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Sunday, February 26, 2012

Starting the Monsterbike Open Source Hpv Project

Monsterbike near Melbourne's Yarra River


This posting introduces the open source bike plans for my long wheelbase bike.  Without further adue, the plans are available in pdf form for free here. And here is the free dxf file of the plans.  Blog posts which could lead you horribly astray but containing a ramshackle description of my bike building process start here

Note that I have appied for some patents relating to this bike design.  At the moment I have no plans for commercialisation.

The plans which are now free were previously available as an online extra content when you bought my book.

I propose calling the bike Monsterbike.  Coincidentally, this gizmag report links to a video called "Monsterbike" and the machine is described as "Monsterbike, the modern day Penny Farthing".  My bike could be just that!  (See footnote.)

For about 6 years I've built and ridden bikes of this style around Melbourne.  The bikes have good load capacity and handling, are aerodynamic and quite fast.  Some videos showing the bikes in action are here, here, and here.

My own versions of the bike have included bikes with cloth fairings, wooden bikes, bikes with aluminium castings, and separable bikes.  But up to now my best success has been with a fairly simple chromoly steel construction.  I also have some aluminium beam frames on order!  While I firmly believe that the bikes are good, I don't have the time and resources and will to develop (say) versions of the bike in carbon fibre and aluminium lug construction, which could be slightly lighter than my current bike builds and really go much faster than the Sunday roady crew on Beach Road Melbourne.  But I'd love to see someone else build it!

I plan to expand the range of my plans available as open source and welcome your input on what would be a good forum for discussions on the topic of these bikes.

If you're keen and live near Melbourne you can borrow one of my bikes and learn how to ride it.

These are the general design principles for a Monsterbike. Not rules just guidlelines. 

* Front wheel drive, fixed botton bracket, recumbent bike with 700c, 26" or  24" front wheel and 20"rear wheel.  With a 700c wheel, the chainstays are parallel to the main frame as shown in the photo above, with a 26"  or 24" wheel, the chainstays are parallel to the ground as shown in the plan.  (This leads to a)
* Sloping main frame tube at about 20 degrees to the ground.  This geometry means that a hole for the steerer tube drilled at a simple right angle through the frame will provide the right geometry for bike stability using standard geometry bike forks. I can ride my bikes no hands but not while pedalling.
* The small back wheel allows a simple tailbox to be built onto the bike. (The rear wheel does not bisect the tailbox.) This tailbox adds visibility, storage capacity and aerodynamics to the bike.
* The seat height is about 600mm allowing for good visibility in traffic and easy stops and starts. 
* Direct front wheel drive, 8 speed derailleur gears with no pulleys guiding the chain

* The general ride quality relies on rear suspension.  Having a large front wheel with good inate suspension characteristics a long way from the rider means front suspension is not required.
* On some of the bikes like the one shown above I use an inertia braking system, turning the brake handles toward the rider, and allowing the natural forward motion of the rider during decelleration to help activate the brakes.  Also on the bike shown above there are 2 brakes on the front wheel - this simplifies the bike and also makes it easy to put a home made or other wheels disk on the back wheel.  No rim braking required on the back so the rims can be covered by a wheel disk without fuss.
*  These bikes work just like any fwd fixed bottom bracket design, that is, the chain comes from somewhere near the steering axis before it goes to the front wheel.  So when the steering twists, the chain twists too, but doesn't actually displace much.  Standard rear derailleurs mash up the chain in a horrible way during gearshifts, so this drive compromise doesn't worry the bike much. You can either have the chain quite close to the steering axis like some front wheel drive bikes with pulleys, or this bevo bike,8669 or limit the steering during pedalling in some way.  I have trouser guards or outside catcher rings on the chainring and limit the steering during pedalling by having my knees inside the steering bars and it all works.

Developements I'd like to see are versions
* with a main tube made from commercial carbon fibre tube stock and
* with standard 24 speed gears (I haven't developed front / top derailleur gear arrangements for the bike to date.

Thanks, Regards

Stephen Nurse

Footnote: My bike is rather big, so the name Monsterbike suits but equally important, the name begins with "MO".  It might be dumb pointing this out but the first two letters of my website name "Modularbikes" are Mo. Recently I came home with some stickers from a vintage bike market which were "Monarch". I promptly used them on my bike. Monarch is a rather stately and old world name for a bike but it did get me thinking that I could name all my bikes "something beginning with Mo".

Saturday, February 25, 2012

A survey of open source recumbent bike and hpv projects


Shortly I will be posting a pdf of my recumbent bike plans on the internet.  To aid discussion I've prepared some links to existing open source or interesting hpv concepts and projects.

