50/34 + 11-34 or 52/36 + 11-34 with the new 12s Shimano Di2 for a long time 50/34 + 11-32 user?

[trex]

Hi,

Quick question.
I'm long time user of 50/34 and 11-32 gearing.

Now I'm wondering which option to go with the new Shimano 12s.
The 50/34 + 11-34 looks a bit overkill (34 vs the currently fully sufficient 32).
However, I'm a little afraid of too big gaps in the 52/36 + 11-34. Also I don't find myself spinning out a lot of 50/11 setup.

Also I love to ride with high cadence about +90 rpm.
Which option would be best?

[bobones]

52/36 with 12 speed 11-34 has same lowest gear and 1 higher gear. Spacing doesn't look too bad, but play around and see for yourself. Depends whether a seldom used lower bail out gear is more valuable to you that a rarely used higher top gear, but spacing doesn't seem to be an issue from my perspective.

[Hexsense]

If 34 is overkill, then you can always go down to 30.
50/34 +11-30 12sp has quite noticably tighter jump than your 11sp 11-32.

https://www.gear-calculator.com/?GR=DER ... 0&UF2=2150

[bobones]

If 34 is overkill, then you can always go down to 30.
50/34 +11-30 12sp has quite noticably tighter jump than your 11sp 11-32.
12sp1130.png
https://www.gear-calculator.com/?GR=DER ... 0&UF2=2150

Only if you sacrifice the low gear offered by his current 32 cog, which I don't think is part of the plan. 52/36 with 11-34 is a nice spread IMO and similar to AXS' 48/35 with 10-33.

[pdlpsher1]

The OP doesn't spin out a lot on 50-11 and he prefers 90+ RPM cadance. The best setup would be the GRX 48/31 crank and D.A. 11-30. That would really make a nice setup for those that don't need a 50-11. I'd would be very interested to know if the GRX crank would work with the 9250 FD. My GRX crank is working well with the 12-speed XTR chain but it doesn't necessarily mean it'll work with the 9250 FD.

[grover]

Other than gear ratios, consider chainline.

Where on the cassette do you currently ride when in the big ring. Going to a 52 will mean you are a little more cross chained. Some of it will be accounted for with the extra cog/tighter spacing.

If you're already a little cross chained in the 50 most of the time I'd stay with the 50 and appreciate a better chainline with the new 12speed groupset.

[sigma]

The OP doesn't spin out a lot on 50-11 and he prefers 90+ RPM cadance. The best setup would be the GRX 48/31 crank and D.A. 11-30. That would really make a nice setup for those that don't need a 50-11. I'd would be very interested to know if the GRX crank would work with the 9250 FD. My GRX crank is working well with the 12-speed XTR chain but it doesn't necessarily mean it'll work with the 9250 FD.

Isn't there a difference in the chainline between GRX and DA? I have a GRX setup on my gravel bike but using a rotor aldhu crank with the offset to match the GRX chainline. Been perfect so far...

[pdlpsher1]

2.5mm vs. 9100 and 1.5mm vs. 9200. GRX crank doesn't work with 9150. I tried it. I didn't try to correct the chainline but I don't think the issue is just the chainline. There are some magic tricks in the GRX FD that aren't present in the 9150 FD. Hence I don't expect the GRX crank will work with 9250. If someone could test it that would be great.

[smokva]

I would never use 12 sp 11-34 cassette because it lacks 16T sprocket which I use alot. To be honest, missing 16T sprocket is something that has bothered me with shimano cassettes for a long time. To me it's a big deal.
Campagnolo's 12s 11-29 is much better with its 11-12-13-14-15-16-17-19-21-23-26-29. I would even trade 11 for an 18 cog, but you cant have everything

The same story was with 11 speed, Campagnolo's 12-29 was much better combo for me than Shimano cassettes which all traded 18 for 11.

If I ever upgrade to 12 speed, this will probably be the reason which will push me to Campagnolo again.

[CampagYOLO]

First time I've realised that Shimano don't currently offer a 12 speed, 11-32 cassette.
Strange omission IMO.
I'd personally go for a 11-30 cassette with a 50/34 or use Campag.

[smokva]

Shimano's new 12 speed Dura-Ace and Ultegra are both:
11-30: 11-12-13-14-15-16-17-19-21-24-27-30T
11:34: 11-12-13-14-15-17-19-21-24-27-30-34T

Campagnolo has:
11-29: 11-12-13-14-15-16-17-19-21-23-26-29
11-32: 11-12-13-14-15-16-17-19-22-25-28-32
11-34: 11-12-13-14-15-16-17-19-22-25-28-34

So, both Shimano and Campagnolo don't have 18T, and if you go 11-29 Campagnolo or 11-30 Shimano you basically get the same thing.
However if you want 32 or 34 biggest cog, than Campagnolo has made imho much better cassettes because on both of their 32 and 34 cassettes they have left 16T cog which is very important and made bigger jumps at the back which is not so important...on the climb i can live with bigger jumps than on the flat.

Looking at all of this I think my perfect combo (if I wanted to move to 12 speed) would be Campagnolo's 50-34/11-29 or 53-39/11-34.
Who ever makes first 12-32(34) cassette: 12-13-14-15-16-17-18-19-22-25-28-32(34) will make me wan't to upgrade to 12 speed. That cassette would have everything I want, untill then Campagnolo is closer to it than Shimano. Now I'm on 11 speed 12-29 cassette with 16 cog and I don't see a single reason to upgrade to 12 speed, especiall in shimano's setup where I would get 11 cog which i almost never need. If they gave me 18 cog it would be something else.
In my eyes 12 speed is nothing else but 11 speed with unnecessary 11 cog.

[satanas]

If they gave me 18 cog it would be something else.
In my eyes 12 speed is nothing else but 11 speed with unnecessary 11 cog.

My thoughts exactly. I was hoping Shimano might offer more useful choices than Campag or SRAM but there's nothing, and no sign of custom cassettes from Miche either so far.

Nigel Tufnel had the right idea.

[satanas]

Double post removed

[Trekspec01]

Did OP make a decision?

I find myself in a similar situation.

I'm looking to ride longer distance 15-20 percent grades.

My bicycle came stock with 11-30t cassette and 52/36T chainrings. Dura Ace 12 speed Di2.

I'm under the impression for such grades, many people would switch out both cassette and chainrings. But as I'm reading this post, would just a different cassette or just different chainrings suffice? I know the new Shimano 12 speed switches things up.

But yeah, 50/34 + 11-34 or 52/36 + 11-34. Kind of in the same situation. Looks like I can find a 11-34 cassette and all chainrings on backorder at the moment. If I run the 52/36 + 11-34 setup, I don't need to change my chainrings.

[ooo]

50-34, because 12s cranks itself (without rings) are heavier than 11s cranks, and 52-36 is more extra weight comparing to 50-34