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INSPIRATION
AFTER PICKING UP A 3D PRINTED ABS PART FOR THE FIRST TIME. I WAS AMAZED BY HOW LIGHT AND STRONG IT WAS. THIS MADE ME WONDER IF I COULD REDESIGN AN EXISTING BICYCLE FRAME AND IMPROVE ITS AERODYNAMIC PERFORMANCE BY BONDING 3D PRINTED PLASTIC CLADDING ONTO IT. I DECIDED TO EXPLORE AND EXPERIMENT WITH 3D PRINTING BIKE PARTS TO SEE WHAT KIND OF AERODYNAMIC IMPROVEMENTS CAN BE ACHIEVED.
PHOTOSHOP SKETCHING
ACCURATELY VISUALISING THE DESIGN WITH THE CHOSEN COMPONENTS. THE SKETCHES ARE BASED ON A SMALL PEUGEOT CR21 FRAME AND A SCOTT ADDICT SL CARBON FIBRE FORK.
3D SKETCH MODEL
THIS IS A SIMPLE ALIAS MODEL THAT BLENDS NACA AIRFOIL SECTIONS TO THE FRAME TUBES.
ROAD BIKE FIT
BEFORE CONTINUING WITH THE PROJECT I THOUGHT IT WOULD BE SENSIBLE TO GET A PROFESSIONAL BIKE FIT. I DISCOVERED THAT I NEEDED A LARGER SIZED FRAMESET THAN I WAS INTENDING TO USE, I HAVE A SHORT TORSO AND VERY LONG LEGS SO THE CHOICE OF SUITABLE FRAMESETS WAS LIMITED.
BIKE BUILD
I THOUGHT IT WOULD BE SAFER TO BOND MY 3D PRINTS ONTO ALUMINIUM RATHER THAN CARBON FIBRE. I BOUGHT THIS PLANET X GALIBIER SL FRAME BECAUSE IT WAS VERY LIGHT, ONLY 1135 GRAMS.THE TOTAL WEIGHT OF THE BIKE WITH PEDALS WAS ONLY 7 KG. I EXPECTED THAT THE 3D PRINTS MIGHT ADD ANOTHER 500 GRAMS WHICH WOULD STILL KEEP IT A LIGHT BIKE. AERO PARTS AND WIRELESS GEARS WERE CHOSEN TO COMPLETE THE AERO BIKE THEME.
3D SKETCH MODEL
HAVING 3D SCANNED THE ENTIRE BIKE, I USED THE SCAN MODEL AS A BASE FOR THIS STYLING SKETCH MODEL, I REWORKED THE ORIGINAL DESIGN TO FIT THE LARGER PLANET X GALIBIER SL FRAME SIZE.
CHANGE OF PLAN
I SAW THIS BEAUTIFUL SCOTT FOIL 15 CARBON FIBRE FRAMESET FOR SALE AT AN IRRESITIBLE PRICE. IT HAD BEEN REPAINTED IN CANDY BLUE - MY FAVOURITE COLOUR SO I BOUGHT IT AND SOLD MY PLANET X FRAMESET. IT'S AN OLDER AERO ROAD FRAME DESIGN SO I DECIDED TO MODERNISE IT WITH SOME BESPOKE 3D PRINTED PARTS.
3D PRINTED HEADSET COVER
A FITTED HEADSET SPACER COVER INSTANTLY BRINGS THE BIKE UP TO DATE WITH THE MODERN, INTEGRATED VISION METRON 5D, CARBON FIBRE HANDLEBARS. I USED CARBON REINFORCED NYLON FOR THE PART WHICH HAS A NICE MATT BLACK FINISH.
AERODYNAMIC ENHANCEMENTS
I CREATED SOME FITTED COVERS TO SMOOTH OUT THE AIRFLOW ON THE UNDERSIDE OF THE HANDLEBARS AND REPLACED THE SHIMANO DI2 BOX HOLDER SUPPLIED WITH THE BARS WITH A SIMPLER VERSION THAT GUIDES THE CABLES SO THAT THEY REMAIN WITHIN THE FRONTAL SURFACE AREA OF THE FRAME. I ALSO CREATED SOME OVAL SECTION TYRE VALVE COVERS, THEY ALSO HAVE THE BENEFIT OF PREVENTING THE VALVES FROM CLANKING AGAINST THE RIMS OVER BUMPS.
2D AND 3D DESIGN
