SOC13: Dirty Sixer Builds 36" Wheeled MTBs for Giants

For a while now, 36 inch wheeled mountain bikes have been sort of a gimmick, or concept bikes for normal sized humans that takes the bigger is better wheel mantra to the extreme. Though if 29ers are more proportional to taller riders, than it should make sense that 36ers are more proportional to really tall riders, right? That’s that way David from Dirty Sixer sees it. The Dirty Sixer is a purpose built 36 inch wheeled mountain bike for riders starting at 6’5″. David himself is 6’6″ and is on the small size for his bike which was raced in the Sea Otter XC race by his tester who is 6’10”!

Building a bike for someone who is a full foot taller than the average human is certainly a challenge and resulted in some very interesting custom parts for the Dirty Sixer.

SOC13: Dirty Sixer Builds 36" Wheeled MTBs for Giants

The crazy part is that most of the 36 inch wheeled bikes we’ve seen really look like the wheels are huge. In order to provide stand over clearance, the tubes are drastically bent but David’s customers have no stand over problems. Under Dirty Sixer’s customers, you may have to look twice to realize just how big the wheels really are.

SOC13: Dirty Sixer Builds 36" Wheeled MTBs for Giants

Built by Dmitry Nechaev who founded Triton Bikes in Russia, and designed by David in California, the Dirty Sixer was built in Titanium and welded up in a week’s time though it had been in development for a few years. The welding was all pretty tidy and had already been torture tested by David’s 6’10” pilot. The bike survived, the seat post – not so much. Building a tall man’s bike is about more than just stuffing comically large wheels in an oversized frame. The Dirty Sixer has quite a few custom bits to actually perform well under such a big rider like the CNC machined disc brake adapters to run Santana tandem 10 inch disc brake rotors on their custom truss fork which runs a 135mm, 20mm thru axle hub. Big guys need big brakes.

SOC13: Dirty Sixer Builds 36" Wheeled MTBs for Giants

Other custom bits include the 220 mm ISIS JK Mountain bike cranks from Joseph Kuosac, which are sold through Lennard Zinn’s Big & Tall Bike Shop. The cranks are mounted to what may be a first – a 100mm wide eccentric bottom bracket to provide the proper Q-Factor for such a big rider.

SOC13: Dirty Sixer Builds 36" Wheeled MTBs for Giants SOC13: Dirty Sixer Builds 36" Wheeled MTBs for Giants

Dirty Sixer rolls on Nimbus Stealth Unicycle rims laced to Phil Wood hubs, a 185mm hub in the rear, and the aforementioned 135 in the front. Tires are a 36x 2.25 made by Vee rubber for a batch that was commissioned by Walt from Waltworks. Probably the only 36 inch tire that is tubeless ready, the 36 TPI tires weigh in at 1625g a piece and will set you back $125 – but they are also around a pound lighter than the other 36s on the market.

SOC13: Dirty Sixer Builds 36" Wheeled MTBs for Giants

The frame has fork bumpers to keep the truss fork from denting the top tube when the full weight of a 36 inch wheel comes crashing down on it. Built with a 49.6mm head tube, the truss fork has a full 1.5 inch steerer to keep things stiff. Not seen on this bike, but something David is working on for the future bikes are handle bars that are designed for big guys as well. Instead of using a 31.8mm clamping surface and tapering down to the grips, David’s bars will be a full 31.8 all the way through. Companies like Felt have used 31.8 straight bars on their bikes, but David’s will be a riser bar, and he says the larger diameter is better for tall guys because they have such big… hands. Of course this will take some custom solutions for grips and shifter and brake mounting, and we’re looking forward to see what he has up his sleeve.

As David was half joking about at the show, let your local NBA player know that he has his next bike.



  1. @ JSE

    I am 6’5″ and only offended by lack of gear/bike/parts made for “Giants”. I think I need a 36er to complete me.

  2. What? No Bamboo frame?
    Love this idea of scaling wheel size to rider size. It actually makes sense.

    Anybody see the add with Kevin Durant (6-10 bball star) saying he rides a MTB to train? Watching him pedaling along it is clear he does not. This bike would be perfect for him if he wants to actually be legit.

  3. As a tall person this bike makes me giddy.

    Most frames made for tall people are poorly-proportioned jokes that just try to grab some market space without adjusting for needs of the very tall (or very short). But this is an extremely well-executed beauty, and I love the fact that if you didn’t know it was using 36ers you would have thought it was a normal bike. Which is exactly how it should be.

  4. The worst thing about the Kevin Durant advert is watching him undergear the whole time. Makes my knees hurt just watching.

  5. Many frame builders say the 36er is not necessary, that 28 inch is a big as a wheel needs to go. While I respect these individuals, having seen how much more comfortable big people look when riding a 36er, it seems clear to me these over-size bikes are the only way to go if you’re 6’5″ and up. Who knows? Maybe somebody will come up with a 30 or 32 incher for people in the 6′-0″ – 6’6″ range. At 6’1″ with a long torso I feel I’d be a lot more comfortable on a bike with bigger than 28 inch wheels (700C).

  6. As a 6’6″ rider of gnar all over BC I can safely say that I won’t be riding small wheels again on any bike of mine. My Enduro 29er is the perfect bike for me right now. If someone ever builds a proper XL-sized 650b DH bike I will ride that too (the Intense 951 EVO is pretty close).

    Seriously: big wheels for big people. It just makes sense.

  7. that bike is so huge, the 1.5″ headset looks like a 1-1/8.
    why the avid mechanicals? disc hose doesnt come in XL?
    “Other custom bits include the 220 mm ISIS JK Mountain bike cranks from Joseph Kuosac”
    i first read that as 220 millimeter ISIS -just kidding- cranks from…. you might as well use a thick 1.5″ pipe as the spindle and just clamp big-ass arms to that.

  8. Alex,
    Lenz sport can make the PBJ downhill bike with 650b wheels in an XL or XXL size. You should check on that bike. it’s bad ass. -N

COMMENT HERE: (For best results, log in through Wordpress or your social media account. Anonymous/fake email comments may be unapproved or deleted. ALL first-time commenter's posts are held for moderation. Check our Comment Policy for full details.)

This site uses Akismet to reduce spam. Learn how your comment data is processed.