Bike Review

A Low Fat Alternative

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The hills around where I live are vivid green and choked with wildflowers. This is a very temporary state, and already the first hints of the coming summer brown are beginning to show in the fading miner's lettuce and the wilting shooting stars. But the vetch is still going gangbusters, the poppies are hanging tough, and a couple recent rains have slowed the headling rush toward summer and the inevitable fire season that follows. It is, however, most definitely not winter anymore. And even though using winter around here to justify a fat bike is pretty sketchy logic to begin with, the questionable need for overkill tires has very obviously passed.

It is instead time to think of that sandy and rocky place to the south of me: the Baja peninsula. It is also time to decide how to rig the Fezzari Kings Peak that I have been using to scratch my fat-curious itch for some arroyobiking.

At the outset of this whole exercise, I had thought that really fat tires would be the key to arroyobiking satisfaction. But after a few weeks pushing around the absolutely MASSIVE 27.5x4.6" Terrene Cake Eaters that came stock on the Kings Peak, I came to the conclusion that it is absolutely possible to have too much of a good thing. Those tires are beyond huge. I am sure they work great in crusty snow at 2 psi, but damn, they were a workout everywhere. So I decided to make turn the Fezzari into something a little less fat:


Fat bike purists, look away!

This was a bit of a leap, but I asked people who know more than me if I was committing some sort of crime, and they said that it was only a really small crime and not the kind that would go on my permanent record...

So, Mike Curiak spun up a beautiful set of hoops: Derby TR40i rims, DT 350 fat hubs, stainless steel DT spokes (shiny and silvery, the way all spokes should be). I slapped some Bontrager 29x3.0" XR4s on them, and then realized that the stock cassette (SRAM SX Eagle) doesn't use an XD driver, it uses an HG driver. Now, any sane person would just order up a new driver and go on with life. But since the stock SX cassette weighs in excess of 650 grams, I saw an opportunity to squander some cash and ordered up a Garbaruk 10-50 cassette.

This set of wheels, without sealant, with the fancy Garbaruk cassette, chopped more than SIX pounds of weight off the bike! The stock wheels, all in, weighed a combined 8.11 kilos (17.8lbs). The 29+ setup that Mike built weighed 5.3 kilos (11.6lbs) ready to ride. Admittedly, the Cake Eaters and big heavy tubes were a big factor, but so were the stock Sun Ringle Mulefüt rims.

The effect on the bike was, as might be expected, profound. I felt like my legs were 30 years younger. The strange heavy steering/pitted headset sensation that no amount of tire pressure experimentation could alleviate went away. The bike was transformed into a modern geometry hardtail that feels ready to go after just about any kind of trail. Stable, longish, slackish, with a ton of meat on the ground; this felt like a bike I could ride just about anywhere.

That newfound snappiness did not come without a price though... Expensive rims, expensive hubs, primo handbuilder labor - this is a $1900 USD setup - basically as expensive as the bike's initial retail price. Add in another $286 USD for that fancy cassette (which is a bargain compared to an XX1 cassette), and no, it's not a free ride. But holy transformation, Batman. What a massive difference. We'll get into that more in a bit.

The wheels alone, while a hefty investment, made for an awesome upgrade. There are options out there for fat spacing/29+ wheelsets that are plug and play, and a lot less expensive, but I really wanted 40mm wide rims, and I really wanted to finally get some time on Derby rims, and I really wanted a set of wheels built by Mike Curiak. So, there I went.

I totally dug the way the bike behaved after the wheel swap, but Mike also twisted up a set of ultra-swank 27.5" fatbike wheels. Once again using DT Swiss 350 hubs, he laced them to Nextie carbon fiber rims. These are single wall, super lightweight rims that Mike swears by for his hellfests in the back of beyond. Being single wall rims, there is no air cavity and there are no vent holes drilled in the rim, which, apparently, is a thing to consider when you're packrafting in Alaska. Holes mean water can get in, and sometimes it takes a long time for that water to drain back out. Noted. Anyway, these beauties, set up tubeless with a set of Bontrager Barbegazi 4.5 tires, are only about 100 grams per wheel heavier than the 29+ setup, and also represent a quantum leap in the rideability and enjoyability of the bike.

