Shimano Deore XT Shadow Medium Cage Rear Derailleur RD-M772: M772 'Shadow': lower profile body with direct cable routing, stronger spring, and redesigned bracket to avoid chainstay contact. Designed for 11-32t & 11-34t cassettes only.
Submitted by
2004_sj_pro
a Cross Country Rider
from Carlsbad, CA
Date Reviewed: February 5, 2012
Strengths: None that come to mind.
Weaknesses: Poor engineering.
Bottom Line:
Absolutely one of the worst derailleurs I've worked with. Setup on this thing took forever, and it seemed like no matter what minute adjust I made, it would go out of adjustment at some other point (e.g. slightly loosen b-tension screw to allow for quicker downshift [which i could never get to happen] and then the high/low goes way out of whack.
I honestly think this thing has been over-engineered and the result is that it has ventured into unfriendly territory as far as the end user is concerned. I can't say I'm a big fan of the sharp angle where the cable exits. Seems like a perfectly good point for the cable to get worn and eventually snap.
Normally, it has taken me about 10-20 minutes to dial in a rear derailleur, and the end result being buttery smooth shifting, up and down the range. This thing was just all over the place. Set the chain on the largest chainring, thought it was dialed in, then shifted down to the middle chainring, only to have it stick before wanting to shift up/down. Totally unpredictable, which is absolutely the last thing you want out on the trail.
Strengths: Low weight, Less likely to get hit or bend your derailleur hanger, shifts good.
Weaknesses: Not at this time......
Bottom Line:
This is the best option at the present time for riding areas with deep ruts, rocks, and tight lines. I've had many other derailleur strikes and bent hangers using the normal non shadow design. This design works good! Some have written about shifting issues but I've had none. Get it set and it does the job fine. I'm hoping SRAM will have an option like Shimanos Shadow RD soon.....
Bike Setup: kona kula 2-9, slx cranks, slx front derailleur, xt rapid fire, xt cassette
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Submitted by
Richard 77
a Weekend Warrior
from Costa Mesa, CA USA
Date Reviewed: May 20, 2010
Strengths: Shirts great. Easy to adjust
Weaknesses: Shift cable breaks every 3 to 6 months
Bottom Line:
A buddy and I both have the same bike & set-up using the "new" shadow XT derailleur. It shifts very smoothly, but the cable breaks after about 500 miles of serious mountain biking. When doing lots of shifting. Both of us have to replace the cable every 3 to 6 months depending on how much we ride. It breaks at the rear bolt where the cable attaches to the derailleur. The cable bends very slightly back and forth while shifting (like you would do to snap a coat hanger wire). It is not a straight pull. People I know who ride up hill on varied terrain and do a lot a shifting have the problem. Don't shift a lot? Then it will probably last a long time. I have gone through 6 or 7 cables in 2 years. XTR replacement cable lasts longer than the generics I tried.
Bike Setup: Turner 5.5 Spot, XT drive train and brake components with Hope rotors, Chris King hubs, Thompson seat post & stem. Easton Monkeylite SL bar, Mavic rims
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Submitted by
pburnsky
a Weekend Warrior
from Olney, Maryland
Date Reviewed: April 24, 2010
Strengths: Less exposed cable routing is well designed. Looks cool. Shifts nice but not as clean and fast as my old XT's.
Weaknesses: I have been trail riding for over 25 years and this derailleur is a stick magnet. I think it is due to the vulnerable extended cable arm. I have enough experience to know when to avoid sticks and when to stop if one jams into the unit. I have both bent and broke the mounting bolt already after 3 hard rides. I'm leery of the future of this design. This maybe good for slick rock, arid climate riders but go in the woods and you WILL eventually break this part.
Bottom Line:
If I can't fix this "designed to shear" mounting bolt, I'm replacing this with a conventional XT design or maybe trying a SRAM.
Bike Setup: Super lite Hardtail KLEIN Attitude Race with Fox front.
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Submitted by
rlock
a Weekend Warrior
from Kanata, Ontario, Canada
Date Reviewed: March 28, 2010
Strengths: Crisp shifts, even under moderate load
Low profile avoids many hits
Direct cable routing
Weaknesses: Weak parallelogram, easily bent
Bottom Line:
Yes it's true the low profile does reduce the number of hits the derailleur takes but I found that, when you do make that inevitable contact with a rock or log, the M772 bends much more easily than the original XT version. Instead of simply straightening your hanger you are faced with a distorted parallelogram which can never be perfectly aligned again. I've gone back to the trusty original XT version. This is unfortunate because the 772 does shift very nicely, even under moderate load.
