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Shimano 12 speed, what a disappointment

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22K views 150 replies 49 participants last post by  smashysmashy  
#1 ·
Now I'll start by saying I've always been a Shimano fan, it's what I grew up with, always expected great performance and smooth shifting at a great price. It's like pc vs apple, I've always preferred pc, that kind of thing.

Now I've just fitted a new Shimano 12 speed drivetrain, XTR cranks, chain and shifter, SLX m7120 derailleur and SLX 45t cassette.

Chain was degreased from new and fresh Silca Synergetic applied.

This thing shifts like crap and is noisy.
Yea it shifts 'slightly' better under load than a Sram setup but the delay in the shift feels awful, the derailleur moves and the chain takes about half a second to shift over. Everything is adjusted correctly, but tension etc and it goes through all the gears fine but this delay in shift is awful. I also expected the shift itself to be much smoother than it actually is, yea it is a bit smoother than Sram in some occasions when under load but it will still clunk in certain gears when pedalling hard and still will make noise.. I'd put the shift smoothness at maybe 10 - 20% smoother than Eagle but the shift delay is like twice as bad and really detracts from the shifting experience. Imo the slight increase in smoothness no way makes up for the hugely slower shift speed, in some ways it makes it feel clunky because the shift on the back is not in sulync with when you push the shifter and the lack of syncy with your leg pressure ends up in with something that doesn't really feel any smoother than Sram and very clumsy.

To top it off the chain on the gears is noisy, you can feel every tooth as it rolls over the cassette even with a clean chain and top end lubricant like the Silca.

Finally the rhythm step 45t cassette..yes the gear ratios feel more evenly spaced but in practice it just feels off, the middle of the cassette feels biased towards the bigger cog so half the cassette just feels too low range and unusable at above moderate speeds. The high gears (small cogs) feel no smoother to shift than Sram or any other drivetrain and those are the gears I use the most.

Overall it just doesn't feel as tightly wound and immediate as Sram, it just feels loose, clumsy, unrefined and barely feels any smoother except in some gears with the huge penalty of lag. There is no reason it should be noisy either when everything is setup properly yet it is probably the noisiest new drivetrain I have ever owned, it just sounds like it is robbing you of power and not silky smooth.

Maybe the smoothness and sound will improve as things wear and bed in over time but the lag is terrible.

There is no way it will be more durable than a gold XX1 cassette and chain or last anywhere near long, it doesn't look anywhere near as trick, it's not as light, it doesn't shift close to as fast, it has clutches that get rough over time and it doesn't have the derailleur cage release to make wheel changes much easier.

Overall I'm not impressed, XX1 Eagle on my last bike was a far superior overall experience to this.

I'm certain it is the chain and cassette and possibly chainring too, as the derailleur and shifter I have already being using on an 11 speed Sram cassette and Chain with no shift lag and smooth shifting. I love the feel of the XTR shifter but in combination with the Shimano cassette and chain the shifting is poor. Hyperglide plus is way overated, the difference is noticeable but marginal but the delay and noise is a total disaster.
 
#4 ·
Something is off, because mine has never behaved that way. When I first installed it, my thought was that it was about as close to electronic shifting as a mech group is likely to get with the immediacy of the shifts. Mine's also been dead silent since I installed it. I've had mine since before it was available in the US (had to order from Germany just to obtain it at the time). There are a couple little quirks with install that are ever so different than previous gen Shimano drivetrains. But once getting that figured out, it's been an excellent drivetrain.
 
#7 ·
Well I've adjusted b tension, adjusted high and low, adjusted barrel adjuster, hanger is straight, measured chain according to the Shimano 12 speed chain install video, mounted chain the right way, cassette is on tight, decreased chain straight from the packet and replaced the Shimano gunk with a quality highly regarded lubricant. I've never been so meticulous about an install, even had to spend over a 100quid on a microspline freehub for my expensive hub and serviced that before cassette install. Was way more meticulous to do things right with this and doubled checking everything than I did with Eagle. You can tell it is the chain and tooth profile because even the chainring on the teeth is not quite as smooth as some other Sram combinations, it all works fine but definitely does not sound and feel like a high end drivetrain. But even if the smoothness and sound beds in there is no denying the lethargic shifting, you can literally see the derailleur move instantly with the shifter press but the chain lags jumping to the next cog.

