Tech Tuesday - Inside Shimano's Shadow Plus Mech and How To Adjust It

Jan 31, 2012 at 0:05
Jan 31, 2012
by Richard Cunningham  
 
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There has been a lot of buzz regarding the friction clutch inside the Shimano XTR Shadow Plus rear derailleur. The one-way clutch runs concentric with the rear derailleur cage pivot and its function is to prevent the chain from becoming slack between the cage and the chainring. The benefit of the Shadow Plus friction clutch is that rough terrain doesn't allow the chain to pull against the rear derailleur cage spring, so the chain stays taught and in control. Some riders claim that the clutch eliminates the need for a roller chain guide, although our experience shows that Shadow Plus is amazing, but not quite up to roller-guide performance.

Why Should I Need To Adjust the Clutch?

Shimano understands that some riders will want more chain control than others, so it designed in two adjustments to tune the friction clutch. The first is external - simply rotate the gold-anodized clutch lever between the engaged and disengaged position to reduce friction from the clutch. Should you want more chain control, however, you'll need to open the clutch housing and add tension to the clutch friction band. When you do open it up, you'll be surprised to see that Shimano tucked an adjustment hex-wrench inside the housing. All you need to tune the clutch is one Allen wrench to remove the housing screws - and the following step-by-step guide.

Shimano s XTR Shadow Plus rear derailleur is similar to the standard item with the addition of a friction clutch and housing at the cage pivot. The clutch engages only when the cage swings forward.
Shimano's XTR Shadow Plus rear derailleur is similar to the standard item, with the addition of a friction clutch and housing at the cage pivot. The clutch engages only when the cage swings forward.

The gold anodized aluminum clutch lever is used to release the friction in order to ease wheel removal. The lever can be set anywhere between closed and open.
The gold anodized aluminum clutch lever is used to release the friction in order to ease wheel removal. The lever can be set anywhere between closed and open.


How to Adjust the Shadow Plus Friction Clutch


Remove the three clutch-housing screws. They are shoulder screws designed to bottom out on the aluminum derailleur chassis to protect the plastic housing. Put the housing and screws in a clean safe place.
Step 1 -Remove the three clutch-housing screws. They are shoulder screws, designed to bottom out on the aluminum derailleur chassis to protect the plastic housing. Put the housing and screws in a clean, safe place.

The one-way roller clutch is the larger cylinder at the lower left. The stainless steel band that encircles it is the friction brake. The adjustment wrench is stowed in the housing above the clutch. The friction adjustment nut is visible in the hex end of the tiny wrench.
Step 2 -The one-way roller clutch is the larger cylinder at the lower left. The stainless steel band that encircles it is the friction brake. The adjustment wrench is stowed in the housing above the clutch. The friction adjustment nut is visible in the hex end of the tiny wrench.

Pull the tiny wrench out from its stowage place.
Step 3 -Pull the tiny wrench out from its stowage place. The wrench is also a structural tension strut that reinforces the clutch mech, so its best to pop it out with the lever in 'off' position.

Use the adjustment wrench to tighten the small hex screw clockwise to add tension to the friction band. A fourth turn makes a noticeable difference.
Step 4 -Use the adjustment wrench to tighten the small hex screw clockwise to add tension to the friction band. A fourth of a turn makes a noticeable difference. Note: I made my adjustments with the clutch tensioned, but It's best to work the nut with the clutch lever in the 'off' position.

How the clutch-lever cam operates Flipping the gold lever upwards left rotates a cam that squeezes the brake band tighter over the clutch cylinder. Rotating the lever downwards right takes pressure off the friction band. The snail-shell design of the cam allows it to remain in position anywhere in between.
Step 5 -How the clutch-lever cam operates: Flipping the gold lever upwards (left) rotates a cam that squeezes the brake band tighter over the clutch cylinder. Rotating the lever downwards (right) takes pressure off the friction band. Shimano intended the lever to be set either 'off 'or 'on,' but the snail-shell design of the cam allows it to remain in position anywhere in between if necessary.

