Entries for Topic: Snow Biking

Salsa Mukluk:  It’s All About The Details

Wednesday August 4th, 2010 | 28 Comments | Joe

With the introduction of the Mukluk, Salsa brings an affordable price aluminum snow bike frameset and complete bike to snow, sand, and chunk riders around the globe. We’ve put hundreds of hours into development of the Mukluk.  Many of them on the bike testing and evaluating concepts, refining them for production.  We've had a lot of fun throughout the entire process. In this article we focus on the details of the frame and why we made critical design decisions.

Geometry

Fit on the Mukluk borrows elements from our existing mountain bikes and blends them with feedback from our test riders and the fatbike community. Two important elements on the Mukluk are standover clearance and taller headtubes.Headtubes are 15-50mm taller depending on frame size than our current 29ers.  We’ve gained an additional 15-20mm of standover clearance for those times when the trail gets too soft and it’s time to hike a bike.

Horizontal toptube lengths compare directly to the El Mariachi steel or titanium models.  If you ride a medium in another of our mountain bikes, you’ll ride a medium Mukluk.  Of course it is always a good idea to work with your dealer to find proper fit.

Handling can be a touchy subject. We all have our own personal preferences of how we like our bikes to ride.  Determining handling geometry on Mukluk was a matter of listening to feedback, producing prototypes, testing, and refinement.  Kid had some strong opinions of the fit and handling characteristics, so we made him a proto frame to test those ideas that was ultimately dubbed the Snowflake.  With another prototype, Rustflake, we tested a few more ideas.  In the end we took what we feel were the best characteristics and applied them to the handling geometry of the Mukluk.

The most notable handling characteristic of the Mukluk is more stability in slow speed situations.  Riding soft trails with 4” tires can often mean fighting the front end of the bike to hold your line.  The more you fight the front wheel, the more you are going to fatigue.  The Mukluk has a wheelbase that is 26.7-28.3mm longer than a comparable El Mariachi titanium (note: I didn't compare the El Mariachi steel because of its variable chainstay length).  The rear center (chainstay length) is 455mm long, 5mm longer than the El Mariachi titanium.  The head angle is 69.5-70.0°, 1.5-2° more relaxed than the 71-72° head angle on the El Mariachi titanium.  Chainstay length, steering angles, fork offset, and a lower bottom bracket all contribute to providing more stability.  More stability equals less fatigue.

Frame Material

By now you’ve dropped on over to the Mukluk page and know that the frame is constructed of 6061-T6 aluminum.  We chose 6061-T6 aluminum because of the ability to build a stiff, relatively light, and durable chassis.  It helps that aluminum also provides more protection from corrosion on those long rides along the coast and through the winter slush.  4” tires at 5-10psi provide compliance that keeps you in the saddle all day long.

Drivetrain

100mm bottom brackets coupled with a spaced out drivetrain have become the norm on fatbikes.  Some of the earliest fatbikes built borrowed this already existing standard from the downhill/freeride community.  Most of the cranksets and bottom brackets available are built with big hit riding in mind, but each year we see more purpose-built components specifically for the fatbike niche.

It’s a simple reality: if you want to build a bike with a 4” tire the drivetrain must be moved outward to clear its girth.  Surly popularized the 17.5mm offset built rear wheel.  The 17.5mm offset standard provides clearance for the chain and tires and gets the chainline in alignment on the chainrings and cassette.  To build a non-offset wheel, moving the drivetrain out 17.5mm it is simple math to arrive at a 170mm hub width.  The 170mm spacing on the Mukluk allows for wheels to be built symmetrically, or using the optional 170-to-135 adapter kit wheels can be built to a 17.5 offset using a 135mm hub.  That’s the basics of Dual Spacing.  What it means is more choices for you, the rider.

Many of you have asked how the 170-to-135 Adapter functions.  Here’s a couple of images that show visually how it all goes together.

and one that shows it in use

The Mukluk frameset and complete bicycle are equipped with a Problem Solvers Direct Mount Adapter.  We chose this standard over E-type mounts to, once again, provide more choice and flexibility to you.  Shimano offers Direct Mount compatible front derailleurs.  The direct mount adapter also allows for better compatibility with a wider range of front chainring setups.  While the Mukluk comes equipped with a standard 22,32,44 chainring range, we know that many of you are experimenting with alternative single, double and triple chainring setups.

fancy image...

and one in use...Sorry I didn't clean it.

