busy with exams till this fri! meanwhile something to share:
motorcycle physics: http://www.motorcyclejazz.com/motorcycle_physics.htm
meanwhile ride safe!
28 November 2012
12 November 2012
wobble?? - part 2, wobble while stopping! / braking
situation 2: wobble when stopping - when does wobble occurs when you are almost slowing down?
some reasons are there, but what you need to know before hand is smooth stopping is related to:
a) slow speed control
b) bike stability management in terms of rear wheel gyroscopic force
reason 1. overuse of brakes! i.e. harsh braking; braking too late??; rushed braking?
> suspension dips! if u hard brake on front, front fork will dip down!
same thing - apply the rear brakes hard and the rear shocks will also dip the bike down!
this basically means that any of this harsh braking will result in upsetting the balance of the bike at low speed!
this will subsequently affect your balance and hence result in a wobble!
solution:
you do not need to use maximum braking force when slowing down. if there's a need to use harsh braking, that means you're braking too late.
key thing is: plan when you want to brake, and plan your time to brake!
* all that is required is engine braking by closing the throttle to slow down and applying the brakes with your finger TIPS so that u do not snatch the brake lever.
know your brake biting point! braking effort should be smooth and natural.
the next time you brake, make an effort to feel for the point where the brake lever starts to slow the bike - that is your biting point. this ability to feel the braking will be even more crucial during e-brake in 3.02. =D
* when to close the throttle? the recommended time if u are braking while in gear 1 or 2 is half the distance before spot u want to stop. (take note if in already in gear 1, remb to clutch in at the same time when u close throttle!)
of course, this may defer from person to person.
* one last thing is to know when you operate the brakes, u should reduce the pressure on the brake lever and the brake pedal gradually. this will reduce the sudden change in momentum and suspension that will result in the stopping wobble. (FYI: this refers to driving a car as well, not just motorcycles!)
>> **note that this is even more important when you pillion next time: this is for the comfort and safety of your pillion rider.
reason 2: rushing to land and put down your foot?
this is similar to when you wobble during moving off - your bike is moving relatively slow when you're almost stopping and the bike is now stable with minimum gyroscopic (upright force) from the rear wheel.
at this very moment before stopping, sudden movement will cause the bike to wobble.
don't rush to put down your foot! u will be stable the moment
if you can stop smoothly and have time to land that left foot. (surprisingly, this is usually coupled with anxiousness or kan chiong spideness with random snatching of the brakes.. see reason 1)
solution
a. momentum must be right when you put down the foot. not too fast, not too slow!
if too fast, you will rush to stop, too slow, your bike doesn't have enough momentum to stay upright and wobbbbble you go!
b. don't rush, feel for the moment when the bike almost stops while stable in a straight line*
c. keep bike in a straight line! *LOOK UP* while your doing so. (this actually leads to reason 3)
d. unfortunately, this needs practice. you need to learn to feel the bike momentum with your body and your butt especially to gauge how the bike is moving before you put down that foot.
e. this landing of the foot should be synchronized with your gradual release of brake pressure when your braking is almost complete.
reason 3. looking down when u brake?
as mentioned before, the eyes of the rider is the aiming device of the motorcycle.
this adage holds even when you're stopping and you decided to look down instead.. immediately you will lose balance and wobble!
"LOOK WHERE YOU WANT TO GO"
if you look down, and don't look up, u will upset your balance
i cant explain in detail why this happens sufficiently but somehow this is the dominant rule all riders had to deal with when learning.
hence the simplest solution is:
*LOOK UP and through the horizon when your almost stopped and keep it that way!
alternatively, if there is another rider stopped ahead of you, LOOK UP and look through his/her helmet.
this will ensure you fixate your gaze at the correct level.
if you fear not stopping at the correct spot before the stop line, and find yourself having to look down to gauge your stopping distance, this also means you have to plan your stopping ahead of time!
do not do panic stops or last minute stops! that is solely reserved for e-brakes!!
so now what? in summary - what to practice as part of your stopping skill sets
- before every lesson commence, always check the amount of braking pressure that you need to exert for different levels of braking pressure!
- make sure you know your brake biting pt to avoid front wheel lock/skid or any jerks in your bike suspension when stopping!
- only finger tips only ! do not use your knuckle to brake!
- when braking, change down gear early, make full use of engine braking, look up through the horizon, make sure your handlebars are straight and not turned to the side!
- momentum must be right - feather the brakes or use light braking pressure, and not too slow on final stopping of bike!
