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Old 16th February 2011, 16:04   #31
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Default Re: Art of taking Speed Breakers(humps) without scraping the belly.

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Originally Posted by Chewbacca View Post
... but Lancer's GC is highest in the sedan class at 175 mm (SFX) and 185 mm (GLX/SLX)
I really doubt it!. I may not know the figures, but, I have very good experience in scraping the bellys of both lancer and my IKON.

With 5 people on board, the lancer scraps even moderate humps, but, believe it or not, with the same 5 people on board, I have never scraped my IKON's belly.

Only three times have I scraped the underbelly of my IKON in its 1L kms, and all those times, were on roads which literally didnt exist, and I was more or less, 'off-roading'.

May be the lancer's suspension is soft, and hence more travel with 5 on board.
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Old 16th February 2011, 16:18   #32
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Default Re: Art of taking Speed Breakers(humps) without scraping the belly.

I did not find this point anywhere in the thread. Say you approach a speedbreaker really fast which was not visible. You see it at the last minute and your doing good speeds. What do you do?

1. Slam the brakes hard.
2. Release your foot off the brakes completely just a few feet from the hump and then dab the accelerator.
3. fly over the speed breaker.
4. stop to the side and make sure nothing got damaged.

If you hit the speed breaker with the brakes on you will damage your suspension and in some cars rip off your front bumper. Why? Cause under braking the weight of the car is on the front suspension which causes the front springs to compress. When you hit the bump the suspension is already compressed and is not able to absorb the speed breaker impact. This can damage your suspension. In cars that experience excessive dive, the bumper is so low, that it hits the hump.

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. :-)

It is very useful on our highways which have unmarked speedbreakers that pop out of nowhere.

Quote:
Originally Posted by Chewbacca View Post

This is OT but Lancer's GC is highest in the sedan class at 175 mm (SFX) and 185 mm (GLX/SLX)
Scraping speed breakers with a Lancer is only possible on the SFX model because it came with stock 14" alloys with lower profile tyres and body skirts, but GLX / SLX came with 175-80/R13 and provides the highest GC at 185 mm -that's higher than Maruti's SX4.

Anythiing lower than the stock 80 profile on a GLX / SLX (after a rim upgrade or switch to tubeless) will reduce the GC by 8 mm at the least and that's too much, especially with 5 people onboard this goes down further because side-wall of tubeless is thin and bulges easily, further reducing the GC.
Yes the SLX has good GC thanks to the 175/80-13 tyres and raised suspension.

In contrast the SFXi had the worst GC amongst all cars. It used to hit every damn hump in bangalore. There came a time when I had to get ppl to get off the car then go over the hump and let them back in. lol.

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

The skirting does not touch the bottom at all. The skirts are higher actually. There are 2 beams that run from front to back in the lancer's underbody, those are what hit the bump and not the side skirts. The front does get lowered and is prone to hitting kerbs with the front skirts.

Last edited by Vid6639 : 16th February 2011 at 16:30.
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Old 16th February 2011, 16:57   #33
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Default Re: Art of taking Speed Breakers(humps) without scraping the belly.

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Originally Posted by vid6639 View Post
1. Slam the brakes hard.
2. Release your foot off the brakes completely just a few feet from the hump and then dab the accelerator.
3. fly over the speed breaker.
4. stop to the side and make sure nothing got damaged.
Great point vid6639 . And very apt explanation. A very right thing to do, when you 'have to' fly over that unnoticed speed breaker. Sometimes, it even saves your car's a** from tailgating cars.

Well, I also follow the exact same practice, on those rumbling speed breakers. Brake hard and throttle, so that there is max suspension travel. Also, saves a lot of time.
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Old 5th March 2011, 13:15   #34
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Default Re: Art of taking Speed Breakers(humps) without scraping the belly.

Have been travelling between mahape - belappur regularly and have seen a new local speed breaker poping up everytime some mishap happens. And they appear to be just dumping the tar and stone mix creating a hump, leaving the leveling part to IMO for trucks/trailors.

Few those were created some 2 years back now have levelled at middle of the road and still have big humps on either sides. Guess what, now everyone tries to reach the levelled part of speed breaker first.
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Old 6th March 2011, 11:22   #35
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Default Re: Art of taking Speed Breakers(humps) without scraping the belly.

Angled approach, as long as one of the wheels gets ontop first thats fine. Secondly, finish all the braking before you touch the speed breaker.

When you brake the weight of the car moves forward and you lose ground clearance on the front which might result in scraping the SB, also weight to the front means your suspension is underload = there is less than 100% suspension travel available to soak up the bump. Finish braking, release the brake, let the weight transfer back to the rear of the car and mount the breaker whilst accelerating softly.

To me, this is the best best method for SB.

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Old 6th May 2011, 13:10   #36
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Default Re: Art of taking Speed Breakers(humps) without scraping the belly.

Now that we know some methods for handling these speed beakers (though some unscientifically built ones continue to taunt us), I would like to know the that IF, one does not get enough time to slow down and softly pass, and runs over it with some serious speed,
  • What are the mechanical damages that is caused to your car.
  • How many cars have underbody protection, or sensibly designed bellies that only minimum damage occur?
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Old 6th May 2011, 15:38   #37
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Default Re: Art of taking Speed Breakers(humps) without scraping the belly.

Perhaps this is a bit , but can I also add what happens if a stone/ rock scrapes the underbody of the car? What parts can be damaged?
Adding as it is relevant to underbody damage by a loose object, dont mean to hijack/ change the topic
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Old 6th May 2011, 16:52   #38
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Default Re: Art of taking Speed Breakers(humps) without scraping the belly.

