why do cyclists bend their head while cycling?
140128
the are trying to reduce wind drag
657231
The last answer is good - within a category of bikes (mountain bikes, road bikes) you will always get some that are aligned more to comfort and control (upright and not so stretched forward), and some that are really racy, and designed for out-and-out speed (forward and stretched out).\n\nAerodynamics is only part of the story however. A lot of it is to do with where the riders hips are in relation to the pedals. The less 'bent over double' a rider is, the easier they can breathe, and the more efficiently they can extend their leg muscles. The optimum for conventional style bicycles is around a 90 degree bend between legs and torso.\n\nEven though both of these bikes are designed to go fast, you'll notice that this one (http://www.cervelo.com/bikes.aspx?bike=P3C2006 - the quicker) has the seat further forward in relation to the pedals than this one (http://www.cervelo.com/bikes.aspx?bike=R32006 ).\n\nHope that helps.
305710
Cross your shins behind your rear end for better balance.
1052731
Any object which is lying at a spot has a centre of gravity. If it is perfectly balanced it will continue to stand without falling unless it is acted upon by an external force. When it is standing by itself every small swirl in the air will disbalance it and it will fall because the centre of gravity will be shifted to one side and because gravity is attracting the bycycle - by Pascals Law - it will transmit the Gravitational Pressure equally in all directions and the bycycle will fall even with a very very small tilt.\nNow consider a moving bike. The inner ear of the rider has 3 small bones - the hammer, stirup and the anvil partially immersed in a fluid which maintains it level like water. Any tilt in the bike will tilt the rider. The body of the rider will immediately send signals to the rider to tilt his body in the opposite direction to maintain perfect equilibrium and balance. The body will immediately lean towards the other side of the tilt and the bike will also be tilted away from the tilt towards the centre of gravity and so the rider is the person who leans his body from side to side and keeps the center of gravity straight and prevents falling - SO PLAY A RIDE BY THE EAR - Ha Ha!
31504
Tilting your head backwards is the WRONG thing to do. Though everyone seems to do this. You are meant to lean your head forward and pinch your nose!
283278
they mostly do that so they don't have to look at the crowd, coaches, or opponent.  It helps them regain and focus, if they were looking around they may loose their composure or get looks of disappointment.
803260
Not all cyclists have a death wish ,some careless riders gives the rest a bad name.\n\nRules I abide by when cycling at night:\n\nDon't ride at night unless its really necessary\nEnsure you have lights front and back and that they work properly.\nWear reflective clothing\nUse cycling lanes if available\nGive way to traffic and pedestrians \nEnsure your bike is roadworthy\nCarry a phone in case of an emergency\nHelp out other road users in an accident if you can, you could save a life\n\nSaying that everyone is riding in the dark without lights is untrue.
907542
Further to Sorro's reply, yes the forces are balanced if the speed is constant and the bike and rider are not changing shape (ha ha).\nIf you are hitting the ground, you are being crushed by gravity because the force of the bike's frame is not strong enough to balance your mass.  Better buy a better bike.\nIf you are slowing down, you are not pedaling fast enough to balance the headwind, and friction with the road and wheel bearings.  Better train more.\nIf you are speeding up, great, you are OVERbalancing the wind and friction.\nFinally, if you are floating into the air, you have overcome the force of gravity and are doing an ET.\nEnjoy your ride.\nMore on the physics of cycling at \nhttp://w3.iac.net/~curta/bp/BikeSheet.html.
822673
The only advantage is improved flat resistance.\n\nThe heavier tubes will increase rotating mass and actually make your bicycle performance lower, making it more difficult to gain and maintain speed.
454772
This could be caused from tension, and when your muscles relax, where the spinal column meets the back of the head it will crack and pop.  kinda like cracking the nuckles?
421227
The child needs to try it out.  When the pedal is at its lowest point, the child's leg should be slightly bent.  You don't want the legs to be perfect straight because that will cause the knees to lock up and create sore muscles.
719050
because they have strong muscles in their legs and they are top heavy        ?
699389
To allow positive and negative motion so that you can bend the elbow or the leg.  Gotta have one to push and one to pull it back.
215857
Because they think with the wrong head.
94957
A person has not learnt cycling, if he has not experienced falling while cycling. So don't be afraid of being hit and just continue doing your sports.
735414
Not all mountain bikers do that.  Watch a pro sometime.  Some mountain bikers prefer to mash, but some prefer to spin.  I aim to spin.  I shift down, keep my cadence as steady as possible and keep my momentum up.  However, occasionally, due to a technical feature, a turn or a super steep hill, I end up mashing a bit more.  \n\nYou will be much more efficient if you spin, however, occasionally, being able to mash up a short steep hill can be beneficial.
1010298
Other than a cardiovascular workout, it strengthens legs (upper and lower) and buttox. Long distance or terrain riding can strenthen upper body over time if enough resistance it provided. And cycling is fun!