- know the moment when your left foot should stick out and land forward down before stopping that causes the least shift in the bike momentum at slow speed!
you might want to look at this link on braking, especially on staged braking (point 10)
http://www.webbikeworld.com/Motorcycle-Safety/braking-tips.htm
on a final note: avoid last minute braking situations. be aware of your surroundings and maintain good following distance. part of the accidents out there involving riders include wheel skidding and lost of control. as a class 2b trainee, your role is to learn the skills of bike control well so that you do not panic and make the wrong move under such situations. I'm saying that because i skidded my phantom and almost didn't make it.. so...
meanwhile good luck in your lessons and ill try to cover the the other wobbles that you will encounter during lane check / blind spot checking and during turning of your motorcycle!
some reasons are there, but what you need to know before hand is smooth stopping is related to:
a) slow speed control
b) bike stability management in terms of rear wheel gyroscopic force
reason 1. overuse of brakes! i.e. harsh braking; braking too late??; rushed braking?
> suspension dips! if u hard brake on front, front fork will dip down!
same thing - apply the rear brakes hard and the rear shocks will also dip the bike down!
this basically means that any of this harsh braking will result in upsetting the balance of the bike at low speed!
this will subsequently affect your balance and hence result in a wobble!
solution:
you do not need to use maximum braking force when slowing down. if there's a need to use harsh braking, that means you're braking too late.
key thing is: plan when you want to brake, and plan your time to brake!
* all that is required is engine braking by closing the throttle to slow down and applying the brakes with your finger TIPS so that u do not snatch the brake lever.
know your brake biting point! braking effort should be smooth and natural.
the next time you brake, make an effort to feel for the point where the brake lever starts to slow the bike - that is your biting point. this ability to feel the braking will be even more crucial during e-brake in 3.02. =D
* when to close the throttle? the recommended time if u are braking while in gear 1 or 2 is half the distance before spot u want to stop. (take note if in already in gear 1, remb to clutch in at the same time when u close throttle!)
of course, this may defer from person to person.
* one last thing is to know when you operate the brakes, u should reduce the pressure on the brake lever and the brake pedal gradually. this will reduce the sudden change in momentum and suspension that will result in the stopping wobble. (FYI: this refers to driving a car as well, not just motorcycles!)
>> **note that this is even more important when you pillion next time: this is for the comfort and safety of your pillion rider.
reason 2: rushing to land and put down your foot?
this is similar to when you wobble during moving off - your bike is moving relatively slow when you're almost stopping and the bike is now stable with minimum gyroscopic (upright force) from the rear wheel.
at this very moment before stopping, sudden movement will cause the bike to wobble.
don't rush to put down your foot! u will be stable the moment
if you can stop smoothly and have time to land that left foot. (surprisingly, this is usually coupled with anxiousness or kan chiong spideness with random snatching of the brakes.. see reason 1)
solution
a. momentum must be right when you put down the foot. not too fast, not too slow!
if too fast, you will rush to stop, too slow, your bike doesn't have enough momentum to stay upright and wobbbbble you go!
b. don't rush, feel for the moment when the bike almost stops while stable in a straight line*
c. keep bike in a straight line! *LOOK UP* while your doing so. (this actually leads to reason 3)
d. unfortunately, this needs practice. you need to learn to feel the bike momentum with your body and your butt especially to gauge how the bike is moving before you put down that foot.
e. this landing of the foot should be synchronized with your gradual release of brake pressure when your braking is almost complete.
reason 3. looking down when u brake?
as mentioned before, the eyes of the rider is the aiming device of the motorcycle.
this adage holds even when you're stopping and you decided to look down instead.. immediately you will lose balance and wobble!
"LOOK WHERE YOU WANT TO GO"
if you look down, and don't look up, u will upset your balance
i cant explain in detail why this happens sufficiently but somehow this is the dominant rule all riders had to deal with when learning.
hence the simplest solution is:
*LOOK UP and through the horizon when your almost stopped and keep it that way!
alternatively, if there is another rider stopped ahead of you, LOOK UP and look through his/her helmet.
this will ensure you fixate your gaze at the correct level.
if you fear not stopping at the correct spot before the stop line, and find yourself having to look down to gauge your stopping distance, this also means you have to plan your stopping ahead of time!
do not do panic stops or last minute stops! that is solely reserved for e-brakes!!
so now what? in summary - what to practice as part of your stopping skill sets
- before every lesson commence, always check the amount of braking pressure that you need to exert for different levels of braking pressure!