A modular bike project using aluminium extrusions as the basis for a range of bikes (from Thibaut Solloignon in France) is reaching an interesting stage, here are some links: Bulletin Board Posts
Crowd Funding:  (Added April 9, 2015)

The AAZZAA project contains open source plans for a recumbent trike.  Plans are quite detailed and there are links to suppliers of various trike parts and services as well as a guide to obtaining free 2d and 3d cad software.  Some parts look quite complex. (Added Mar 15, 2015)

PVC Pipe should make an interesting and not much explored material for recumbents. The pipe comes in different sizes and glues together very easily with a large range of accessories intended for plumbing application like reducers, joiners, tees, thread adapters, elbows and couplings.   Some examples of recumbent builds are here (pipe and gaffer tape python recumbent) and here (mockup for bamboo trike, which seems to include some very fine building techniques)
     PVC pipe and sockets seem to be incredibly cheap and easy to work with and the idea of building bikes from it only came to me after working on a pump shed at work, making up and connecting pipe fittings.
     Because it is so simple, the technique lends itself to large scale recumbent builds (including surrys / pedal cars all the way up to a recumbent Porsche) and bike accessories including parking stands, luggage racks, fairings and repair stands.  I have mentioned making bikes from plastic pipe to one of my bosses at work. He has a grudging respect for my wooden bike but is completely horrified at the idea of a plastic pipe bike!

Peter from the Netherlands is posting some interesting material about building a laminated wooden recumbent here (added Feb 2014) is the site of a Russian group I stumbled across via Youtube.   An interesting modular trike concept. They have a great footbrake on the trike, its interesting to see the suspended seat in action, and possibly most amusingly, their video has incredibly cheesy music! (added Feb 2014) and associated web pages like relate to the PYTHON low-racer centre-steer recumbent bike.  Lots of projects listed and photographed.  Its easy to remember and find a name like Python! (Since initially writing this post, I have posted a new Monsterbike page off the main Wiki page. ) seems like a great website, it is gently commercial and works on collaborative principles.  Some great designs have come out of this site and an email to me from Rick Willoughby got me thinking about the collaborative approach to bike improvement.

The Tin Lisa Project shows a simple recumbent cycle but  there are no sign of any plans being available. is devoted to one form of recumbent delta trike.  Lots of features like discussion groups. shows pictures of modular trikes and accessories and cargo trikes made from the aluminium tube common as a sort of Meccano set for building conveyors and other engineering machinery  .  There are no plans for the trikes that I can see. The group's home page is one of the most underwhelming I have seen but seems to bounce off to a range of interesting ideas regarding recycling and low-tech or no-tech construction. (2 Nov 2013) Although this link to "Mindbike" does not include any bike plans, the site is very interesting in that the bikes shown illustrate what can be done with a custom extrusion design in a compact format bike. Some of the modular possibilities of the bike are shown on this page.  Mindbike is from Japan.

Instructables, seems to be a rich source of recumbent bike plans and discussions with several many bike builders contributing.  And how could you resist this: "What could be more practical than a bicycle that doubles as a pencil?! "  Users pay a small fee to be able to download plans (pdfs) of bikes, trikes and probably just about everything else.

Atomic Zombie has a blog supporting its business of selling bike plans and its home page links to a wealth of bike building ideas,

The setup for discussions and postings at Xtracycles is a link to a yahoo discussion group via the Community / Roots Radicals menu selection.

This link leads to a range of recumbent bikes and trikes and parts designed in 3d cad programs such as Solidworks.  Not sure if the plans are immediately useful unless you have Solidworks or a similar 3d cad program.  As well drawings, practical descriptions and photos are the things that most people need to start building a bike, I don't think grabcad provides this.

This recumbent share page contains an extensive variety of homebuilt recumbent bike projects.

Evolve Trikes founders Eric and Alan Ball posted some plans for their early trikes and bikes on the net, jump off from here.
Here is a report on eventual closure of the Vicnet site where these plans are posted.  The same link includes links to plans for my own "Zeica" bike.

Two articles about velomobiles are near the bottom of the articles on this page of  the Australsian Transport Research Forum site .  Rather wordy articles, and not much in the form of actual plans, but some interesting ideas are discussed.

There is a wealth of material available from the Wisil site.  Jump off from here.

(March 10, 2013) My latest wooden bike bears some resemblance  to the 2 x 4 lowracer.  Plans for this bike are for sale through James Robinson.  There are several versions of this bike documented on the internet:

Peter from the Netherlands is posting some interesting material about a lowracer build here (added Feb 2014)

Nick has a version on his Ligneus Bikes site,
The marvellous XnTRICK cycles has a version here.

(Nov 2, 2013) After some correspondance with Paul Needham about bikes, he sent me this link .  There seems to be quite a lot of information there and Paul had used Edgar Atkins work as a basic reference for bending plywood for recumbent seats.

(4 Feb 2014) A google image search found me looking at this blog page  .   This trike is by Lothar Kochtokrax, its one of many shown on the site, which also includes descriptions of several home builds, tips on building with corflute, etc. etc. etc. A very good resource

Thats it, I'll be posting a link to my bike plans in the next post. Regards Steve Nurse