11-36 with tiagra RD and it works well, no issues.

I run 11-32 with a 6800 short cage with a 50-33, the 33 only gives you a couple of % lower ratio than a 34 but every little helps.

As Kevvjj alludes too, the older 6700 actually had a bigger capacity than the 6800 that replaced it, the short cage was specced by Shimano to run to a 30T sprocket as standard, and as we all know that's always been conservative. Given the capacity of the mid cage not quite sure why you couldn't just fit a mid cage 6700/5700 with the longer chain and screw the B screw all the way in, it should do the 34T sprocket as per Kevvjj's example.

the 6700 chain was directional but you can also use the previous 6600 chain, in fact Specialized used the HG93 9 speed on its 10 speed road triples for its higher end Sirrus range in the late 00s and this shifted beautifully. I currently use a YABAN with my 10 speed set up

I use XT/XTR Di2 derailleurs with either 11-32 or 11-40 cassettes.  I have triple crankset 48/36/26. It's my do it all bike from sportives to mountain climbing.  I have no fear of any climb with my gearing, just spin

I used a 11-34 R7000 cassette with the new R8000 ultegra rear mech this summer in the Pyrenees, no issues what so ever. But that's 11 speed

I had tried an English version of for the road link which worked fine, as well, I just preferred the look of the above

As others said, on my gravel bike, which was 10speed, I used a Deore rear mech with Tiagra road shifters. The pull ratio is the same, and I used up to 32 tooth cassette

some 10 speed chains from Shimano are directional... have you checked this?

I'm running 11-34 with 50-34 up front - 10 speed. The rear derailleur is an aging Ultegra 6700 medium cage. I do run an 11 speed SRAM chain and find the shifting just fine.

I've just put a 11-34 on one of my bikes but I also changed the derailleur from a 105 to an ultegra rx800 at the same time.

I think my 105 I had on before would have been able to handle the 34 without a roadlink, but I didn't try it to find out.  Have you tried it without and adjusted the B screw accordingly?

This reminds me of Alan's "big plate".

https://www.youtube.com/watch?v=swJFOE49LRQ

I run an SLX 11-34. My old Tiagra RD didn’t cope well, so replaced it with an Ultegra RD. Night and day difference, Ultegra is smooth and crisp and copes with range. 

You don’t say what the rest of your set up is, but someone on the forum posted a link to the Shimano compatibility chart, would suggest you check this and consider ditching the gear extender.

I suspect the issue is additional flex in the link or the dropout, but have you adjusted the B-screw to compensate for the new length too? Some people advocate swapping the jockey wheels or changing them for a better quality one which dont have play in them (upper wheel usually has a bit to compensate for shoddy indexing apparently).

I use an SLX 11-34 cassette on best wheel, I used it for a while with a standard 105 derailleur with the B screw reversed, but shifting wasnt as nice as before, so I changed to a Shimano Deore derailleur.

If you arent happy with the performance I would suggest getting a new derailleur - a shimano 9spd mtb derailleur will work with a 10spd road shifter, but not 10spd mtb/10spd road as shimano changed the pull ratios!

You can get a new XT der for £50 or a Deore for £28.