strange anti-cycling posters up in Howth

magicbastarder

thejaguar wrote: »

who's brakes are better?

are we talking about disc or rim brakes here?

P_1

thejaguar wrote: »

Genuine question:

If a bike and a car are travelling at 40kmh and need to make an emergency stop - say a child runs on to the road - who's brakes are better?

I feel like I might stop more quickly and with more control in the car. I'd almost certainly fall off the bike.

I'd imagine the car as it would have 4 powerful hydraulic brakes whereas a bike would only have the 2. Certainly the case with a bike with rim brakes but a bike with disk brakes may fare better if that makes any sense

Doeshedare

My family live in Howth (above the village) and I was speaking with them at the weekend. I cycle, they don't. I argued strongly against the posters and in the end their main issue came down to 'speeding' into the village. I rarely cycle down that side but when I do it is probably at about 30 and ready to stop if necessary, when I drive it is about the same speed and with the same attitude. I fairly sure I would find it harder to stop on a bike than in a car while going steeply downhill at a given speed but maybe that's me.
One of the things that annoys me about car drivers is their lack of appreciation of what it is like for the other road users outside their bubble- so they pass too close (serious) and don't let pedestrians cross the road in pissing rain (not so serious) etc etc. I find myself falling into this behaviour when driving as well. Sometimes cyclists are guilty of this too - 'I can stop on in an instant while going downhill at 50kph through a village so that freaked out oul wan I just passed shouldn't be so ignorant'.
As for the two abreast going uphill, the family weren't too happy with this but then when I am soloing up the hill they get in my way too so I am not so happy either...doesn't mean its wrong though.

07Lapierre

magicbastarder wrote: »

are we talking about disc or rim brakes here?

How far away is the child?
Has the child seen the car/bike or is it oblivious to everything?
Is the road wet or dry?
Is there traffic coming in the opposite direction?
Is there traffic coming behind a cyclist or a car?

These are all factors that will affect the outcome..

OleRodrigo

Arequipa wrote: »

We could just single out... Be nice about it!

So the posters were ott... But i think local people in Howth have some valid points to raise....


A

Agreed

But, its hard to keep a chat going with your cycling buddies and maintain awareness of traffic, particularly going up through the village on the narrow stretch until past the Asgard road lights ( and at some points on the Carrickbrack road ). Its easier just to let the cars wait and continue your chat - after all the law is on your side. But is it good manners?

This is compounded by executing hill start maneuvers to overtake, at some points, or as Mercian Pro pointed out, to cut across the road. There are a lot of elderly and retirees around the area. The volume of cycling groups at weekends and the maneuvers some local motorists need to make to engage with them safely are stressful.

A bit of consideration for locals around the village church and by St Fintans cemetery will improve the relations, IMO.

As for those elephants, some intervals on the hill will sort that out. But keep the thick skin

buffalo

Arequipa wrote: »

essentially a cul de sac of a road

Where is this cul de sac? Are all the drivers frustrated by cyclists heading to the golf club? Or to the summit car park? The statistics show that most riders are doing a loop, or one side or the other of that loop, or variations of it.

magicbastarder

P_1 wrote: »

I'd imagine the car as it would have 4 powerful hydraulic brakes whereas a bike would only have the 2.

but the car is also carrying probably between ten and twenty times the kinetic energy, so they kinda cancel out.
last time i remember trying to find out, the thinking seemed to be that bikes had longer braking distances than cars, but certainly less than twice the distance. will try to find the link again.

magicbastarder

07Lapierre wrote: »

How far away is the child?

and most importantly, is the child wearing hi-vis?

Chips Lovell

Forget whether you're on a bike or in a car. The same practice should apply regardless: travel at a speed that will give you enough to time to react should you encounter a hazard.

Fighting Tao

thejaguar wrote: »

Genuine question:

If a bike and a car are travelling at 40kmh and need to make an emergency stop - say a child runs on to the road - who's brakes are better?

I feel like I might stop more quickly and with more control in the car. I'd almost certainly fall off the bike.

Genuine question. How many people have been killed by mechanically propelled vehicles compared to cyclists? I think your risk assembly methods are wrong.

