Acceleration from a standstill - truth or misconception?
Discussion
Afternoon all.
I've quite frequently seen people on here in various threads commenting that bikes accelerate faster than cars from a standing start. Is this really the case?
Certainly in every day life, I have the impression that it is, but then again given that this is primarily a motoring forum, I'm sure I'm not the only person who frequently finds myself second or third car back, utterly bemused as to how the person at the front can actually make their car pull away as slowly as they do without stalling.
So, is there anything out there to show that bikes really can accelerate faster than cars over that initial short distance, or is this just a misconception based on the fact that most drivers don't bother putting their foot down?
I've quite frequently seen people on here in various threads commenting that bikes accelerate faster than cars from a standing start. Is this really the case?
Certainly in every day life, I have the impression that it is, but then again given that this is primarily a motoring forum, I'm sure I'm not the only person who frequently finds myself second or third car back, utterly bemused as to how the person at the front can actually make their car pull away as slowly as they do without stalling.
So, is there anything out there to show that bikes really can accelerate faster than cars over that initial short distance, or is this just a misconception based on the fact that most drivers don't bother putting their foot down?
robbyd said:
for the first four metres?
In the context of most of the times I see it talking about getting in front of traffic off the lights, then yes, I'd say about that sort of distance.It doesn't need to be overly scientific. I just got bored and this was what popped into my mind!
If you are talking about a side by side drag race, the car sitting holding revs ,then dumping the clutch, I would suggest a car will be quicker.
In the scenario of a set of traffic lights, someone waiting for a green, taking handbrake off pulling away, i think that a bike will always have the initial jump on the car.
In the scenario of a set of traffic lights, someone waiting for a green, taking handbrake off pulling away, i think that a bike will always have the initial jump on the car.
OK, applying a little bit of SCIENCE here.
Accelerating from 0 to 20mph in a normal-ish 5 seconds is an acceleration of 1.788 m/s/s.
To accelerate a 1500kg car at 1.788m/s/s requires 2.682 kN.
To accelerate a 100kg bike and rider at 1.788m/s/s requires 0.1788kN.
An average car probably puts out about 100lb/ft at 2000rpm = 40bhp = 28,000W.
An average cyclist can probably put out 750W for a handful of seconds.
Erm... So, yes.
Accelerating from 0 to 20mph in a normal-ish 5 seconds is an acceleration of 1.788 m/s/s.
To accelerate a 1500kg car at 1.788m/s/s requires 2.682 kN.
To accelerate a 100kg bike and rider at 1.788m/s/s requires 0.1788kN.
An average car probably puts out about 100lb/ft at 2000rpm = 40bhp = 28,000W.
An average cyclist can probably put out 750W for a handful of seconds.
Erm... So, yes.
Gizmoish said:
OK, applying a little bit of SCIENCE here.
Accelerating from 0 to 20mph in a normal-ish 5 seconds is an acceleration of 1.788 m/s/s.
To accelerate a 1500kg car at 1.788m/s/s requires 2.682 kN.
To accelerate a 100kg bike and rider at 1.788m/s/s requires 0.1788kN.
An average car probably puts out about 100lb/ft at 2000rpm = 40bhp = 28,000W.
An average cyclist can probably put out 750W for a handful of seconds.
Erm... So, yes.
Excellent work. I will now tell my friends I'm quicker than a veyron Accelerating from 0 to 20mph in a normal-ish 5 seconds is an acceleration of 1.788 m/s/s.
To accelerate a 1500kg car at 1.788m/s/s requires 2.682 kN.
To accelerate a 100kg bike and rider at 1.788m/s/s requires 0.1788kN.
An average car probably puts out about 100lb/ft at 2000rpm = 40bhp = 28,000W.
An average cyclist can probably put out 750W for a handful of seconds.
Erm... So, yes.
My old VX220 Turbo was pretty quick off the line, and after owning the car for years I'd gotten reasonably handy with it.
Straight line, off the mark... Bikes piss on cars so hard it's not even funny.
I'd easily see them off on the twisties, but unless you're in a GTR (scary fast) there's no point.
NB. I'm not a charv.
Straight line, off the mark... Bikes piss on cars so hard it's not even funny.
I'd easily see them off on the twisties, but unless you're in a GTR (scary fast) there's no point.
NB. I'm not a charv.
MocMocaMoc said:
My old VX220 Turbo was pretty quick off the line, and after owning the car for years I'd gotten reasonably handy with it.
Straight line, off the mark... Bikes piss on cars so hard it's not even funny.
I'd easily see them off on the twisties, but unless you're in a GTR (scary fast) there's no point.
NB. I'm not a charv.
Ha! Sorry, I thought motorbikes...Straight line, off the mark... Bikes piss on cars so hard it's not even funny.
I'd easily see them off on the twisties, but unless you're in a GTR (scary fast) there's no point.
NB. I'm not a charv.
MocMocaMoc said:
My old VX220 Turbo was pretty quick off the line, and after owning the car for years I'd gotten reasonably handy with it.
Straight line, off the mark... Bikes piss on cars so hard it's not even funny.
I'd easily see them off on the twisties, but unless you're in a GTR (scary fast) there's no point.
NB. I'm not a charv.
Slowest vx220 everStraight line, off the mark... Bikes piss on cars so hard it's not even funny.
