2. WHAT IS A RECUMBENT TRIKE ?
A RECUMBENT BICYCLE IS A BICYCLE THAT PLACES THE RIDER IN A
LAID-BACK RECLINING POSITION.
3. WHY USE A RECUMBENT FOR RACING?
RIDERS CHOOSE THIS TYPE OF DESIGN FOR ERGONOMIC REASONS
MOST RECUMBENT MODELS ALSO HAVE AN AERODYNAMIC
ADVANTAGE
DID YOU KNOW?
A RECUMBENT HOLDS THE WORLD SPEED RECORD FOR A BICYCLE,
AND THEY WERE BANNED FROM RACING UNDER THE UCI IN 1934,
AND NOW RACE UNDER THE BANNER OF THE HUMAN POWERED
VEHICLE ASSOCIATION (HPVA).
4. BRIEF HISTORY
• THE BANNING OF RECUMBENTS FROM BICYCLE RACING IN 1934 HAD THE EFFECT OF PUTTING
THE RECUMBENT BICYCLE DESIGN IN THE CLOSET FOR FIFTY YEARS, UNTIL IT WAS REDISCOVERED THERE PRIMARILY BY MIT PROFESSOR DAVID GORDON WILSON AND HIS
STUDENT.
•
BUT LET'S GO BACK TO SLIGHTLY BEFORE THAT UNFORTUNATE DAY IN
1934 AND LOOK AT
THREE RECUMBENT PIONEERS: CHARLES MOCHET, HIS SON GEORGE MOCHET AND CYCLIST
FRANCIS FAURE.
6. 2 TYPES OF RECUMBENT TRIKES
PROS:
DELTA CONFIGURATION
• EASY TO DESIGN, CONCEPTS FOLLOW THAT OF A
STANDARD BICYCLE
LOWER COST TO MANUFACTURER, USES STANDARD
BICYCLE’S COMPONENTS
•
CONS:
• QUICK MOMENT OF INERTIA CAUSES EXCESSIVE
ROLL.
• THIS CONDITION CAN BE CORRECTED USING A
LEAN STEERING MECHANISM.
• BRAKING IS COMPROMISED BY A SINGLE FRONT
WHEEL WHICH MUST PROVIDE THE MAJORITY OF
BRAKING FOR THE VEHICLE.
Greenspeed Anura Delta Trike
Source:
http://www.hellbentcycles.com/trike_projects/Recum
bent%20Trike%20Design%20Primer.pdf
7. 2 TYPES OF RECUMBENT TRIKES
PROS:
• TWO WHEELS IN FRONT OFFER EXCELLENT
TADPOLE CONFIGURATION
OVERALL BRAKING
• OVERALL EXCELLENT HANDLING
CONS:
• STEERING SYSTEMS ARE MORE COMPLICATED
AND REQUIRE UNIQUE PARTS
• DESIGN IS COMPLICATED AND DEPENDENT ON
MANY CONTINGENCIES
Source:
http://www.hellbentcycles.com/trike_projects/Recum
bent%20Trike%20Design%20Primer.pdf
Innesenti tadpole trike
9. TADPOLE CONFIGURATION
ADVANTAGES
• TWO WHEELS
IN FRONT OFFER EXCELLENT
OVERALL BRAKING
• OVERALL EXCELLENT
HANDLING
DISADVANTAGES
• STEERING SYSTEMS ARE MORE
COMPLICATED AND REQUIRE UNIQUE PARTS
• DESIGN IS COMPLICATED AND DEPENDENT
ON MANY CONTINGENCIES
Innesenti tadpole trike
11. THE TADPOLE ADVANTAGE
• THE TADPOLE CONFIGURATION WITH A PROPERLY CENTERED COG PROVIDES
EXCELLENT TRACTION, TURNING AND BRAKING STABILITY. IT PROVIDES A
LARGER TILTING RANGE, SO YOU DON'T HAVE TO GET THE TILT ANGLE EXACTLY
RIGHT, AND IT CAN ALSO BE TILTED FURTHER WHILE STATIONARY WITHOUT
TIPPING OVER.
