Mullets Are Back And Definitely Ready To Party
If you haven’t updated your pop-culture cycling dictionary with the term “Mullet”, now’s the time, as the definition has expanded….
For the last several years, the moniker of our favorite “haute coiffure” from the New Wave era has referred solely to the use of two different tire/wheel diameters on a bike. For example, several trail bike models are currently available with a 29” front wheel and a 27.5" in the rear. The “mullet” wheel configuration also extends into the gravel world, with some riders choosing to run a 650b(27.5") wheel in the rear with a larger tire.
The gravel world is also where we find the latest use of the mullet designation, referring in this case to the drivetrain setup. I’ll lay out the what, why, how, and help answer the question “Do I need a mullet?” Or possibly “another” mullet? I'll share a quick real world mullet-geared case study as well. If you’re already by chance rocking a gravel rig with 700c/650b wheels as well as hair shaping that says “business in the front, party in the back”, prepare yourself for Mullet x 3!
What Makes Up This Mullet?
One of the aims with a gravel bike setup is to arrange the gearing such that getting up and over steep climbs takes a bit of precedence over top speed on flats and descents. The ideal balance has so far landed somewhere between road and MTB gear ratios, with the individual “sweet spot” largely in control of the rider and how they set up the bike. Manufacturers have realized this and offered up nicely optimized, gravel-oriented groupsets. These setups, as well as generously geared road groups have done a great job of covering the all-road bases, especially with 1x (single ring) cranksets in the mix to simplify the setup and reduce maintenance and the number of parts involved. Every now and again however, even the strongest gravelers are likely to encounter a climb, or series of climbs that might over-tax even the most forgiving traditional gear setup. So what to do? What if you could split the difference between road and MTB gearing even further, widen the gear ratios and provide a wall-climbing MTB low end, while retaining the final top-end ratio of your gravel gearing? Jump in the figurative barber chair, we’re going to tell you how to do it!
How It’s Done
Up until recently, the idea of using an MTB cassette with a road-like shifting setup was limited mostly by the interface between road (drop-bar) shifters and a rear derailleur that could accommodate the enormous cogs at the top of an MTB cassette like a SRAM Eagle, with its prodigious 52t large plate. Mechanical shifters/derailleurs have most often used different pull ratios for road and MTB setups, which makes shifting problematic between the two without special adapters or using friction shifters. We’ve seen setups using Shimano XT Di2 rear derailleurs, XT or E-Thirteen cassettes and sometimes funky, sometimes ingenious uses of Shimano’s remote Di2 shifters with varying success. But the use of the 12 speed, 52t cassette was still essentially off the table, until SRAM pulled all the pieces together with their AXS road shifters being able to seamlessly communicate with the Eagle AXS rear derailleurs. It’s a bit like when mainstream stylists finally agreed to provide you a professional mullet cut, rather than having your friend do it after school with sewing shears. But I digress….The easy pairing of electronic road shifters to an AXS rear derailleur officially opened the door to super low-end climbing ability along with still reasonable top end speed. So what’s the trade off? Again, much like the original mullet, there must be a downside… In this case, the minuses are far outweighed by the pluses, the former being few and minor.
When you stretch the gearing spectrum of a cassette, you also stretch the rations in between. 12 speed cassettes make this much less of an issue with so many cogs to work with, but you’ll still notice some “gaps” throughout the cassette and may have trouble finding the “perfect” gear for any situation short of epically steep climbs. But riding off road is generally a much friendlier environment for this, compared to the road. Similarly, you can be pretty well covered at the top end with a 40-42t front chainring. You’ll rarely if ever need a 50+t chainring on the gravel.
The only other moderately noticeable characteristic you might notice when riding a 12 speed mullet setup is that the shifting feels much like an MTB, which is to say a bit “clunkier” than a road setup. The mullet requires a pretty long chain to properly wrap the 52t cog and 40-ish tooth chainring, and run through that long cage derailleur. So, is it the right way to go?
Does It Work Well, Or Just Look Good?
I’ve been lucky enough to try both setups essentially back to back, on the same bike, over the course of two long, arduous gravel events. The bike is set up with SRAM Force AXS road shifters and the primary gearing setup is a 2x12 Red/Force crank, cassette and front/rear derailleurs. The cassette is the Force 10-36t, the crankset uses the 46/33t chainrings. For nearly every situation I’ve found myself in on the bike in question, the 33/36 low-end ratio has been mostly fine. But there are climbs where “spinning” is simply not an option with this setup, and I’ve found myself really having to grind up some overly steep sections. These are the times where the idea of trying a mullet setup entered my mind.
On the other hand, one of the two events I’m referring to above had about 25 miles of descending combined with even more hardpan and paved flats and rollers. During these sections, having a larger (2nd) chainring and wider gearing throughout the cassette helped even out the pedaling cadence, aid in recovery, etc. The 2x12 does indeed have some perks. However, looking down the barrel of the infamous Crusher In The Tushar gravel race got the figurative wheels turning in my head. If you’re not familiar with the Crusher, the long and short is 10,000 feet of climbing, squeezed into a fairly short 69 miles. Oh yeah, and most of it is 8,000 feet above sea level with the finish topping out above 10,000 feet. Temps at the lower parts of the course often exceed 100 degrees as well. This would be the ideal time to try out the mullet setup. I’d just need to round up the required parts…
How I Did My Own Mullet
With apologies to my MTB, I temporarily demoted it to “parts bin” status for the mullet experiment. The bike shares it's SRAM-based build with the gravel bike, including both bikes using rear hubs equipped with an XD/XDR hub driver. I dismantled the MTB and borrowed its XX1 AXS derailleur and cassette. A new Eagle chain was required, due to the aforementioned increased chain length. Other accommodations to the gravel bike were minimal, consisting only of a B-tension adjustment to the derailleur, some minor micro shifting adjustments once the shifters were paired, and a .85mm cassette spacer was used to interface with the XDR driver on the wheel (XD MTB and XDR Road driver bodies have a slightly different base profile).
I had a 1x SRAM spider from a previous bike that I used with the SRAM Red crank arms and (can 2x spider be used as 1x?) overall, the parts swap and adjustments were straightforward and relatively easy to accomplish. It’s a bit wild the first time you click into the 52 on a gravel bike, but the gearing felt great across the range and it was ready to face the Crusher. The event starts out with about 11 miles on pavement before the real work begins. You’re then faced with about 20 miles of solid climbing, reaching the 10k foot mark for the first time of the day. Without going too deep into the course itself, suffice it to say that the mullet setup was more than amazing. Having the extreme low end of the 52t cassette was nothing less than a lifesaver, several times during the day. Over the paved, flat sections of the event I didn’t miss the 2x setup and felt like the 40t chainring and 3 smallest cassette cogs provided ample top end speed and cadence. The last mile of the race that takes the riders up to and through the finish section is severely steep and relentless, and I found myself happily locked in the 52t for the entire final climb.
Should You Try It?
My personal take on the mullet drivetrain setup and whether it’s THE way to go or not is that if you find yourself tackling really steep climbs more than about 30% of the time you’re on your gravel bike, the mullet may be the best option for you. My own bike is back to its original 2x12 configuration and my MTB is whole again, but I won’t hesitate to swap back to the mullet next time I sign on for anything with more than moderate climbing involved.
If you’re mullet-curious or need any assistance getting your own perfect gravel setup, give us a call and come visit us at the shop! We’ll get you rolling with the best fit for what you ride. When it comes to hairstyles however, we can only offer opinions.