THIS BIKE BUILD WAS DONE FOR MY SISTER USING THE PEUGEOT CR21 FRAME AND SCOTT ADDICT SL FORK THAT I HAD INTENDED TO USES FOR THE EXPAERO PROJECT. WITH A LIMITED BUDGET I WANTED TO CREATE A VERY LIGHTWEIGHT BIKE THAT LOOKS LIKE IT COST MORE MUCH THAN IT DID. I WAS STILL CURIOUS TO FIND OUT HOW MUCH WEIGHT 3D PRINTED PLASTIC CLADDING WOULD ADD SO I RECORDED THE WEIGHTS FROM THE BARE METAL FRAME TO THE FULLY COMPLETED ONE. AN ACCURATE PHOTOSHOP SKETCH WAS USED AS AN IMAGE PLANE FROM WHICH CURVES WERE TRACED TO CREATE THE 3D STYLING MODEL IN ALIAS.
INTERNAL SURFACE MODELLING AND 3D PRINTING
IT WAS COMPLICATED TO DESIGN THE INTERNAL SURFACES OF THE CLADDING HALVES SO THAT THEY WOULD FIT WITH ENOUGH TOLERANCE TO ALLOW MINOR ADJUSTMENTS. EACH HALF WAS PRINTED IN PLA FILAMENT AND SET TO MEDIUM QUALITY. THEY TOOK ABOUT 7 HOURS EACH TO 3D PRINT. MY PRINTER IS A CREALITY CR-10S WITH SOME IMPROVEMENTS THAT ALLOW ME TO PRINT NYLON AND FLEXIBLE FILAMENTS.
TRIAL FIT - GLUEING WITH EPOXY - FILLING AND SANDING
A TRIAL FIT WAS REQUIRED TO CORRECTLY POSITION 2 INTERNAL GEAR CABLE GUIDES MADE FROM BRASS TUBE (NOT SHOWN). ONCE GLUED INTO PLACE, A LARGE AMOUNT OF SLOW CURING EPOXY WAS SMEARED OVER ALL THE INTERNAL SURFACES AND THE 2 HALVES WERE LINED UP WITH 4 PLASTIC LOCATING RODS AND SQUEEZED ONTO EITHER SIDE OF THE FRAME. TAPE, VELCRO STRAPS, POLYSTYRENE WEDGES AND WOOD CLAMPS MADE SURE THE 3D PRINTED PARTS MAINTAINED CONTACT WITH THE FRAME. THE CLADDING AND WELDS WERE ALL BLENDED INTO THE FRAME USING ULTRA LIGHTWEIGHT POLYESTER BODY FILLER AND SAND PAPER.
WEIGHT: BARE FRAME VS CLAD AND FILLED FRAME
THE BONDED AND FILLED CLADDING (+ SMOOTHED WELDS) ONLY ADDS 96 GRAMS OF EXTRA WEIGHT, OF WHICH THE EPOXY GLUE AND FILLER MAKES UP 43 GRAMS.
WEIGHT: 3D PRINTED PLASTIC PARTS AND FINISHED FRAME
THE CLADDING PARTS ARE EXTREMELY LIGHT. PRIMER, PAINT AND STICKERS ADD AN EXTRA 52 GRAMS TO THE FRAME.
AERO MOUNT FOR B-TWIN 500 WIRELESS COMPUTER
THE ORIGINAL MOUNT IS DESIGNED TO FIT ON TOP OF THE HANDLEBAR STEM AND IS HELD IN PLACE BY ELASTIC BANDS. THIS ISN'T THE MOST ELEGANT SOLUTION SO I DECIDED TO CREATE AND 3D PRINT AN 'OUT FRONT' CLAMP-ON MOUNT. IT USES THE ORIGINAL MOUNT'S BASE BUT THE ELASTIC HOOKS HAVE BEEN REMOVED AND IT HAS BEEN GLUED INTO THE 3D PRINTED PART.
PHOTOS
PHOTOSHOOT OF THE COMPLETED BIKE. THE COLOUR SCHEME WAS INSPIRED BY FERRARI SPORTS CARS FROM THE 1960S
LOOKS LIKE A CARBON FIBRE FRAME
AT ONLY 7.8KG WITH PEDALS, IT WEIGHS AS LITTLE AS A CARBON FRAMED BIKE. ONLY A TRAINED EYE CAN SEE THAT THIS FRAME IS MADE FROM ALUMINIUM.
DETAIL SHOTS
FRAME WELDS ARE NO LONGER VISIBLE
CUSTOM MADE STICKERS
CHROME TO MATCH THE BIKE'S BLING DETAILS
THE CHALLENGE:
