Stable as a quadracycle.
Agile as a single bicycle.
The Design
Four link bars for torsional stability
Link bars as long as possible to minimize changes in separation distance when leaning into turns.
Link bars as short as possible to avoid interfering with other cyclists.
Horizontal diagonal link bars to prevent back and forth movement relative to the other bicycle.
Vertical diagonal bar with compression springs to maintain upright position at rest.
2018/20 - Prototype 4
Custom frames we built at United Bicycle Institute.
10 x 1 speed and disk brakes on left side bike.
Double Action Chain Tensioner and 3 speed internal hub with coaster brake on right side bike.
2020/21 – Prototype 6
Travel Twin Bicycle – Lightweight
Custom built CrMo thin wall double butted tube frames.
Lower step through frame, shorter crank arms.
26” tires, front disk brakes on both operated from left bike.
Lightweight anodized aluminum tube link bars.
Fast Disassembly
Skybolt CLoc® SK4002 quarter turn fasteners – connect link bars to frames.
S and S Frame Couplings – split frames to fit into travel case.
Fit each bicycle plus link bars into a 26”x26”x10” travel case.
Not a new concept
There are dozens of patents of side-by-side twin bicycles.
Fourteen samples from 1892 to 2012.
The oldest found was issued to Mr. Rudolph W. Riess in 1892.
Evidence of a 100 plus year desire for this type of bicycle.
A lot of inventive effort and creativity.
Shortcomings show the difficulty of going from concept into a functional design.
Prior Art
None is simultaneously flexible in both the longitudinal and the transverse axes.
There is no commercially successful product to our knowledge.
Side-by-side Flexible Twin Bicycle
Patents issued:
US 9,340,250 - May 17, 2016
US 9,944,343 - April 17, 2018
Mexico 383,358 – June 8, 2021
Canada 2,957,112 – December 7, 2021
Pending Patent Applications
European Union
Brazil
Origin of the idea
My wife Enid Olivieri had hip replacement surgeries in 2010 and 2011.
The surgeon recommended exercise in a stationary bicycle to avoid the risk of a fall that could damage the implants.
In her adolescence she enjoyed the feeling of flying like a bird when riding a bicycle. She did not see herself pedaling in front of a wall.
We developed the Side-by-Side Flexible Twin Bicycle as a safer alternative.
Prototype 1 - First functional Side-by-Side Flexible Twin Bicycle – 2014 - 2016
Side-by-Side Flexible Twin Bicycle
Since the initial tests of Prototype 1 in 2014, many people inquired if we could build them one or provide a “kit” to join their two bicycles.
Build, “not yet.” A kit, “not easy”. “We will let you know when ready.”
I knew there were several problems that needed to be resolved first. A “trial and error” process that took nine years.
Now, we can build a small number of custom designs for specific clients.
However, I think there is a “blue ocean” market that has been waiting for this type of bicycle for more than a hundred years. City cycling, tourism, rental, tours, retirees, etc.
We are searching for an established manufacturer of quality bicycles willing to partner with us to market the Side-by-side Flexible Twin Bicycle at an attractive cost.
Side-by-Side Flexible Twin Bicycle
A functional and safer option that is easy to ride even for non-riders and beginners.
It rides and leans into turns like a regular bicycle.
Its stability allows holding a conversation while riding at a leisure pace.
It is a safer exercise option for seniors and people with disabilities that wish to remain active through cycling.
Prototype 6 Travel Twin Bike – August 2021
Eurobike 2021 Award Finalist
Friedrichshafen, Germany