The Barbegazi tires are not anywhere near as hefty as the Cake Eaters, which, if one is riding in a landscape of sharp rocks, might be cause for concern. In snowy conditions, though, the five and a half pound reduction in rotating mass is (in my very limited experience and therefore questionable opinion) likely to be a much bigger performance draw than the potential ruggedness of ones tires. Feel free to crucify me in the comments on that one.

So, I loved the way the bike rode with lighter wheels, whether they were fat or just pleasantly girthy. Shocker. What I didn't love, however, was the realization that rigid bikes are still rigid, even at really low tire pressures, and that my wrists are still 58 years old. And getting older every day.

Enter the final pieces of the puzzle:

Yep, I got forked. I've tried going back to rigid a few times, but am coming to the realization that my wrists aren't too stoked even on smooth road rides anymore. So, enter the Manitou Mastodon Pro. Adjustable internally between 100 and 140mm travel, I'm leaving it at 120mm for now. This kicks the head and seat angles out by about a degree (from 67/75 out to a little under 66/74), and brings the bb height back up enough to make up for most of what I lost in the wheel swap.

This will be my first extended amount of time on a Manitou fork in a donkey's age, and I am mighty impressed with what I see so far. Separate hi-lo speed compression damping adjustment, rebound adjustment with a huge range, adjustable air volume, 34mm stanchions, cool hex-axle, rad throwback decals, and a welcome buttery smoothness right out of the box. I'm really looking forward to futzing around with it. Coulda saved a couple hundred bucks and lost a ton of adjustability by going with a Mastodon Comp, but at this point, who's even counting the money anymore?

And CushCore. I love CushCore. A few years ago I was doing some bracket testing between tires running CushCore inserts and tires without, and at any given tire pressure the change in cornering characteristics along with the damping of trail chatter was eye opening. As one tester described the ride feel; "more signal, less noise." But, being a weight weenie, I haven't been using them lately. Now, having chopped all this rotating mass out of the equation, but also still wanting to go low with tire pressures, it seemed like a good time to get Cushy again. Running CushCore Plus inserts with the 29x3.0" XR4s, I am currently exploring between 13 and 17psi. Not sure where things will end up, but even as low as 13psi the tires are holding up nicely in the corners. This is my first go with these particular tires in this size, though, so I need to get some real hours in a lot of different terrain before I spout off much more. Speaking of tires, here's the tale of the calipers:

Will the skinny/fat wheels work in Baja? I'm heading down in two weeks to find out. I'll be bringing the light/fat Nextie/Barbegazi setup as well, just in case. As for the bike, I am stoked with how it currently rides and handles. Far more impressed with its behavior than I expected I would be. The q-factor is still a country mile wide, and the hoped for cranks to slim that down haven't shown up yet, but it hasn't really bothered me either. I'm running flats instead of clips on this bike, so that may be a factor. I also haven't been grinding out huge miles, which is almost certainly a factor. But overall, I am pleasantly surprised by the Kings Peak (even though it now costs more than twice as much as when I started down this rabbit hole).

Does this have any relevance in the real mountain biking world, aside from some old kook chasing his curiosity around? I dunno. On one hand, I think hardtails absolutely need to be in the general mountain biking conversation. And I emphatically believe that utility, adaptability and versatility are crucial to the whole hardtail gestalt. In this case, the Fezzari rules. Even with Very Fancy Wheels, it is still a somewhat reasonably priced bike by today's standards. But there are caveats - it was on sale when I started this.

Now you'd be looking at a base price of $2499 USD to start this experiment. For that price, the Kona Honzo I reviewed recently has better parts, a narrow q-factor and comes with a suspension fork. But the Fezzari can fit a whole lot more tires in between its seatstays. And in my mind, that has got to be worth something. Even if I never take any of our well intentioned readership up on their offers to go spend a winter in the Upper Peninsula of Michigan, having a bike that can swing that kind of use, and still be a legitimate summertime rowdy hardtail that can get roped into bikepacking duty, well, that's kind of awesome.

