Fat Bikes: The New Ships Of The Simpson Desert

There’s been a fair bit of chat about fat bikes since Flow ran stories on their first appearance in the Simpson Desert Bike Challenge last year. (See ‘No Way in Hell’ in Flow #2 and our online feature ‘Five Days in Hell’.)

Designed for snow, and made and sold in places like Alaska, fat bikes are establishing strong migrant communities in Australia and New Zealand. With names like Fatback, Salsa Mukluk, 9:ZERO:7 and Surley Pugsley, these bikes sound like a pack of rappers – tough, kinda wide-looking, and ready for anything.

In the Antipodes, however, the rude four-letter s-word that strikes fear into mountain bikers is not ‘snow,’ it’s ‘sand’. So how do the fatties compare to their skinny cuzzies in Australia’s s***y test piece, the Simpson Desert? [private]

We can rattle on about tyre sizes and contact patches all we like, but none of the crew at Flow HQ has actually ridden any kind of bike through the Simpson. Better to get the word from the camel’s mouth, we thought, so we tracked down a couple of the riders from last year’s race through the Simpson to get the low-down.

Ten of the 16 riders in the 2012 Simpson Desert Bike Challenge were on fat bikes. Perhaps more telling, five of the seven riders who managed to ride the entire course were full-fledged members of Team Fat Bike.

Murray Rook won last year’s race, coming first equal with his good mate and loyal training buddy Alan Kleeneside. This was Murray’s second Simpson race, and he and Al were on fat bikes. (With Scott Spark rider Lynton Stretton hot on their tails.)

New-comer Ronn Slusser rode his Trek Rumblefish. Despite being on a skinny-wheeled steed and being a first-timer, Ronn completed every stage of the notoriously difficult 10-stage race and clocked in at a tidy sixth place.

Murray Rook

Salsa Mukluk ‘Heavy Judy’

The bike was imported by Wayne Chapman at Dirtworks. It’s called Heavy Judy because that was what those wide-eyed recreational riders on the Sydney bike paths said when they saw me out on training rides: ‘Jeez, mate, those tyres are Heavy Judy!’

Heavy Judy weighs 18kg in race format.

Winning last year’s Simpson Desert Bike Challenge was a real bonus. We didn’t set out to do that. Al and I planned to ride separately for the first two stages and reunite in the third stage to see how we were going, but things worked out differently. Al’s a strong rider and I’ve been lucky to be there at his side.

I think fat bikes are a lot of fun, and they’re very under-rated. Fat bikes are so much more versatile than people think – they’re good for all kinds of terrain, not just sand. I’d much rather ride up and down on the firetrails in the Blue Mountains on a fat bike.

Wheels

Uma IIs

It came with the 80ml Graceful Fat Sheba wheels, which Al and I converted to tubeless. But I wanted to be able to drop the tyre pressures, to widen the footprint as much as possible. So I got some Uma IIs from Speedway Cycles in Alaska. The Uma II has a locking bead, which stops burping, so it is perfect for tubeless conversion.

(Check out Murray and Al’s ‘Fatbike Tubeless’ how-to on Youtube.)

Hadley Fatback hubs.

That’s a US-made hub specially for Fatback bikes. I had to change the front disc alignment and mill off 2mm from the inside of the adapter to allow the disc brake callipers to line up with disc. I did that myself, by hand.

Tyres

Surly Larry 3.7″ on the front.

Surly Endomorph 3.7″ reverse-mounted on the back.

I did a lot of testing – Al reckons I have an obsessive-compulsive disorder – and the reverse Endo gave the best grip on loose sand

We run tubeless to allow really low pressure, which gives better flotation over softer sand. I accidentally lowered to 3psi one training session, and I walked all over Alan on the soft sand at the beach.

Drivetrain

Middleburn chainring

Sram X7 derailleur with a Sram cassette (reduced to an 8-speed for clearance with the chain and tyres).

Pedals

Shimano XT SPDs

Cockpit

Argon handlebar grips. They give more support.

The bike comes with Sram twist gearshifts – I quite like those, actually.

Thudbuster seatpost with a Crudbuster cover.

A big super-soft gel seat

Carrying water and fuel

I had four hydration backpacks filled with water and muesli bars and sugar –snakes and jubes – so when I got to the water stops I just had to pull off the old backpack and grab the new one, and I was ready to go.

And I had one 750ml bidon with Staminade electrolyte half-strength solution, with an extra ¼ teaspoon of salt, to make it easier to swallow in the heat. (Electrolyte solutions can go off in the heat of the desert and riders will throw up if they try to drink them.)

And next time?

I plan to revise my seat choice if I ride that bike in the Simpson again.

Ronn Slusser

Trek Rumblefish ‘the Ronnblefish’

I’m pretty hard on bikes because of my size. I’m a big boy – 6’4″ – so I snap a lot of chains and break a lot of spokes. I wanted a Rumblefish because I thought it would handle my size better. It wasn’t easy, finding one that would fit me – I needed an XXL frame. I finally tracked down the Ronnblefish through My Mountain in Melbourne.

Pretty much everything on the Ronnblefish was stock when I did the Simpson.

Wheels

Bontrager Rhythm Pros (29-inch)

Tyres

Maxxis Ardent 2.4″ tyres, UST

Tyre pressure is the key to everything. I ran 6psi in the front, 8psi in the rear in the sand.

Gruppo

Shimano XT everything.

Pedals

Shimano XT SPDs

Cockpit

Ergon handlebar grips. They’re more comfortable, stop my hands going numb.

Selle SMP Extra seat

Carrying water and fuel

I had two bidons, one with Berocca, one with Staminade, and a two-litre Camelbak with a bit of glucodin that I filled up at the water stations. And I had a snack box on my top bar with honey and Twisties for out on the bike.

What about next time?

The Rumblefish is awesome. But when I ride the Simpson this year, I’m doing it on a fat bike. I’m in the middle of building 9:ZERO:7.

I’ll probably put Surly Black Floyd 3.8″ tyres on it. There’s no grip on them – they’re a road sort of tyre. But in the sand you don’t really need traction, you just need roll-over-ability.

And seat-wise, I’ll use the same one as I had on my Rumblefish.

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