13. RELATED PRODUCTS
UPRIGHT BIKE
ADVANTAGES
RELATIVELY EASY TO BALANCE AT SPEEDS
BELOW 2 MPH.
TRANSPORTATION IS EASY
LIGHTWEIGHT
CAPABLE OF VARIOUS STUNTS SUCH AS
BUNNYHOPPING, JUMPING UP CURBS,
WHEELIES, AND TRACKSTANDS.
GOOD FOR UPHILL CLIMBING
MORE VISIBLE
14. DISADVANTAGES
RIDER IS ADVISED TO CHANGE
POSITIONS OFTEN TO AVOID SORE
SPOTS.
SADDLESORE I.E. BRUISED PERCH
BONE AREA, CARPAL TUNNEL
PROBLEMS I.E. SORE PALMS AND
NUMB FINGERS, ALSO SORE WRISTS,
ELBOWS, SHOULDERS, AND NECK,
TENDER KNEES.
TOO MUCH WEIGHT PUT ON
LEANING POSITION.
BACK IS NOT RELAXED
NECK STRAIN
16. ADVANTAGES
WORKOUT OF GLUTEAL MUSCLE.
NO MORE SORE OR NUMB WRISTS BECAUSE
PALMS NO LONGER ASSIST THE BURDEN OF
THE ENTIRE BODY.
17. ADVANTAGES
RIDER SITS INTO THE BIKE FRAME
SEAT LOCATED ALMOST IN-LINE WITH THE
PEDALS
LOW COG (CENTER OF GRAVITY)
MAKING THE BIKE AND RIDER VERY STABLE
NATURAL, RECLINED POSITION WITHOUT
NEED TO BEND HEAD OR BACK
NATURALLY COMFORTABLE SEAT = MORE
COMFORTABLE WORKOUT
CYCLING IN A MORE NATURAL POSITION OF
BODY ALIGNMENT REDUCES FATIGUE
18. THE “Q FACTOR"
THE Q FACTOR OF A BICYCLE IS THE
DISTANCE BETWEEN THE PEDAL ATTACHMENT
POINTS ON THE CRANK ARMS
SOME RECUMBENT BIKES MAY HAVE A WIDER
Q FACTOR TO ALLOW FOR BRAKING
MECHANISM, PULLEYS, DRIVING
COMPONENTS, AND COSMETIC COVERS
A NARROWER Q FACTOR IS ERGONOMICALLY
SUPERIOR BECAUSE IT CLOSELY MATCHES THE
NEARLY INLINE PATTERN OF HUMAN FOOTSTEPS
19. RECUMBENT BIKE
ADVANTAGES
NO MORE SEAT PROBLEMS: RECLINED
SEATING
NO STRESS AND WEIGHT PUT ON BY
LEANING
NO SORE HANDS: ARMS NATURALLY
HANGING ON THE SIDES
NO NECK PAIN
20. MORE ADVANTAGES
COMFORT - LONG RIDES ON AN
UPRIGHT BIKE CAUSE TOO MUCH
PAIN
AERODYNAMICS - MANY
RECUMBENT SETUPS HAVE A SMALLER
FRONTAL AREA, WHICH MAKES THE
BIKE FASTER IN A HEADWIND
HEADS-UP POSITION
PROTECTION FROM ADVERSE
WEATHER
PRACTICALITY
21. DISADVANTAGES
UNNERVING ON STEEP
(WOBBLE FACTOR)
CLIMBS
UNSTABLE(2 WHEELS ONLY):
INCREASED CHANCE OF
FALLING OVER
SLOWER CLIMB BUT FASTER
DOWNHILL
22. MORE DISADVANTAGES
LESS STABLE AT VERY LOW SPEEDS; HARDER
TO KEEP RECUMBENT IN A STRAIGHT LINE
WHEN GOING UP A STEEP HILL
HARDER TO RIDE ON GRAVEL ROADS
CAN’T SHIFT BODY WEIGHT TO
COMPENSATE FOR MINOR FISHTAILING
OF THE WHEELS
CAN’T ―FALL STANDING UP‖ WHEN
YOU LOSE CONTROL AT LOW SPEED
BECAUSE LEGS ARE HORIZONTAL
HARDER TO SEE OVER TRAFFIC DUE TO
LOWER SEAT HEIGHT
23. 2 TYPES OF STEERING ON RECUMBENT BIKES
OVER SEAT STEERING
PROS
THERE IS A PLACE FOR A REARVIEW
MIRROR ON THE HANDLE BAR.
