Monday, August 11, 2014


MukTruk V1
What is a "MukTruk"? That's the name Mike Johnson gave to his titanium Mukluk outfitted with 29+ wheels. The story started with Mike wanting to fit these tires and wheels to his Ti Muk, and then having past Trans Iowa winner Dennis Grelk machine him some modified Alternator drop outs to help gain better mud clearances.

So, as long as Dennis was going to go to the trouble of making one set, he figured he may as well make a couple more, (at least, I am not sure if another set exists or not), and so that is how I came into possession of a set of these drop outs. I'll show why those are necessary here in a moment. First though, I want to share the long and winding road that took me to the point where you see my Ti Muk today.

This all started when I rode a Krampus at Interbike a few years back. I figured the versatile Ti Muk might work with these wheels, but I didn't have the tires, nor the right wheel set to do that with. I do have a fat bike hubbed wheel set that spin Stan's Flow rims, but those were deemed too skinny by myself for this project.

Clearance is super tight with stock Alternators
So, a new wheel set, or at least a re-lacing of those hubs would need to be done. Then Salsa Cycles introduced the new, front disc spaced Conversion hub set, and in my favorite color- purple! I ordered up a set at the end of Winter and those sat until very recently when I had them laced to Velocity Dually rims in black ano with purple alloy nipples.

Getting up to speed with what would work with fat bikes going forward, the Conversion Hubs were a good move, but that made my Enabler fork, a rear disc mount/rear disc spaced hub compatible fork, obsolete. A new fork was in order then. Being somewhat limited to a few forks with this front disc standard and 1 1/8th steer tube standard, I chose the MRP alloy Fat Fork. It is a little heavier than its carbon counterpart, but it was significantly less expensive. I saved 234 grams from the switch of forks, which isn't huge, but it is something.

There are going to be a lot of 29+ tires soon, but as for right now, I like the Knards. I've seen what they can do, and I have also experienced what they can do. (The Borealis Echo test recently, for instance.) Of course, I got the 120TPI versions and set them up tubeless using my buddy MG's special sauce and a combination of Gorilla Tape, (one layer), and a round of Velocity USA blue tubeless tape to reinforce the spoke hole area.

Using the "DG Alternator Drops"  makes more room
The tubeless mixture was mixed a bit on the thicker side to aid in sealing up the Knard casings and bead interface on the Duallys. It was a laborious prep process and mounting session, but it all paid off in a successful set up of these tires tubeless. You have to really spend the time in set up to pull this off well. I'm confident, (after seeing Mike Johnson's performances and in the use of the Borealis Echo), that this tubeless set up will be bombproof.

The final key to the successful MukTruk transformation was the Dennis Grelk custom machined Alternator style drop outs. Dennis expertly figured out how to move the wheel rearward in relation to the seat stay bridge without raising the bottom bracket. This required a bit of a mod to the design of the original Alternator in that Dennis had to move the brake caliper upper mount to its own, dedicated threaded hole instead of ganging it with the upper swing pivot point, as Salsa Cycles' design utilizes. This required a little extra hardware, but I had everything I needed there to make the swap. With the new "DG-Alternator Drop" slammed all the way up, I have gobs of mud clearance, and no doubt I could probably also slot in a Surly Bud or Lou fat bike tire on a wide rim as well with this set up.

MukTruk V2: With the "DG-Alternator Drop" set up, new fork, and 29+ wheels and tires I am set for adventure!
No questions on clearances here!
Mike Johnson told me recently that his MukTruk set up is his "go-to" bike now, and I can already say that I am pretty darn sure that this bike will also be one of my very favorite rigs as well. Capable of mountain biking, gravel riding, light Winter duty, and more, I will likely be using this bicycle more and more also, just like Mike does.

Mike has his rig set up with a Luxy Bar, and I may do something like that at some point, but honestly, I may just get some Ergon BioKork grips with integral bar ends first, as I really like their feel and performance. The bar may get swapped for something wider though, as I've become accustomed to the short stem/wide bar feel of some other rigs I have ridden. Then there is the upcoming release of Jeff Jones' carbon Loop Bar.

The only bummer about this Ti Muk is the pigeon hole you find yourself in with the head tube size. 1 1/8th is something of an antiquated standard. No fork manufacturers are really supporting it with new releases anymore, so as long as I can live with the rigid fork, I suppose I'll be okay.  Otherwise I like almost everything else just fine. I may have to swap to a more modern crank and bottom bracket soon. I don't suppose 100mm ISIS bottom brackets will be around much longer! That's something that may force my hand, and honestly, it would make the bike better. Maybe one of those fancy Race Face Next fat bike cranks is on the horizon.....

I did get a short ride on this Saturday evening and it feels.......normal. At least to me it does. The thing is, it steers better with the Knard 29 X 3" tires than with fat bike tires and I already know what this tire and wheel combination is capable of having ridden three different bicycles fitted with wide rims and 29+ Knards previously. It should prove out to be a ton of fun!


Tyler Loewens said...

Wow! Any idea if the clearance on stock Aluminum Mukluk Alternators with 29+ is the same? That is really close until you use your modified dropouts.

Looks great BTW!

Guitar Ted said...

@Tyler Loewens: I imagine it would be less. Salsa shortened up the rear ends of the Mukluks beginning with the 2013 model year, (first year with Alternators), and I am guessing they are shorter than my almost 18" stays on this 2012 Ti Muk.

hiker said...

Awesome, I also wanted to have some longer alternator dropouts made for my mariachi. I was going to take the idea to a local machinist but did some searching to see if anyone else had tried it and here you are. Does this guy sell these dropouts?

Guitar Ted said...

@hiker: No, not that I am aware of. I believe it was a one-off project he did for a few people.