I'd easily see them off on the twisties, but unless you're in a GTR (scary fast) there's no point.
NB. I'm not a charv.
Love this thread. I'm forever getting held up by cars slow away at lights and junctions. Damned annoying, when you you give it everything you've got, only for Dawdling Derek to seemingly forget the fact that there's more than one gear in his box, and have to back off. There is after all no point in passing the car, as the driver will take it as a personal offence, and then drive like a complete dick to 're-take' his/her 'rightful place' ahead of the PITA cyclist.
If there's space, and time, I'll get myself to the front of the queue, to the right of waiting cars. I'm always careful, and don't pass the lead vehicle if I'm in in any doubt as to it's intention and the time I have to get past safely. If I get it properly right, I time it so that I don't need to unclip, and give it what for from a rolling start. Only been beaten in that situation once, by an orange GT3 who's driver was obviously up for some sport (grinning like a loon as he floored it).
From a standing start, it depends if I can clip in first time, but again, if it's done right, I can lift the front wheel up for the first 4/5 complete pedal revolutions. I've no idea what it looks like from a driver's point of view - I probably come across as a complete lunatic - but I don't care. I get all of my power down right from the get-go, and I'm across the junction, usually well before the first couple of drivers have woken up. Getting that extra bit of breathing space is vital, I reckon, to ensure my personal safety.
It's also nice to get one over on the knobbers who absolutely MUST overtake you on the approach to the back of a long line of queuing traffic. Childish, I know, but there you go. Little things.....
....all I have to do now is to train harder, so the rest of my ride matches the impressive drag strip start that I've developed. Which means I need to get out on the bike more. Which will inevitably, at this time of year, mean getting cold and wet. Looks like I will have to become a Badass. Period.
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
If there's space, and time, I'll get myself to the front of the queue, to the right of waiting cars. I'm always careful, and don't pass the lead vehicle if I'm in in any doubt as to it's intention and the time I have to get past safely. If I get it properly right, I time it so that I don't need to unclip, and give it what for from a rolling start. Only been beaten in that situation once, by an orange GT3 who's driver was obviously up for some sport (grinning like a loon as he floored it).
From a standing start, it depends if I can clip in first time, but again, if it's done right, I can lift the front wheel up for the first 4/5 complete pedal revolutions. I've no idea what it looks like from a driver's point of view - I probably come across as a complete lunatic - but I don't care. I get all of my power down right from the get-go, and I'm across the junction, usually well before the first couple of drivers have woken up. Getting that extra bit of breathing space is vital, I reckon, to ensure my personal safety.
It's also nice to get one over on the knobbers who absolutely MUST overtake you on the approach to the back of a long line of queuing traffic. Childish, I know, but there you go. Little things.....
....all I have to do now is to train harder, so the rest of my ride matches the impressive drag strip start that I've developed. Which means I need to get out on the bike more. Which will inevitably, at this time of year, mean getting cold and wet. Looks like I will have to become a Badass. Period.
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
Gizmoish said:
OK, applying a little bit of SCIENCE here.
Accelerating from 0 to 20mph in a normal-ish 5 seconds is an acceleration of 1.788 m/s/s.
To accelerate a 1500kg car at 1.788m/s/s requires 2.682 kN.
To accelerate a 100kg bike and rider at 1.788m/s/s requires 0.1788kN.
An average car probably puts out about 100lb/ft at 2000rpm = 40bhp = 28,000W.
An average cyclist can probably put out 750W for a handful of seconds.
Erm... So, yes.
Yes, if you dawdle like hell from every junction. At full crack, I'd be at 64 ish mph after 5 seconds. I reckon in normal driving, 0-20 would be more like 3s max. Accelerating from 0 to 20mph in a normal-ish 5 seconds is an acceleration of 1.788 m/s/s.
To accelerate a 1500kg car at 1.788m/s/s requires 2.682 kN.
To accelerate a 100kg bike and rider at 1.788m/s/s requires 0.1788kN.
An average car probably puts out about 100lb/ft at 2000rpm = 40bhp = 28,000W.
An average cyclist can probably put out 750W for a handful of seconds.
Erm... So, yes.
Meanwhile, on my bike I try not to get in anyone's way, so do tend to launch from junctions as quick as possible to avoid frustrating drivers - and there's no chance I'm pulling 750 watts!
contango said:
yellowjack...clip in 1st time?....That's what a track-stand is for!
Aye, but I can't hold a track-stand indefinitely! There are quite a few traffic lights which I know have a long phase on red, and if they've just turned to red there's too much potential for embarrassment if I try showing off. Best to swallow my pride and unclip so that I can avoid renewing my membership to 'That Club' in full view of the public 
Some Gump said:
Yes, if you dawdle like hell from every junction. At full crack, I'd be at 64 ish mph after 5 seconds. I reckon in normal driving, 0-20 would be more like 3s max.
Meanwhile, on my bike I try not to get in anyone's way, so do tend to launch from junctions as quick as possible to avoid frustrating drivers - and there's no chance I'm pulling 750 watts!
You'll note that my example referred to an average car and cyclist being driven up to a normal normal that both could achieve. On a quarter-mile strip I expect most pro cyclists would lose to a G-Waz. Meanwhile, on my bike I try not to get in anyone's way, so do tend to launch from junctions as quick as possible to avoid frustrating drivers - and there's no chance I'm pulling 750 watts!
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