BIKERS ARE MORE USED TO THIS STEERING.
ALTHOUGH IT MIGHT CAUSE WRIST SORES
AND NUMBNESS OF FINGERS.
EASIER TO ―WALK‖ YOUR BIKE.
CONS
o SLIGHTLY HARD TO USE
24. 2 TYPES OF STEERING ON RECUMBENT BIKES
UNDER SEAT STEERING
PROS
EXTREMELY COMFORTABLE AND EASIER
TO RIDE
GETTING ON AND OFF IS EASIER SINCE
THERE IS NO HANDLE BAR IN THE WAY
CONS
o ALTHOUGH MOST BIKERS ARE NOT USE
TO THIS POSITION
o IT HAS NO PLACE FOR REARVIEW
MIRROR
26. SEATING
HAMMOCK MESH
PROS
OFFERS BREATHABLE COMFORT.
LIGHTWEIGHT
CONS
o DUE TO THEIR DESIGN, A MESH BASE
CAN MAKE THE BIKE DIFFICULT TO
HOLD UP AT A STOP (EVEN FOR A TALL
RIDER).
27. MOLDED SEAT
PROS
EURO MOLDED SEATS HAVE A
DISTINCT LUMBAR CURVE AND ARE
DESIGNED TO FOR A VERY LAID-BACK
POSITION.
FOAM AND COVER OFFERS A MORE
FIRM BASE TO PUSH AGAINST,
CONS
o
THOUGH IT MAY BE LESS
COMFORTABLE
29. WHEEL SIZE
20 INCH FRONT WHEELS
PROS
MORE MANEUVERABLE
MORE AERODYNAMIC
CONS
IT MAY FEEL WOBBLY FOR BEGINNERS
700 C OR 26 INCH REAR WHEEL
PROS
FASTER
SMOOTHER RIDES
CONS
IT DOESN’T WORK
BASIS
ON DELTA TRIKES WITH LONG WHEEL
30. TADPOLE TRIKES BRAKE
•
MOST TADPOLE TRIKES USE ONLYFRONT BRAKES.
• FRONT BRAKING SYSTEM: DRUM, DISC
A BACK BRAKE IS RARELY USED.
33. TADPOLE TRIKES BRAKE
DRUM BRAKES
• CLASSIFIED AS A SINGLE, LEADING SHOE BRAKE.
• USES TWO BRAKE SHOES INSIDE A CYLINDER
DRUM.
DISC BRAKES
• APPLIES A SET OF FLAT PADS ON OPPOSING SIDES
OF A REVOLVING ROTOR
• THE BRAKE IS INFALLIBLE TO FADING OR MOISTURE
BUILDUP.
34. DRUM BRAKES
ADVANTAGE
• IT PROVIDES SOLID AND RELIABLE BRAKING AND
IS OPTIMIZED FOR TADPOLE TRIKE DESIGNS.
DISADVANTAGE
• IS THAT A DRUM BRAKE PERFORMS POORLY IN
WET WEATHER CONDITIONS (IF MOISTURE GETS
INTO THE DRUM)
• IS SUSCEPTIBLE TO HEAT FADING.
• THE SELF-ENERGIZING DRUM BRAKEACTION IS
NONLINEAR AND MAY BE SLIGHTLY
UNPREDICTABLE.