CONVERT MY OLD STEEL FRAMED COMMUTER INTO AN AERO TT BIKE - I WANTED TO ADD VARIETY TO MY TRAINING REGIME BUT AFTER SPENDING THOUSANDS OF EUROS ON MY AERO ROAD BIKE, I COULDN'T JUSTIFY SPENDING THOUSANDS MORE ON A MODERN AERO TT BIKE SO I DECIDED TO CONVERT MY TRUSTY STEEL FRAMED 1979 MILLENIUM FALCON COMMUTER INTO AN AERO TT BIKE USING MY DESIGNER SKILLS AND MY 3D PRINTER.
TIME TRIAL BIKE FIT
I FELT TOO STRETCHED OUT AND UNCOMFORTABLE IN THE AERO POSITION WHEN RIDING MY FALCON AS IT WAS SET UP SO I BOOKED ANOTHER BIKE FIT. THE TT RIDING POSITION IS VERY DIFFERENT FROM MY ROAD BIKE SET UP AND THE FALCON'S VINTAGE GEOMETRY ISN'T IDEAL WITH IT'S LAYED BACK SEAT TUBE. THE RESULTING POSITION FROM THE BIKE FIT WAS MUCH MORE COMFORTABLE THAN BEFORE AND I WAS ABLE TO STAY AERO FOR 40 KM NO PROBLEM, HOWEVER THE SADDLE WAS STILL SEVERAL CENTIMETRES TOO FAR BACK BUT THE WORST THING WAS HOW ODD THE BIKE LOOKED.
CUSTOM TITANIUM SEATPOST
HAVING SPENT HOURS LOOKING FOR A SOLUTION, I CAME ACCROSS A CHINESE COMPANY THAT SPECIALISES IN TITANIUM FABRICATION - COMEPLAYBIKE.COM, THEY HAD A RANGE OF SEAT POSTS AND COULD DO CUSTOM JOBS. SO I SENT A DRAWING OF WHAT I REQUIRED AND RECEIVED MY NEW SEATPOST WITHIN A FEW WEEKS. I DESIGNED AND 3D PRINTED A CLIP-ON AERO FAIRING BASED ON A SCOTT FOIL TUBE SECTION AFTER EXPERIMENTING WITH DIFFERENT SHAPES IN MY VIRTUAL WIND TUNNEL SOFTWARE.
VIRTUAL WIND TUNNEL TESTING
RIDING POSITION - AUTODESK FLOW DESIGN IS A VERY BASIC CFD SOFTWARE THAT ALLOWS YOU TO PLACE 3D MODELS INTO A VIRTUAL WIND TUNNEL. THE DATA IS GOOD ENOUGH TO COMPARE VARIANTS OF A DESIGN SO HERE I COMPARED 2 AEROBAR POSITIONS AND THE BEST PERFORMING COCKPIT FAIRING I HAD TESTED SO FAR. THE MODEL IS PARTIAL BECAUSE I DON'T HAVE A VERY POWERFUL COMPUTER AND CALCULATIONS CAN TAKE A VERY LONG TIME WITH COMPLEX MODELS.
VIRTUAL WIND TUNNEL TESTING
FRAMESET AND WHEELS - IT'S CLEARFROM THE STANDARD FRAME WIND TUNNEL TEST THAT ROUND TUBES HAVE VERY POOR AERODYNAMICS. EACH OF THE 3D PRINTED FAIRINGS I DESIGNED WAS TESTED AND DEVELOPED SEPARATELY BUT WHEN THEY ARE ALL FITTED TOGETHER THERE IS A BIG REDUCTION IN OVERALL DRAG.
AERO RIDING POSITION
I DID A LOT OF TESTING AND GETTING USED TO THE MOST AERO POSITION. IT CERTAINLY FEELS FASTER BUT IT'S NOT COMFORTABLE AND IT TAKES PRACTICE TO GET USED TO. I PURCHASED A FULL AERO TT CYCLING KIT WHICH PROVIDES A MUCH BIGGER REDUCTION IN DRAG THAN CAN BE ACHIEVED THROUGH BIKE DESIGN.
TURBULATORS
