2016-01-02 First Frame Design from Cody

Cody provided the first pass at the Electric Handcycle, as shown in his email below. It is interesting to see how he approached, which I think is better than what I did in my Sketchup experiment with Geoffrey. While we both used a 55 degree head angle, Cody fixed the trail at the same as the Travel Bike. In my Sketchup model, we used 55 degrees, but also set the pedal offset at 4”. Cody let the pedal offset float as needed. See the end of this blog post to see why Cody’s method is better.

Hey Bill,

I was able to spend a little time today on the handcycle.  

Anyway, I set out to start to get the geometry of the electric handcycle to start to make sense and see how everything fits together and relates.  I started with the travel bike and started with adjusting the geometry for a 20" wheel.  I decided to keep the following constant:

 - Head tube angle (55 degrees)
 - Amount of trail (.981 inches)
 - Wheelbase (50.375 inches)
 - The position of the pedals in relation to the position of the seat
 - Seat height off of the ground

Everything else was up for adjustment.
I found that as I moved the front axle up (necessitated by the larger front wheel) the pedals moved forward.  So, the seat moves forward as well to maintain the same relationship.  This has the added benefit of putting more weight over the front wheels which should help with traction.

To maintain the same amount of trail, the headtube/steerer offset changes to a little under 5 inches.

You will also notice a little L-shape near the bottom, these are the footrests.  Since we didn't take this geometry from the travel bike, I took it from the NEH.  I think it will be important to have that in the model to determine how to place the miter in the main tube.

Moving forward a little bit I roughed in some tubes, using the same diameters as the travel bike.

I found that the miter in the main tube is probably going to be a requirement.  Since the increased front tire diameter would otherwise increase the height of the main tube by almost two inches, it would be very difficult to get your leg over the main tube if it were not mitered. I just kept the main tube horizontal in this version which works well aesthetically I think.
If we were to use a continuous main tube, rather than a mitered one, this is what it would look like.I would imagine this gives it more of a rakish look than you were going for.
I also know you didn't want a bent main tube for aesthetic reasons, but it was easy enough to model it, so I made a quick version like that

Probably difficult to get a good idea at this point but as we get more detail in there with wheels, crank, etc. we can play with these things some more.

Next up, I'll be going to the shop tomorrow so I can get some good fork dimensions and start to design the whole pedal/steerer assembly in a bit more detail.

Let me know what you think so far.

I went into the Sketchup model from the prior post, and extended the head tube axis to the ground. Somehow I thought we’d have very little trail, but in fact with the Sketchup model we have 2.2 inches of trail, which is becoming more than we want. Even as much as I’ve been thinking about this, my mental picture was 180 degrees off. Having a smaller pedal offset will INCREASE trail because it pulls the head tube up, and thus makes the extension of the steering axis hit further ahead of the contact patch, thus increasing trail.

Requires Sketchup 15.  Download here:  http://www.sketchup.com/download

2015-12-31 Parts and Assembly Database Using Quickbase

We're still at an early stage of the design for the Electric Handcycle. Many design choices depend on the components being used. So I started a database of components being used, and how these components fit together into assemblies. The fabricated components will eventually get drawings, and these will be accessible in the database as well.

Click here to see the live status of the Parts table in the database. It will open in a new window. Note that these parts are only an intial cut at selections. Ted and Cody and I are going to take a new pass through the components soon. 

Note that you can click around the database all you want, but even if presented with a button like "Add Part" it won't let you. It might say to ask for permission, but we have to restrict editing of the database to those on the team. So view all you want, but please leave any editing buttons as they are (strangely, Quickbase doesn't let us take away all the buttons that Web viewers should avoid.)

This a screenshot of the Assemblies table in the database. Again, as of this post, these are preliminary. But if you click on this link much later than this post, the state of the database might be more reflecting of the actual plan (or even the reality.)

And here is the Vendors table from the database.

This is a look at a Part Record for the Front End Assembly. Parts and assemblies are handled the same. Parts can contain other parts, and then we call them assemblies. This screen shot shows some of the parts in the Front End Assembly AS2-1032

2015-12-29 Initial Sketchup Model for the Electric Handcycle

This post will review an initial Sketchup model for the Electric Handcycle. It is based on measurements made at our kickoff meeting. Mostly, we'll use the design parameters of the Travel Bike, but with a 20" instead of a 16" wheel.