35. DISC BRAKES
ADVANTAGE
• THE SELF-ENERGIZING DRUM BRAKE ACTION IS
NONLINEAR AND MAY BE SLIGHTLY
UNPREDICTABLE.
• ACTION IS PROPORTIONAL AND PROVIDES
SMOOTH BRAKINGEVEN DURING THE HARSHEST
WEATHER CONDITIONS.
DISADVANTAGE
• HEAVY COMPARED TO DRUM BRAKES.
• LIGHTER DISC BRAKES ARE AVAILABLE BUT VERY
EXPENSIVE
• MOST DISC BRAKES ARE PRONE TO RUBBING
AND ALSO A PERFORMANCE ROBBER
37. SHELL
VARNA TEMPEST
•
AN AERODYNAMIC CARBON FIBER AND
•
CAN MAKE A TOP SPEED OF
KEVLAR SHELL BUILT AROUND A LOW-PROFILE
RECUMBENT BICYCLE.
82.819 MPH
38. All-Weather Firefly Trike
•
CAN HANDLE ANY KIND OF INCLEMENT WEATHER
AND IT’S EQUIPPED WITH
LED LIGHTS TO MAKE IT
VISIBLE TO CARS AT NIGHT.
39. Capsule Shields Cyclists
•
A SLEEK AERODYNAMIC SHELL THAT
SNAPS ONTO ANY BICYCLE TO PROVIDE
PROTECTION FROM THE ELEMENTS ONCE
THE WEATHER TURNS FOR THE WORSE.
40. AEROK BICYCLE
• PROS:
• THE SHELL RESISTS THE OPPOSING WIND AND
THUS, HELPS THE BIKE TO SAIL THROUGH WITH
MAXIMUM EASE.
• THE AERODYNAMIC OUTER BODY OF THE BIKE IS
CALLED THE SHELL, MADE OF STURDY CARBON
FIBER, WHICH NOT ONLY ENHANCES THE VISOR OF
THE BIKE, BUT ALSO HELPS IT TO RUN FASTER BY
LETTING THE AIRFLOW GO SMOOTHLY.
• THIS SHELL OFFERS COMPLETE SAFETY FOR THE
RIDER IN CASE OF ANY ACCIDENTS.
41. TURNING
DELTA
• LONG WHEEL BASE OF DELTA
DECREASES THE TWITCHINESS OF THE
STEERING, IMPROVING HIGH SPEED
CONTROL AND PRECISION
• REARWARD WEIGHT DISTRIBUTION FAVORS
OVERSTEER. TEND TO SPIN OUT AND LOSE
TRACTION ON LOOSE GRAVEL.
42. TURNING
TADPOLE
• MORE STABLE THAN THE DELTA
• POSSIBILITY OF TIPPING FORWARD WHEN
COMBINING TURNING AND BRAKING FORCES.
43. LEAN STEERING
A LEAN STEERING TRIKE IS A THREE WHEELED VEHICLE THAT STEERS BY VIRTUE OF LEANING THE RIDER'S BODY
INTO THE DESIRED DIRECTION OF THE TURN.
ALTHOUGH SEVERAL VARIATIONS EXIST, THE MOST NOTABLE
IMPLEMENTATION IS WHERE THE SEAT MOVES IN RELATION TO THE FRAME CAUSING THE VEHICLE WHEELS TO
TURN OR ALTER THE WHEEL GEOMETRY.
BE A
A STATIONARY HORN OR TILLER IS FIXED TO THE FRAME (THIS CAN ALSO
U-BAR) ALLOWING THE RIDER TO LEAN THE SEAT LEFT OR RIGHT (THE SEAT IS LINKED TO A STEERING
MECHANISM), HENCE STEERING THE VEHICLE. SINCE THE RIDER LEANS INTO THE DIRECTION OF THE TURN,
THE CENTER OF GRAVITY IS OPTIMIZED PRODUCING A TRIKE WITH EXCELLENT LOW SPEED HANDLING. THE
CONCEPT IS SIMILAR TO STEERING A BICYCLE WITH ONE OBVIOUS EXCEPTION: THE LEANING IS LINEAR TO THE
STEERING AND NOT BY THE
G FORCES APPLIED. CONSEQUENTLY, THE STEERING IN THIS IMPLEMENTATION IS
NOT OPTIMIZED FOR HIGHER SPEEDS.
