It's Time To Get Technical
27 August 2015 - The Science
The Tech behind our Kids Bike Geometry
As well as re-designing the geometry of kids bikes, every single Frog bikes aluminium frame, fork and component conforms to standards set by EN and International Standards body (ISO).This means they have to undergo very rigorous testing, but what does that actually involve?
Bike Frame Testing
The list below shows the tests that our frames are put through to ensure we offer the best quality kids bike frames.
A weight of 22kg is dropped on both the frame and the fork from a height of at least 120mm (Fig 1 & Fig 2)
Bending Fatigue Test For Forks
Cycles of ±400 N dynamic force are applied to the fork, perpendicular to the steerer-tube, for 100,000 test cycles.
The handlebars have a force of 190 N applied to them 50 mm from the free end on each side, parallel to the stem axis for 100,000 repetitions.
The wheels are secured to the frame and fork as per our manufacturer’s recommendations. A force of 1,000 N is applied symmetrically to both ends of the axle for 1 min in the direction of the removal of the wheel.
Pedal clearance from the ground. With the pedal at its lowest point, parallel to the ground, the bike must be leaned over at an angle of 23° from the vertical before any part of the pedal touches the ground.
Pedal clearance from the tyre. Bikes shall have at least 89 mm clearance between the pedal and front tyre or mudguard (when turned to any position).
The pedal-spindle is struck by a weight of 15 kg from a height of 200 mm, hitting the pedal at the centre of the tread surface.
Wheel rotational accuracy and truing. The maximum variation of the rim relative to the axle is measured through one complete rotation. We measure both axial run out (lateral) and radial runout (concentricity) - see diagram left. All the Frog wheels go through a truing machine to make sure the spoke tension is accurate to 0.15mm.
Adhering to British Standards
These are the specific standards that our bikes conform to:
The Tadpole and Tadpole plus have passed EN71 (Toys) which is the standard for Balance Bikes.
The Frog 43 and 48 have passed EN14765 and are supplied with a full chainguard as standard which stores can fit if requested when you collect the bike.
The Frog 52, 55, 62, 69 and 70 have passed EN14781.
The Frog Road and Track 58, 67 and 70 have passed EN14781.
All bikes made from May 2015 onwards also comply and have been tested with the new ISO standards.
Frog 43 and 48 comply with ISO8098 (2014).
Frog 52, 55, 62, 69, 73 and all Frog Track and Frog Road bikes now comply with ISO4210 (1-9): 2014.
The Tadpole and tadpole Plus conform to EN71