Camberley U3A Science & Technology. Modern bicycle technology

Transcription

1 Camberley U3A Science & Technology Modern bicycle technology 1

2 Overview Why cycle? Bikes - many different types and functions Comfort, weight and aerodynamics Frames and forks; structure, components and materials Wheels, tyres and inner tubes Gears and shifters Brakes Lights, spares and tools Electronics; power, heart rate, speed, distance, altitude, cadence etc. Safety and comfort; helmets, clothing, eye protection Training, nutrition, hydration Maintenance 2

3 Why cycle? As much or as little exercise as you want Aerobic Go at your own speed or with group of friends Rotational exercise, no impact on knees and other joints Alternative to use of car for (shorter?) distances No pollution No fuel cost Cycling infrastructure improving all the time Lovely countryside, see over hedges 3

4 Types and functions Mountain bike, no suspension, hard tail, full suspension Hybrid - flat bars Road - drop bars Single speed Folding. many other variations 4

5 Structure, components and materials Classic double-triangle road bike frame 5

6 Mountain Bike, full suspension 6

7 Hybrid 7

8 Single speed (fixie) 8

9 Comfort, weight and aerodynamics Frame materials: Steel - heavy, fairly flexible, absorbs some vibration Aluminium - lighter - harsh ride Titanium - expensive, lighter, fairly flexible Carbon fibre - light, flexible, can be expensive Mixed, e.g., aluminium frame with carbon-fibre forks Too flexible can mean power loss Weight - hills, acceleration, braking, but bike weight fraction of total 70kg rider, 10kg bike Aerodynamics very important - pushing the rider through the air, headwinds Flapping clothing Drop vs flat bars Internal cable routing Saddles - comfort, padding, weight, Pedals - flat, MTB, toeclips, clipless 9

10 Pedals 10

11 Wheels, tyres and inner tubes Wheels - rims and spokes Steel, aluminium, carbon fibre Braking surfaces Weight and aerodynamics Rim tape Sizes Tyres - road, off-road and in-between Puncture protection Rolling resistance, contact area Weight Tread Sizes Inner tubes - must match tyre size Recent news - solid tyres 11

12 Gears, chain and shifters Combined brake levers and gear shifters - road bikes Separate levers - hybrids, mountain bikes 1, 2 or 3 front chainrings Up to 12 rear sprockets Examples 2x10 front 53/39 or 50/34, rear 11-25, 3x9 front 48/36/28 rear More sprockets = smaller gaps but harder to set up More sprockets = thinner chain Lower gears = hills easier Chain angle, avoid extremes so not all ratios usable Single speed Hub gears (epicyclic, planetary) - sealed, stationary change, some with quieter and low-maintenance belt drive Electronic shifters - straight chain line 12

13 Brakes Cable Hydraulic Rim brakes Simple operation, easy to adjust and maintain Wheel rim wear Dirt and water on rims Lighter Disc brakes Initial use on MTBs Increasingly used on hybrids and a few newer road bikes Can be heavier Reduces effect of dirt and water Can be harder to adjust and maintain 13

14 Disc brake 14

15 Lights, spares and tools See and be seen LEDs and Halogen Rechargeable and standard replaceable batteries Fixed and/or flashing Helmet lights Small emergency lights Tyre pumps, bike and at home CO2 inflators Multi-tool Spare tube and/or repair kits Tyre levers Rubber gloves Home toolkit, cleaning materials, track pump 15

16 Training, nutrition, hydration Training information Power, heart rate, speed, distance, altitude, cadence, etc. Endurance, speed, rest and recovery Water, energy drinks Food, carbohydrates, fat, gels, energy bars Tiredness and concentration Indoor training Turbo / resistance Rollers Power, cadence, HR, etc. 16

17 Training information 1 17

18 Training information 2 18

19 Training information 3 19

20 Safety and comfort Helmets Lights Bike set up for individual - very important (comfort, avoid injuries) Well-maintained bike Observation - road and surrounding environment, consider others Potholes (snakebites), puddles, metal manhole covers, white lines, speed humps Bike appropriate for use Mudguards Clothing - warm, dry, breathable, close-fitting; layers Visible Windproof, waterproof, showerproof Eye protection Contact points Padded shorts and chamois cream Gloves Shoes and socks Different riding positions, stretching, Relax 20

21 Bike setup 21

22 Maintenance Tyres - damage, thorns, flints, excessive wear Wheels - damage from potholes, distortion, rim wear Spokes Correct tyre pressures - rolling resistance, minimise puncture risk Brakes No rattles or squeaks All rotating parts rotate as they should Chain - clean and lubricated, no rust Clean - cables, brakes, rims Clean - frame, bar tape etc Cleaning and lubrication materials 22

23 Touring Supported holidays B&B Camping Racks, front, rear Panniers Keep centre of gravity low Suitable (strong) bike with appropriate fixings Keeping everything dry 23

24 Thanks for listening Any questions? 24