TO MAKE UP FOR THE LACK OF LONG TAPERING AIRFOIL TUBE SHAPES FOUND ON MODERN AERO TT BIKES, I NEEDED A WAY OF CONTROLLING THE AIRFLOW AT THE REAR OF EACH ELEMENT IN CONTACT WITH THE AIR FLOW. I CAME ACROSS TURBULATORS DURING MY RESEARCH WHICH ARE MICRO VORTEX GENERTAING, SLIGHTLY RAISED SURFACES ON THE LEADING SIDE OF AIRCRAFT WINGS. ZIG-ZAG TAPE USED TO IMPROVE RADIO CONTROLLED MODEL GLIDERS' PERFORMANCE WAS AVAILABLE TO BUY SO I PURCHASED AND FITTED SOME TO MY BIKE WHEREVER APPROPRIATE. I'M HOPING THAT THE AIRFLOW WILL DETACH FURTHER BACK AND ENCOURAGE A MORE LAMINAR AIRFLOW WITH REDUCED WAKE - SIMILAR TO THE WAY THAT DIMPLES IMPROVE THE AERODYNAMICS OF A GOLF BALL. UNFORTUNATELY I DON'T HAVE AN ACCURATE MEANS OF TESTING AT THE MOMENT.
PHOTOS
EACH FAIRING CAN BE EASILY REMOVED, THEY WERE ALL DESIGNED TO EITHER CLIP ON OR BE SCREWED IN PLACE. THE FINISHED MILLENIUM FALCON TT IS NOTICABLY FASTER THAN BEFORE, THERE IS MUCH LESS WIND NOISE AT HIGHER SPEEDS, IT IS SOMEWHAT HEAVIER THOUGH.
THE FAIRINGS ARE DESIGNED TO ELONGATE THE CROSS SECTION OF THE OBLIQUE FRAME TUBES. A SECTION THAT CAN BE DESCRIBED AS THE CROPPED TIP OF AN ELONGATED AIRFOIL, WAS CHOSEN TO GUIDE THE AIRFLOW PAST THE TRAILING, ROUND FRAME TUBES. THE FRONTAL SURFACE AREA OF THE BIKE HAS BEEN REDUCED AND TIDIED UP, THE CABLES ARE NOW HIDDEN AND AIR IS GUIDED SMOOTHLY PAST THE STEM AND CLIP-ON AERO BAR CLAMPS.
I FITTED VINTAGE SHIMANO 600AX BRAKES AND REAR DERAILLEUR BECAUSE THEY HELP REDUCE THE FRONTAL SURFACE AREA AND STILL LOOK REALLY MODERN. A SHIMANO AX BOTTLE ALSO LOOKS GREAT AND GUIDES AIRFLOW PAST THE BUSY LOWER FRAME AREA.
THE MORE VERTICAL FRAME TUBES ALL HAVE AERO FAIRINGS FITTED IN FRONT OF THEM. THE EASIEST WAY TO DO THIS WITH THE SEAT TUBE WAS TO COVER AN OLD ZEFAL FRAME MOUNTED PUMP WITH A 3D PRINTED SCOTT FOIL FRAME TUBE SECTION. ONLY THE UPPER HALF OF THE REAR STAYS ARE FAIRED BECAUSE I DIDN'T WANT TO RISK ANY FRAGILE PARTS BREAKING AND JAMMING THE REAR WHEEL. I WAS THINKING ABOUT FITTING A SHIMANO 600 AX FRONT DERAILLEUR BUT THE ONE I ALREADY HAD LOOKS LIKE IT IS MORE AERODYNAMIC.
THE HEAD TUBE FAIRING WAS DESIGNED TO FIT SEAMLESSLY WITH THE SHIMANO AX FRONT BRAKE CALIPERS. THE WHOLE COCKPIT FAIRING IS MADE UP OF 8 SEPARATE 3D PRINTS AND CLAMPS ON TO THE NITTO RB-021 HANDLEBARS WITH 6 SCREWS. THE BOTTOM BRACKET FAIRING ALSO HIDES (AND IS SUPPORTED BY) THE BOTTLE CAGE CLAMPS.
THE HANDLEBAR GRIPS AND BRAKE LEVER TIPS WERE PRINTED IN TPU FLEXIBLE FILAMENT - RECREUS FILAFLEX. THE SADDLE IS A SPECIALIZED POWER PRO THAT HAS BEEN CUSTOMISED, THE TITANIUM RAILS HAVE BEEN POLISHED, THE SEAT WAS PAINTED WITH SILVER LEATHER SPRAY PAINT AND THE UNDERSIDE WAS AIRBRUSHED USING MOLOTOW'S LIQUID CHROME INK - LIKE MOST OF THE OTHER 3D PRINTED PARTS.
THE WHEELS WERE ANOTHER AERO UPGRADE, 40MM POLISHED ALUMINIUM RIMS ARE LACED WITH SAPIM CX-RAY OVAL SECTION SPOKES ON VINTAGE MICHE 6 SPEED HUBS. THEY'RE NOT VERY LIGHTWEIGHT BUT THEY LOOK STUNNING AND ARE VERY STRONG.
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SUMMARY

