Design: Lessons from the One-Off Titanium Travel Bike to be Used in the Morph

2010 Photo of Bill Warner on the One-Off Titanium Travel Bike in Miami, Florida (not so warm)

This post will outline some of the abilities of a special purpose bike I helped design with Mike Augspurger of One-Off Titanium. Only one of these bikes was ever made, but it is truly fantastic, and it powers my travel all around the world. With it, I can travel with a wheelchair for indoors, and my small, nimble, and lightweight Travel Bike for outside, and many inside travels.

The Travel Bike weighs only 34 lbs. It fits easily, with no disassembly, in a minivan.

Pop the quick-release wheels off, spin the coupler, fold the bike seat down, and presto - it fits anywhere, including behind the last row of seats.

With the bike disassembled (which takes minutes), it can go through the luggage system. I protected it here due to an old gear shifter that was really fragile. It eventually broke anyway, and the new shifter hub is really tough and requires no bubble wrap.

On full-size aircraft, I just fold down the seat, and give it to the baggage guys. It goes full size, and comes through ready to ride. I've done this maybe 50 times or more with various handcylces over the years.

Discussion

The Morph will borrow many characteristics from the Travel Bike:

1. It will use the same coupler. This is a proven device, and its great. It does require a steel main tube - it cannot be mounted in aluminum.

2. The seat will fold down - just like the Tavel Bike.

3. The wheels will be quick-release - But better than the Travel Bike because they will use a different design that will clamp tightly into place.

We expect that the Morph will come in around 40 lbs. Just six pounds more (or so) than the Travel Bike, and full 15 pounds lighter than non-morphing handcycles I built in the 1980s.

Design: Making a Better Quick Release Wheel for the Morph

Pictured above is an example of an "over-the-center" cam-lockiing clamp. You find them on many parts of a bike. This one is meant for the seat post, and it's a fancy one selling for $45. They are a great way to cinch a tube. They are fast and reliable, and available in many price levels.

An example of a typical quick release wheelchair hub - with button activated removable axel (which can separate and get lost!)

Because the Morph is made to be part one's everyday life, it needs to fit in a regular car - in the back seat, in the trunk, etc. One can't require a van if you've ridden far at night and want to catch a ride home with a friend.

So, the Morph makes it easy to fit into small storage spaces three ways:

1. Main Tube Coupler - this is a fancy piece of stainless steel magic made in Switzerland. It lets us make the 2" main tube break in half with a spin of the collar. 

2. Fold Down Seat Back - This reduces the height dimension by about 10" (my guess)

3. Quick Release Wheels - The wheels pop off really fast. No tools. 

The problem is that standard quick release hubs are pretty darn bad:

1. They Wobble - The hubs never fit that well because the removable shaft relies on a perfect fit into the receiver.

2. The Axle is Separate - You can loose it. Just push the button, remove it from the hub. Drop it down a sewer. Your week or month is ruined till you get a new one.

So, Graham has proposed a very simple design: 

Use a fixed axle with a smooth shaft. Put a cam-lock clamp on the receiver on the Morph. Presto. Instant quick release. No wobbling because the cam lock grabs the axel really tight. The axle is fixed and you can't lose it.

These three elements should provide a very fast breakdown of the Morph into a small size in no time.

Seat angle tests - is 90 too steep?

From graham butler: 

I have attached pictures of the seat with the 3 angles that we talked about.

Conclusion:  sitting on it 110 is definitely a nice low rider position.  With this particular handcycle I end up too far from the cranks.

I definitely want to be more upright for high rider.  90 is too upright, but I think that 95 will be quite comfortable for high rider.  It feels upright enough to be good for interacting with people.

Backpedal Brake: Post 3: "Deadman Release" and Bumper

[From Graham Butler March 15, 2011 Input from Bill Warner and a mechanical engineer in at a Cambridge rotary compressor company who suggested the "deadman switch" idea like on a chain saw.]

I just got back from Brazil at the end of last week, things got hectic the last couple of weeks before leaving.

I think that the last we left the design, we had talked about a 'deadman's switch' for the brake release.  It makes sense.  Check out the attached screen shots of my first hash.  It is very simple.

Talked to Seth today.  We are getting material ordered so that he can build front forks.  I figured that while some aspects of seating might change, it is very unlikely that the front fork geometry would change substantially.

Seat Angle Dimensions

[From Graham Butler February 16, 2011

Here are the screen shots of the seat vs base measurements.  SolidWorks takes the smaller angle as default to the actual seat angle is 180 less the measurement.

 

We're worried that the seat angle is too acute in high rider mode.

Low rider mode seat angle is 109 degrees, same as Bobby Hall bike.

Morphing Handcycle Reference Design V1 Released

 

 
Morphing Handcycle Reference Design - Low Rider, Side View
 

 

 
Morphing Handcycle Reference Design - High Rider, Side View

Move With Freedom has been working on the design of a practical Morphing Handcycle for a few years. We are now at an important juncture where we switch from the design process to that of helping the product get into production.
 
Move With Freedom makes open source designs. The design process can be traced right to its beginnings by looking at the posts in this blog: http://morphhc.posterous.com.  You can see a movie of the Morph in action here.
 
Our designs are free and open to anyone who wants to use them. At the same time, we want to encourage manufacturers to add value to our designs and put them into production.
 
So, today we are announcing two important developments:
 
1. Availability of the Morphing Handcycle Reference Design V1 (PDF)
 
2. Move With Freedom, Inc. has placed an order with Intrepid Cycles for four production Morphing Handcycles, 
 
If you would like to design your own production versions of the Morph, we are ready to help. Just ask for what you need.
 
What follows are some illustrations from the document:
 

 

 
Morphing Handcycle Reference Design - Schematic of Key Components
 

 

 
Key dimensions are provided for all schematic parts.
 

 

 
Automatic Seat Tilt Linkage is explained.
 

 

 
Calculations for the Adjustable Lift System are provided.
 

 

 
A detailed design for the morphing pivots is proposed.
 

 

 
Dimensioned drawings are provided for all key parts. (This is a partial view)

Here is the Morphing Handcycle Reference Design V1 (PDF)
Note that you can download this document by clicking the link at the end of the post.

 

Backpedal Brake: Post 1: Arms and Pins

[From Graham Butler January 31, 2011]

(Editor's note: We began a series of designs aimed at allowing the backpedal-activated brake to be released so you you can ...for example... back out of an elevator without having the brake come on. This was the first of many designs, which we document for posterity...on Posterous.)

OK, so I have been going backwards and forwards all day with the rollback brake system.

I started with a counter cam to relieve the cable tension.  I think I have a system that would work.  It will engage when pedaling forward only and disengage manually.  I have attached screen shots.  My problem was that it seems very cumbersome and hard to fabricate with tough angles and lots of small parts.  It seemed to me that a simple pin system would be much more reliable, and easier to fabricate.  Screen shots are attached.

Goal is to have foward pedaling re-engage the brake.

 

Photo: Bike-On Backpedal Brake

[From Rory McCarthy November 23, 2010]

Check out this offered by Bike-On on their website
"This is the prototype design of the reverse brake. We've enhanced it so that it can be de-activated to allow for rolling backwards (doing a 3-point turn for instance) without the brake stopping "