2014 Paris Motor Show highlights

MaynoothBike uses linear fork pedals for comfier ride

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May 22, 2014

The MaynoothBike fork contains linear drive hardware in each prong

The MaynoothBike fork contains linear drive hardware in each prong

Image Gallery (16 images)

Seeking to cross the relaxed-back comfort of a recumbent with a higher seating position, German engineer Christoph Lenz has innovated the MaynoothBike, named after his home in Maynooth, Ireland. In place of the usual bottom bracket-mounted crankset, the dual drivetrain is built into the fork. The linear drive not only creates a more relaxed seating position, it offers some claimed efficiency advantages, too.

Back in 2010, Lenz, an avid cyclist, found himself unsatisfied with the typical cycle options. He didn't like the high saddle or bent-forward biomechanics of traditional bike geometry, and he didn't like the low, long positioning of the recumbent. He began brainstorming, sketching designs and collecting usable parts from local scrapyards, piecing together a bike more suitable to his tastes with some help from a friend with a machine shop. He assembled and tweaked several prototypes, eventually getting a German patent for the design in 2013.

Lenz's design is a bike with pedals mounted to either side of the fork, rather than a circular-motion crankset on the bottom of the frame's midsection. When one pedal is muscled down, the other automatically comes up courtesy of the central pulley. The chain doesn't rotate full circle, but simply moves up and down in reaction to the pedal-connected inner slides. Each pedal has its own chain and set of gears, and each pedal stroke adds momentum to the freewheel sprockets mounted to the front bicycle wheel.

As applied to Lenz's initial complaints, the MaynoothBike's drive allows for a lounge-like seat with backrest. The legs aren't stretched out or raised up, and the rider is more level with traffic than on a recumbent. The rider is also lower than on a traditional bike, allowing him to put his feet to the ground with ease. Lenz has put 4,000 km (2,485 mi) on his MaynoothBike and is convinced that the design is more suited to his tastes than other bike options.

Designer Christoph Lenz enjoys a ride on his MaynoothBike

Lenz also claims that linear motion creates more efficient cycling than the traditional circular motion. His evidence is incidental, citing a race with a friend on a traditional bike and the general view that stepping is superior to spinning.

"The higher performance of a down push of the legs compared to a circular move is well known and documented," he says, without citing any specific studies. "On a step machine you will have a higher performance than on an exercise bike at the same pulse frequency."

By rethinking the drivetrain, Lenz has also created a simpler, more compact frame. Looking through Lenz's photos, it's clear that he's experimented with several different frame and wheel set-ups. The version that appears the most replaces the ubiquitous dual-triangle frame design with a single-tube fork connecting the head tube with the rear wheel and a small rear triangle supporting the seat. Lenz tells us that the most current design uses 20-in wheels in front and back, measures 1,550-mm (61 in) in overall length, and has a 1,050-mm (41.3-in) wheelbase. The seat height is adjustable between 550 and 650 mm (21.7 and 25.6 in), and the handlebars are set at around 1,080 mm (42.5 in).

Of course, while the MaynoothBike works great for Chrisotph Lenz, it's not necessarily for everyone. The linear drive allows for only a single speed, so there's no switching gears when the pedals get heavy or the ride becomes slow. Having the drivetrain built into the front fork eliminates a lot of aftermarket components designed for traditional bikes, such as a suspension fork.

A simple Maynooth design with small rear wheel

They say you never forget how to ride a bike, so we imagine unlearning can be difficult. Lenz alludes to this issue on his website, saying that it can take a little while to get accustomed to the up-down pedaling and the fact that the bike can't be pushed backward. We'd also imagine that the altered biking might open a rider up to different types of muscle and joint pains and injuries.

Lenz doesn't seem all that concerned with how much of a market his design will attract. He plans to offer several levels of DIY build kits, as opposed to working on a production run of bikes. The "build a bike kit" will include the specialized components of the design that aren't readily available in shops. The €490 (plus shipping) kit will allow mechanically inclined bike hackers to build up their own linear-drive MaynoothBikes using common tools and bicycle components, without the need to weld, mill or metal turn. For those that are less mechanically inclined, Lenz also plans to offer a full "bike in a box," which can be assembled within half an hour, for €980 plus shipping.

Lenz plans to offer the 'bike in a box' kit for €980  plus shipping

Lenz launched a crowd-funding campaign earlier this year in an attempt to fund the launch of the build kits. While he fell short of his goal, he received enough interest to pursue the launch and plans to have the kits available within the next six weeks. He also plans to sell spare parts via his website, which is linked below. He has been touring bike shows around Europe to show the MaynoothBike to interested gear heads.

For those that have access to specialized tools and shops, Lenz currently offers a pamphlet with basic information, drawings and instructions. It comes complete with a MaynoothBike serial number and provides access to a community, where users can share information about their builds, ask questions, provide tips on metal workshops and suppliers in the area, etc. That pamphlet is available in both German and English for €15, including shipping.

We're not sure whether or not we'd like the ride of the MaynoothBike more than the average bicycle, but we love Lenz's tenacity in seeing his design through. We also like that he's passing that spirit along to others, fostering a hacking community rather than simply selling a production model for thousands of euros. We hope to cover more MaynoothBike designs in the future.