EXPAERO = EXPERIMENTATION IN AERODYNAMICS WITH 3D PRINTING.

EXPAERO 1

AN EXPERIMENT USING 3D PRINTING TO IMPROVE THE AERODYNAMICS OF A ROAD RACING BICYCLE

AFTER PICKING UP A 3D PRINTED ABS PART FOR THE FIRST TIME, I WAS AMAZED BY HOW LIGHT AND STRONG IT WAS. THIS MADE ME WONDER IF I COULD REDESIGN AN EXISTING BICYCLE FRAME AND IMPROVE ITS AERODYNAMIC PERFORMANCE BY BONDING 3D  PRINTED PLASTIC CLADDING ONTO IT. I DECIDED TO EXPLORE AND EXPERIMENT WITH 3D PRINTING BIKE PARTS TO SEE WHAT KIND OF AERODYNAMIC IMPROVEMENTS CAN BE ACHIEVED.

I STARTED SKETCHING IN PHOTOSHOP,  ACCURATELY VISUALISING THE DESIGN WITH THE CHOSEN COMPONENTS. THE SKETCHES WERE BASED ON A SMALL PEUGEOT CR21 ALUMINIUM FRAME AND A SCOTT ADDICT SL CARBON FIBRE FORK.
FROM THESE SKETCHES I CONSTRUCTED A SIMPLE ALIAS MODEL THAT BLENDS NACA AIRFOIL SECTIONS TO THE FRAME TUBES.

BEFORE CONTINUING WITH THE PROJECT I THOUGHT IT WOULD BE SENSIBLE TO GET A PROFESSIONAL BIKE FIT. I DISCOVERED THAT I NEEDED A LARGER SIZED FRAMESET THAN I WAS INTENDING TO USE, I HAVE A SHORT TORSO AND VERY LONG LEGS SO THE CHOICE OF SUITABLE FRAMESETS WAS LIMITED.

I THOUGHT IT WOULD BE SAFER TO BOND MY 3D PRINTS ONTO ALUMINIUM RATHER THAN CARBON FIBRE. I BOUGHT A PLANET X GALIBIER SL FRAME BECAUSE IT WAS VERY LIGHT, ONLY 1135 GRAMS. THE TOTAL WEIGHT OF THE BIKE WITH PEDALS WAS ONLY 7 KG. I EXPECTED THAT THE 3D PRINTS MIGHT ADD ANOTHER 500 GRAMS WHICH WOULD STILL KEEP IT A LIGHT BIKE. AERO PARTS AND WIRELESS GEARS WERE CHOSEN TO COMPLETE THE AERO BIKE THEME.

HAVING 3D SCANNED THE ENTIRE BIKE, I USED THE SCAN MODEL AS A BASE FOR A STYLING SKETCH MODEL, I REWORKED THE ORIGINAL DESIGN TO FIT THE LARGER PLANET X GALIBIER SL FRAME SIZE.

CHANGE OF PLAN!

I SAW A BEAUTIFUL SCOTT FOIL 15 CARBON FIBRE FRAMESET FOR SALE AT AN IRRESITIBLE PRICE. IT HAD BEEN REPAINTED IN CANDY BLUE – MY FAVOURITE COLOUR SO I BOUGHT IT AND SOLD MY PLANET X FRAMESET. IT’S AN OLDER AERO ROAD FRAME DESIGN SO I DECIDED TO MODERNISE IT WITH SOME BESPOKE 3D PRINTED PARTS.

A FITTED 3D PRINTED HEADSET SPACER COVER INSTANTLY BRINGS THE BIKE UP TO DATE WITH THE MODERN, INTEGRATED VISION METRON 5D, CARBON FIBRE HANDLEBARS.
I USED CARBON REINFORCED NYLON FOR THE PART WHICH HAS A NICE MATT BLACK FINISH.

I THEN CREATED SOME FITTED COVERS TO SMOOTH OUT THE AIRFLOW ON THE UNDERSIDE OF THE HANDLEBARS AND REPLACED THE ORIGINAL SHIMANO DI2 BOX HOLDER WITH A SIMPLER VERSION THAT GUIDES THE CABLES SO THAT THEY REMAIN WITHIN THE FRONTAL SURFACE AREA OF THE FRAME.

I THEN CREATED SOME OVAL SECTION TYRE VALVE COVERS, THEY ALSO HAVE THE BENEFIT OF PREVENTING THE VALVES FROM CLANKING AGAINST THE RIMS OVER BUMPS.

EXPAERO 2

IMPROVING THE STYLE AND AERODYNAMICS OF A ROAD BIKE WITH 3D PRINTED CLADDING.

THIS BIKE BUILD WAS DONE FOR MY SISTER USING THE PEUGEOT CR21 FRAME AND SCOTT ADDICT SL FORK THAT I HAD INTENDED TO USE FOR THE ORIGINAL EXPAERO PROJECT. WITH A LIMITED BUDGET I WANTED TO CREATE A VERY LIGHTWEIGHT BIKE THAT LOOKS LIKE IT COST MORE MUCH THAN IT DID. I WAS STILL CURIOUS TO FIND OUT HOW MUCH WEIGHT 3D PRINTED PLASTIC CLADDING WOULD ADD SO I RECORDED THE WEIGHTS FROM THE BARE METAL FRAME TO THE FULLY COMPLETED ONE.
AN ACCURATE PHOTOSHOP SKETCH WAS USED AS AN IMAGE PLANE FROM WHICH CURVES WERE TRACED TO CREATE THE 3D STYLING MODEL IN ALIAS.