But then add on a swank fork, and some tire inserts, and complain some more about my wrists, and... then the logic gets a bit fuzzy. So I'm not gonna make any hard calls here. I'm gonna go ride some janky arroyos and drink some beer and think about it some more.

All I gotta do now is run the gauntlet down to Baja Sur, strap a ballena into my King Cage, and head out into the empty desert.


Truth be told, the real reason I fell down this whole fat bike rabbit hole was so that I could have a bike with a ton of different mounting points for these beauties. But then I went and took the fork off, damnit. Anyway, behold the mighty King Cage Manythings cage. 'Tween this and a Voile strap you can load just about anything you want on your bike. Tall cans, 40-ouncers, fire logs? No problem. Free your mind, and your ass will follow, someone once said...

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+8 TristanC bushtrucker Cr4w cxfahrer Mike Ferrentino Lu Kz Velocipedestrian BarryW

Mike - it sounds like you've been comparing notes with Andrew Major.... 

If it does work out maybe 29+ is the one bike to rule them all.

I'm enjoying where this rabbit hole has taken you and can't wait to read more.


+5 Lu Kz Blofeld fartymarty BarryW Jeremy Hiebert

Well, except for the rigid thing. And all that purple...

One Bike To Rule Them All. I have a hard rule about never, ever, ever saying that. HOWEVER, I spent the better part of last week arguing with the VP of marketing at a company I was brought in to write some web copy for. This is a company that is squarely in the center of the red meat eating, shooting and fishing and truck driving end of Americana. 90% white male customer base with a bit of a macho streak. Aaaanyway, VP was absolutely stuck on "One * To Rule Them All" as a product tagline. At first I thought maybe he was a closet LOTR nerd like me, but apparently has NEVER read the books and doesn't remember the films, and could not for the life of himself see how that tagline might not fly with a bunch of rednecks. But then again, maybe NONE of the redneck consumer base has heard of LOTR either, in which case it'd make a great tagline.

Obviously, this is why I got fired from that marketing gig back in 2012...


+3 Vik Banerjee Andrew Major BarryW

Purple ano is well nice tho... I think he maybe onto something.

My reference had a bit of LOTR in it (I do quite like the movies).  Maybe I wont go there again... but if I could have the geo and suppleness of my Solaris Max with the 29+ability of my Krampus and horizontal dropouts I would be as happy as Peppa Pig jumping in a muddy puddle.


+2 BarryW Lynx .

A custom frame builder can deliver all those specs. If you find someone who isn't famous the cost wouldn't be outrageous. 

I essentially created the bike you are after when I went custom. Basically a Krampus with modern geo and supple tubing.


+6 Andrew Major Mike Ferrentino Lu Kz Lynx . hankthespacecowboy OneShavedLeg

If you're not into racing (I'm not) then I feel like this

>Does this have any relevance in the real mountain biking world, aside from some old kook chasing his curiosity around?

Is where mountain biking eventually leads. They're so versatile that at some point we're just hermit crabs shaping our chosen shells into the best crust for us.


+3 fartymarty bushtrucker Mike Ferrentino

If I had to choose to keep one of my bikes, it would be my Surly Ice Cream Truck with two wheelsets. In the winter, I'm riding either 26x5.05 Vee Snowshoe XXLs or 26x4.8 Bud and Lou, and in the summer, 26x4.8 Knards or 29x2.6 Vittoria Mezcals. It doesn't go particularly fast anywhere, but it goes everywhere. I'm also running a Mastodon at 140mm, but I might drop that down to 100mm or 120mm.

For really sandy stuff (dry, loose sand), I've found that full-fat tires still work better than reduced-fat tires, but you'll get through it either way. They're incredibly versatile bikes.


+2 Mike Ferrentino Lynx .

After 4.5 years of ice cream trucking, I only recently did the full summer wheelset thing with some Onyx/WTBs laced by Mike... I should have done it years ago, really opens up a new dimension of riding for that bike.


+3 Mike Ferrentino bishopsmike Lu Kz

A week of riding in the UP in January or February would blow your mind. I hope you take them up on it!