With the clutch lever engaged swing the cage forward and check that there is smooth but firm resistance. If it is higher than you d like remember that you can reduce the friction by relaxing the clutch lever slightly.
Step 6 -With the clutch lever engaged, swing the cage forward and check that there is smooth but firm resistance. If it is higher than you'd like, remember that you can reduce the friction by relaxing the clutch lever slightly.

Backup pic
Step 7 -Replace the wrench. It snaps into place with the lever in the off position and is retained by plastic grippers on either side of the rectangular cut-out.

Replace the housing and set the housing screws snugly in place don t over-tighten them please .
Step 8 -Replace the housing and set the housing screws snugly in place (don't over-tighten them please).

Engage the clutch lever and run the rear derailleur through the gears in each chainring combination to check for excessive resistance at the shift lever or poor shifting across the cassette. Use the clutch lever to reduce friction and compare results.
Step 9 -Engage the clutch lever and run the rear derailleur through the gears in each chainring combination to check for excessive resistance at the shift lever or poor shifting across the cassette. Use the clutch lever to reduce friction and compare results. Too much clutch friction can make shifting feel notchy. Before you pass judgement, however, give your clutch tune a ride test. Not happy? Pop the housing off and reduce or add tension to the friction band one-fourth turn at a time until the chain stays on over the bumps and your shifting feels Shimano smooth.



About adjusting Shimano's XTR Shadow Plus rear derailleur...




Past Tech Tuesdays:
TT #1 - How to change a tube.
TT #2 - How to set up your SRAM rear derailleur
TT #3 - How to remove and install pedals
T #4 - How To Bleed Your Avid Elixir Brakes
TT #5 - How To Check And Adjust Your Headset
TT #6 - How To Fix A Broken Chain
TT #7 - Tubeless Conversion
TT #8 - Chain Wear
TT #9 - SRAM Shift Cable Replacement
TT #10 - Removing And Installing a Headset
TT #11 - Chain Lube Explained
TT #12 - RockShox Totem and Lyric Mission Control Damper Mod
TT #13 - Shimano XT Crank and Bottom Bracket Installation
TT #14 - Straightening Your Derailleur Hanger
TT #15 - Setting Up Your Front Derailleur
TT #16 - Setting Up Your Cockpit
TT #17 - Suspension Basics
TT #18 - Adjusting The Fox DHX 5.0
TT #19 - Adjusting The RockShox BoXXer World Cup
TT #20 - Servicing Your Fox Float Shock
TT #21 - Wheel Truing Basics
TT #22 - Shimano Brake Pad Replacement
TT #23 - Shimano brake bleed
TT #24 - Fox Lower Leg Removal And Service
TT #25 - RockShox Motion Control Service
TT #26 - Avid BB7 Cable Disk Brake Setup
TT #27 - Manitou Dorado Fork Rebuild
TT #28 - Manitou Circus Fork Rebuild
TT #29 - MRP G2 SL Chain Guide Install
TT #30 - Cane Creek Angleset Installation
TT #31 - RockShox Maxle Lite DH
TT #32 - Find Your Tire Pressure Sweet Spot
TT #33 - Three Minute Bike Preflight Check
TT #34 - MRP XCG Install
TT #35 - Stem Choice and Cockpit Setup
TT #36 - Handlebars - How Wide Affects Your Ride
TT #37 - Repairing A Torn Tire
TT #38 - Coil spring swap
TT #39 - Trailside help: Broken Shift Cable
TT #40 - Installing a Fox Float Air-Volume Spacer
TT #41 - Replace the Seals on Your 2011 RockShox Boxxer World Cup Fork
TT #42 - Clean and Lubricate Your Fox F32 Dust Wiper Seals
TT #43 - Thread Locker Basics
TT #44 - Install a SRAM X.0 Two-By-Ten Crankset
TT #45 - VPP Suspension Bearing Service
TT #46 - Rotor Straightening
TeT #47 - Finding and fixing that creak
TT #48 - Bleed and Service Magura Marta Disc Brakes
TT #49 - Cup and Cone Hub Basics
TT #50 - Install and Adjust Pedal Cleats
TT #51 - Cup and Cone Hub Rebuild
TT #52 - Converting Mavic Crossmax SX Axles
TT #53 - Cassette Removal and Installation
TT #54 - Cane Creek AngleSet Installation
TT #55 - American Classic Tubeless Conversion
TT #56 - Wider Rims Are Better and Why Tubeless Tires Burp Air
TT #57 - Pedal Pin Retrofit
TT #58 - Bleed RockShox Reverb Remote Lines
TT #59 - Cutting Carbon
TT #60 - Silence That Squeaky Disc Brake
TT #61 - Five Minute Wheel True
TT #62 - Removing Bike Rack Rattle