IT WAS COMPLICATED TO DESIGN THE INTERNAL SURFACES OF THE CLADDING HALVES SO THAT THEY WOULD FIT WITH ENOUGH TOLERANCE TO ALLOW MINOR ADJUSTMENTS. EACH HALF WAS PRINTED IN PLA FILAMENT AND SET TO MEDIUM QUALITY. THEY TOOK ABOUT 7 HOURS EACH TO 3D PRINT.

MY PRINTER IS A CREALITY CR-10S WITH SOME IMPROVEMENTS THAT ALLOW ME TO PRINT NYLON AND FLEXIBLE FILAMENTS.

A TRIAL FIT WAS REQUIRED TO CORRECTLY POSITION 2 INTERNAL GEAR CABLE GUIDES MADE FROM BRASS TUBE. ONCE GLUED INTO PLACE, A LARGE AMOUNT OF SLOW CURING EPOXY WAS SMEARED OVER ALL THE INTERNAL SURFACES AND THE BOTH HALVES WERE LINED UP WITH THE 4 LOCATING RODS AND SQUEEZED ONTO EITHER SIDE OF THE FRAME. TAPE, VELCRO STRAPS, POLYSTYRENE WEDGES AND WOOD CLAMPS MADE SURE THE 3D PRINTED PARTS MAINTAINED CONTACT WITH THE FRAME. THE CLADDING AND WELDS WERE ALL BLENDED INTO THE FRAME USING ULTRA LIGHTWEIGHT POLYESTER BODY FILLER AND SAND PAPER.

I WEIGHED THE FRAME AT 3 DIFFERENT STAGES, THE BARE ALUMINIUM FRAME, AFTER THE CLADDING WAS STUCK ON AND THE GAPS AND WELDS WERE SMOOTHED OUT WITH FILLER AND THE FINISHED, PAINTED FRAME.
THE BONDED AND FILLED CLADDING (+ SMOOTHED WELDS) ONLY ADDS 96 GRAMS OF EXTRA WEIGHT, OF WHICH THE EPOXY GLUE AND FILLER MAKES UP 43 GRAMS. THE CLADDING PARTS ARE EXTREMELY LIGHT AT 53 GRAMS. PRIMER, PAINT AND STICKERS ADD AN EXTRA 52 GRAMS TO THE FRAME.

THE B-TWIN 500 WIRELESS COMPUTER WAS THE BEST CHOICE OF FOR MY SISTER’S RIDING NEEDS. THE ORIGINAL MOUNT IS DESIGNED TO FIT ON TOP OF THE HANDLEBAR STEM AND IS HELD IN PLACE BY ELASTIC BANDS. THIS ISN’T THE MOST ELEGANT SOLUTION SO I DECIDED TO CREATE AND 3D PRINT AN ‘OUT FRONT’ CLAMP-ON MOUNT. IT USES THE ORIGINAL MOUNT’S BASE BUT THE ELASTIC HOOKS WERE REMOVED AND THEN IT WAS GLUED INTO THE 3D PRINTED PART.

THE RED, BLACK AND CHROME COLOUR SCHEME WAS INSPIRED BY FERRARI SPORTS CARS FROM THE 1960S. CUSTOM CHROME STICKERS WERE CREATED TO MATCH THE BIKE’S BLING DETAILS.

THE FINISHED BIKE FRAME LOOKS MORE LIKE A CARBON FIBRE FRAME THAN AN ALUMINIUM ONE BECAUSE THERE ARE NO VISIBLE WELDS. ONLY A TRAINED EYE CAN SEE THAT THIS FRAME IS MADE FROM ALUMINIUM.

AT ONLY 7.8KG WITH PEDALS, THE BIKE WEIGHS AS LITTLE AS A MID RANGE BIKE THAT COSTS TWICE THE PRICE.

EXPAERO 3

THE CHALLENGE: CONVERT MY OLD STEEL FRAMED COMMUTER INTO AN AERO TT BIKE

I WANTED TO ADD VARIETY TO MY TRAINING REGIME BUT AFTER SPENDING THOUSANDS OF EUROS ON MY AERO ROAD BIKE, I COULDN’T JUSTIFY SPENDING THOUSANDS MORE ON A MODERN AERO TT BIKE SO I DECIDED TO CONVERT MY TRUSTY STEEL FRAMED 1979 MILLENIUM FALCON COMMUTER INTO AN AERO TT BIKE USING MY DESIGNER SKILLSET AND MY 3D PRINTER.