This model was made using my instructions by:

Geoff Bostwick


303 919 8131

Note that the real design is being done by Cody Wojcik using Solidworks. This model is for visualizing the machine. It's reasonably accurate, but not at all suitable for dimensioning parts like the Solidworks model will be. Still, it is efficient, because Geoff made the model in 90 minutes based on my instructions over a Skype screen share. I had previously searched for lots of bike components, so we were ready to move quickly.

Key parameters for the Electric Handcycle:

Overall length: 72"

Front wheel: 20"

Head tube angle: 55 degrees

Pedal height: 39 inches

Pedal tube offset from head tube: 4 inches

Rear track between tire centers: 24.5 inches

With these parameters, Geoff and I were able to collaborate (with him driving Sketchup) to make the model
Side view. Overall length, tip of front wheel to tip of back wheel is 72"
Front view. Width is 24.5" to the center of the wheels. Overall width including the hubs will be a few inches wider. This width is from the NEH bike, which has a wider track. That bike is 28" wide overall, compared to 25" wide overall for the Travel Bike. But the travel bike has a major focus of indoor use, and those extra 3" matter a lot. The Electric Bike will also go indoors, but will be focused more on outdoors and speed. So an extra few inches of track width gives better stability.

The electric motor will be supplied by Bionx   This is a 350 watt motor that runs at 48 V. It is supposed to perform well without much drag if you are paddling on your own. It is an assist-based motor system that multiplies your own energy.
The Bionx kit shown with a 26" wheel. It can also be mounted in a 20" wheel.

An earlier post showed the gearing range of the NEH vs Travel Bike. The NEH has a much wider gear range due to an intermediate derailleur. The Electric Handcycle will also have an intermediate derailleur. We're hoping to use a 9 to 44 tooth derailleur used on mountain bikes that use a single chainring.

Click the link below to download the Sketchup Model. It was made using Sketchup 2015.

Click on the link above to open the Sketchup model (made with Sketchup 2015)

2015-12-27 Electric Handcycle Gearing - Excel Spreadsheet

The New England Handcycle (NEH) is on the left, and the Travel Bike on the right. The NEH bike shown here was built in about 1982 by my company, New England Handcycles. It built handcycles in the basement of my house in Brookline, from 1980 to 1990 when Chris Hager, my frame builder and partner, moved to Africa.

The NEH bike uses a two stage drive, using two clusters. The intermediate cluster is circled. The Travel Bike uses an 8-speed internal brake hub. 

The following chart shows the existing gearing on both bikes, and a proposed gearing for the Electric Handcycle:

The key figure to look at is the right hand column. The Full High Gear Inches. The NEH bike high gear is 82 gear inches. For each turn of the pedals, the bike will move 82 inches times pi (to get the wheel circumference). This about 21 feet per pedal revolution, and about 21 MPH at a cadence of 90. This is fast enough for gentle downhills, but on a big downhill, you begin to wind out.

The Electric bike is proposed to have the following gearing:

Upper Chainring: 25t

Intermediate derailleur small cog: 9t
Intermediate derailleur large cog: 44t

Intermediate drive: 24t

Front derailleur small: 13t
Front derailleur large: 36t

This yields a full high gear of 106, and a low gear of 7.8 gear inches. This low gear is lower than both existing bikes, and the high gear is higher. But this is done in large part by using a pretty extreme 9-44 cassette at the intermediate drive. We’ll see if that really works out.

This photo shows the chain draping over four gears in the intermediate cluster on the NEH bike. Also shown is the chain driving down to the other cluster at the wheel.

On the NEH bike, we used an old freewheel and rearranged the cogs so we have four drive cogs (13 to 38t). A fifth cog with proper spacing is used to drive the next stage gearing at the hub.

Pardon the viewer image below. It does a bad job showing the Excel spreadsheet. Better if you click the download link after the viewer and view the spreadsheet directly in Excel.

2015-12-20 Kickoff Meeting and Video - Measuring the Past to Build the Future Electric Handcycle

This video shows Ted and Cody riding my two main handcycles. The first one is called the Travel Bike. It is a lightweight, narrow handcycle that comes apart and is perfect for travel. The second handcycle is my everyday bike that I keep at home. I’m mainly seen running my two border collies with this bike. That is my bio-assist version. 

The kickoff meeting was held at Wojcik Cycles on December 20, 2015. Our main goal was to make detailed measurements of both existing handcycles and be able to design a new bike using the best features of both.