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81 Comments

  • + 40
 Video tech tuesdays were a lot cooler
  • + 4
 Definitely and they got the message across much better than the text version
  • + 18
 better then no tech tuesdays
  • + 7
 I actually prefer the written format. (But that may have something to do with my 18yrs experience as a bike-mechanic and being used to reading a lot of manuals and walk throughs on tech-stuff.)
  • + 5
 video tech tuesdays were a lot more cooler, and having mike's bloopers at the end was a bonus
  • + 8
 I watched a number of videos on the subject and none got macro enough to show exactly what was going on in there. That said, an SLR with a macro lens could probably do a good video (I don't have that capability yet). The largest component is about the size of a US dime. I wanted to get in closer than most people can focus with the naked eye to enable the reader to get a handle on how the clutch mech' operates.
RC
  • + 3
 video with recap with pictures is the best.
  • + 0
 Do a video on how to acctully adjust and tune any derailer so it shifts easier. this way it can apply to anyone because most bikes have a derailer and it would save alot of us money not having to go to the shop every 5-7 rides
  • + 2
 richard you have a point there, but you gotta admit that doing it on video is a lot more interesting for us "PB viewers" anyway I think that taking what you said into account would be good to decide if a TT can be done on video or if you really need to zoom it in and give some good detail, make it written format.
  • + 3
 and to sa-glory, if you read the list of Tech Tuesdays it wont take long to figure out that what you are suggesting to be done has already been done, TT#2 is for adjusting a SRAM derailleur, anyway those same steps apply on any derailleur
  • + 3
 OK then. I'll shoot some vids for ya. RC
  • + 1
 Yeah Richard I see your point for this particular tech tuesday and it is true, I was talking more in a general sense. There was a time when you guys kinda did the video and posted some photos and/or important notes and that was the ultimate combo, epic
[Reply]
  • + 12
 This is all nice and helpful, but why did you mount the chain behind the little guide inside the cage? Won't the chain eat the guide? And isn't the derailleur loud?
  • + 5
 Haha, saw exactly the same immediately. This must be noisy as hell and I know where the additional "friction" does come from. Excellent technical skills I must say...
  • + 6
 That's probably why there's no video this week. Too many sound issues.
  • + 4
 True! But it does look cooler that the chain is completely hidden. (not that I would recommend doing this, but it just happens to look cool)
  • + 1
 this is the best derailleur yet for silence....if you hit a rock with it with the tensioner on, it will make a loud noise as it snaps! i have it, its great, have not hit any rocks yet (that wont move).
  • + 2
 HAHAHA thats funny, he totally has the chain on the wrong side of the guide in the cage and its eating it away for sure!!!
[Reply]
  • + 10
 I'll stick with my "dated" Sram mech...All this clutch stuff seems like trying to fix a problem that doesn't need fixing. All of my bikes have chain guides and barely make a sound. I just don't really see the point in it.
  • + 11
 not the point he was making at all
  • + 3
 I love my SRAM too, but the Shadow's been getting a lot of love from people that know what they're talking about.. Looks like Shimano is onto something.. and, considering something's in the pipe from SRAM, it would appear they agree.

