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Now a few years in the making, Kate Leeming is still preparing to become the first person to pedal across Antarctica via the South Pole. Originally scheduled for the winter of 2015/16, ‘Breaking the Cycle South Pole’ has been postponed until winter of 2017/18. When we last checked in with Kate, she had just taken delivery of the first Christini All Wheel Drive fat bike prototypes. After getting out of the bicycle business to focus on AWD dirt bikes, Steve Christini mentions it was at Kate’s request for an AWD fat bike that got them back in the bicycle building mindset. After building up the first prototype with parts left over from their mountain bike days, that first bike was split rail design with a solid drive shaft from the rear axle to the head tube. The design worked, but the frame was limited to 4″ fat bike tires.

In order to help Kate accomplish her goal of becoming the first person to pedal across Antarctica, Christini developed a new frame capable of running 5″ fat bike tires which becomes important with constantly changing snow conditions across the entire continent…

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Whether 4″ or 5″ compatible, both frames operate the AWD system by transferring drive from the rear hub to the drive shaft with a bevel gear system on a custom Carver hub. At the head tube, another bevel gear drives a small drive shaft that then drives a step over chain that spins another driveshaft that then transfers power to the front hub with another bevel gear system. Interestingly, the custom fork lacks a traditional steerer tube since the gearing system occupies the needed space so there is an external brace to hold the two ends of the assembly together.

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The 4″ fat bike frame was able to make due with a solid rear driveshaft since the smaller tires would clear the seat stays. To enable 5″ tires to be run though, Christini had to redesign the entire frame. The new system makes use of universal joints to angle the driveshaft in at the seatstay/seat tube junction and allow clearance for the rider’s legs while pedaling. It also made the switch from a 170 to a 190mm rear hub. Compared to her initial 4″ split frame bike, the new 5″ tire version only added about 2 lbs, with a claimed weight of 33lbs for the 18″ complete.

Along with standard drivetrain versions, Christini will also be offering both the 4″ & 5″ tire fat bike frames with the addition of 1000W mid-drive electric motors with a 48v battery.

Kate seems to be getting along well with the new bike during testing in Greenland, but demonstrates the need for AWD in soft snow conditions. Even with the new bike, this certainly won’t be an easy task to pedal across Antarctica, but if someone can do it – Kate certainly has the determination and the skills. In addition to selling the first fat bike completes through the Kickstarter, Christini will also be helping to support Kate’s expedition with proceeds from those sales. Pricing starts at $4,995 for the AWD 4″ Split fat bike, or $5,995 for the 5″, and goes up based on builds.

Kickstarter.com

ChristiniBicycles.com

KateLeeming.com

20 comments

  1. Ol'shel' on

    I’ve not ridden one, and maybe someone can comment, but the flex and wind-up of the shaft going to the front seems like it would result in delay and jerking when the rear slips and load is transferred to the front wheel.

    I wonder what the efficiency difference would be between these and something with a short rubber track.

    Reply
  2. dave on

    How is this company still in business? I’ve been seeing these Christini bikes at trade shows etc for literally decades, never actually seen anybody riding one.

    Reply
  3. Cryogenii on

    So this is a bike with torque steer? I mean there is going to be a reaction force on that gear in the steerer.

    Also what happens when grit gets in the exposed bevel gears at the hubs?

    Reply
  4. ChknBreast on

    I’ve owned one for many years. It does work as advertised. There is absolutely no wind up since the AWD system consists of shafts not cables. Steve has been a pleasure to deal with, still supplying me with parts over the last 10+ years. Their bread and butter are the motorbikes they make.
    The headtube/fork steerer setup has worried me over the years, but it has never failed me. It’s not the first bike I’d grab when rides are steep with gnarly descents. The fat bike version certainly interested me and I probably would have ended up with one if I wasn’t so impatient. I bought a Rocky Mountain Blizzard back in March and haven’t ridden any of my other bikes since (Sorry Steve).

    Reply
  5. Ryan S on

    Who else remembers the AWD/2-wheel drive system that made cover of Mountain Bike Action in the early 2000’s? Can’t remember the company, but it was retrofitted on a Specialized FSR.

    Reply
  6. Dylan on

    Armchair engineer alert – that external brace design looks a whole lot less structurally sound than a dual crown fork would have been, for no discernible advantage other than adding to the Heath Robinson vibe about the bike.

    Good luck to her, and I know this is BIKERUMOR.com but I can’t help thinking there’s a reason why snow shoes were invented, and that it would make a whole lot more sense to carry a pair and push the bike up hills when traction becomes marginal. Alternatively, a climbing skin as used on skis should be relatively simple to design which would boost traction from the rear wheel to at least what you gain by adding drive from the front wheel. Either way, it’s not like every inch is going to be ride-able anyway, even with superhuman stamina – just look at the effort it too her to climb a fairly benign slope in hard-pack conditions. Everything I’ve learned about expeditioning (not all of it from the armchair, much from personal experience, some from friends who have biked the length of the Americas or across Australia, acquaintances and colleagues who have climbed and guided 8000m peaks or set hard new routes on 6000m peaks) suggests that the more extreme your environment, and the more ambitious your mission, the more you need to KISS.

    Maybe there’s a distant cousin to this contraption on skirumor.com, where someone is planning to ski across Africa along the equator, and is finding ingenious ways to decrease traction on the long stretches that aren’t snowy?:)

    Reply
  7. Q Well on

    I hate to say it but those aren’t hills or snow soft enough to slow a normal fat bike down. Smooth out the pedal stroke and she would do much better on a normal one than that. Her bouncing around is breaking the tires loose.

    Reply
  8. Jeff on

    hope they do good research on the proper grease, I wintered at the South Pole and have seen what happens to geared devices when grease is used that is only designed for only 0F

    Reply
  9. patrick_ on

    it is just ridiculous to use this bike with a normal drivetrain
    if you really need such a bike you would go for a pinion gearbox or a rohloff hub and you would also use a belt (conti or gates)

    Reply
  10. Mr. P on

    I know a rider who had a 2wd bike in the high Sierra in winter and raved about it. “Yes, it works very well” is what he said. And he later went on to the Ride Divide (but on a single speed).

    So I do have to wonder about the commenters who have not tried it, what level of ego are you on to say what works and what doesn’t?

    Reply
  11. Walt on

    The bike will make it…if she has the quads. Her biggest problem, by far, will be route finding. Antarctica is heavily criss crossed with crevasses. Many are hidden under the snowpack. You can literally break through at any time and fall 3000′ and become entombed eons.

    Reply

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