The Travel Bike getting measured. Notice the silver coupler in the black tube. This is a stainless steel S&S Coupler http://www.sandsmachine.com/spec_ssc.htm that allows the bike to break down in minutes and fit just about anywhere, including the back of a Fiat taxi in Italy.

We measured the head tube angles and the steering trail. This illustration shows that the travel bike has just a little bit of trail. We’ll probably use a similar head tube angle (55 degrees) and trail on the Electric Handcycle, but we’ll use a 20” wheel.

Measuring the trail on the New England Handcycle. Again, the trail is small…a few centimeters.

Ted Wojcik (left) and Cody Wojcik (right) with the tools of the day. We got all the key measurements made, and Cody started a Solidworks model of the geometry of both existing bikes.

2015-12-27 The Electric Handcycle Design and Build Vendor - Ted Wojcik Cycles

The Electric Handcycle project formally got kicked off when I visited Ted Wojcik cycles and worked with Ted and his son Cody. Ted is a long time framebuilder and Cody is a mechanical engineer. Between the two, they have plenty of talent and experience to build a great machine. Ted has made all sorts of bikes, and has worked with electric bikes for years. Cody has worked on drones, so he know electric motors and mechanical design.

4 Wilder Dr.
Unit 10D
Plaistow, NH 03865

phone: 603-479-3799 - Monday-Friday - 9am-5pm EST.
email: tedwojcik1@comcast.net - anytime!

Ted’s shop is in a modern industrial park off of Route 125 in Plaistow, NH. Its a big shop, with easy wheelchair access, and plenty of room in the shop and offices.

Ted has a full shop, lots of machine tools, and full welding ability. I asked if he could weld titanium. Ted said (and I’m sure he’s said this before) “The only thing we can’t weld here is a broken heart or the crack of dawn.” Good line. I do think we’ll be using some titanium on this project.

Ted and Cody at the front door.

I look forward to working with both of them. I believe that an electric assist handcycle will let me keep up with able bodied riders, even when climbing hills. This will mean I  can go out with able bodied cyclists and spend more time riding and having fun. I’ll get more exercise, even as the motor provides an assist.

Video: Morph Tests and Punch List

This video shows a detailed test of the Morph 4's morphing ability, along with videos showing six items that need to be updated on this bike and on the subsequent 5 units that we are building.

Overall, it works very well, and the most difficult item -- morphing -- works really well. But some of the issues are significant and make riding difficult. The main issue is the seat tilts forward in high mode. This is due to an interference in the automatic seat adjuster, and it will be fixed on the next unit, and hopefully retrofitted on this one.

Here's the punch list:

1. Seat tilted down in high mode.

2. Pedal post clamp too weak - pedaling forces let the chain tension get too low.

3.Cable fraying on the centering spring support (minor issue)

4. Front end holder - how to keep the front end stable when released when getting on the machine. (turns out when the footrests are far enough forward, it will stay put)

5. Parking brake too weak - You need to put a lot of forward force on the front wheel when you morph up. The current parking brake actuator isn't strong enough.

6. Crutch holder - needs to to be much easier to load and secure the crutches.

Overall, not a bad list. I hope to take the Morph for some real rides soon.

A couple other items not shown:

7. Footrest clamps not strong enough - the footrests droop after a while. But they are super convenient - easy to adjust the footrests and to fold them when storing the bike.

8. Hand pedals - need something more to grab onto - they are just an aluminum stub right now.

1. Seat tilted down in high mode.
2. Pedal post clamp too weak - pedaling forces let the chain tension get too low.
3.Cable fraying on the centering spring support (minor issue)
4. Front end holder - how to keep the front end stable when released
5. Parking brake too weak - You need to put a lot of forward force on the front wheel when you morph up.
6. Crutch holder - needs to to be much easier to load and secure the crutches.
7. Footrest clamps not strong enough - the footrests droop after a while.
Hand pedals - need something more to grab onto

Could the Travel Bike Front End and Footrests Work on the Morph?

I just got the new Morphing Handcycle, and I'm of course comparing it to the main handcycle that I ride today, which is what I call the "Travel Bike." That bike was built to come apart, so you'll see a steel coupler that lets the frame break apart. The Morph uses the same coupler. But the Morph puts your feet way over the front wheel to reduce overall length. This post uses some cheap photoshop-like techniques to compare the Morph with a theoretical coupling of the Morph rear end with the travel bike front end. After all, they use the identical coupler. So click through the images to take a look.