A preview

Last Update -4/15/03


The Diablo recumbent tricycle is aimed towards the recumbent aficionado.  This trike is the successor to the award winning Zephyr recumbent trike.  Like it's predecessor, it strives at elegant and ergonomic styling with an abundant array of features.


In the previous generations of Zephyrs, most of the focus  was on styling.   As the trike progressed towards improved functionality and performance, retaining the styling became impossible.   The project took another direction and became a whole new concept.  Instead taking a great looking design into functionality, a fully functional platform was modified into kinetic art.   This is what initiated the Diablo project.    The Diablo design concept is based on the high performance Spitfire platform. 

Although a Diablo pre-production trike will not be available until company funding is raised,  a preview is provided along with a finalized drawing of this amazing new trike.

Design Objective

The Diablo is designed to be the worlds lightest, highest performance, fully suspended recumbent trike ever produced.



Since aesthetic quality is in the eye of the beholder, I find it difficult to make factual claims.  However, our vehicle designs have won awards in the past.  Therefore, no one should expect anything less than excellent.


Suspension System

The main feature of the Diablo trike is the state-of-the-art tuned suspension front and aft.  Both front and rear suspension systems are based on the Cane Creek AD-5, giving this trike a featherbed ride.  This design is the effort of eight years of research and experimentation.


The rear suspension uses a dual linked parallelogram suspension with 2 full inches of deflection.  This design was chosen for a number of reasons.  First, the four pivot points solve the problem of high side loading forces.  Secondly, the parallelogram reduces all effects of pedal induced rear-end pogo.  Last, by removing the lower link the rear-end can fold over the main frame section making the trike compact for storage and or shipment.


The front suspension is a dual A-frame design with anti-dive compensation and 1.5 inches of deflection.   This system allows full deflection without compromising the steering geometry.  The 1.5" (37mm) of deflection provides adequate shock absorption without causing excessive roll.


Model Designations

The Diablo is based on two models; The Sporty RS26 with a 26" rear wheel and front suspended, and the RST20 fully suspended touring trike with all 20 inch wheels and 2 speed mid-drive. 


Diablo RST20

The RST20 will be one of the most sophisticated recumbent trikes ever manufactured.  The trike offers three 20 inch wheels, a 2 speed mid-drive, and front and rear suspension.   this model is available in either an USS U-bar or with an OSS club tiller.

Diablo RS26

The Diablo RS26 is the sportier sibling to the RST20.   This model follows in the footsteps of it's predecessor, the Zephyr Mk III.  Instead of using a 20 inch rear wheel with suspension and a mid-drive, the RS26 uses a standard 26" rear wheel mounted on a removable hard-tail rear-end.  Like the RST, this model is available in either an USS U-bar or with an OSS club tiller.



Front view of both RS and RST Diablo models

The drawing below illustrates the parallelogram suspension.   The narrow cruciform allows extra clearance for the front wheels giving the trike a tighter turning radius.  

Upper/Lower Wishbone and Steering Knuckle Photo

These components are currently intricately machined from a single billet of aluminum stock giving the assembly phenomenal strength and stiffness.  The six rod-end bearings per each side are all industrial standard items.   Although heavy in appearance this complete assembly adds less than 24 oz. (675 g.) net total weight to the trike.   For our anticipated production version we plan to invest into intricate cast tooling so that we can integrate the bearings into the castings, making the assembly much lighter, reliable and less expensive.

Stay tuned! In the next few weeks, several more photos will be showcased.


The Diablo incorporates the following features:


Ultra light-weight, fully suspended frame (RST only)


Parallelogram type rear suspension (RST only)


Dual 'A' frame front suspension with anti brake dive compensation


Ultra-high efficiency low weight mid-drive system with 2 speeds gives a total of 54 gears! (optional on RS).  We also plan to offer the Sachs 3x9 for a total of 84 speeds.


Uses conventional light-weight road chain-rings and cranks.


ERTO 406 size tires for all three wheels (RST only)


Easy frame breakdown for travel or storage


Midi-size seat back offers neck support without interfering with the helmet


Seat back angle is adjustable while keeping base seat stationary


Standard Hydraulic disc brakes


All cabling is routed internally where possible


Optional rear brake


Available in OSS or USS configurations  


Total net weight under 35 lbs!!! (RS is 33.6 Lbs)

Specifications (preliminary)

Subject to change frequently!

Wheelbase:     40" (RST20)

                        43" (RS26)

Wheel Track:    32.5"

Ground clearance:

                        2.6" to 4.6"

Turning circle:  15 Ft. 

                        15.8 ft (RS26)

Weight:            34.7 lbs (RST20)

                        33.6 lbs (RS26)

Work in Process

Currently we are researching alternative manufacturing technologies to reduce overall cost.  In addition, we are modifying the suspension components so that this vehicle can use a wider variety of shock components.



The Diablo recumbent trike requires extensive amount of tooling for production manufacturing.  Consequently, this product is placed on hold until significant venture capital is raised.  If you would like to be part of this success, please visit Hell-bent's investors-partnership page .  In the meantime, progress on this project will be posted on Hell-bents What's New Page