Co-sign, Marquette is just as fun in the winter as it is in the summer.


+3 Mike Ferrentino Lu Kz Geof Harries

Why, you've built yourself a Stache!

"Anyway, these beauties, set up tubeless with a set of Bontrager Barbegazi 4.5 tires, are only about 100 grams per wheel heavier than the 29+ setup, and also represent a quantum leap in the rideability and enjoyability of the bike."

Went the same route on my base-level Beargrease. Then a GX shifter. And an XO1 cassette. And a ti post. No regrets!


+3 Andrew Major Mike Ferrentino Jeremy Hiebert

So as far as a value proposition goes, you'd get far better performance per dollar as a regular consumer picking something aluminum and reasonably priced up, like the Rocky Mountain Blizzard alloy, and then dropping the big bucks into your wheelset(s). So like the "alloy-bike-with-factory-suspension" builds some companies do, but for fatbikes instead of enduro frames.

I'll admit, I've been a little string-spoke curious the past few months, and an ultra light fatbike wheelset looks like the ideal application. Too bad I don't own a fatbike.



More or less. The Fezzari was being blown out for $1999US at the time I started in on this, and prices have climbed since then. The current Blizzard Alloy 10 lists on Rocky's site for $1899US and while Deore is probably a better quality than SRAM SX, it's a 10 speed setup, so not as receptive to upgrade-itis. The screaming deal would be last year's Blizzard 10, on sale for $1299 (which is a screamer of a deal), or last year's Blizzard Carbon 30 for $2159.


+3 Blofeld Kos steelispossiblyreal

Nice! I'm in Minnesota and have a 2018 Cannondale Fat Caad 1 (Lefty Olaf 100mm of travel) and have been running 2 wheelsets and several size tires. It's fun to adapt the bike to seasonal conditions or just change it up depending on my mood.

Wheelsets - stock 26 x 80mm Mulefut and the LBS laced up a set of Stan's 29 x 32mm with DTSwiss big ride in back and the Lefty hub up front.

Tires - had factory Jumbo Jim's 26x4.8. Currently Terrene Johnny5 studded, Maxxis FBF and FBR in 4" and 4.8 (4" lowered the bike too much leading to pedal strikes when riding dirt). Maxxis Minions in 29 x 3 (about the same height at the Johnny5), and Maxxis Rekon 29 x 2.6.

If the winter trails are hardpacked, running a fat up front with 29 x 3 rear is awesome. I do not recommend for winter time downhill though (have new helmet to prove it). Go full fat.

Mullet on occasion in the summer too but not if it is super dry (skinny tires will bite better in the corners).

If I have to ride pavement, 26 x 4.8 for sure (leg day).

I do have a carbon full squish also, so I'm not calling fat/plus/skinny hardtail one to rule them all, but if I could only have one, it would need to be four season compatible.

Good luck!

26 x 4.8

29 x 3.0

29 x 2.6

26 x 5 studded

26 x 5 29 x 3 Mullet

29 x 3 vs 26 x 4Height differences



The riding picture suggests the pilot is a Righty, to counter the Lefty up front.



Ha! I am a righty, but normally ride left foot forward.

Might be counterintuitive, but when riding a Lefty no handed, you actually lean a little left. Easy to do from 5" to 3", gets scary with the 2.6".



I meant you look like your left leg is missing in that shot.



lol I see it now


+3 Mike Ferrentino Velocipedestrian Joseph Crabtree

I 100% agree on silver spokes.


+2 Jeremy Hiebert steelispossiblyreal

You'd be hard pressed to find a wheelbuilder anywhere who doesn't also think the same way. But apparently this is a case of the market getting exactly what it asked for: color-based fashion with an extra helping of corrosion and weakness. I was talking with one of the engineers at Roval about silver spokes, and he said that even though stainless spokes are better for every application, it is currently an act of market suicide to spec them on bikes. Customers want their spokes black.


+1 Lu Kz
+2 Mike Ferrentino gubbinalia

On the subject of BB height… do those big Cake Eaters have more ‘sag’ due to the low pressures compared to the 29+ ? 