Similar Products Used: Shimano LX, XT, XTR, SRAM X.0
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Submitted by
kiwi_matt
a Weekend Warrior
from New Zealand
Date Reviewed: March 22, 2010
Strengths: It has a stiffer spring and shifting is much sharper than the regular XT.
More direct cable routing.
Looks cool
Sits more in line with the frame with its lower profile
Weaknesses: None yet
Bottom Line:
I had the normal XT, when late last year it had a fight with a stick and lost... So I upgraded to the Shadow and have never been happier. It's setup wasn't too hard, it just required a little adjustment to the B screw. Shifting is nice and crisp as others have mentioned. Not only that, it looks cool!
I am totally happy with it and wonder why Shimano don't make it standard.
Bike Setup: 07 Stumpyjumper Pro, Fox Float RL, R/S Recon 351's, Hayes Strokers.
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Submitted by
panzer07
a Cross Country Rider
from Fremont CA USA
Date Reviewed: November 29, 2009
Strengths: light and looks cool
Weaknesses: NO BARREL ADJUSTER!!! Does not stay in adjustment very long and paired with XT shifters requires lots of shift pressure on thumbs.
Bottom Line:
Girlfriends bike came with this POS and it has caused a lot of grief - adjusted itself into the spokes twice now breaking spokes and ruining a chain. I know how to adjust the limit screws as I have built several bikes now but this thing does not stay in tune for very long, again the lack of barrel adjuster rears its head. Going to replace with older XT as I have on my bike and it shifts perfectly.
Similar Products Used: XTR, SLX, LX, and the older XT with barrel adjuster.
Bike Setup: 08 Santa Cruz Heckler, XT drivetrain, King hubs, bottom bracket, and headset, monkey bars and seatpost.
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Submitted by
buzz white
a Cross Country Rider
from mccall, idaho
Date Reviewed: September 29, 2009
Strengths: Worked well. Reliable shifts.
Weaknesses: The engineering on the Shadow must have been reditioned to a black ops area. The tapped and threaded derailleur screw that adusts the throw in ralation to your largest cog has less than 1mm of holding metal on one side and maybe (?) 2-2.5 mm on the other side. My snapped clean right there when a less than hardball sized rock richoceted into it. It confirmed my suspicions when putting the bike together.
Weak link.
Bottom Line:
I don't know what they were thinking but this is not the place to save a gram or even an ounce. Very poor engineering. It's on it's way to Shimano for replacement hopefully with something other than a Shadow.
Anything that leaves you stranded 12 miles from the nearest trailhead is not worthy.
Similar Products Used: Shimano for over 25 years, mostly XT
Campagnolo for over 40 years, all Record
Bike Setup: Kona Hei Hei 29r with Shimano M525 tubeless wheelset.
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Submitted by
Zilo
a Weekend Warrior
from Reno Nevada
Date Reviewed: August 25, 2009
Strengths: buttery smooth shifting, stays in adjustment longer than other derailleurs, design looks nice, lightweight
Weaknesses: doesnt seem strong enough, its hard to adjust when it does get out of alignment
Bottom Line:
Being that this is my first "high end" shimano product, I am really impressed by the performance. I converted my single speed iron horse to a 1x9 set up and my LBS suggested that i try Shimano XT. Ive used sram for 3 years and I was a bit skeptical at first, being that ive had low end shimano derailleurs before. However, this is by far the best derailleur ive used. The shifting is buttery smooth with little effort. And it shifts accurately with no gear jumping. Very good product.
Weaknesses: Lightweight, Weak, breaks easily. On about my 4th ride a stick became lodged in the derailleur and snapped the "X" plate, making the whole thing fall apart.
Bottom Line:
This derailleur shifts well and looks great. It is lightweight, but this makes it more fragile and breakable. Because of a small stick I have to pay $185 and wait a week for it to be repaired. This is a great XC derailleur but may not suit your purpose if you ride in trails with lots of low branches and obstacles.