On the question of cable routing, there isn’t one.  Full cable housing from handlebars to rear derailleur means less chance you'll be walking home, chipping away ice, or building a campfire because your cables froze in place.  For best compatibility with both Shimano and SRAM derailleurs and better clearance on the top tube, both shift and brake housing is under the down tube.  We’ve provided all of the necessary braze-on's to keep it securely stowed away. It does also create a nice clean package and works well with front triangle frame bags.

There’s a few other details worth mentioning here.

The Mukluk frameset is compatible with up to 100mm rims and Surly Larry/Endomorph tires.  100mm rims provide the maximum in flotation and are quickly becoming the standard on race bikes at the Iditasport Trail Invitational and the Arrowhead 135. 

As Kid mentioned in the introduction to the Mukluk I have been testing the bike with a set of 29er wheels.  Measuring everything out, the geometry of the bike changed very little.  The difference between the outer wheel diameter on a Larry tire mounted on a 100mm wide rim and the 2.4 Schwalbe Racing Ralph mounted to a Salsa Gordo rim is 8mm.  My bottom bracket height has changed ever so slightly and I've been pleasantly surprised at just how normal the bike feels in the 10+ hours of riding and testing.  Honestly, I've forgotten that I'm spinning a 100mm wide bottom bracket, even though Q factor has changed drastically.  The human body adapts remarkably well.  Especially in these conditions...

Braze-ons abound on the Mukluk Frameset.  You already know that the Enabler has provisions for front racks, water bottles, and our Everything Cage.  We’ve provided rack mounts on the frame as well, along with three sets of water bottle mounts.   On M, L, and XL frames the downtube water bottle cage mount is configured to accept the Everything Cage as well.  You’ll have no problem carrying ‘stuff’ where you want it.

Mukluk is one frame where the graphics are both visual and functional.  The trees remind me of last winter’s tour in the northwoods, where Tim and I awoke to a world blanketed in heavy white snow.  The reflective decals would have made us significantly more visible to the snow machine riders as we pedaled through the dense pine forest.  They will certainly be a welcome addition at events like the Arrowhead 135, where reflective material isn't just a suggestion, but a requirement.

So there you have it, a glimpse into the decisions we made in developing the Mukluk and why.  We hope this answers the questions that are lingering out there.

If you have other questions, please use the Comment function and I'll answer them as they come.

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This post filed under the topic(s): new product , Joe , Mukluk , Snow Biking

Introducing: Mukluk

Monday August 2nd, 2010 | 61 Comments | Kid Riemer

Within the Salsa crew we have a handful of dedicated snow bike riders. We’ve dreamed, talked, and schemed for years over just what we would create when we got the chance. This past year, we finally decided to pull the trigger.

Jason testing an Enabler-equipped El Mariachi aka Snow Bike Lite this past March

Today it is my distinct pleasure to introduce the Mukluk, Salsa’s first snow bike.



My personal experience on snow bikes goes back five years or so, but my interest in snow riding goes back much further. I first heard of the Iditasport race in Alaska in the early 90’s. In those days, the names surrounding that race included the likes of Stamstad, Reifenstuhl, Curiak, and Irwin. The bikes of that era didn’t usually have the super wide tires and rims that we have today. They were primarily stock mountain bikes equipped with 40-something millimeter rims and the widest tires that would fit in a desperate search for floatation.

Today, some of the names in the game have changed (Petervary, Basinger, Oatley, and Pramann come to mind) while others remain (Reifenstuhl and Curiak are still at it) and so have the machines they (and we) ride.

Mukluk prototype Rustflake in Alaska. Rustflake was unpainted steel to test geometry. Photo by Dan Bailey   www.danbaileyphoto.com

We’ve come a long way snowbaby!

It is only proper to acknowledge Salsa’s sister-brand Surly for the important role they played in the modern development of the snow bike. Their snow bike, the Pugsley, was the first to be widely available. Their tires continue to drive the category. Without the product development risks they took, who knows what the modern snow bike world would look like. But I’m thankful that they did, when they did, and I’m thankful the snow bike market has grown enough to support multiple brands.