45. TILTING
45 DEGREE TILT
• THE BODY IS TOO HIGH, THEN I'LL NEED A
REALLY WIDE TRACK TO MEET ONE OF MY
MINOR DESIGN CRITERIA — THAT LEANED
FULLY OVER, THE VEHICLE WILL NOT
ACTUALLY TIP OVER AND FALL IF NOT
MOVING. WITH NO ABILITY TO PUT MY
FEET DOWN, THIS LITTLE DETAIL IS CRUCIAL.
ON THE POSITIVE, IT'D MEAN A NICE HIGH
LINE-OF-SIGHT. IT WOULD SEEM PRUDENT
TO FIND SOMETHING IN BETWEEN.
46. TILTING
• BY ALIGNING THE BOTTOM
OF THE
BODY WITH ESSENTIALLY THE AXLE
HEIGHT, I THINK I'VE FOUND THE
SWEET SPOT.
40º SEEMED EASY
WITH ONLY THE WHEEL PANT IN
DANGER OF INTERFERENCE THIS
PUTS IT ALMOST EXACTLY WHERE
MY LINE-OF-SIGHT IS IN MY
MINI,
WHICH IS ACTUALLY VERY GOOD.
•
VERY CLEAN AERODYNAMICS AND
EASY ROAD GOING OVER FAIRLY
SUBSTANTIAL ROAD HAZARDS.
47. DESIGN PARAMETERS
• FRAME DESIGN-
CARBON FIBER (LIKE THE AEROK BICYCLE SHELL)
• STEERING- UNDER SEAT STEERING
• TADPOLE CONFIGURATION
• MESH SEAT
• 20 INCH FRONT WHEEL AND 700 C OR 26 INCH REAR WHEEL
• BRAKING SYSTEM- DRUM BRAKE
•
TILTING
Aerok bicycle shell
48. DESIGN PARAMETERS
• SADDLE WIDTH- 355MM TO 406MM (TILTED UP TO 5 DEGREES AT THE FRONT)
• BACKREST ANGLE- 30 T0 40 DEGREES
LENGTH- 450 MM
•
CRANK LENGTH – 160 MM (MIN=640MM, MEDIAN 790MM MAX=940MM)
•
BOTTOM BRACKET TO BACK OF SEAT 800MM TO 1100 MM
•
BOTTOM BRACKET CLEARANCE- 350 T0 400 MM
•
BOTTOM BRACKET HEIGHT- 400 MM
•
SEAT HEIGHT- 400 TO 470 MM
•
LUMBAR -190 MM
•
SHOULDER SUPPORT-120 MM
52. RECUMBENT BIKE
ONE OF THE MOST COMMON REASONS FOR USING A RECUMBENT BIKE IS COMFORT. NOT
ONLY DO THEY HAVE A LARGE SEAT, BUT THE BIKES ALSO OFFER COMPLETE BACK SUPPORT. THIS
ERGONOMIC ADVANTAGE IS ESPECIALLY IMPORTANT FOR PEOPLE WITH BACK OR NECK
PROBLEMS.
BECAUSE OF THEIR LOW CENTER OF GRAVITY, RECUMBENT BIKES ARE ALSO MORE
AERODYNAMIC AND CAN PICK UP SPEED MORE EASILY.
54. SEAT POSITIONING
• IN A RECUMBENT BIKE, YOU ADJUST THE SEAT EITHER FORWARD OR BACKWARDS, RATHER THAN
UP OR DOWN LIKE AN UPRIGHT BIKE.