I'm just annoyed because I can't ride my new bike for a week :(
Bike Setup: Scott Scale 50 // Avid Juicy 3.5's // Deore/Deore XT // Continental Mounyain King Tyres
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Submitted by
str8.cash
a Cross Country Rider
from PC, UT
Date Reviewed: July 16, 2009
Strengths: Spot on, inexpensive, low-profile
Weaknesses: Jagged edged design
Bottom Line:
**Looks like MTBR has two listings for this der, also calling it an "XT shadow". This review is for the m772 GS- mid-sized cage
I have had this product for less than one month so this review is more of my first impressions than an in-depth product test.
First thing that strikes me is the quality of the product. There is no extraneous metal from the casting process and the cage is solidly attached.
The "shadow" profile with it's trick cable routing is novel. It uses a steel sub-hanger incorporated into the top of the derailleur to offset the actual hanging point of the derailleur. This allows the cable to follow the seat stay directly to the bolt-down, eliminating that big loop of cable.
On the second ride with the m772 I dumped pretty hard, bending the derailleur hanger on my bike's frame. The sub-hanger, despite my initial concerns, remained true and straight, successfully transferring the stress of the impact to the weaker aluminum hanger on the bike.
I am not going to critique other's installations of the m772 and deride their bike mech skills but I have had NO issues whatsoever with cables being eaten, ghost shifting or chains being thrown. I can stand on the pedals with all the confidence in the world. Frankly, all derailleurs should enable trouble free use initially, the test is after several crashes and impacts and when the entire drivetrain starts to get worn down. I am not there yet and I hope to follow up with another review- something tells me that I will still be impressed.
On the down side, if there is really any, the m772 seems to be a departure from the streamlined design philosophy so popular in bike design. The body seems to be constructed of flat, congruent pieces of metal; the main pivot is not bulbous and smooth like previous iterations; the cage has sharp corners and narrow guards. This amounts to more vegetation in the pulleys, pivots and spring, but so far the m772 has been able to shed anything that interferes.
In sum, the m772 is a fine piece of engineering and the 'shadow' design will almost certainly be emulated by competitors because it does work. The main pivot on the derailleur which used to be the most prominent feature on the drive-side of the bike is now outreached by the axle bolt. The cable routing is crucial for riders who tangle with tight underbrush.
Weaknesses: the angle on the shifter cable makes it necessary to replace cables on a monthly basis
Bottom Line:
If you want to have a product that needs maintenance every month by replacing shifter cables the this is it. I have 3 bikes all with this derailler and if you ride daily a cable will not last any longer than 6 weeks. Make sure to bring a spare cable with you if your on a long ride.
Submitted by
Energetik
a Cross Country Rider
from Reading, PA, USA
Date Reviewed: June 3, 2009
Strengths: I found this derailleur to be easy to setup in combination with my 770 level XT shifters. It took me 15 minutes out of the box to get this thing shifting smoothly. I liked the fact that I didn't have to run a huge cable loop from the frame stop.
The stronger spring and low profile design have reduced the sound of my drive train considerably.
Weaknesses: Reminds me of SRAM designs a bit. It does tend to pick up sticks occasionally, and I have had to pull a good bit of grass, and mud out of the cage where my previous derailleur would shed that stuff.
No in line barrel adjuster, but I found that I didn't really need one.
Bottom Line:
The bottom line here is that if I crashed and wrecked this derailleur then I would definitely buy another one to replace it. I have had no major issues with this and I have recommended it numerous times to my fellow riders. This derailleur combined with the other XT components on my ride are by far the strongest parts of my bike, and I consider that aspect of it finished. The rest has a ways to go, but my drive train, in part because of this derailleur, has been smooth from day one.
Similar Products Used: Shimano Deore level products.
Bike Setup: Cannondale Caffeine with full 2008 M770 drivetrain, Rock Shox Dart 3, Sun Ditch Witch wheels, thomson stem, generic seat/saddle/pedals, and WTB Exiwolf 2.1 tires. Deore m535 disc brakes as well.
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Submitted by
Ericmopar
a Weekend Warrior
from Henderson NV
Date Reviewed: May 23, 2009
Strengths: Stays in adjustment for long periods.
Holds up well to rocky environments.
Controls chain better than standard type dérailleurs.
Stronger springs make for more positive shifts.
Weaknesses: None that I know of.
Bottom Line:
It's been working great for over a year.
It's pretty much set and forget.
Some say the mounting tab will break, but they are full of it.
That tab is forged plate steel.
I recommend it for XC and all mountain.
If you're doing DH, then get a Saint or X9, X0.