I haven’t spent time on a 29+ since I worked at a Shop that had a Niner ROS9+ in the fleet … that bike was a unique kind of fun. Tires (and inserts) as well as geometry have definitely evolved since then. 

I’d love to see some more hardtails that can take 2.3 up to 3.0 29in rubber (with appropriate adjustments) 

I’m currently riding (and loving) a Chromag Surface Voyager SS. I have a nice full suspension bike, but I just keep grabbing the SS hardtail this year.


+1 Mike Ferrentino

If you're riding soft surfaces and running appropriate pressures to the design intent of the tire, then yes, there is a healthy amount of sag.  Maybe doesn't make 'em exact to the millimeter, but close enough for gub'mint work.


+1 Mike Ferrentino

Please report back on how the cassette holds up. I have an HG driver and am also keen to loose the 600+ gram nx cassette. However I might just get XT linkglide and go for durability.

I love manitou forks. So easy to work on, great engineering, and I think they look awesome. Can you upgrade the mastodon with an IRT? If you like monkeying around with suspension, IRT is really fun to play with. You can make the spring curve linear or bump up the pressure in the IRT and have a lot of support. 

Great article. I have a blizzard and having another wheel set to make the bike work in all 4 seasons could be fun. However, it could be an expensive experiment.


+1 Mike Ferrentino

Being running a garbaruk cassette for over a year their great. Closest in performance to a full shimano 12 speed setup in terms of shifting under load. But the weight reduction is incredible and a big plus is even the hg cassette is one piece




Lots of discussion from other customers in the comments as well.


+1 Lynx .

Welcome to the world of frankenbiking. You're gonna meet a lotta interesting cats with a lotta interesting ideas.


+1 Mike Ferrentino

Great, great article. I know I'm the weirdo, but full-on fat bikes just feel wrong to me in the same ways you described. Clunky, icky-steering, awkward contraptions that only make sense in soft snow, and then I'd rather be skiing. When I switched to a Commencal Meta HT hardtail after a decade of 160/160mm rides, I started with the usual 2.4-2.6" tires, but I didn't truly love the bike until I started running 2.8" Minions. 3" might be even better, and would fit the frame, but 2.8 is great in any conditions other than deeper snow or ice. Incredibly versatile bike that takes anything this old man can throw at it.



That 29+ setup looks fantastic!



Man Mike, really digging those 29+ wheels/tyre setup, super dope. I thought I'd done well and had a great feeling dropping about 2 pounds switching from Maxxis 29x3.0" EXO casing tyres on i39 Dually45 rims to 29x2.6" Schwalbe NN/HD on i35 WTB Asyms, but damn, 6lbs rotational, weight loss, that's insane :-O

Really enjoying the rabbit hole stories, truly a man after my own heart, although going after the full fattie would be a hard one for me, wrists still doing pretty OK with only 53 years on them - may be time to really get all lost in the rabbit hole of weirdness and try some alt bars, or at least the SQ Lab 16 degree sweep alu bar.



Great article per usual. Love to hear about all the tinkering, especially with unique bikes like fat bikes.

I've been harping on in the comments about my REEB Donkadonk since I made an account here but why not do it some more? I currently have 3 wheelsets for it--

+ 26" Surly My Other Brother Darryls with studded 4.6" fat tires for actual winter riding (I'm in Michigan so studs are pretty essential in my opinion),

+ 27.5" Stan's Hugos, usually running Bontrager Hodags. This is my "mid fat" (as I'm calling it) setup.

+ 29" Alexrims MD50 wheelset currently with a Duro Crux front and Ranger rear for summer. I have also tried the Donk with Sunringle Duroc 35 with 29x2.6" tires as well.

The Donkadonk geometry is so good that it feels great with all 3 of the wheelsets, although you do notice the difference in trail figures when you change wheel sizes.

I still have this idea of lacing up the carbon Pub 27.5 x 45mm internal hoops I have laying around to a dynamo front hub and running some Cushcore in there to really dampen the ride while still having a wash with the weight gain.


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