- make sure you know your brake biting pt to avoid front wheel lock/skid or any jerks in your bike suspension when stopping!
- only finger tips only ! do not use your knuckle to brake!
- when braking, change down gear early, make full use of engine braking, look up through the horizon, make sure your handlebars are straight and not turned to the side!
- momentum must be right - feather the brakes or use light braking pressure, and not too slow on final stopping of bike!
- know the moment when your left foot should stick out and land forward down before stopping that causes the least shift in the bike momentum at slow speed!
you might want to look at this link on braking, especially on staged braking (point 10)
http://www.webbikeworld.com/Motorcycle-Safety/braking-tips.htm
on a final note: avoid last minute braking situations. be aware of your surroundings and maintain good following distance. part of the accidents out there involving riders include wheel skidding and lost of control. as a class 2b trainee, your role is to learn the skills of bike control well so that you do not panic and make the wrong move under such situations. I'm saying that because i skidded my phantom and almost didn't make it.. so...
meanwhile good luck in your lessons and ill try to cover the the other wobbles that you will encounter during lane check / blind spot checking and during turning of your motorcycle!
09 November 2012
sorry folks, i have been busy with work and motorcycle maintenance since i passed months back!
perhaps will cover some part of the experience as a new rider here..
well.. class 2b isnt as simple as just passing and getting yr licence!
somethings i'll wish to cover in the future with time to come..
1. u-turns!
2. a proper lane change! (and why this is impt in the real nasssssty world
3. part 3 and 4 on wobble!
4. class 2b cheat sheet =DDDD
5. things to know or be concerned about after your class 2b when u want to get a bike or already have a bike but is lossst
i'll try to time my updates on Sundays so at least there's something to read! =DD
meanwhile enjoy learning and RIDE SAFE.
10 July 2012
motorcycle control - control sensitivity
by the end of class 2b lessons, the below finer details of bike control should be familiar then:
- throttle sensitivity:
- jerking the throttle causes sudden changes in momentum
- eye point:
- looking ahead, planning ahead, looking where you want to go
- clutch sensitivity:
- use finger tips to control,
- control the rear wheel's willingness to upright due to gyroscopic forces,
- controls low speed,
- must be able to link to rear wheel's response and rolling momemtum
- front brake/rear brake:
- brake's biting point,
- ability to squeeze hard like squeezing a lemon and not snatching the brake,
- 4 stages of braking
- and also not locking up the wheels
- butt sensitivity:
- to sense wheel traction,
- to sense momentum of rear wheel at low speed
- and changes in suspension position due to acceleration/deceleration changes
- to be further continued...
wobble? - part 1
intro
what never fails to intrigue me was the instructors always deduct points for 8.01, 5.02, 4.02 for WOBBLE. i had spent most of the time during my free time wondering if "wobble" is just a ill conceived notion to make us repeat modules and take more lessons =D
most of us will not be able to detect wobble in the beginning stages of learning, at least until we see one for ourselves. i had learnt to recognize one when i first spotted someone wobbling on his cruiser.
(it was pretty obvious 'cos the bajaj avenger had a really long wheel base and u can really see wobble in slowwww-mo)
to simplify, a wobble to my own understanding is given that your bike is on 2 wheels rolling along, the bike wobbles when it either tilts to the side and back and so on!
(you can visualise it as a roly poly toy tilting side to side only that your bike is still rolling forward!) see http://en.wikipedia.org/wiki/Roly-poly_toy
i.e. to say, the balance of the bike was UPSET when the wobble occurs while the bike was rolling forward.
you will note that the bike does not really wobble when the bike is turning or cornering.
(more on that later, when i discuss moving off from stopping with a sharp turn in a later post)
so when does your bike wobble?
the first key important thing is eye-point.
this applies to all 3 situations.
it seems that as long the head and the eye points towards a certain area, the bike will go there!
you may consider your eye, nose and the level of your chin as a motorcycle path aiming device!
i.e. to say to avoid wobble, heads up level, focus on something far, so as to get used to the head position required!
- look up and don't look down when you're moving off!
- look up and don't look down when you are braking to stop!
- look up at something in the horizon.
if a biker is in front of you "see" through his/her helmet!
this is repetitive, but it make sense! you have to try to know it.
situation 1: moving off
besides eye-point, wobble occurs commonly when you rush to bring your left foot up onto the pegs!
this would probably more obvious when you're practicing low speed control.
guide line:
i'll post more on situations 2 and 3 in a later post.
what never fails to intrigue me was the instructors always deduct points for 8.01, 5.02, 4.02 for WOBBLE. i had spent most of the time during my free time wondering if "wobble" is just a ill conceived notion to make us repeat modules and take more lessons =D
most of us will not be able to detect wobble in the beginning stages of learning, at least until we see one for ourselves. i had learnt to recognize one when i first spotted someone wobbling on his cruiser.
