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racing recumbent bike
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RACING RECUMBENT TRIKE
WHAT IS A RECUMBENT TRIKE ?
A RECUMBENT BICYCLE IS A BICYCLE THAT PLACES THE RIDER IN A LAID-BACK RECLINING POSITION.
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).
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 RE-DISCOVERED 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.
2 TYPES OF RECUMBENT TRIKES
DELTA CONFIGURATIONTADPOLE CONFIGURATION
Greenspeed Anura Delta Trike Innesenti tadpole trike
2 TYPES OF RECUMBENT TRIKES
DELTA CONFIGURATION
Greenspeed Anura Delta Trike
PROS:
• 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.
Source: http://www.hellbentcycles.com/trike_projects/Recumbent%20Trike%20Design%20Primer.pdf
2 TYPES OF RECUMBENT TRIKESTADPOLE CONFIGURATION
Innesenti tadpole trike
PROS:
• TWO WHEELS IN FRONT OFFER EXCELLENT 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/Recumbent%20Trike%20Design%20Primer.pdf
TADPOLE
VS.
DELTA
TADPOLE CONFIGURATION
Innesenti tadpole trike
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
BERSERKER TRIKE
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.
RELATED PRODUCTSADVANTAGES AND DISADVANTAGES
RELATED PRODUCTSUPRIGHT 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
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
RECUMBENT BIKE EXERCISE MACHINE
IT IS USED FOR THE BENEFIT OF PEOPLE WHO HAVE CARDIOVASCULAR PROBLEMS OR THOSE WHO ARE LESS FIT.
ADVANTAGES
WORKOUT OF GLUTEAL MUSCLE.
NO MORE SORE OR NUMB WRISTS BECAUSE PALMS NO LONGER ASSIST THE BURDEN OF THE ENTIRE BODY.
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
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
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
RECUMBENT BIKE
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
DISADVANTAGES
UNNERVING ON STEEP CLIMBS (WOBBLE FACTOR)
UNSTABLE(2 WHEELS ONLY): INCREASED CHANCE OF FALLING OVER
SLOWER CLIMB BUT FASTER DOWNHILL
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
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
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
UNDER SEAT STEERING
VS.
OVER SEAT STEERING
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).
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
MESH
VS.
MOLDED
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 ON DELTA TRIKES WITH LONG WHEEL BASIS
TADPOLE TRIKES BRAKE
• MOST TADPOLE TRIKES USE ONLYFRONT BRAKES. A BACK BRAKE IS RARELY USED.
• FRONT BRAKING SYSTEM: DRUM, DISC
DRUM BRAKES
DISC BRAKES
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.
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.
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
DRUM BRAKE
VS.
DISC BRAKE
SHELL
• AN AERODYNAMIC CARBON FIBER AND KEVLAR SHELL BUILT AROUND A LOW-PROFILE RECUMBENT BICYCLE.
• CAN MAKE A TOP SPEED OF 82.819 MPH
VARNA TEMPEST
• CAN HANDLE ANY KIND OF INCLEMENT WEATHER AND IT’S EQUIPPED WITH LED LIGHTS TO MAKE IT VISIBLE TO CARS AT NIGHT.
All-Weather Firefly Trike
• A SLEEK AERODYNAMIC SHELL THAT SNAPS ONTO ANY BICYCLE TO PROVIDE PROTECTION FROM THE ELEMENTS ONCE THE WEATHER TURNS FOR THE WORSE.
Capsule Shields Cyclists
• 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.
AEROK BICYCLE
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.
TURNING
TADPOLE• MORE STABLE THAN THE DELTA
• POSSIBILITY OF TIPPING FORWARD WHEN COMBINING TURNING AND BRAKING FORCES.
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. A STATIONARY HORN OR TILLER IS FIXED TO THE FRAME (THIS CAN ALSO
BE A 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.
TILTING
30 DEGREE TILT
PROS
POSSIBILITY OF LOW SIDE TITLTING TRIKE
CONS
o SITTING TOO LOW IS A SAFETY CONCERN
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.
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.
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
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
CONCLUSION AND SUMMARY
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.
POSITIONING
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.
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.
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.
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.
• 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.
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.
• 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.
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