Quote:
Originally Posted by dhanushs View Post
Now that we know some methods for handling these speed beakers (though some unscientifically built ones continue to taunt us), I would like to know the that IF, one does not get enough time to slow down and softly pass, and runs over it with some serious speed,
  • What are the mechanical damages that is caused to your car.
  • How many cars have underbody protection, or sensibly designed bellies that only minimum damage occur?
Luckily, almost all cars have a sheet of metal/extremely thick rubber projecting the under side of the engine bay.

So, even if you scrape the speed breaker or you go fast over it and your car bangs on the road after coming off the speedbreaker, it is the engine protector that gets scraped.

That itself is pretty sturdy and the most damage it will suffer is a slight bend which can get straightened out by A.S.S.

The rest of the underbelly is extremely unlikely to suffer any damage as it is mostly the bottom of the engine bay that takes the hit.

And all cars have a nice strong sheet to protect that.
Quote:
Originally Posted by selfdrive View Post
Perhaps this is a bit , but can I also add what happens if a stone/ rock scrapes the underbody of the car? What parts can be damaged?
Adding as it is relevant to underbody damage by a loose object, dont mean to hijack/ change the topic
Anything from the engine bay to the fuel pump, fuel assembly can get damaged.
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Old 6th May 2011, 17:10   #39
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Default Re: Art of taking Speed Breakers(humps) without scraping the belly.

Considering this aspect, perhaps we should request our TD gurus to include a snapshot of the underbody. If only to check how this differs (if at all) by manufacturer/ model

This is the only angle which we perhaps never see on any of the TD threads
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Old 6th May 2011, 17:35   #40
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Default Re: Art of taking Speed Breakers(humps) without scraping the belly.

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Originally Posted by selfdrive View Post
Considering this aspect, perhaps we should request our TD gurus to include a snapshot of the underbody. If only to check how this differs (if at all) by manufacturer/ model
Actually, they do differ.

There is NO protection on our Zen. The Corsa has a metal sheet that covers the entire engine bay area at the bottom. On the last service, I had a look at the underbelly and looking at the scratches on the sheet, I had a fair idea of how many hits it has saved the engine from.

The ANHC has a cover; but it has 2 separate metal sheets protecting the LHS and RHS of the engine bay; the centre part is left exposed.
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Old 6th May 2011, 20:08   #41
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Default Re: Art of taking Speed Breakers(humps) without scraping the belly.

ANHC also has thick steel beams on the bottom which are targeted and strengthened for such hits.
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Old 6th May 2011, 22:55   #42
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Default Re: Art of taking Speed Breakers(humps) without scraping the belly.

Quote:
Originally Posted by vid6639 View Post
This requires practice but once you get the hang of it, you can go faster over relatively small bumps. :-)

It is very useful on our highways which have unmarked speedbreakers that pop out of nowhere.
Hi Vid, agree with the technique but shouldn't it be only during emergency situations when you fail to spot the speed breaker and not otherwise?

If done regularly for all small humps one comes across like somebody mentioned, it will surely damage the rim. Used to do it often with my old car which had steel rims. More careful now due to alloy wheels.
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Old 29th August 2011, 00:30   #43
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Default Re: Art of taking Speed Breakers(humps) without scraping the belly.

Waking up a fairly old thread.

I have a query on tackling speed breakers, related to Gears.

I have an Esteem and I usually tackle speed breakers on Gear 2 at close to 1000 RPM and rarely do I manage to accelerate away smoothly, there are always jerks. Am I on the wrong gear? Is my clutch and accelerator combination not right?

Its a 2005 model and Odo is at 49k. Would love to learn to pull away from a speed breaker smoothly.

An observation, if I accelerate to about 2000 RPM and release clutch slowly, its much smoother. But is it OK to do that? This is my first car and I am still learning the finer tricks.


MaSh
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Old 29th August 2011, 08:58   #44
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Default Re: Art of taking Speed Breakers(humps) without scraping the belly.

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Originally Posted by mashmash View Post
I have an Esteem and I usually tackle speed breakers on Gear 2 at close to 1000 RPM and rarely do I manage to accelerate away smoothly, there are always jerks. Am I on the wrong gear? Is my clutch and accelerator combination not right?
Stick to the 1st gear and you shouldn't have much of problems.. At 1000rpm your car is pretty close to the idling rpm and the 2nd gear wouldn't help as much since you are lugging the engine. There aint much of torque or power to be thrown around by the 1.3 engine
Am sure you must be even trying to double clutch once or twice to retain power ? Dont do that , you will end up with a fried clutch.

Quote:
Originally Posted by mashmash View Post
An observation, if I accelerate to about 2000 RPM and release clutch slowly, its much smoother. But is it OK to do that?

MaSh
Stay around the 1000-1200 rpm mark in the 1st gear and you can glide through the speed breaker.
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Old 29th August 2011, 11:33   #45
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Default Re: Art of taking Speed Breakers(humps) without scraping the belly.

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Originally Posted by rjstyles69 View Post
Stick to the 1st gear and you shouldn't have much of problems.. At 1000rpm your car is pretty close to the idling rpm and the 2nd gear wouldn't help as much since you are lugging the engine. There aint much of torque or power to be thrown around by the 1.3 engine
Am sure you must be even trying to double clutch once or twice to retain power ? Dont do that , you will end up with a fried clutch.

Stay around the 1000-1200 rpm mark in the 1st gear and you can glide through the speed breaker.
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
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