If a cyclist or motorist travel at 40 kph without due care and attention in a 50 kph zone then they are both breaking the law. I know which I'd prefer hitting me though.

magicbastarder

if a child runs out in front of you and you're on a bike, braking to one side, you've more leeway to swerve than in a car - simply due to being far narrower than a car.

07Lapierre

A cyclist also has a greater chance of avoiding any obstacles as they travel at lower speeds and can usually pass/overtake the "obstacle".

On a narrow roads, cars are much more dependent on their brakes as overtaking/passing any obstacle is much harder due to the narrowness of the road and the width of modern cars.

Also, most cars are fitted with ABS brakes which actually INCREASE braking distances, as it's intended to assist a driver to steer while braking. So cars are designed to overtake/pass obstacles, which is not possible most of the time!

One last point. Most drivers never "practice" emergency braking, which I think should be part of the driving test.

magicbastarder

i have heard urban legends - but know of no actual examples - of drivers not realising what is going on when the brake pedal judders because of ABS, and lifting off.

seamus

thejaguar wrote: »

Genuine question:

If a bike and a car are travelling at 40kmh and need to make an emergency stop - say a child runs on to the road - who's brakes are better?

I feel like I might stop more quickly and with more control in the car. I'd almost certainly fall off the bike.

As others express here, it's actually not that simple and is very multi-factorial.
Cars have stronger brakes, wider tyres and are heavier. Although weight is a factor in how much energy it requires to stop, it's also a relatively important factor in emergency stops; heavier vehicles have more grip on the road if the wheels lock.

On paper the energy required to stop a cyclist is far less, in practice the actual act of braking by the cyclist may take longer than the car for a multitude of reasons, be that fear, poor braking performance, poor traction, etc etc.

Ultimately a cyclist hitting anything at 40km/h will cause far less damage (to the 3rd party) than a car, but as Jep points out everyone travelling in any mode of travel shouldn't be travelling faster than would allow them to stop in the distance they know to be clear.

So the argument about who can stop faster is kind of moot. One cyclist might feel that 30km/h is the safest speed for them on a particular stretch, another might feel that 40km/h is fine for them and a motorist might think 50km/h is fine.

And they can all be correct at the same time, because they can all stop within the distance they know to be clear.

07Lapierre

magicbastarder wrote: »

i have heard urban legends - but know of no actual examples - of drivers not realising what is going on when the brake pedal judders because of ABS, and lifting off.

I work in the motor trade... lots of people call me to report faults with their brakes... judder from the pedal/ warning light on the dash etc.
I had one guy tell me gets the same fault at the same junction every morning. When I asked a few questions, turned out the right road wheel was hitting gravel each time he brakes and the ABS/traction control was kicking in!

magicbastarder

you're familiar with the story of the toyota 'stuck accelerator' i guess? i was listening to malcolm gladwell's podcast on it recently.

07Lapierre

magicbastarder wrote: »

you're familiar with the story of the toyota 'stuck accelerator' i guess? i was listening to malcolm gladwell's podcast on it recently.

Haven't heard that podcast but yes...we got lots of calls after that!

rodneyTrotter.

Another danger point worth noting . If you're coming down the hill towards the graveyard , there is a building site on the left . They have railings outside and this obstructs a vehicle coming out . I've had to brake suddenly there twice now as a car came out.
I avoid the village most times by heading up the hill to the summit and turning around and coming back . The descent into Howth with the traffic lights etc isn't as enjoyable but you do have to have your wits about you cycling around there mainly due to bad inconsiderate driving.

magicbastarder

07Lapierre wrote: »

Haven't heard that podcast but yes...we got lots of calls after that!

http://revisionisthistory.com/episodes/08-blame-game

worth 40 minutes or so.

Moflojo

Building on my earlier suggestion for a one-way traffic system around Howth, here's my suggestion for how it might work. I'd be inclined to retain a two-way system through Howth village itself. There are plenty of counter-flow back routes to make it easy for locals to get to the city centre or into Howth village.