(it was pretty obvious 'cos the bajaj avenger had a really long wheel base and u can really see wobble in slowwww-mo)
to simplify, a wobble to my own understanding is given that your bike is on 2 wheels rolling along, the bike wobbles when it either tilts to the side and back and so on!
(you can visualise it as a roly poly toy tilting side to side only that your bike is still rolling forward!) see http://en.wikipedia.org/wiki/Roly-poly_toy
i.e. to say, the balance of the bike was UPSET when the wobble occurs while the bike was rolling forward.
you will note that the bike does not really wobble when the bike is turning or cornering.
(more on that later, when i discuss moving off from stopping with a sharp turn in a later post)
so when does your bike wobble?
- when you're moving off
- when you're stopping
- when you are checking your blind spot,especially when you're doing your lane change!
the first key important thing is eye-point.
this applies to all 3 situations.
it seems that as long the head and the eye points towards a certain area, the bike will go there!
you may consider your eye, nose and the level of your chin as a motorcycle path aiming device!
i.e. to say to avoid wobble, heads up level, focus on something far, so as to get used to the head position required!
- look up and don't look down when you're moving off!
- look up and don't look down when you are braking to stop!
- look up at something in the horizon.
if a biker is in front of you "see" through his/her helmet!
this is repetitive, but it make sense! you have to try to know it.
situation 1: moving off
besides eye-point, wobble occurs commonly when you rush to bring your left foot up onto the pegs!
this would probably more obvious when you're practicing low speed control.
guide line:
- if you're moving off and stopping within a bike distance, you do not have to bring up your left foot immediately! (hang your foot)
- if you're moving off and stopping beyond a bike's distance, bring up your left foot only when the bike has traveled straight with enough momemtum. foot should not be rushed to the peg or else it will upset the balance of the bike!
- for the more curious folks, a bike is around 2m in length. a car is typically 4m long.
- before the bike moves off, you're balancing the bike with your left foot, right foot holding the rear wheel stationary.
- when the bike moves off, 2 phases occur:
- 1: bike attempts to roll forward and is unstable. bringing up your foot will caused the bike to wobble!
- 2: bike gains enough forward momentum, feeding the throttle the rear wheel causes the rear wheel to upright due to gyroscopic effect!
- its only during the 2nd phase onwards u can start controlling your body position so that wobble does not occur with sudden adjustment of the body!
i'll post more on situations 2 and 3 in a later post.
02 July 2012
low speed control
important on motorcycle directional control:
****look UP, where you want to go!
your eyes and head should be horizontally up, pick a target point to look at e.g. a building in the horizon, or look through the helmet of the guy in front of you! =D
there is a saying that if you look at the ground or the kerb, you will hit the ground or kerb =)
moving off:
- open throttle slightly
- ease clutch out to the biting point
(if you find it difficult to maintain the clutch lever position at biting point, try using only your FINGERTIPS to release the clutch lever. it makes a BIG difference. holding the lever closer to the end makes it easier as well.)
- left foot should not go immediately up
- do not rush to bring your left foot to the foot peg; this will affect balance and cause WOBBLE
- left foot should go onto the foot peg only if the bike has gained momentum enough to maintain a straight line.
if distance too short, don't have to bring up left leg!
why? motorcycles are most stable when power is fed to the rear wheel and the bike is moving ina straight line. (read up on gyroscopic effect!)
that's when additional movement during this stage will cause less wobble. if the bike is still not stable yet with insufficient speed and still picking up momentum.
yes. bikes are more stable at higher speeds! at lower speeds feed more power to the rear wheel using the throttle for stability.. but power application should be smooth! (read: throttle sensitivity)
stopping (if / while in gear 1):
- identify your target stopping point early.
- at half the distance before the stopping point, close the throttle.
- once throttle closed, apply both brakes, but use more rear brake!
- do not snatch or use too much front brake!
(one instructor said, 99,9% rear brake, 0.1% front brake )
- whole point is, application of both brakes must be smooth!