•
THE SEAT RECLINE ALLOWS FOR ADJUSTMENTS, START AT A MID-POSITION.
ACCORDING TO
BACCHETTA BIKES, BEING TOO STRAIGHT OR TOO RECLINED CAN CAUSE DISCOMFORT AND
PAIN FOR BEGINNER RIDERS. AN UNCOMFORTABLE SEAT POSITION CAN ALSO PUT ADDITIONAL
STRESS ON YOUR KNEES AND MAKE RIDING MORE DIFFICULT.
55. LEG POSITIONING
• THE LEG SHOULD HAVE ONLY A VERY SMALL BEND
•
IN A RECUMBENT BIKE, THIS MEANS AN ANGLE OF JUST A FEW DEGREES. THE LEGS SHOULD
NOT BEND TOO MUCH AT ANY GIVEN TIME, SINCE THIS PUTS A LOT OF PRESSURE ON THE KNEES.
56. KNEE POSITIONING
•
THE LEGS ARE ALWAYS
EXTENDED FORWARD, THE RIDER MIGHT END UP WITH SORE KNEES
AFTER RIDING A RECUMBENT BIKE.
• THE MORE YOU LEAN BACK ON YOUR SEAT, THE MORE YOU HAVE TO USE YOUR LEGS AND THE
LESS PRESSURE YOU PUT ON YOUR BACK AND OTHER PARTS OF YOUR BODY. RECUMBENT BIKES
ALSO REQUIRE LITTLE WRIST AND LOWER ARM STRENGTH.
57. STEERING POSITION
• UNDER SEAT STEERING
GOES WAY BEYOND WHAT MOST RECUMBENT WILL DO FOR COMFORT.
• THERE ARE TWO TYPES OF USS, DIRECT AND INDIRECT. DIRECT IS BEST THOUGHT OF AS A
HANDLE BAR MOUNTED TO THE BACK SIDE OF THE FORK AND EXTENDING BACK FAR ENOUGH
TO DROP YOUR ARMS STRAIGHT DOWN BESIDE THE SEAT AND GRAB ON.
A COUPLE OF THE
DRAWBACKS TO THIS DESIGN ARE HAND POSITION AND INTERFERENCE WITH THE SEAT IN SHARP
TURNS.
58. • LONG BIKES USES AN INDIRECT STEERING. INDIRECT IN THAT THE HANDLE BAR IS MOUNTED TO
THE FRAME AND USES LINKAGE (IN AUTOMOTIVE TERMS, A DRAG LINK) TO CONNECT TO THE
FORK
•
A COUPLE OF ADVANTAGES ARE THAT THE STEERING RATIO OR SPEED CAN BE ADJUSTABLE
AND THE HANDLE BAR ROTATES ABOUT A PIVOT POINT UNDER THE SEAT. THE ENDS OF THE
HANDLE BAR MOVE IN AN ARC BESIDE YOUR LEGS, WITH A MOVEMENT THAT IS ESSENTIALLY A
PUSH PULL BY THE RIDER.
59. USS (UNDER SEAT STEERING
• ADVANTAGES
• RELAXING AND DOESN'T PUT ANY STRAIN ON THE UPPER BODY.
• BETTER SUITED TO CYCLISTS BEARING HAND, ARM OR SHOULDER INJURIES
• A GREAT WAY TO ENSURE YOUR KNEES AREN'T GETTING BASHED ON THE HANDLEBARS.
60. • DISADVANTAGES
• MORE COMPLICATED MECHANICALLY AND THUS REQUIRES MORE MAINTENANCE AND
ADJUSTMENTS.
• FAR MORE EASILY DAMAGED IN EVEN A MINOR ACCIDENT.
• MORE UNUSUAL AND THUS CAN BE MORE DIFFICULT FOR AN INEXPERIENCED RECUMBENT CYCLISTS
TO ADJUST TO.
• MORE DIFFICULT TO MANHANDLE.