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Hack!? Shimano XT Crank on a Fatbike

Written by Zach Overholt
30 Comments
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Photo by Diglloyd

Recently, we got a tip informing us that someone had seen a Moots FrosTi out there with a Shimano XT crankset. They had sent some pictures, but with zero information and pictures that really didn’t prove it was a 100mm BB we had little to go on. It didn’t take us long though to stumble on Lloyd Chamber’s cycling blog, that happened to have a gallery of photos of a Moots FrosTi with an XT crank. It just so happens that not only is Lloyd an amazing photographer, he is also quite the cyclist with his fleet of Moots being some of his favorite subject matter among other cycling related photos. There it was, clear as day – a Shimano M780 crankset on a Moots FrosTi.

How did he do it? Find out after the break.

Hack!? Shimano XT Crank on a Fatbike
Photo by Diglloyd

This puzzle was on my mind this past weekend while down at CX Worlds, so I asked around at the Shimano tent if they knew of any way this was possible, or if they were dabbling in fatbike cranks. Not only did they not think it was possible, but even more disappointing they didn’t think Shimano would get around to making a fatbike crank soon – or, if ever. The market is simply too small apparently. It’s not a matter of “if” Shimano could make a fatbike crank, it’s more if they did, how many would they sell? I quickly forgot about the fatbike issues with the roar of the cyclocross crowd.

Hack!? Shimano XT Crank on a Fatbike
Photo by Diglloyd

That is, until I spoke to Lloyd. I had been told by a friend in the know that since the spindle is simply pressed into the crank arm, it might be possible to press it out and have a longer one pressed in. After asking Lloyd about it, the answer I got was “special project for the crank.”

Hmmph.

Prying a little farther, it turns out Lloyd was simply being conscious of his connections and was being careful about what he said. Finally, he came back and said that the crank modification was a custom job he had made to his specs by a member of the Shimano staff who prefers to remain anonymous. So there you have it. Possibly one of the only, or very very few XT fatbike cranks on the market with no plans for production. Still cool none the less.

Thanks to Lloyd for sharing his photos and his FrosTi with us!
Zach Overholt
5,730 articles

Zach Overholt is the Editor in Chief of Bikerumor. He has been writing about what’s new in the bicycle world for 12+ years. Prior to that, Zach spent many years in the back of a bicycle shop building and repairing nearly every type of bike, while figuring out how to (occasionally) ride them.

Based in Ohio, Zach is now slowly introducing a new generation to cycling and still trying to figure out how to fit the most rides into a busy schedule as a new dad.

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truman
truman
11 years ago

Man it helps to know people!

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Roy
Roy
11 years ago

If you are the kind of guy that has a Moots fat bike, then you are the kind of guy that would pay anything for a custom crank setup…or potentially have the connections to get one made…

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isaac
isaac
11 years ago

Since Sram has an X9 and X5 fatbike crank coming out this year ,plus 4 fatbike offerings from race face, shimano can suck my knards

1
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Kovas
Kovas
11 years ago

We do a similar mod on SRAM and Shimano cranks to fit our 100mm shells. Our spindle-mod only ads a few grams, but works as good as factory fresh… Fat is where it’s at!

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The Dude
The Dude
11 years ago

Can’t wait for fatbike trends to die hard in a year and people having 100mm shells with cranks good on nothing else. Worst bikes ever.

-1
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Fatrider
Fatrider
8 years ago
Reply to  The Dude

Well, knucklehead. Its 2016 and they’re going stronger than ever. You loose.

1
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yanks phan
yanks phan
5 years ago
Reply to  The Dude

2019……tick, tock, tick……

1
Reply
Poopeediaper
Poopeediaper
1 year ago
Reply to  The Dude

2023….

0
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pablo
pablo
11 years ago

isaac: Funny, all the brands you mentioned have no endplay adjustment. It still baffles me that mfgs continue down that path.

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Ben
Ben
11 years ago

@The Dude as a tried and true roadie who was absolutely sure I would never have fun off road, I think you are completely wrong. If you honestly believe they are the worst bikes ever it would seem to me you have never ridden one. Haven’t spoken to one person who hasn’t loved it the moment they stepped on one

2
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mrcykel
mrcykel
11 years ago

The Dude —–> Haters Gonna Hate

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Mindless
Mindless
11 years ago

If they come out with 100mm SLX they will own the market.