I think it was in BIKE mag, one of the editors said, of the Shadow Plus "who cares about chain slap, it's just something that normally happens.. well it turns out I do.. After using the shadow, the nearly silent running of of the bike is a welcome improvement".. or something to that effect..
  • - 6
 Yeah products that arent new and innovative shouldnt get so much hype. In two years time this will probably be 'dated' anyway
  • + 4
 pike14: for you it's not that big of a deal, but if you're on the new 10 speed AM/trail stuff that comes stock on most new XC or AM bikes, in order to wrap the 36 tooth cog on the cassette, you need longer cage mechs. With a longer cage, there's more momentum once the rear d starts bouncing around on a tech trail, and you start getting more slap--particularly Shimano with their lighter springs for light action shifting. I ride a Shimano non clutch XTR on a Lapierre Spicy and it makes a fair bit of racket, even with a chain guide.

norris122--same comment as bennett346, plus I had a stick get tossed into an X9 rear d 30 seconds from the parking lot and destroy it. Name brand doesn't matter for stuff like that.
  • + 2
 Those of us with no ISCG tabs and chain-slap woes, this is a welcome innovation. I'm loathe to toss my whole SRAM setup though so I'll wait for SRAM's version
  • + 1
 This derailleur is the best thing I have bought for my bike since a dropper post. I now run this derailleur with a 2 by XT crank and no chain device or roller what so ever, my bike is silent and my chain never comes off EVER and my all mountain bike is ridden more like a DH bike. I used to run a bash guard with 2 rings and BS stinger and I would loose my chain more. Having the tension on the chain that the shadow plus provides does a lot. The only reason derailleur cages need to have so much free play is to get the wheel out.
  • + 1
 i see this as been a good idea for the likes of XC and AM bikes as already mentioned a long cage has more momentum once the rear ends starts moving, however for the likes of DH i really don't think its an issue however if chainslap bothers you that much for DH get some sticky velcro (fluffy side) and wrap all over the chainstay, i've just redone mine and it's totally silent running with a short cage saint
[Reply]
  • + 8
 props to shimano for putting the wrench inside the housing. that little thing would be a pain to keep track of
  • + 5
 Props to Shimano for engineering the wrench into the structure of the derailleur. Seriously brilliant. I'm surprised that this feature wasn't mentioned in the initial press release. I'm looking forward to an XT and SLX (aka far more affordable/practical) version of this design.
[Reply]
  • + 8
 A fourth of a turn? you mean a quarter...?
  • + 3
 English may have been invented over there, but it was perfected over here. HAHAH! Cheers. RC
  • + 4
 touché
oh wait.. thats french...
[Reply]
  • + 5
 You can notice the chain is incorrectly routed through the cage. Were they rushing with the article?
Shitmano would probably steam seeing that Smile
  • + 2
 Thanks for the catch on the chain routing error Bikemaniac and kovaldesign. Its a test bike I just got my hands on - came that way. Fixin' it should save a few clicks on the climbs tomorrow. It's an Ibis Mojo HD. RC
  • + 4
 ya know richard... Ibis just officially signed off on the Mojo HD as being 650B compatible... perhaps you should be testing the wheelsize as well on it.
  • + 2
 Yeah, prepare for a lot of noise about 650b on Pinkbike. EVERYONE is working on it (shhh, big secret).
RC
[Reply]
  • + 2
 i understand the theory but cant see this being any good on mid-long travel bikes??

is chain slap realy a problem with a good mech an chain guide?? seems like theyre creating a problem that isnt realy a problem to sell the next gimmick???