But this post is about Mukluk, and that brings a smile to my face.

Rustflake's sister Snowflake also developed a serious case of iron oxide during testing in Minnesota

Mukluk is designed first and foremost to be a snow bike. Snowy singletrack, snowmobile trails, and snow-covered frozen lakes and rivers are its home.

A snow bike is nothing without floatation. Wide rims, and wide tires run at proper pressure for the conditions, make the difference between riding and pushing.

Floatation, floatation, floatation...

Proper frame geometry is equally important. Mukluk’s geometry is extremely effective for snow riding. It is stable with slower handling than a ‘typical’ hardtail mountain bike. Mukluk rides comfortably at slow speed without sacrificing handling at faster speeds. You learn to lean the bike a bit more and it carves a fair turn. Mukluk feels ‘normal’ to me.

These handling traits are incredibly beneficial while snow biking because the trail/surface conditions can vary dramatically and change so quickly. Snow is not just snow. It can be heavy and wet or dry and powdery and anything in-between. It can feel like concrete or corduroy, a mix of sand and brown sugar or a fragile layer of wafer-thin glass.

Rustflake floating an Alaskan beach...

No matter how good the geometry, there will always be conditions that will bring any bike (snow bike or not) to a halt. We’ve designed Mukluk with a very low standover height to aid when forced to dab, stop/start, or dismount/remount.

Mukluk has a comfort-based cockpit. The tall head tube helps riders set their bike up for slow-speed snow slogging and long distance ultra events.

Mukluk sizing works in line with our other Salsa sizing. If you ride a Medium El Mariachi, you ride a Medium Mukluk

Later this week we’ll have a post explaining other design features and why we chose them.

Mukluk came to be with the help of others beyond the Salsa crew. We developed and tested the geometry here in Minnesota, but also in Alaska. We took input from slow guys like me, fast trail rippers, and a snow bike champion. We like what we’ve come up with. It works well. It feels good.

Joe rolling the bank of the Minnesota River

So the questions are formulating in your mind, and I’ll address just a couple. How does it work on dirt?

The short answer: Fantastic. We’ve put in loads of miles on dirt, sand, cobblestone beaches, and flood debris. Fat wheels will always take a fair bit of energy to bring up to speed, but there’s a heck of a lot of momentum once they are rolling. They are really just bigger, wider, and heavier 29’er wheels.

Mukluk thunder soon drowned out the hum of the flourescent lightbulbs

There is nothing better than floatation for sand riding though and we had a perfect spring with massive flooding that left us with trails that were only rideable on a snow bike. The large contact patch and ability to run low pressure make rock gardens, debris fields, and rough surface riding easier than on a ‘regular’ mountain bike.

Rumbling through the spring flood debris of the flood plain

Can I run regular wheels on Mukluk?

The short answer: Yes, but you’ll need to build wheels for it (more on that in the follow-up post). Also keep in mind that the geometry will be different from a ‘typical’ hardtail. If the feel of the bike works for you (as it does for me), you might love it. Joe is testing his right now in this configuration and will provide his feedback in the near future.

Joe is testing this setup with Gordo 29'er rims and some 2.4" Schwalbe treads

Please use our Comments area to ask any questions you have, and we’ll do our best to answer them in a follow-up post.

Jason on the mud flats

Back in ’89, the idea of riding on snow somehow captured a special place within me, and it hasn’t let go. While I’ve taken part in Minnesota’s Arrowhead Ultra 135, I haven’t yet done the Iditarod Trail Invitational (formerly known as Iditabike/Iditasport) but the idea of that grand adventure still tugs at me.

Most of my winter riding is simply about pleasure. It is my favorite season for biking.

Whether a cold, pre-dawn ride with a headlamp gently illuminating the terrain ahead, or a moonlit roll through a surprisingly bright world. Spinning silently on a soft snow-covered trail. Changing cadence based on the surface beneath me. Focusing on where I put my wheels, while relaxing the mind enough to let the clutter evaporate. Stopping to look at the beauty all around me. Watching as the sun begins to throw its warm, golden rays. Breathing in that clean, crisp, sometimes cold, air.

This year, those rides will be aboard Mukluk. I invite you to come along for the ride.

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This post filed under the topic(s): new product , Kid , Mukluk , Snow Biking