Source: MaynoothBike

About the Author
C.C. Weiss Upon graduating college with a poli sci degree, Chris toiled in the political world for several years. Realizing he was better off making cynical comments from afar than actually getting involved in all that mess, he turned away from matters of government and news to cover the things that really matter: outdoor recreation, cool cars, technology, wild gadgets and all forms of other toys. He's happily following the wisdom of his father who told him that if you find something you love to do, it won't really be work.   All articles by C.C. Weiss
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13 Comments

Interesting concept, I think it needs a redesigned frame, a drum gearing system could be installed into the front axle, the seat should employ contouring so the rider would have more control in corners, and the list goes on, but it's a very interesting development. I hope he's patented his "linear" drive, because I could see it being used for commuter bicycles.

Neon
22nd May, 2014 @ 05:26 pm PDT

Hmmm..interesting concept.

But those forks look like they are hungry for trouser legs and/or leg skin! Rubbing up and down so close to the fork will surely catch on some material or your skin?

Maybe it would be good for very flat lands such as Denmark or the Netherlands, but the lack of gears would not make it so suitable for any hilly areas.

it certainly looks cool, and would be awesome to cruise through the city (not Sydney, where I live and you'd be quickly killed by our considerate motorists) - but I personally cannot see that it is so practical as a daily commuter.

[climbs into flameproof suit] 8-)

Fantastic Mista Fox
22nd May, 2014 @ 07:14 pm PDT

I like the idea of being seen by traffic while stlll easier to put foot on ground without the almost invisible supine arrangement of recumbants.

As for the single gear problem, any decent e-bike artisan and mechanic should be able to fit a battery pack in that triangular frame's space and fit a hub motor on the rear wheel.

The electronics for speed control have been solved for ages.

The Skud
22nd May, 2014 @ 07:33 pm PDT

He should have checked out Cruzbike as shown in Gizmag: http://www.gizmag.com/cruzbike-silvio-recumbent-racing-bike/13024/ or their own site where they now have multiple variations on the theme, including a folding version. http://cruzbike.com/ The version I have, a Sofrider, is superbly comfortable, has all the advantages Lenz talks about (except the weird pedal system) but uses standard components throughout.

KenM
23rd May, 2014 @ 03:25 am PDT

George Georgiev also sold a semi-recumbent to support his world record racers. The problems with drive systems like this are well known, and I don't see any attempt to remedy them here yet. At the ends of each stroke, the momentum of the leg is not only wasted, but requires muscle power to overcome. A spring can help, but it needs to be variable to feel good over much of a range. Linear systems that use a crank don't have such a jerky "boxing" motion. There are lots of ways to add variable gearing, a very popular option. This bike also forces the rider to hold the steering steady against power reactions, a waste of muscles and a liability for control.

Bob Stuart
23rd May, 2014 @ 04:13 am PDT

I think that is a really nice design. I like how compact it is, easier to store / transport in the trunk of cars. It would be interesting to see how others might adapt the design.

Where I live, it is flat (mostly). With that seat, I can see myself riding around a lot which means I would get a lot of exercise. :)

BigGoofyGuy
23rd May, 2014 @ 05:40 am PDT

There are plenty of single-ratio regular bicycles out there, but if shiftable gearing is needed, it appears the bike could be adapted to use an in-hub planetary gearbox---in the front hub, of course.

Freederick
23rd May, 2014 @ 06:07 am PDT

As the designer claims this is a more efficient way of transmitting the riders effort to the wheel.

The Cruz bike mentioned above uses a rotary crank with its inherent deficiencies this bike uses a reciprocating system; THEY ARE NOT THE SAME.

As a proof of concept it's fine but more work is needed.

Stuart Wilf Wilshaw
23rd May, 2014 @ 08:25 am PDT

I think @Bob Stuart makes good points, and also have to wonder how maneuverable this bike would be if steering forces the pedals to swing sideways (with the fork) as well - what efficiencies are lost when my left leg has to reach further than my right leg during a turn to the right?

f8lee
23rd May, 2014 @ 10:25 am PDT

If you feel the need to be "high up" in traffic and "laid back" try a Dursley-Pedersen. Patented in 1893 but still being made and apart from frame, hammock saddle and handlebars entirely compatible with 21st Century technological advances. Mine is fitted with a 14 speed Rohloff hub gear system and hydraulic brakes. As for comfort; my back thinks it has died and gone to Heaven!

Jaime
23rd May, 2014 @ 12:21 pm PDT

@The Skud,

"I like the idea of being seen by traffic while stlll easier to put foot on ground without the almost invisible supine arrangement of recumbants."

Take a look at crank-forward bicycles, specifically the Rans brand if you want a great mix of performance and comfort, or the more upright cruisers like Day 6 or Electra Townie for lower cost but not as much of either trait.

Gadgeteer
23rd May, 2014 @ 04:22 pm PDT

He could have just got an old high-rise with a banana seat and modified it. Short wheelbase, upright seating position, lots of cushioning (usually) in the seat, and many were available with normal handlebars instead of the "ape hangers".

Gregg Eshelman
23rd May, 2014 @ 06:38 pm PDT

I should state I'm quite OK with unusual (even weird) cycle design - I own 2 Cruzbikes ( and that largely due to the Gizmag article).

But: "Lenz believes the linear motion allows for more efficient pedalling."

OK, but are there any real comparisons?

Still for single gear, round town stuff it might not matter much - if it works well enough, and the rider likes it, then ...

Gannet
24th May, 2014 @ 12:53 am PDT
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