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Shimano XT Dyna-Sys FC-M785 Double Crankset

$189.99 $269.95 30% off

Item # SHI0403

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  • Black, 170mm/28-40 ($189.99)
  • Black, 170mm/26-38 ($189.99)
  • Black, 175mm/28-40 ($189.99)
  • Black, 175mm/26-38 ($189.99)
  • Black, 170mm/24-38 ($189.99)
  • Black, 175mm/24-38 ($189.99)
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Item # SHI0403

When one isn’t quite enough.

Shimano’s XT Dyna-Sys FC-M785 Double Crankset crosses the line between a more limited one-by gearing and a cumbersome 3x10 with gears you never use.

Shimano is notorious for sending technology from its high-end groupsets down the pipeline, and true to that mantra, the XT Hollowtech II crank arms receive the asymmetric design that is a marker of XTR. A 24mm hollow spindle is pressed into the right arm in the factory. Two pinch bolts secure the arm once the bearing preload is set. As far as the design of the chainrings themselves, the small ring is designed to move the chain up and then back down without slipping. When paired with the asymmetric chain, you’ll never miss a beat.

  • Hollowtech II Crankset
  • Compatible with Shimano

Tech Specs

Arm Material:
Arm Length:
170 mm, 172.5 mm, 175 mm, 180 mm
Chainring Sizes:
28 / 40 t, 26 / 38 t
Bolt Circle Diameter:
104 mm
Bottom Bracket:
Shimano XT
BB Type:
BB Threading:
Recommended Use:
mountain biking
Manufacturer Warranty:
2 years
Actual Weight:
Black, 170mm/28-40: 740g

Reviews & Community

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Shimano XT Dyna-Sys FC-M785 Double Crankset

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Here's what others have to say...

5 5

Dyna-sys 44/28 double

  • Familiarity: I gave it as a gift but have feedback to share

Can I use a 44t ring with the dyna-sys double (44/28)? Will the dyna-sys FD work with my existing XT shifter?

3 5

Old time amigo

  • Familiarity: I've put it through the wringer

Have just over a thousand miles on these and no issues. From xc to chair lifts they are spot on. Work well and are pretty light. Using them with all XT drivetrain on my SC Blur LTC.

really too big for my mother's xs bike...

Responded on

If you're talkin' arm length, the smallest they come in is 165mm. If it's gear inches, then you'll need to swap out those rings.

5 5

why spend more on XTR?

  • Familiarity: I've used it several times

as with several components in the shimano line, I find it hard to justify the additional cost of the XTR crankset vs. the XT crankset. this 2x (mine is 40/28) is incredibly stiff with only minor weight concessions. i paired it with the e-type XTR front derailleur and XTR shifters. set-up is incredibly easy, and shifting is smooth on all trail conditions. solid performance/price ratio.


Out training on the trails in middle Tennessee with my fresh new XT cranks running a single ring, for you know, maximum pain.

5 5


  • Familiarity: I've put it through the wringer

I've been using XT cranks on many of my builds since the late 90's. They are relatively light weight and eXTremely durable (see what I did there?) Sure, they are not as lightweight as XTR's, but you only need those if you're some kinda pro racer! Seriously, who are you trying to kid?! The most awesome thing about these XT cranks (besides coming in 2 different colors, hollah!) is that they are quite affordable, even more so when they're on sale! The included BB installs easily and is smooth like buttah. You won't be disappointed with these cranks.

Unanswered Question

Hello, you send to Brazil? free shipping...

Hello, you send to Brazil? free shipping?

If I got the 28-40, could i replace the...

If I got the 28-40, could i replace the 28 with a 26?

Responded on

Yes, you should have no problem swapping out the 28t with a 26t. You can actually go down to a 24t if needed. That's the smallest you can use on these double-ring cranks.

5 5


  • Familiarity: I've put it through the wringer

As we all know XT is the workhorse of Shimano. Not only will it not break the bank but it will last forever. I ordered my girlfriend a full XT groupo because I knew it would withstand the punishment. I just upgraded her group to a 1X setup with a wolftooth and I must say that I’m jealous of her little ripper now.

Responded on

i see your set up and like it. i'm currently running a single speed with a 104 bcd crankset. do you know if i could remove the rings on this SHIMANO XT DYNA-SYS FC-M785 DOUBLE CRANKSET and put on my single current chain ring? your (or anyone else's) advice would be appreciated). what do i need to think about?

Unanswered Question

Is the listed weight of 740g including the...

Is the listed weight of 740g including the BB or no? Other websites list it and comparable cranks at around 820g. Shimano itself does not list weights of their products. Hard to find the truth it seems. Have any customers here weighed theirs?

Unanswered Question

specs say BB Threading: English, yet lists...

specs say BB Threading: English, yet lists a press fit bottom bracket part number. So is it press fit or threaded?

Will this crankset work on frame with a...

Will this crankset work on frame with a PF30 bottom bracket?

Responded on

Yes, I'm running it on my Dogma XC 9.9 with a Chris King PF30. you will need the adapters for the PF30 (sold separately), on Chris King it is conversion #2 for 24-mm MTN.

5 5


  • Familiarity: I've put it through the wringer

This crankset combined solid Shimano shifting performance with a package this is lightweight and Strong for a steed from XC to DH. DH? Really? Yes, the 104 BCD allows you to run a single ring easily if you'd prefer. From the hollow crank arms to sturdy chainrings, this crankset can take some abuse. It includes an English threaded BB.

5 5

The Standard in Cranksets

  • Familiarity: I've put it through the wringer

Shimano's Hollowtech II system is the best crankset design on the market. It delivers top-notch stiffness with bombproof durability. When the time comes to overhaul your crank/BB (which isn't very often with Shimano), the simplicity and ease of doing so is also the best out there. The non-driveside crankarm is secured with triple redundancy, so there is simply no way it will loosen. My only complaint with Shimano doubles is the chainline is a bit closer than with SRAM, something to note if you are running any sort of guide system.

5 5

You Don't Actually Need "Better" Crank

  • Familiarity: I've put it through the wringer

The Shimano XT Dyna-Sys Double crankset is a get it done well component...Light, stiff, and solid...the Dyna-Sys chainrings are stiff and shift awesome. Don't hesitate to upgrade your heavier, old crank with this badass...you won't regret it.

5 5

Light, bombproof, stiff.

You get all three. It's a wonderful thing. Truthfully, you could run most any crank from Shimano and be happy with it. This one looks better, is a tiny bit stiffer and lighter, and shifts marginally better than lower-tier cranks. Well worth the dollars.

My current bottome bracket is a 73, is...

My current bottome bracket is a 73, is this one compatible with the 68/73 standard

Best Answer Responded on

Yes, the BB comes with spacers to run with 68mm frames.