Hey everyone!
With my many bikes over the years
I have never ever purchased an 11 speed Shimano crankset.
This bike came with the full SLX groupset and that's the only reason why I have it.
Otherwise I didn't really like the new narrow wide profile of their chainrings,
the asymmetrical spider for the chainring as well.
Price wasn't too attractive so I gave them a pass.
However, the new 12-speed groupsets introduced a new series of cranksets
that I think are worth taking a look at.
Cranksets are usually shipped in big boxes like this.
I don't have the one for the SLX but you can see here,
this was a 3x crankset that I converted to 1x very easily.
However, the details of this specific crankset are usually found here, next to the pedal mount.
This is an FC-M7100 crankset, made in Japan,
and the length that I've chosen is 170 mm.
And I wanted to show you the new crankset next to the old 9 speed crankset because even though this is redesigned,
Shimano kept some of their characteristics.
Specifically, if you look here, the 24 mm axle,
this is a steel axle that's used on older cranks including XTR and this would be different lengths
depending on the type of spacing that you have on your bike.
They have one for non-Boost, one for Boost and for Super Boost,
so that's the main difference between those cranksets.
And because of that 24 mm spindle,
the same Hollowtech 2 bottom brackets are used with this series as well.
You look at the old BB52, this is the Deore,
the MT800, they had this before and is the same one used today.
You can see the different types over here, from the threaded all the way to press fit BBs.
The same old 16 notch BB tool is used with this type of bottom brackets,
however the new one, also used on the road so Ultegra,
would need this adapter because the cups are a bit smaller.
So this is an adapter that would make the old tool work with the new BBs,
TL-FC25 or 24 is the Shimano part number.
However, the threaded BB MT800 includes one in the box.
In the new SLX lineup, they still have the 4 bolt attached chainrings,
they also have a 2x version,
but on this specific 1x version, chainring is a one piece
and most importantly this is finally Direct Mount (DM),
and that's something new for Shimano.
And when I say one piece chainring, well, think about that it could be one piece chainring,
it is actually for XTR.
However, SLX, XT and Deore have it built around an aluminum spider,
and then you have the steel chainring bolted down with these non removable special Torx bolts.
The same idea used by the center lock rotors is used here,
you see the torque 35-50 Nm,
and over here it's gonna say that this is specific for XT and SLX, and I would mention Deore.
XTR has a different lock ring.
Here's the catch: they will tell you that a standard BB tool is used to install and remove these chairings,
however you need a socket type because there's no way you can fit this underneath to undo it.
So you need a tool that's called TL-FC41,
I was told that XT and XTR cranks already come with the tool.
Shimano narrow wide tooth profile was changed again,
it's machined a bit more so these teeth are skinnier
to accommodate for the special chain that their HYPERGLIDE+ requires.
In comparison, if you look at the old 11 speed chainring,
look at the teeth: they are just wide and big.
If you look at the third-party manufacturers of chainrings for Shimano 12-speed drivetrains,
they will highly suggest using Shimano chains with them.
Otherwise, because of the skinnier profile of the teeth,
you won't have the proper chain retention with something like a SRAM Eagle chain.
Chainring size, 12 speed generation and the Shimano logo is also on the chainring.
And here on the back, part number is SM-CRM75, and these chainrings are made in Japan.
Same hollow forged aluminum design of Hollowtech 2,
same anodized finish, but this time darker.
Finish that doesn't look too bad as it wears out as you see here on the old 11 speed cranks.
Also, this design of the SLX and XT was used by the XTR stop-gap FC-MT900,
when they're struggling to build the current XTR M9100.
Interestingly, the weight of this crankset is 636 grams,
XTR is about 100 grams less,
however the one-piece chainring on that XTR weights about 50 grams less.
So 50-60 grams difference between SLX and XT, and XTR?
The same two pinch bolts with the preload cap that was used by this 9 speed
is actually used by today's Deore, SLX and XT cranksets.
And to install it, you would remove that outside bolt,
just for this little plastic safety pin to lift up.
Then slide the crank arm onto the spindle, this only goes in one way,
and push in that little plastic tab.
Then take the provided torque cap and you're going to install it using an TL-FC16 tool from Shimano.
This is pretty popular, so fairly easy to find.
You would tighten this up all the way to snug,
trying to take out all the play here.
Then finally you're going to reinstall that outside bolt using a 5 mm hex.
The details of tightening these bolts are here on the crank arm,
but in a nutshell you would alternate tightening the two bolts.
If you want a full procedure on how to get this installed,
I have a full series on How-to build a bike from scratch,
make sure you check that out!
I think Shimano took what was good in the past
and improved with that direct amount chainring.
Also, the compatibility of the chairings on all their series from Deore to XTR,
they kept the 24 mm spindle and the reliable bottom brackets,
so all good reasons to consider the Shimano cranksets again.
What do you guys think?
Would you be interested in buying this for your future builds?
Let me know what you think in the comments below.
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And I'll see you folks on the trails, cheers!