Convertabike
Convert-a-Bike-Trike Velomobile project
By Rick Wianecki
Several years ago I started to think about a project to build a front wheel drive bike that would be easily converted to a leaning delta trike and then build a easily removable faring and body for it, sort of a Convert-a-Bike-Trike-Velomobile. I have no timetable for the completion of the project and there are no plans to do anything commercial. There is a guy in Europe that has a separate-able FWD low racer and delta trike, so you can buy one from him if you like. This builds onto the technology of my earlier leaning tadpole trike project.
3/13/06
Drawings posted are not 100% complete. They are developed to show the major concepts and dimensions. Details are worked out as the project progresses. Final details and dimensions are not included at this time. I am not planning on creating As-Built drawings.

This is the general arrangement bike drawing.

This is the main frame arrangement drawing, showing tube lengths and angles.

 

You can click on any of these drawings to see a larger image.

This is the bike rear triangle drawing 
This is the trike general arrangement drawing
This is the trike parallelogram tilting mechanism drawing.
This is the trike rear parallelogram detail drawing showing the rear of the trike frame, and the vertical control arm.
This drawing showing the detail of the upper / lower parallelogram arms.
This photo shows the bike frame and seat with wheels and tires. The tires are the Tioga Comp Pool and just clear the down tube frame in the front. For an all weather Velomobile this will not do since there is no room for a front fender. A smaller tire will solve this issue for now. I would increasing the clearance with some frame modification by changing the head tube angle if I build another frame. 
After I assembled the bike and rode it for a while I found that I did not like the U shaped bars. The bars were changed to tiller arrangement that tilts up. Note the third brake leaver, this lever is for the lean lock when the tilting rear is added.
This view shows the FWD arrangement; the fork is an aluminum Barcroft FWD disk brake fork with a 9-speed cassette. A single chain is used. The front boom adjusts to allow for other riders besides me. When adjusting the boom the chain need to be lengthened or shortened. This takes some time so it is not done often. The seat also can be rotated to change the seat back angle. 
This is a close-up view of the FWD idlers. The power side idler is a 4 diameter from McMaster Carr, I made the return idler from delrin and it is 2 in diameter, it is mounted to a rubber mount to allow it to twist slightly as the front wheel turns. A chain keeper is added to try to keep the chain from jumping off.

Side view of the bike. Note that the extra cable used for the lean lock when the trike rear is added. The seat frame is made from 5/8X.035 cromoly 
 Drum brakes were modified for one-sided attachment before they were built into wheels. Wheels were built and parts were purchased from Gearlan (http://www.gaerlan.com/bikeparts/bike.html) I have been doing business with him for a number of years and he provided great service and does great work.
The delta rear section is based on a parallelogram, with end uprights that the wheels are bolted to. The parallelogram has adjustable ends so camber at each wheel can be adjusted. Bump stop were added to limit the amount of the lean. Maximum lean is 45 degrees. This is the same tilting arrangement that is used on my leaning tadpole trike.
Delta rear attached to the drive section. Both rear brakes are activated by one brake lever. The lean lock is a sliding stainless steel bar and a disk brake caliper. The brake lever has a locking button so the trike will be able to locked in the upright position at stops. All the pivots are in bronze/nylon bearings with thrust washers and locking nuts so a preload resistance can be added to the leaning motion. Currently the camber is set to 0 at the wheels.
A cable connector from daVinci Designs is used for the rear brake cables; this allows the rear brakes to be easily disconnected and connected when the rear sections are changed. 
The single cable from the rear brake lever is split at a balancer to provide equal braking force on each rear wheel
view of the delta trike configuration.
Side view of the delta trike. 
This picture shows both of the rear sections. It takes less than 5 minutes to convert from bike to trike
Two carbon nosecones were made from a nosecone mold I have. One was cut down more then the other. Clear blown tops will be added to complete the shape. 
Dave Johnson and I built a plastic forming oven to fabricate blown canopies for our recumbent projects. The oven has an inside area of 28 X 28 X 100 and is powered by all of the heating elements from an old electric range. Oven can reach temperatures of 400 deg. F

View of the oven with the door open waiting for the blown bubble inside to cool.

Close up view of one of the bubbles (look close!). The bubble will be cut down to fit the top of the carbon nosecones.

Also in this picture you can see the copper tubing wrapped around the inside of the oven, which is used to pre-heat the compressed air before it is pumped into the bubble.

   
This page will be updated as the project progresses...  

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