WHY: if you apply brake suddenly, the suspension with respect to the brake you are applying DIPS down, i.e. it will jerk!
e.g. if you snatched the front brake, the front fork / wheel will sink down immediately!
do it hard enough it will jerk you forward and unbalance you off the bike!
give it a try to understand how it feels.
fyi: when i used to ride a bicycle i tend to use the front brake lever quite harshly. this actually gave me a hard time when i was trying to master and perfect motorcycle braking since i tended to snatch the front brake lever in the past.
one instructor taught me to use only my finger tips to apply the brake. i realised i have been using my knuckles to brake and the force using knuckles was too strong, that it always caused front jerks on my bike and i always lost balance in the beginning when trying to stop!
in fact i locked up my front wheel once because i braked too hard during emergency braking! (road rash for a month on my forearm was a harsh lesson on braking!)
****look UP, where you want to go!
your eyes and head should be horizontally up, pick a target point to look at e.g. a building in the horizon, or look through the helmet of the guy in front of you! =D
there is a saying that if you look at the ground or the kerb, you will hit the ground or kerb =)
moving off:
- open throttle slightly
- ease clutch out to the biting point
(if you find it difficult to maintain the clutch lever position at biting point, try using only your FINGERTIPS to release the clutch lever. it makes a BIG difference. holding the lever closer to the end makes it easier as well.)
- left foot should not go immediately up
- do not rush to bring your left foot to the foot peg; this will affect balance and cause WOBBLE
- left foot should go onto the foot peg only if the bike has gained momentum enough to maintain a straight line.
if distance too short, don't have to bring up left leg!
why? motorcycles are most stable when power is fed to the rear wheel and the bike is moving ina straight line. (read up on gyroscopic effect!)
that's when additional movement during this stage will cause less wobble. if the bike is still not stable yet with insufficient speed and still picking up momentum.
yes. bikes are more stable at higher speeds! at lower speeds feed more power to the rear wheel using the throttle for stability.. but power application should be smooth! (read: throttle sensitivity)
stopping (if / while in gear 1):
- identify your target stopping point early.
- at half the distance before the stopping point, close the throttle.
- once throttle closed, apply both brakes, but use more rear brake!
- do not snatch or use too much front brake!
(one instructor said, 99,9% rear brake, 0.1% front brake )
- whole point is, application of both brakes must be smooth!
WHY: if you apply brake suddenly, the suspension with respect to the brake you are applying DIPS down, i.e. it will jerk!
e.g. if you snatched the front brake, the front fork / wheel will sink down immediately!
do it hard enough it will jerk you forward and unbalance you off the bike!
give it a try to understand how it feels.
fyi: when i used to ride a bicycle i tend to use the front brake lever quite harshly. this actually gave me a hard time when i was trying to master and perfect motorcycle braking since i tended to snatch the front brake lever in the past.
one instructor taught me to use only my finger tips to apply the brake. i realised i have been using my knuckles to brake and the force using knuckles was too strong, that it always caused front jerks on my bike and i always lost balance in the beginning when trying to stop!
in fact i locked up my front wheel once because i braked too hard during emergency braking! (road rash for a month on my forearm was a harsh lesson on braking!)
prologue
the whole point of this blog is to document the knowledge gained during my lessons @ bbdc while taking my class 2b lessons. i've passed my class 2b assessment just recently.
learning to ride a motorcycle wasn't easy, especially when i toke my lessons at a later age where psychomotor skills ain't working so well for me.
to further add on, i was on the road riding a bicycle long before i took my class 3 and class 2b, so some cycling habits really do die hard during the beginning while i'm trying to master the basics.
i'll attempt to blog in an order where other future class 2b trainees would find it easier to reference their learning to their current stage (especially if you're from bbdc and yes SINGAPORE!)
also, the focus of my inputs here would be more on WHY certain things are done as opposed to just how they're done. i find it most useful and easier to learn when i understand why certain things are done that way especially to how a motorcycle behaves.
hope you've fun learning! the whole point is to get a class 2b license, not a CRASS 2b license!
learning to ride a motorcycle wasn't easy, especially when i toke my lessons at a later age where psychomotor skills ain't working so well for me.
to further add on, i was on the road riding a bicycle long before i took my class 3 and class 2b, so some cycling habits really do die hard during the beginning while i'm trying to master the basics.
i'll attempt to blog in an order where other future class 2b trainees would find it easier to reference their learning to their current stage (especially if you're from bbdc and yes SINGAPORE!)
also, the focus of my inputs here would be more on WHY certain things are done as opposed to just how they're done. i find it most useful and easier to learn when i understand why certain things are done that way especially to how a motorcycle behaves.
hope you've fun learning! the whole point is to get a class 2b license, not a CRASS 2b license!
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