Does anyone have tips for making a 34T → 52T shift smoother? I do a lot of climbing and descending, so I like having the best of both worlds. Currently running Dura-Ace 34/52T with an 11–34T cassette.
I know 105 has an 11–36T option, and I imagine if Ultegra releases one I’ll try that on my next cassette. For now, I’m looking for ways to make this shift a little less clunky.
I’ve tried using Synchro Shift, but it doesn’t seem to help much unless I’m shifting from the middle of the cassette. Any advice would be appreciated!
Edit. Here’s a worst case scenario. Sometimes it’s smooth. Sometimes it take one revolution. Sometimes it’s this bad. IMG_5604
I have been running the 52/34T with an 11-34T on my DA, Di2, 12 speed for almost 2 years now and have had no clunky shifting issues. But maybe I haven’t noticed.
Wow, It takes 1-3 seconds for me to shift from the small to the big ring. And I’ve tried everything in changing the set up to make it shift better. I wonder what I’m doing wrong.
5.000 miles. It’s been happening since the beginning. Not sure if you caught the video link i added to my initial post but you can v see how bad it can get there.
How old is your derailleur? Asking because the way the Di2 front mechs should work is that they over shift and then correct themselves. Watching your video it is clear that it moves only a small amount at first then moves the rest of the way to get it up to the big ring.
I agree with Chuck - that shifting behaviour looks odd. My 12 speed (Ultegra) front shifter visibly “overshifts” to complete the shift, then “settles back” once the shift is complete.
Might be worth getting an expert opinion - @BetterShifting_Terry or message Di2 GP on insta?
As an aside, even if it worked smoothly, I would still suggest avoiding cross-chaining whenever possible and so not shifting into the big ring whilst still in your biggest cassette sprocket. Which is to say I don’t see that switching to a 11–36T cassette will help the issue.
Interesting, I’ll try turning off synchro to see if it still behaves that way. For the record I only tried synchro because someone suggested it as a fix. Either way this has been happening since day 1.
I don’t cross-chain. the 11-36 could be an option to avoid using the 34t on the front. so i would go back to a stock 36/52 on the front and an 11-36 on the back giving me the 1:1.
The front derailleur’s shifting behavior is dependent on which part of the cassette the chain is on, and also what brand of chainring one is using (due to the difference in relative lateral spacing, Shimano being the widest). The over shift is most noticeable when in the easier gears, as the derailleur cage has to “trim” itself for clearance after the shift has completed. I suspect in the video the OP is in one of the harder gears.
This may be a silly question, but are you sure the derailleur cage is aligned with the chainring? Is the support bolt being utilized?
Also, if this has been happening for an extended period of time, it’s possible that even if the derailleur adjustments are corrected, the damage done to the shifting ramps on the large chainring and to the derailleur’s cage will ensure the symptoms continue.
Not a silly question at all (and honestly I wouldn’t know for sure either way). I just swung by the mechanic on the way home and he lowered the cage a few mm to see if that would help. He also built the bike (and the one before that) and it’s been that way since the beginning.
Never thought of that. I can take close up pics of both later. Not sure it would tell us anything. I always assumed it was the ramps not lining up from the 34t up to the 52t but everyone seems to think it should still shift smoothly or smoother, 100% of the time. Right now I’m at about 1 in the 3 shifts being super clunky.
Just a quick note from me. My understanding is that Shimano chainrings are optimised for 36/52 - modern compact and 34/50 - compact. Depending on the age of your kit shifting may be less than optimal outside these ranges. I’m aware that pros sometimes run 52 / 34 but as I said shifting maybe less than optimal. Happy to be corrected - particularly as my set up dates back to 2017/18 I think.
(ex shop mechanic) 34/52 is a really common modification - my entire riding group did it last year at my suggestion for a hilly UK sportive and left their bikes set like that because there was no loss in performance. People were doing something similar BITD when full size chainrings were still a common fitment.
Front mech adjustment is key, as others have said. Alignment moreso than height: a degree in angle has way more impact than a millimeter in height.
I’d have a look at both the official Shimano manual and Better Shifting guides and see how yours compares.
My understanding as a mechanic is that the 52/34 combination is not officially compatible due to the ramp required to the 52t and the gates being optimised for 36t. I have heard of some getting it working fine but others have had issues. I had a customer once ask for it on an older Dura Ace setup and we just couldn’t get it working as smoothly as 52/36. It’s possible some generations may work better than others. Good luck!
I’ve been running 52/30-11/34 on my gravel bike since August and only dropped a chain when it was particularly muddy. At first I babied it and figured this setup would be really finnicky, shifts under regular load just fine. I will note the 52 ring is pretty close to end of life so it’s even more surprising this works as well as it does.
it makes getting up the Boulder gravel walls easier. On the road I’ve had good success with 53/34, 54/36, and 56/39.