I FELT TOO STRETCHED OUT AND UNCOMFORTABLE IN THE AERO POSITION WHEN RIDING MY FALCON AS IT WAS SET UP SO I BOOKED ANOTHER BIKE FIT. THE TT RIDING POSITION IS VERY DIFFERENT FROM MY ROAD BIKE SET UP AND THE FALCON’S VINTAGE GEOMETRY ISN’T IDEAL WITH IT’S LAYED BACK SEAT TUBE. THE RESULTING POSITION FROM THE BIKE FIT WAS MUCH MORE COMFORTABLE THAN BEFORE AND I WAS ABLE TO STAY AERO FOR 40 KM NO PROBLEM, HOWEVER THE SADDLE WAS STILL SEVERAL CENTIMETRES TOO FAR BACK BUT THE WORST THING WAS HOW ODD THE BIKE LOOKED.

HAVING SPENT HOURS LOOKING FOR A SOLUTION, I CAME ACCROSS A CHINESE COMPANY THAT SPECIALISES IN TITANIUM FABRICATION – COMEPLAYBIKE.COM, THEY HAD A RANGE OF SEAT POSTS AND COULD DO CUSTOM JOBS. SO I SENT A DRAWING OF WHAT I REQUIRED AND RECEIVED MY NEW SEATPOST WITHIN A FEW WEEKS. I DESIGNED AND 3D PRINTED A CLIP-ON AERO FAIRING BASED ON A SCOTT FOIL TUBE SECTION AFTER EXPERIMENTING WITH DIFFERENT SHAPES IN MY VIRTUAL WIND TUNNEL SOFTWARE.

VIRTUAL WIND TUNNEL TESTING – RIDING POSITION:

AUTODESK FLOW DESIGN IS A VERY BASIC CFD SOFTWARE THAT ALLOWS YOU TO PLACE 3D MODELS INTO A VIRTUAL WIND TUNNEL. THE DATA IS GOOD ENOUGH TO COMPARE VARIANTS OF A DESIGN SO I COMPARED 2 AEROBAR POSITIONS AND THE BEST PERFORMING COCKPIT FAIRING I HAD TESTED SO FAR. THE MODEL IS PARTIAL BECAUSE I DON’T HAVE A VERY POWERFUL COMPUTER AND CALCULATIONS CAN TAKE A VERY LONG TIME WITH COMPLEX MODELS.

HORIZONTAL AEROBARS = CD. 0.33

PRAYING MANTIS, HANDS HIGH = CD. 0.31

PRAYING MANTIS, HANDS HIGH WITH COCKPIT FAIRING = CD. 0.29

VIRTUAL WIND TUNNEL TESTING – FRAMESET AND WHEELS:

IT’S CLEAR FROM THE STANDARD FRAME WIND TUNNEL TEST THAT ROUND TUBES HAVE VERY POOR AERODYNAMICS. EACH OF THE 3D PRINTED FAIRINGS I DESIGNED WAS TESTED AND DEVELOPED SEPARATELY BUT WHEN THEY ARE ALL FITTED TOGETHER THERE IS A BIG REDUCTION IN OVERALL DRAG.

STANDARD FRAME = CD. 0.54

FRAME WITH AERO FAIRINGS = CD 0.41

TURBULATORS.

TO MAKE UP FOR THE LACK OF LONG TAPERING AIRFOIL TUBE SHAPES FOUND ON MODERN AERO TT BIKES, I NEEDED A WAY OF CONTROLLING THE AIRFLOW AT THE REAR OF EACH ELEMENT IN CONTACT WITH THE AIR FLOW. I CAME ACROSS TURBULATORS DURING MY RESEARCH WHICH ARE MICRO VORTEX GENERATING, SLIGHTLY RAISED SURFACES ON THE LEADING SIDE OF AIRCRAFT WINGS. ZIG-ZAG TAPE USED TO IMPROVE RADIO CONTROLLED MODEL GLIDERS’ PERFORMANCE WAS AVAILABLE TO BUY SO I PURCHASED AND FITTED SOME TO MY BIKE WHEREVER APPROPRIATE. I’M HOPING THAT THE AIRFLOW WILL DETACH FURTHER BACK AND ENCOURAGE A MORE LAMINAR AIRFLOW WITH REDUCED WAKE – SIMILAR TO THE WAY THAT DIMPLES IMPROVE THE AERODYNAMICS OF A GOLF BALL. UNFORTUNATELY I DON’T HAVE AN ACCURATE MEANS OF TESTING AT THE MOMENT.

POSITION.

I DID A LOT OF TESTING AND GETTING USED TO THE MOST AERO POSITION. IT CERTAINLY FEELS FASTER BUT IT’S NOT COMFORTABLE AND IT TAKES PRACTICE TO GET USED TO.
I PURCHASED A FULL AERO TT CYCLING KIT WHICH PROVIDES A MUCH BIGGER REDUCTION IN DRAG THAN CAN BE ACHIEVED THROUGH BIKE DESIGN.