Such a one-way traffic system would allow one traffic lane of the existing road space to be given over to a dedicated two-way cycle path. Who could possibly be against that?

(@buffalo I stole your map graphic - what is the source for it? It's a very clear graphic.)

C3PO

Thankfully I live in Shankill and have the "Garden of Ireland" on my doorstep ... rarely bother with the hazards of Howth!!

morana

Moflojo wrote: »

Building on my earlier suggestion for a one-way traffic system around Howth, here's my suggestion for how it might work. I'd be inclined to retain a two-way system through Howth village itself. There are plenty of counter-flow back routes to make it easy for locals to get to the city centre or into Howth village.

Such a one-way traffic system would allow one traffic lane of the existing road space to be given over to a dedicated two-way cycle path. Who could possibly be against that?

(@buffalo I stole your map graphic - what is the source for it? It's a very clear graphic.)

you need to consider fat blokes like myself...i will never make it up the steep side....ah ok 2 way dedicated cycling lanes for Howth. I like it

thejaguar

07Lapierre wrote: »

Genuine answer: Fine, don't cycle at 40kph if you are not comfortable doing so.

Helpful advice, thanks.
Doesn't answer the question at all though.

thejaguar

07Lapierre wrote: »

How far away is the child?
Has the child seen the car/bike or is it oblivious to everything?
Is the road wet or dry?
Is there traffic coming in the opposite direction?
Is there traffic coming behind a cyclist or a car?

These are all factors that will affect the outcome..

Rim or disk brakes? Rim
How far away is the child? 100 metres (not actually relevant to the question)
Has the child seen the car/bike or is it oblivious to everything? Oblivious (not actually relevant to the question)
Is the road wet or dry? Dry (possibly relevant to the question)
Is there traffic coming in the opposite direction? No (not actually relevant to the question)
Is there traffic coming behind a cyclist or a car? No (not actually relevant to the question)

Can you answer now? Which brakes are better?

07Lapierre

thejaguar wrote: »

Helpful advice, thanks.
Doesn't answer the question at all though.

Sorry, wasn't meant to be offensive. I thought it was helpful. I'm not comfortable cycling over 50kph thru Howth, so i don't.

thejaguar

07Lapierre wrote: »

Sorry, wasn't meant to be offensive. I thought it was helpful. I'm not comfortable cycling over 50kph thru Howth, so i don't.

Fair enough. I'm the same - I was just wondering who could actually stop first. I think some people (me included I think) feel safer with a car coming towards them - because they are more used to it perhaps.

I get the multiple factors that come into play - including which I'd prefer to be hit by.

P_1

magicbastarder wrote: »

but the car is also carrying probably between ten and twenty times the kinetic energy, so they kinda cancel out.
last time i remember trying to find out, the thinking seemed to be that bikes had longer braking distances than cars, but certainly less than twice the distance. will try to find the link again.

Thinking about I'd say that while the car would need more energy to stop the brakes on a car would have a lot more than the brakes on a bike. If you apply good old f=ma or some kind of a derivative just like how a car can accelerate quicker it would also decelerate quicker.

Of couse a side by side controlled experiment could sort that out one way or the other

Weepsie

You're comparing apples and oranges though. I'd be confident the brakes I have on my bike are maintained well enough that the child need not worry. * Except my cx bike, they're completely shot at the moment

07Lapierre

thejaguar wrote: »

Can you answer now? Which brakes are better?

All my questions are relevant and the fact that you don't think they are says a lot.

Does the car have ABS/ESP?
Is the driver experienced?
Is the driver on the phone?
Is the driver on any medication?

Do you know for a fact the answers to these questions?

magicbastarder

thejaguar wrote: »

How far away is the child? 100 metres (not actually relevant to the question)
Is the road wet or dry? Dry (possibly relevant to the question)
Can you answer now? Which brakes are better?

with 100m to play, a bike descending on a 9% grade (not far off the steeper sections on howth) has enough time to brake from 50km/h.
that's according to this link, and does seem to include reaction times:
http://www.muggaccinos.com/Liability/BrakeCalcs/Braking_formula/TwoDistanceToBrakeToStopFormulae.htm