With hyperglide plus I expected a seamless transition between cogs. It certainly is not seamless, you can still feel the chain drop onto the next cog just like all other drivetrains.

The smoothest drivetrain I ever had was the old XTR 9 speed stuff, that stuff was buttery and I don't know if it even lagged as much as this twelve speed stuff.
 
#18 ·
So just took it for spin after fixing it. Obviously it is much much better and doesn't make any noise or feel draggy, the shifting is a bit quicker, not quite as fast as Sram but it's liveable. Smoothness has improved a bit but it's still not quite what I expected, you certainly can still feel the chain grab the tooth of the next gear when pedalling hard but you can certainly pedal as hard as you want and it will shift every time. Weirdly I'm using a longer cage than I probably could use but it seems quieter from chain slap, probably because the chain is nowhere near the chainstays lol.

Overall it seems good, I'm happy with it, at least for the money. I still think XX1 Eagle still has it beat simply due to durability, bling and easy of wheel change. The shifting is slightly smoother than a brand new XX1 setup correctly but then again it is also slower so can't say it shifts better just a bit different, now I fixed it though it doesn't feel massively different to XX1.

The rhythm step cassette I will have to see how I get along with it, the gear spacing does feel nice and even but because of that half the cassette feels closer to the low gears than I would probably prefer. Also I had an oval on the previous drivetrain and I can definitely feel the difference in fatigue in even just a few short runs down the street, the bottom part of the pedal stroke is taking more energy than needed but I'm not going any faster. I did buy the Shimano chainring though firstly for compatibility but also because the XT and SLX rings have steel teeth as opposed to alloy so should last a bit longer and not wear the chain down as fast. The SLX 45t cassette is certainly a lot heavier than a 42t 11 speed GX cassette, you can really feel it when you pick them both up, though the 11 speed GX cassette cost me like twice the price at the time. The XX1 cassette on my previous bike was obviously a work of art, the lightness, bling and durability of XX1 gold is another level in my opinion. But in terms of shifting performance and value for money this Shimano stuff is very good, if it lasts half as long as XX1 but at a 1/4 of the price for the SLX cassette and XTR chain then I'm happy with that. Wish it looked a bit more trick as my bike has a load of custom coloured stuff like forks, stem, 11.6 with painted coil etc but the backend just looks a bit cheap and bland as it's a black bike, but hopefully it isn't as desirable and grabs as much unwanted attention as my last bike that went walkies.....
 
#38 ·
It doesn’t, the SLX wear items wear out way faster than X01. I did a cost analysis and it’s cheaper to buy X01 cassettes over SLX.
 
#21 ·
I had crappy shifting last week after changing cables and housing on my x01 drivetrain. It turns out that the o rings in the ferrules were too tight and causing lots of drag on the cable. It made upshifts slow and downshifts uncertain. I swapped them out for non oring ferrules and shifting is great.


Sent from my SM-G975U using Tapatalk
 
#22 ·
You're not the only one that routed the chain wrong. I also did it but didn't find out until like a year later when the mech at the bike shop asked me how old the chain was. And then he said, "oh it looks like your chain is routed incorrectly through the cage". Duh! Won't do that again. It didn't make mine work bad though. Just wore out my XTR carbon fiber cage a bit.
 
#28 ·
Two things about Shimano 12 speed mech experience.
1) It is very sensitive to B-gap. Set it up correctly with no sag and it perform okay. I found mine to work better by setting it correctly with rear shock sag. Or, simply, make the pulley a bit closer to cassette than the line suggest when it is unsagged.

2) Deore and SLX shifter work different than XT/XTR.

XT/XTR have instant release. That make the shift lever stiff and require more effort to press. But the benefit you get is that the RD move instantly into the new location once it click. All the cable released at once.
Deore/SLX shifter work in a conventional way. The cable is released halfway (50%) at the click. And then it release another halfway as the lever move back to rest position. Sram Shifter work this way too.
However, the implication on the cassette shift ramp is different.
Sram cassette assume the shifter to tame the shifting action. So the cassette itself doesn't try to delay the shift for smoothness.