MILLENIUM FALCON TT – FINISHED BIKE.

THE FAIRINGS ARE DESIGNED TO ELONGATE THE CROSS SECTION OF THE OBLIQUE FRAME TUBES. A SECTION THAT CAN BE DESCRIBED AS THE CROPPED, FRONT TIP OF AN ELONGATED AIRFOIL, WAS CHOSEN TO GUIDE THE AIRFLOW PAST THE TRAILING, ROUND FRAME TUBES. THE FRONTAL SURFACE AREA OF THE BIKE HAS BEEN REDUCED AND TIDIED UP, THE CABLES ARE NOW HIDDEN AND AIR IS GUIDED SMOOTHLY PAST THE STEM AND CLIP-ON AERO BAR CLAMPS.

EACH AERO FAIRING CAN BE EASILY REMOVED, THEY WERE ALL DESIGNED TO EITHER CLIP ON OR BE SCREWED IN PLACE. THE FINISHED MILLENIUM FALCON TT IS NOTICABLY FASTER THAN BEFORE, THERE IS MUCH LESS WIND NOISE AT HIGHER SPEEDS, IT IS SOMEWHAT HEAVIER THOUGH.

I FITTED VINTAGE A SHIMANO 600AX REAR DERAILLEUR AND BRAKES BECAUSE THEY HELP REDUCE THE FRONTAL SURFACE AREA AND STILL LOOK REALLY MODERN. A SHIMANO AX BOTTLE ALSO LOOKS GREAT AND GUIDES AIRFLOW PAST THE BUSY LOWER FRAME AREA.

THE MORE VERTICAL FRAME TUBES ALL HAVE AERO FAIRINGS FITTED IN FRONT OF THEM. THE EASIEST WAY TO DO THIS WITH THE SEAT TUBE WAS TO COVER AN OLD ZEFAL FRAME MOUNTED PUMP WITH A 3D PRINTED SCOTT FOIL FRAME TUBE SECTION. ONLY THE UPPER HALF OF THE REAR STAYS ARE FAIRED BECAUSE I DIDN’T WANT TO RISK ANY FRAGILE PARTS BREAKING AND JAMMING THE REAR WHEEL.
I WAS THINKING ABOUT FITTING A SHIMANO 600 AX FRONT DERAILLEUR BUT THE ONE I ALREADY HAD LOOKS LIKE IT IS MORE AERODYNAMIC.

THE HEAD TUBE FAIRING WAS DESIGNED TO FIT SEAMLESSLY WITH THE SHIMANO AX FRONT BRAKE CALIPERS. THE WHOLE COCKPIT FAIRING IS MADE UP OF 8 SEPARATE 3D PRINTS AND CLAMPS ON TO THE NITTO RB-021 HANDLEBARS WITH 6 SCREWS. THE BOTTOM BRACKET FAIRING ALSO HIDES (AND IS SUPPORTED BY) THE BOTTLE CAGE CLAMPS.

THE HANDLEBAR GRIPS AND BRAKE LEVER TIPS WERE PRINTED IN TPU FLEXIBLE FILAMENT – RECREUS FILAFLEX. THE SADDLE IS A SPECIALIZED POWER PRO THAT HAS BEEN CUSTOMISED, THE TITANIUM RAILS HAVE BEEN POLISHED, THE SEAT WAS PAINTED WITH SILVER LEATHER SPRAY PAINT AND THE UNDERSIDE WAS AIRBRUSHED USING MOLOTOW’S LIQUID CHROME INK – AS WERE MOST OF THE OTHER 3D PRINTED PARTS.

THE WHEELS WERE ANOTHER AERO UPGRADE, 40MM POLISHED ALUMINIUM RIMS ARE LACED WITH SAPIM CX-RAY OVAL SECTION SPOKES ON VINTAGE MICHE 6 SPEED HUBS. THEY’RE NOT VERY LIGHTWEIGHT BUT THEY LOOK STUNNING AND ARE VERY STRONG.

WHAT NEXT?

EVEN THOUGH THIS WAS A PERSONAL PROJECT, I THINK IT DEMONSTRATES MANY PARTS OF MY INDUSTRIAL DESIGNER SKILL SET. I’D REALLY LIKE TO COLLABORATE WITH BIKE MANUFACTURERS ON FUTURISTIC PROJECTS THAT PUSH THE LIMITS OF WHAT IS POSSIBLE IN BICYCLE DESIGN, PARTICULARLY IN THE FIELD OF AERODYNAMICS. SO PLEASE CONTACT ME IF YOU’D LIKE TO WORK TOGETHER ON SOMETHING SPECIAL.

GALLERY

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