Bicycles

Rungu fat-trike puts a lot o' rubber on loose terrain

Rungu fat-trike puts a lot o' rubber on loose terrain
The design of the Rungu was inspired by trying to transport surfboards across the sand
The design of the Rungu was inspired by trying to transport surfboards across the sand
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The Rungu Juggernaut fat-trike
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The Rungu Juggernaut fat-trike
The Juggernaut weighs 55.8 lb (25. 4 kg), and is priced starting at $2,500
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The Juggernaut weighs 55.8 lb (25. 4 kg), and is priced starting at $2,500
The Rungu Kilimanjaro fat-trike
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The Rungu Kilimanjaro fat-trike
The Kilimanjaro weighs 53.8 lb (24.4 kg), and costs $2,600
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The Kilimanjaro weighs 53.8 lb (24.4 kg), and costs $2,600
The Rungu's steering linkage system allows the front wheels to pivot together
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The Rungu's steering linkage system allows the front wheels to pivot together
The design of the Rungu was inspired by trying to transport surfboards across the sand
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The design of the Rungu was inspired by trying to transport surfboards across the sand
View gallery - 6 images

With their huge, soft tires that allow them to "float" over snow and sand, fatbikes have experienced a surge in popularity over the past few years. Last December, British adventurer Maria Leijerstam took things a step further, using a custom fat trike to ride to the South Pole. Now, California-based Standard Bearer Machines is offering a fat-trike of its own, known as the Rungu.

Unlike Leijerstam's recumbent trike, the Rungu is an upright. While the pros and cons of recumbents versus uprights could be (and are) debated endlessly, the designers of the Rungu claim that their configuration offers better pedaling efficiency than a recumbent. As can be seen in the photos, it's a tadpole trike, in which the single wheel is in the rear. A steering linkage system allows the two front wheels to pivot together.

So, what's the point? Well, the father and son team who developed the Rungu found that when transporting surfboards across the sand on a conventional two-wheeler, stability was an issue. The dual front wheels spread the weight out wider, helping to keep the bike and rider upright. The trike can also reportedly climb up short flights of steps with ease.

That said, while the Rungu might indeed make a good beach bike, its usefulness on singletrack trails would presumably be limited – it looks like the two front wheels might straddle the trail instead of staying centered on it.

The Rungu Juggernaut fat-trike
The Rungu Juggernaut fat-trike

There are actually two models of Rungu. The Juggernaut (above) features fat 26 x 4.7-inch tires all around, and is intended mostly for use on the traditional sand and snow. It weighs 55.8 lb (25. 4 kg), and is priced starting at US$2,500.

The Kilimanjaro still has a fat tire in the back, but utilizes skinnier 29 x 2.5-inch tires in the front, along with 100-mm Rockshox coil spring suspension forks. It's designed more for use on the road or hard-packed dirt, where speed and agility are more of a factor than having a wide footprint. It weighs 53.8 lb (24.4 kg), and costs $2,600.

Both models feature mounting points for accessories such as e-bike kits and overhead racks. You can see them in action, in the video below.

Source: Rungu

View gallery - 6 images
9 comments
9 comments
Michael Crumpton
I imagine that going around a sharp corner or going down those steps at an angle would be a little hairy, with one tire in the air.
Daishi
It's kind of a cool idea but with something like this it seems like they might as well just make a couple small tweaks to the frame to allow for the easy addition of a motor mount.
You could put one above the wheel but not really in the frame like this: http://i.imgur.com/74ShneE.jpg
It's hard to improve on standard bicycle design but motorized/power assist bicycle either fall into the category of really expensive or $130 2 stroke kits sold on ebay that have to be retrofitted like the one in the picture.
If there is any place for new ideas to disrupt bicycles its probably there. With the skill, talent, and resources spent refining bicycle designs stuff like this bicycle: http://i.imgur.com/MhgAPal.jpg shoudln't represent the best powered cycling product on the market.
Maybe the answer is a factory bicycle platform intended for after market motor mounts that can support a power plant of choice, maybe it is a slimmer 2 stroke engine design, maybe its something else but if I want a power assist bicycle there is no reason my options should be either some $4,000 proprietary e-bike or a garbage $130 product I buy parts for and assemble from eBay.
I want to see a company (like this) build a platform intended for powered bike hobbyists to use. Use standard mounts etc. and let teenagers in their garage mess around with trading parts and souping up off the shelf engine kits (gas or electric).
You know, stuff people haven't done since my parents were kids.
Rehab
Add a rear hub motor and this is a great off roader. The price is reasonable. Good Luck and nice work.
Doc Rock
I don't see any leaning mechanism.. All front dual wheel trikes (the motorized kind) have a leaning facility .. without it you'd be lucky to top 10 MPH withoutserious stability issues.. What's up, then?
JR
Tried riding a bike with tires like this on a beach in S. Florida. Absolutely did not work. I think you would need 8" wide tires, as on a Hanebrink, for serious sand work.
Walt Stawicki
totaly agree michaelc. that is my project, but some preference to beefier and cheaper m.c. parts like breaks. my plarform would be wider with a solid axle ala fors model t, so there is cornering. think the old morgan from brittain. i plan a two passenger with room for babby and groceries. it it a true pedal machine to replace the car, license, insurance, tabs and all. disrupt, dont go backwards or accomodate, dont settle for less utility. waltinseattle at gmail drop me a line.
Marie Autrey
I can't agree that the video shows it 'in action.' Seems kind of stilted, like it's too wide to lean and too narrow to stand up. Oh, and by the way, an upright three-wheeler with two wheels in front is called a Welsh trike.
Slowburn
That narrow stance is really going to limit the speed it is safe to ride at.
unklmurray
Doe Rock,I own a trike that has no leaning ability,I built it B 4 the leaning ability was ever around and I get about 20-25mph human power alone..... And Dashi,the 2stroke engines have been outlawed in most western states but you can get 4stroke engines that are about the same size,After I stopped carrying children on my trike I added a 48cc 4stroke engine to the bottom bracket and now I cruise at 30-45mph depending on where and if I think the cops don't care.........LOL :-)