Shimano cassette design for maximum smoothness whereas you can get the speed back with instant release shifter (XT/XTR) anyway.
If you use SLX/Deore, it'll then show off its overly smooth shifting at cost of a bit of slower shift.
 
#30 ·
Two things about Shimano 12 speed mech experience.
1) It is very sensitive to B-gap. Set it up correctly with no sag and it perform okay. I found mine to work better by setting it correctly with rear shock sag. Or, simply, make the pulley a bit closer to cassette than the line suggest when it is unsagged.

2) Deore and SLX shifter work different than XT/XTR.

XT/XTR have instant release. That make the shift lever stiff and require more effort to press. But the benefit you get is that the RD move instantly into the new location once it click. All the cable released at once.
Deore/SLX shifter work in a conventional way. The cable is released halfway (50%) at the click. And then it release another halfway as the lever move back to rest position. Sram Shifter work this way too.
However, the implication on the cassette shift ramp is different.
Sram cassette assume the shifter to tame the shifting action. So the cassette itself doesn't try to delay the shift for smoothness.

Shimano cassette design for maximum smoothness whereas you can get the speed back with instant release shifter (XT/XTR) anyway.
If you use SLX/Deore, it'll then show off its overly smooth shifting at cost of a bit of slower shift.
Does this mean that an XT cassette would play nicer with an XT shifter, and SLX/Deore with SLX/Deore?
 
#29 ·
I wouldn’t feel too bad.

I had two of the listed problems with my Deore 12: first the wrong side of the tab in the rear mech when I replaced the chain, then I bent the hanger shortly thereafter. It’s a wonder I got the chain in the right direction…

I know that when I do things myself, I’m going to make mistakes. It is frustrating, but it’s how I learn. Thank goodness for the forum so I don’t have to troubleshoot all my screw ups alone.
 
#31 · (Edited)
I am using the XTR shifter, I was using this setup with shifter set to 11 speeds with a SRAM GX 11 speed cassette. That definitely shifted faster but a bit less smooth. What I noticed with the XTR 12 speed is it can shift smooth as long as you're going quite fast and your cadence is high, if you are pottering about at lower speeds trying to shift into high gears for lower cadence with a bit of leg force it feels a bit lethargic to shift, it feels like the chain skips a little and then it clunk's down onto the next cog. It is smoother if you let of the power when you shift just like all other derailleur setups but the difference is I'm so preprogrammed to let off the power when I click the shifter with other setups that when I do it on this new shimano 12 speed stuff I'm letting off power too early as it takes 0.5 second for the chain to shift fully to the next cog by which time I start to apply power again. I need to get in the habit of laying off power slightly after I shift rather than during it. Don't get me wrong it is still crisp clean shifting but it isn't as good as I expected it to be given the hype. Looking at how it supposedly works riding 2 cogs at a time and transitioning I expected the shift to be almost not noticeable but it still makes all the clunk's, pings, clicks like all other derailleur setups especially in the smaller sprockets...it's not a game changer if you ask me but I guess maybe I will notice the difference more when in the lower gears u der high torque on a climb. To sum it up I would say it's good, not spectacular, imo 9 speed XTR such as the m960 groupset shifted much smoother with it's rapid rise tech than any current groups etc.... but then SRAM brought out the original XO1 with it's 'crisp' shifting and Shimano seemed to have followed suit.
In regards to my xx1 setup on my previous bike I was running xx1 eagle gripshift so maybe it was smoother than a typical trigger shifter eagle setup..I don't know.
 
#40 ·
Next piece of the puzzle.

After 4 years on 11sp XT Di2 I was forced to mechanical 12sp XTR and the difference in shifting was undetectable.

Roll forward 4 months and the XTR has lost a little bit of immediacy. Upon closer inspection, the polymer coating on the cable has disintegrated at the derailleur where it exits the outer housing.

It's kinda noticeable, but not enough for me to actually do anything about it. If anyone who hasn't used XTR rides it, they'll never pick it.