Team-BHP - Art of taking Speed Breakers(humps) without scraping the belly.

Quote:

Originally Posted by mashmash (Post 2485496)

Thank You so much, shall give this a try.

Yes, I seem to be lugging the engine, once or twice it even went below 1000RPM and close to stalling. The problem is that engaging gear 1, while in motion, is not very smooth. Maybe I need to slow down some more, almost close to a halt and engage Gear 1. Is this the case with Esteem or all cars?

MaSh

Most cars I would say, unless you have some serious mods under the hood.

i drive on the same road everyday, so know which part of the breaker to go over.
howver, a standard practice i have now is whtever you speed you approach the hump at, let the front wheels go over, and then brake a little more once the front wheels are riding down the other side, and keep braking till the rear wheels start climbing.
scraping problem avoided.
physics tells me that the second braking transfers more weight forward, raising the bum by the at max 2-3 cm, which raises the mid-floor by the crucial millimetres to avoid scrapes.
of course, for extreme breakers, which were designed literally, the angled approach, or the go-back-home approach...:)

I recently did some 300 KM trip in My Honda City from Delhi - > Rohtak - > Jhajjar - > Gurgaon - > Faridabad - > Delhi.

In the entire trip I faced some very dangerous speed breakers while en route to Rohtak, Jhajjar and farukhnagar. We were four people on board. I followed angle technique and found it successful for around 95% except when I could not angle more than 15-20% then it did scrapped.

But I must say that this technique is very helpful as we saw few sedan owners (City, Linea) scrapping badly on these breakers. I guess those people are not aware of this technique.

PS - Those who are from Haryana must know what kind of speed breakers we have on our state roads.

I hit a huge speed breaker at speed today. I saw it late, I was going at 80ish. I braked hard and slowed down marginally, and let the brakes go when very close to the speed breaker. I flew off the speed bump at a decent speed (40 to 70). After flying off, I landed on the road.
It is a Linea and it seems to be alright after the incident. Car is not pulling off to either side and driving , no rattling etc. should I be worried and get something checked?

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Originally Posted by e1t1bet (Post 2925382)

The bit of the car that takes the brunt of an aerial excursion is the suspension system as you land on that. Provided there was no banging and scraping noises when you land nothing else has hit the ground. Given this, just be alert for how the suspension is reacting over the next few days or so. Am guessing nothing much would have happened. Also, the suspension is engineered to be able to take an impact like this.

Do not worry about this but if you want to be cautious, you can have the suspension checked. I would recommend you dont open the car up for this, unless it is making a strange noise

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Originally Posted by msdivy (Post 2190170)

Instead of car at 45 degrees, I wish all the speed breakers are at 45 degrees to the road.

I think if they were made that way one would bear more damages or even result in an accident due to loss in control if somehow they overlooked the breaker & were not able to slow down in time.

Angled or not, I make sure that I am off the brake paddle once the front wheel is about the step up on the inclination of the breaker. Also, braking when the wheel is on the declination puts more load on the suspension and it will sag down further, increasing the chances of being hit. So, slight acceleration at this point of time, if conditions permit is better as it will take the weight off the suspension & will also give a few much needed millimeters for tackling that hump.

Regards

Quote:

Originally Posted by Vid6639 (Post 2247182)

Basically take the speed breaker while accelerating and not while braking. This causes the front suspension to have lesser load and you glide over the bump even at speed.

This requires practice but once you get the hang of it, you can go faster over relatively small bumps. :-)

I changed from 185/60-14 to 195/60-14 and that helped a lot in increasing the GC.

Not only does increasing tyre size improve ground clearance but it also means there is more give in the tyre sidewall which allows the tyres to soak up smaller and sharp-edged or sudden bumps. Ride comfort will improve as well as reducing shock loads on the suspension - and reducing the risk of damage if you come across a road hump or big pothole at short notice. Wider, low profile tyres are damaged a lot here in England, as are their wheel rims.

Another way of taking weight off the front suspension is to compress it before hitting the bump by braking, then decompress as you are about to hit the bump. Accelerating, as mentioned above, also helps take weight of the front wheels. These techniques depend on the compliance of the shock absorbers - which also have a big effect on how the humps are taken.

Here's a rather poor video of how a good suspension almost eliminates speed humps - poor in the sense the hump is quite low and gentle compared with many. The red car would have travelled over a much more violent hump with similar equanimity and made the video much more dramatic. But it makes it clear enough how most suspension is less than ideal in soaking up bumps.

http://www.youtube.com/watch?v=ghUInp1JBRo

If you watch closely, you will see the body move slightly at the lower speed. With a bigger hump, the faster you go the less the car is affected, to the point it isn't at all providing the bump isn't higher than the suspension travel.

The following short video shows the same car's suspension working rather more effectively.

http://www.youtube.com/watch?v=Z-QZxohrImM

Quote:

Originally Posted by aashish.shah (Post 3291980)

In many parts of Chennai, the new Rubber speed breakers are installed, these are rather low in height but are sharp and do a excellent job to hurt the back. Apart from going slow ( dead slow ) and the 45% option is there some other way in which these humps can be tackeled ( these humps extend to the end of the road and how no low points.)

You'll have to be dead slow over these rubber ones else you will be landing with a tyre + wheel + suspension damage other than backache. It won't be evident at that time rather it is a slow killer. Since the bum is small and sharp the damage is higher if the car is at a higher speed.

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Originally Posted by B747 (Post 3292272)

Accelerating over the hump is easier said than done as the rear wheels may jump the hump bit harshly. More easy to do will be to release the brakes just before the hump so that suspension won't be in compressed state and glide over the hump without brakes nor acceleration.

You will not get good traction to accelerate over them and if done the front bumper will hit the road or the rear end would lift as you said. Neither of it is comfortable and good for the car and the driver.

Keep the speeds below 10 kmph and on 1st gear. If the bump is tall then the only way to tackle is by going cross instead of straight over that would hit the mud flaps and the under body. The most times that my car has had an impact is where the Jack mounting points hit the pothole (This is not the speed breaker menace but the craters on our roads).

Anurag.

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Originally Posted by sunil_93 (Post 3315274)

Trying to revive this thread. I think angled speed breakers are a good idea, it would be great to know views of all other esteemed members.

Also the article in Forbes says that angled speed breakers have been implemented in Karnataka as well! I am yet to come across one, so request fellow bhpians to please confirm if they have gone over angled speed breakers in Karnataka.

I have a daily tryst with the unscientific speed breakers near Gear School on the Panathur-Doddakanelli road, Bangalore. Have seen quite a few sedans scraping their bellies pretty badly.
Hoping for the BBMP to take corrective action on all such unscientific speed breakers.

Quote:

Originally Posted by sunil_93 (Post 3315274)

It seems that some people have taken up the work of changing the angle of speed breaker instead of using the angled approach to the speed breaker. Got to see this article on Forbes India. It says that the angled speed breaker shall be good for safety at railway crossing points also. Worth a read
http://forbesindia.com/article/work-...danger/34303/1

Quote:

Originally Posted by gearedup (Post 3477239)

Trying to revive this thread. I think angled speed breakers are a good idea, it would be great to know views of all other esteemed members.

This angled design benefits only users of low slung cars. For others, especially tall vehicles like buses, this introduces excess body roll. More people will be rushing to the windows if this comes into effect :D

Forbes can beat around the bush, but the issue is with the bad design of the humps, not their angle. If all the humps followed a scientific design when constructed, even low slung sedans wouldn't face any issue.

Also, has anyone considered what might happen if someone doesn't notice an unmarked angled speed breaker and goes over them at speed?