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Mindless
Mindless
11 years ago

@Dude is an idiot and lives where there is no snow.

1
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Mindless
Mindless
11 years ago

@pablo: exactly. SRAM and RaceFace still can’t figure out how to attach their cranks properly.

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bin judgin
bin judgin
11 years ago

sram and raceface can’t attach their cranks? what???

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King County
King County
11 years ago

I have never ridden a fat bike, but love the concept.

A few questions for those with experience: If there is 2 feet of fresh / untouched snow, can a fat bike make it through? How is a fat bike on dry, loose beach sand? Thanks

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Champs
Champs
11 years ago

… why not XTR?

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Pete
Pete
11 years ago

Champs got it right. Why go through all that trouble and not use an XTR? Does Shimano use a different manufacturing process that would have made it impossible?

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Mindless
Mindless
11 years ago

XTR has lower Q factor – maybe it would not clear chainstays? It could be a different press fit too..

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biassuit
biassuit
11 years ago

@King County – My experience is that 2 feet of fresh powder is as unrideable on a fatbike as it would be on a road bike. You would need 12 inch wide tires and a rider weight of 20 lbs to get enough float. On less powder and/or packed snow, the fatbike rules. My experience on sand is that the fatbike performs really well.

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Greg
Greg
11 years ago

@ King Country,
We did a ride at an undisclosed location here in the 4 corners area of New Mexico and we were constantly going in an out and through and down an arroyo (spanish for wash or dry creek). My buddy on fatbike never even slowed down…the rest of us were spinning like crazy, often washing out and having to walk.
The point of a Fatbike could not have been made more clearly.

cheers,
Greg

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Canucklehead
Canucklehead
11 years ago

I got a similar answer when I asked about how Lloyd got Cannondale Hollogram SiSL cranks on a Moots PF30 BB — “my mechanic took care of it”.

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Contador
Contador
11 years ago

A Canonndale SI crank has a 30mm spindle, why would you need anything special to install on a Moots PF30 BB? Plenty of PF30 bottom bracket options available.

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Seitenryu
Seitenryu
11 years ago

@Canucklehead — SiSL cranks are compatible with BOTH BB30 and PF30. A hardware substitution needs to be made, but Cannondale makes both types as they make frames of both types as well.

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Canucklehead
Canucklehead
11 years ago

@Seitenryu: Thx, will talk to my local Cannondale distributor!

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Jason
Jason
11 years ago

If only there was a way to use a normal crankset on a fat bike. The Q factor on those cranks kills my knees.

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Mindless
Mindless
11 years ago

@Jason: You can use 83mm, if you are willing to live without granny gear. Get DH Isis BB and something like Middleburn with 28t chainwheel and 11-36 rear.

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Mindless
Mindless
11 years ago

P.S. Obviously not for any frame, got to clear chainstays.

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Rome
Rome
11 years ago

Look closely: the axle is not hollow anymore, or at least something is stuffed inside.

leads me to thinking that they cut the axle in two pieces and welded a spacer inside. that spacer has a smaller diameter at both ends, that fits tightly into the old axle, the middle part is just as big as the axle itself is. this way welding is much easier and the spacer is centered nicely. the thingy one can see inside the axle is that spacer. at least this is, what i would try, cause i think swapping the axle itself will likely damage the pressing surface. all you need is a center lathe and a TIG welder.

if one would really like to tech up, the same might be done with a diagonal cut and weld. this would spread the forces while pedaling even better, but the spacer itself is more difficult to produce.

sorry if some words sound funny, i am not a native speaker.

ciao,
romeo

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David
David
11 years ago

Hej,
Sure Romeo must be right, i am about to attempt this exact modification, a bit of stainless steel, and a pair of unused xt cranks are actually my starting point for building a fatty….
I don,t like parts just lying around…..
Eventually if there is an interest i can share my experience, we will see how this goes… and hopefully i remember making some pics in the heat of the action.
Greatings from Sweden, David

0
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