maybe on a triple chainset hardtail
  • + 3
 It's really not designed to eliminate chain slap. It's to negate the need for a full chain guide on a short to medium travel full suspension bike. It eliminates the need for a bottom guide by providing more tension on the chain as it travels from the chain ring to the derailleur.
  • + 4
 i have to say i've been running a shadow plus on my Patriot for 6 months now and i can't believe the difference it's made,i use my bike for AM (3 x10) and used to get all sorts of problems with my chain,i couldn't keep the fecker on but i'm sold on my triple and i tried a triple chain guide as well and that was not only the ugliest piece of turd going but it was noisy as hell,my shadow plus however is way quieter,a lot neater and not once has my bike dropped it's chain since i got it,now i'm not the fastest rider out there but i'm way faster than a lot and i've thrown my bike off all sorts and smashed it to hell and because i keep my chain always i just want to throw myself off bigger stuff,ok yeah shifting's a little stiffer but your body adapts to it,

I have to say Shadow Plus is the best upgrade i've made for a very long time,i'm totaly sold on it!!!
  • + 2
 See post above - best thing ever, I kid you not. I will never run anything different.
  • + 1
 it's going to be awesome as a DH dedicated mech if it's this good on AM it really is guy's !!!
  • + 2
 The design looks simple enough that it should last. All in all it looks like a great idea. Maybe I'll buy one in ten years when yhey are available for slx and much cheaper
  • + 1
 i would love to see it on SLX m8,it would open up so many more riders options and might even breath life back into running triple chainset's,i do a lot of road linkage to and from my local trails so i'm hooked on my triple,i can mile munch way better on a triple and often do 60-70 miles because of it,i'm looking at a 100 miler in the summer and i just couldn't do it with a double it would drive me mad.
[Reply]
  • + 5
 that mini spanner is ace i want one
[Reply]
  • + 1
 Shimano and SRAM obviously know more than your average guy about everything to do with bikes, and tell us frequently that they do. One question nags me slightly though........ My bike's rear suspension feels infinitely better without a chain on it. Not having any chain growth pulling on a rear mech means the linkage moves with no resistance. Apply that to a mech with a clutch. Does that not mean that there will be more resistance to chain growth (necessary on all full suspension bikes where the bottom bracket to rear axle distance changes throughout the travel)? I am asking this honestly as a question and not trying to be clever, as I realise this mech has been created off the back of much expertise and years of experience.
[Reply]
  • + 1
 Shifting is a little more effort and when it's the stand, rotating the rear wheels is noisier with the clutch on. I'm a Shimano fan but I do have a bike with SRAM XO and it's a lot smoother then the XTR. Glad to know you can adjust this thing, hopefully I can get it running as smooth as my XO setup.
[Reply]
  • + 1
 I've been running XT exclusively for years now, and when Shadow came out I thought it was great. And then came DynaSys and things got even better. I'm so happy with what I have now this can only add to the stoke I have about my RD. Shifters work SO much better than they used to. And if I don't like it, I keep it in the off position. There are no downsides to Shadow Plus.
[Reply]
  • + 1
 I'm running this derailleur on my Tallboy and SB-66 and it is a great derailleur. It has three real benefits for me:

1/ No chain drops at all since I've started using it on my 2x10 systems. The derailleur controls the chain so well that it never bounces off cogs or chainrings. My Sram XX and X0 did this occasionally and my XT Shadow did this all the time.
2/ No chain suck. If you ride in lousy conditions like many of us, you'll get chainsuck at some point. This is particularly important on carbon frames (even if they have the stainless steel armour).
3/ Very little chain slap noise and pristine chainstays. I've been running this on my SB-66 since day one and I haven't added any additional wrap on the chainstay. The paint still looks like new!

