Shimano Shadow Plus XT Derailleur: Quick Test- by Guitar Ted
Shimano’s workhorse mountain bike gruppo, Deore XT, has gone 10 speed, of course, (we tested the first DynaSys version here), and is being refined even further. The latest iteration of Deore XT now sports an innovation in rear derailleur technology that has me thinking, “Why hasn’t someone done this before now?” Well, at least it has been done! 
What is all the fuss? Take a look after the image to see….
The “Plus” stands for the clutch mechanism that Shimano has integrated into this derailleur. (See the round shape under the “Shimano” logo on the derailleur? That’s the clutch cover.) This trickles down from Shimano’s XTR level, and looks to be a feature on several 2013 bikes spec’ed with XT and SLX component groups. (Yes- SLX will also get Shadow Plus) The clutch mechanism stabilizes the cage assembly so that when you hit some rough stuff, the cage doesn’t flop up and down in reaction to the trail, which causes chain slap, and on some 1X equipped bikes, chain derailment. (Of course, that has spawned a whole chain retention device market to solve the problem, but that’s another story…) Shadow Plus may not eliminate chain retention devices, but it will go a long way toward that end, perhaps, and at the least, will make mountain biking nearly as silent as riding a single speed.
The XTR version
I’ve been riding the XTR and XT versions of Shadow Plus for a couple of months now. The addition of the clutch mechanism has made the derailleurs slightly heavier than their non-Plus equipped versions, but the benefit is snappy shifting, and an “oh-so-quiet” ride. To my mind, the latter is the biggest advantage here. In fact, I cringe now when I ride a bicycle with traditional derailleurs over rough terrain and here the chain clattering on the chain stay. Something I took for granted before Shadow Plus came along.
Did I mention “snappy shifting”? Well, maybe I should say “authoritative kerchunk“instead. Unlike previous Shimano shift feel, where sometimes only a slight “snick” would be heard when switching gears, the Shadow Plus drops the chain into a higher gear with a feel and sound you won’t mistake for anything else. I suspect it has to do with the stiffness of the cage when the clutch is “on”. Oh…..yes, you can turn the clutch “Off”. In fact, you will want to remember to flip the switch above the Shimano logo to “Off” when you remove and replace a wheel. (On the XTR Shadow Plus derailleur shown above, the switch is anodized orange.)
Interestingly, the clutch mechanism is also adjustable, so one could tweak the level of resistance that the cage has to movement when the clutch is engaged. You will also probably need to periodically adjust the clutch due to wear. I’ve noticed mine have gotten freer movement with time on the trails. Oh yes….you’ll have one more thing to maintenance as well. The clutch mechanism will need cleaning and greasing from time to time.
Conclusions: Shadow Plus may be slightly heavier, need more maintenance than standard derailleurs, and is louder when shifting into higher gears, but the silence is golden ride over the rough stuff is really attractive, while the promise of better chain retention is also realized. Shifting is typical Shimano precise and fast and the typical Shimano build quality is retained, thankfully. Overall, I see this as an advancement in mountain bike componentry, and the quick trickle down to STX will make this a widely appreciated advancement as well. I wouldn’t go pitching the chain retention device in the parts bin just yet, but this technology may prove to be perfect for some folks 1X set ups. Good stuff here and it gets my thumbs up.
NOTE: Shimano provided an XT Shadow Plus rear mech and 10 speed DynaSys shifter for testing and review at no charge to Twenty Nine Inches. The XTR Shadow Plus rear mech was spec’ed on our Fuji SLM LTD 29 test bike and was included on this review. Fuji and Shimano has not paid, nor bribed us for these reviews and we always strive to give our honest thoughts and opinions throughout.
Haven’t you recently posted about how great grip shift is and how you are glad to have it back? Now what do we do?
@John (AKA Wish I Were Riding) What? You don’t have more than one bicycle?
Besides, that was Grannygear who was posting about Grip Shift. (Although I really like it too.)
