Components Update

Another generation of the drive components. We designed them to be functional yet as simple as possible so that we can machine them all by next Tuesday and then get on to other things in this wild ride. We've got some good progress already - someone on our team served up a cafeteria tray of a few of the components the other day.

Bottom Bracket

Just like before, we are still designing the drive to go inside of a hollow frame. So on this here bottom bracket, we are centering the chainring on the spindle. Note the flat areas on the spindle to key with the spider and thereby prevent slippage.

A guide to the parts:

• Red = outer plates
• Green = frame inserts (embedded in carbon fiber frame)
• Yellow = bearings
• Gray = spindle
• Purple = spider
• Black = chainring

Transfer Gear

We are using an internally-geared 3-speed hub as a transmission. It will have two chains - one input and one output, similar to the chains on a tandem. Here is a system for adjusting the dropout angle so that we can tension both chains with one adjustment.

Red = adjustable plates

Green = frame inserts (embedded in carbon fiber frame)

Gray = input cog / 3-speed hub.

Black = output cog

Rear Hub

The rear hub is designed so that the rider can remove the wheel from the side - without messing with the chain. The rear axle fits into the hub, and the axle rotates with the wheel.

 

Orange - hub

Gray = axle

Red = outer plates

Green = frame inserts (embedded in carbon fiber frame)

Yellow = bearings

Purple = spider

Black = output cog

Here's a closeup on the spider, which is basically a modified split collar. It's going to be a small but action-packed machining job.

Front Hub

We've yet to detail it fully, but we're going to be modifying an existing Shimano Nexave roller brake. The brake engages with the hub from the side, so it will be fairly simple to modify it to fit on a one-sided fork. Here's an exploded view drawing from Shimano.

Bottom Bracket Assembly

In order to enclose the drivetrain inside the frame, we are machining some custom components. Here is the bottom bracket assembly:

And an exploded view:

Note that the spider is actually a split collar which clamps onto the center of the spindle with a bolt.

  

Nick is currently having fun turning the spindle on the lathe - and he is eagerly looking forward (really!) to tackling that spider.

OVERALL DESIGN DECISION

During our work on our specific parts we realize that there is an outstanding decision about the overall design, which hold us back from ordering parts and getting hard data for the bike. Both versions had their pros and cons.
V1:

V2:

After a discussion in the group we chose Variant 1. As a consequence we have the following hard points for our bike:

• one sided fork in the front and the back.
• 20"wheel
• intermediate hub
• foldable handlebars as part of the locking system
• collapsible saddle
  
• integrated lighting in the frame
• a body out of carbon fibre
  

TIME TO GET CONCRETE

With all the won information it is now time to get precise informations and a clear concept for every part of the bike. To be more effective we split the group and assigned one part of the bike to members:

• Storage: Krisa
• Locking/Foldable Handlebar: Adrian
• Over all design: Erik
• Chain wheel: Mike
• Visibility: Ashley
• Seat fixation: Hemi
• Seat shape: Hemi/ Nick
• Handle bars: Harry

IMPROVED PROTOTYPE

With our modified prototype we went out again and did some more testings. The results were confirming us: Smaller wheels will offer a more compact package, with acceptable loss of comfort. It also opens up a niche in the bike segments: Compact Crank Forward.

EVALUATION OF THE TEST RIDES

Based on our test rides we found out some valuable informations:

The bike as it is now is too big. -->As a consequence of that we will put on 20" wheels and test it with smaller wheels

The seat doesn´t have to have a big back-rest to garanty enough support for efficient pedaling --> Find out the minimum solution for the back rest

The handling is very unpractical. -->New handlebars and a better relation to the body has to be found.

The frame has to much flex. --> After finding the right relation between the crank and the seat, we´ll fix and support the frame.

TESTS

Under perfect conditions we were able to do some first test rides

RIDABLE PROTOTYPE

As a result of the feedback, the rest of the team built this modular ridable protoype. It will help us to find out valuable informations about the seat, hard points for the final bike and most important information about the handling of the bike.

DAILY USER SCENARIO

The "identity-group" also developed two user-scenarios to get an idea of the daily challenges the bike has to face.

1. Gabriel Smith, 20 years old, Anthropology Student, Nice Weather Commuter

2. Michael Stange, 37 years old, Social Worker, Everyday-Commuter
Short summary:
Distance: ca. 2Miles
Mostly in city, a lot of signals, where has to wait
Mostly flat path, only one tunnel underneath the tracks.
Has to carry food and drinks, a laptop and some documents

IDENTITY OF THE BIKE

To get a clearer idea of the identity the group was asking themselves: What is our Innovation? What separates us from the rest of the market? After analyzing our progress so far, we came up with a list of specific problems we´re trying to tackle:

• small people can not blance on a normal bike
• it is hard to get on a diamond frame bike
• no convincing locking solutions
  
• uncomfortable seating position on a upright bike
• people don´t know how to change the wheels
• dirty pants from the chain
• no working lights
• diamond framed bikes need a lot of space for storage
  

Based on that we had the idea for a marketing campaign that would focus on this problems and how we solved them. For example showing dirty fingers and tell that this is history, because we solved the problem.