I do wonder how it'll work with the Saint derailleur on frames with lots of chain growth as the suspension cycles. I imagine that the clutch mechanism may get worn out rather quickly given how often and how far the suspension cycles on DH bikes.
  • + 1
 looks pretty tough. I could having to tighten it a lot on a rig with a lot of chain grown. I think the key would be to add a mechanism for finger tightening and to coat the band with brake pad material and make it easy to replace. Once a season or more you could just change it.
[Reply]
  • + 6
 i choose Sram
  • + 1
 I Choose both
  • + 4
 choosie moms choose jif
[Reply]
  • + 1
 Thanks for this tip! I just got one of these derailleurs and so far it's the bomb! It's nice to run 1x10 with just 1x (upper only) guide. These guides won't replace a chainguide - but they sure help!
[Reply]
  • + 0
 isnt this almost the same than a short-cage rear derailleur? my X0 and Saint short cage's do not make any noise at all, why to spend more money and having a complex thing hanging there?
[Reply]
  • + 3
 Do I need this? Probably not. Do I want? Yes. Want.
[Reply]
  • + 1
 Looks great but what everyone really want's is a short cage SLX mech that is cheap enough to replace for everyday riders.
[Reply]
  • + 2
 bikes just keep getting more complicated...
  • + 20
 Yeah, I mean forget multilink suspension and 6 piston hydraulic brakes, and imagine the horror of having to adjust a hex nut by a 1/4 turn Razz
[Reply]
  • + 2
 ill stick with my sram...
[Reply]
  • + 2
 I have a f*cking wrench in my derailleur? Dope!
[Reply]
  • + 1
 come on pinkbike! where's the video?!
[Reply]
  • + 1
 haha looks like the arm optimus prime, FTW! yet better , need more inputs.
[Reply]
  • + 1
 Does anyone know if this applies to the XT rear derailleur (RD-M786)?
[Reply]
  • + 0
 actually started to install and set up my one on my mojo last night guide couldn't of come at a better time...
[Reply]
  • + 0
 'derailleurs suck' should be an option on the poll thats what I would check
[Reply]
  • + 1
 will this eliminate chainguides forever?
  • + 2
 Not entirely because this won't stop the chain slipping of the top of the chain ring. It also wont protect the bottom half of the chain ring from rock and root strikes like a chain guide with a taco or bash guard.
  • + 0
 It does help the chain from slipping off the top of the chainring because it adds tension to the chain (when coasting) and stops the chain from bouncing around. It won't replace a chainguide on a DH bike but it definitely stops my chain from dropping on my AM and XC bikes.

You just need to run a bash guard to help from chainring damage.
  • + 2
 @bogey It won't stop the chain coming offdue to dodgy chain line when in the extremities of the gear ratios, which is what a top guide (like the XC ones made by most chain guide companies these days) or a front derailleur will do.
[Reply]
  • + 0
 is it compatible with a 9speed cassette and shifter?
  • + 4
 No, because the new 10 speed shimano shifters pull a different amount of cable to the old 9 speed ones.
  • - 1
 Really? Pretty sure its just the shifter that determines that. Used a 9 speed rear mech on a 8 speed cassette back in the day...
  • + 0
 at least change to 9spd pulleys
  • + 3
 Ugh... you'd think by now people would stop asking this sorta thing.

Shimano 10 speed MOUNTAIN (aka DynaSys) shifters and derailleurs are ONLY compatible with each other. Yes you can mix the SLX, XT, and XTR versions amongst themselves but that's it. They're not compatible with any of the shimano 10 speed road shifters or derailleurs (which themselves however are compatible with the shimano 7 to 9 speed road or off-road model components). Ten speed DuraAce bar-end shifters will work perfectly with 8speed Alivio derailleurs for example if you want to mix that way.

Likewise, SRAM's 10 speed shifters and derailleurs are NOT compatible with any of their 9 speed or less model shifters and derailleurs, but they are cross compatible between the road and off-road models (Red shifters will work with the 10 speed X9 derailleurs for example).
[Reply]
  • + 0
 So, how does it perform?
  • + 3
 Very well - makes a noticeble difference to chain slap. Feels harder to push at the lever butyou soon get used to it.
[Reply]

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