How’s this clutch feature compare to a chain dangler, like the Spec one found on the SJ 29er EVO, and aftermarket ones like the Bionicon C Guide v.02?
@MissedThePoint: Well, theoretically, their is less chain friction with the Shimano derailleur. Plus, the derailleur still would be whipping the chain with that retention device, unless it was a Shadow Plus, or SRAMS version of the same.
Shadow Plus is simpler and doesn’t cause drag on the chain, which takes away incrementally from your power. That said, I haven’t used the examples you state and this is pure conjecture on my part.
Is the Shadow Plus XT derailleur available now? What’s the model number?
For 1×10 set up I bought a shimano zee shadow plus derailleur with a short cage. It’s cheaper than the XT derailleur and the short cage works great with the one chainring on the front. Looks good too. Although it is dedicated for freeride, I don’t mind to put it on my XC 29er
When will this be in the shops?
Now if we could only get ride of Hope and Chris King hubs, the woods would be silent again…
I thought the benefit was how easy it is to change wheels?
We like the Shadow+ mechs a lot for the reasons you have stated, but have now started to see more broken hangers come through the workshop with these fitted. Our thoughts being that if riders catch a stick in their wheel there is no chance for the mech to ride up and give you that momentary warning to stop pedalling. Has anyone had similar occurences?
Does this mean an end to the use of ugly chainstay protectors?
@Yogi, “…the woods would be silent again”
could also be interpreted as “…. Lots more single track head on collisions.”
Question…. has there been any tests on the impact on power between a shadow+ and standard derailleur?
@JT: I don’t detect any feeling of loss of efficiency with the Shadow Plus. If there is any, it must me very minimal. I count myself as being pretty sensitive to such things, but I am not a precision laboratory instrument either. Take that for what it is worth.
I have this exact xt plus deraileur on my GT Force 1.0…and it is indeed sweet as…coming from a hard tail Merida matts tfs 900D(all XT fitout-few years old now) to a full custom GT Force 1.0 that sports all the latest XT stuff that i had built 1 week ago , this rear derailer is exceptionally quiet and I too cannot feel any lose in power….for those stressing about such stuff as G’Ted implies you’d need to be a lab machine to notice any power sapping from these…I cant tell …totally love it and never going back to conventional deraileurs
Can you use the 10 speed XT model on a 9 speed set up, Using the adjusters to stop overiding the top and bottom cog.
@Glenn: 10spd XT has a completely different pull ratio from 9spd, so it must be mated to a 10spd shifter. After that, you will have the difference in spacing which the shifter is matched to.
I doubt it would be “optimal”, but I have never tried this.
I have 2013 XT shadow plus on my 2013 Marin FRS120, it’s so sweet man, worth it so far any way!
Well I was loving my xt shadow plus for the last 3 months until yesterday when I noticed the clutch mechanism no longer functioning. I removed the cover and found the little stabilizer piece is no longer fixed in place, seems to have broken free from the derailleur body. I am not sure if this is a common occurrence. The bright side is I am giving myself an excuse for an xtr upgrade. I think the mechanism looks more sturdy in the XTR.
ok ok ok ,I just bought my first 29er, a left over specialized stumpjumper comp hard tail. It has a sram x9 derailuer and a 10 ring cassette. I’m getting tons of ghost shifts, chunking, (i’m not sure of all the terminology) and other assorted things that suck. My qusestions are; if I switch to the plus derailuer do i need to change the shifters? I think I want to change to a 9 ring cassette can I with the plus derailuer? what is the spacing between rings on a 9 ring cassette compared to a 10 ring? will it help? Cause i really dont need all these gears. I’m thinkin like 2 up front(which I have) and 7 in the back.
Typically a new bike will come out of adjustment due to cables housings seating in and compressing. You should visit your local bike shop, (or a mechanical savvy friend), to have adjustments made. Your choice in shifters/derailleurs must match, so SRAM and Shimano shouldn’t be mixed in terms of shifters/derailleurs. Finally, you may want to make note that 10 speed shifters will not work with 9 speed cassettes, so that also is not a good idea.