How to reduce car sway and bounce when crossing road hump?

[keenklee]

You guys cross hump and corner at the same time? Why need strut bar? Sway bar? Anti roll bar? Just replace shocks..

IMHO.
Some humps like not standard one... slanted... so like cross hump and taking corner.

 

[standarture]

There is a sweet spot to cross humps. Normally between 20-30km/hr and no acceleration.

 

[osimese]

8 yrs old car can try buy a can of wd40 and spray on all 4 shock, spring and linkage..... lol

 

[hachi]

8 yrs old car can try buy a can of wd40 and spray on all 4 shock, spring and linkage..... lol

Don't bother just replace shocks.. Wore shocks are dangerous... Once you brake harder in wet and around a turn... Then you have fun....
Cos the load bounce on wore shocks may cause the tyres to lock and spin you around...

 

[serverxeon]

Thanks all for feedback.
So this is about something being worn out over time, nothing to do with a better tech like Air suspension or what not.

But 8 years old, dunno to change/repair or not itching for new car liao.

Anyway. I ask because my carpark design like sh1t. Got humps near a corner and humps of different heights. At Carpark exit roads are sloped, Somemore is turn into main road. So need pick up speed. So slope + turning + accelerate = sway and bounce.

 

[Orphan]

I driving a 8 year old Kia Cerato.
Everytime go over hump I feel like my car sway and bounce gaolat gaolat.

Sometime the feeling is like on a boat rocking and it keep bumping into the berth that kinda feeling. Sibeh uncomfortable.

Is there any mechanism to look for when changing new car to avoid such feel? What Air suspension and what not?

Do you have similar issues with rocking/abrupt stops during the previous 7 years?

There are 2 main parts to a suspension system the spring and the shock absorbers.

How easily the stiffness of the spring contracts when the wheels hit a bump controls how much of the initial impact is felt. Ie how much the car dips or lifts when hitting a pothole or a bump.

Shocks control how slowly the spring returns back to its normal height so that the car don't freely bounce up and down.

Which part to look at depends which issue you are experiencing.

Besides the 2 main components above, there are other components involved as well.

Anti-sway bars, which someone has already mentioned. Cars by default, should already have this. Though it might be weakened or damaged through time.

What it does - when 1 wheel hits a bump first or when going around a bend, that corner where the wheel is will dip or raise. Without an anti sway bar, one will feel the car dip/raise in that direction.

The anti sway bay forces forces the paired wheel that is on the opposite side to dip/raise in tandem, and keep the car level.

In short, less side to side swaying. Why it's called anti-sway bar.



Tyres are another component. They actually can provide more comfort compared to the suspension. Simpler bicycles switched to air filled tyres from solid wooden tyres, and that alone provided sufficient rdie comfort without complicated suspension systems.

Tyres are filled with compressible air just like air suspension. This, along with the sidewalls of the tyre, is technically also part of the suspension.

If you are over inflating your tyres for better fuel economy, you can try inflating it to the lowest psi recommended by your car manufacturer (there will be a sticker or metal plate to show the recommended psi ranges near the driver/passenger door frame, sometimes need to open the car door to see).

Free to do. But will cause slightly more wear on tyres since more of the tyre will be in contact with the ground.



Air suspension do give smoother rides in general, because air is much much compressible compared to mechanical springs. Same concept as filling tyres with air. Stiffness and ride quality, ride height, ground clearance is much more easily adjustable compared to even adjustable EDFC coilovers.

Of coz, they also tend to fail slightly more in general. Compared to metallic springs, the rubber inflatable airbags may leak or rupture.

The other problem is they are more complicated and expensive compared to coilovers or stock suspension. So it's normally only available on more expensive cars unless you want to mod with aftermarket air suspension. Which is also more expensive than aftermarket coilovers.



For purely aftermarket options besides changing to coilovers, there's also something called "magic collar". Originally developed by Spoon, other companies have since stole the idea. Basically semi soft metal "washers" that fills in the small gap between the wheel structs to the chassis. These gives the bolts a snug fit to reduce the slight lateral "shifts". The type of shifts which drivers may experience when the bolts move around in the larger bolt holes in the chassis.

Manufacturers normally drill holes in the chassis which are a tad larger. This is so that they can easily fit the bolts through. Then the use normal flat metal washers to kiap the bolt to the chassis. Due to this small gap, the bolts can still move a bit.

It's sort of like a screw that is a bit smaller than a drilled hole, due to the gap, it can shake a bit.

Magic collar is like those plastic plugs we push into the drilled hole. When the screw goes in, the plug fills the gap, and the screw won't have gaps to move.



Rubber spring buffer also another type. Slide in between the top few rungs in the suspension spring to stiffen it. Does make it stiffer, so the car shakes less. But the lower rungs of the spring now needs to do more work, so up to you to decide if this addresses your requirements. They are quite cheap though.

 

[Shutterbox]

Thanks all for feedback.
So this is about something being worn out over time, nothing to do with a better tech like Air suspension or what not.

But 8 years old, dunno to change/repair or not itching for new car liao.

Anyway. I ask because my carpark design like sh1t. Got humps near a corner and humps of different heights. At Carpark exit roads are sloped, Somemore is turn into main road. So need pick up speed. So slope + turning + accelerate = sway and bounce.

assume drive till coe ends, that 2 years of road safety is worth spending on new shocks?
typically new ones with installation is less than 1k i think

 

[hotamp]

i find some humps at bigger roads tends to be more gradual and wider, some at smaller roads are higher and " pointy". best is slow down b4 the hump and then slowly roll over it.

 

[serverxeon]

Do you have similar issues with rocking/abrupt stops during the previous 7 years?

There are 2 main parts to a suspension system the spring and the shock absorbers.

How easily the stiffness of the spring contracts when the wheels hit a bump controls how much of the initial impact is felt. Ie how much the car dips or lifts when hitting a pothole or a bump.

Shocks control how slowly the spring returns back to its normal height so that the car don't freely bounce up and down.

Which part to look at depends which issue you are experiencing.

Besides the 2 main components above, there are other components involved as well.

Anti-sway bars, which someone has already mentioned. Cars by default, should already have this. Though it might be weakened or damaged through time.

What it does - when 1 wheel hits a bump first or when going around a bend, that corner where the wheel is will dip or raise. Without an anti sway bar, one will feel the car dip/raise in that direction.

The anti sway bay forces forces the paired wheel that is on the opposite side to dip/raise in tandem, and keep the car level.

In short, less side to side swaying. Why it's called anti-sway bar.



Tyres are another component. They actually can provide more comfort compared to the suspension. Simpler bicycles switched to air filled tyres from solid wooden tyres, and that alone provided sufficient rdie comfort without complicated suspension systems.

Tyres are filled with compressible air just like air suspension. This, along with the sidewalls of the tyre, is technically also part of the suspension.

If you are over inflating your tyres for better fuel economy, you can try inflating it to the lowest psi recommended by your car manufacturer (there will be a sticker or metal plate to show the recommended psi ranges near the driver/passenger door frame, sometimes need to open the car door to see).

Free to do. But will cause slightly more wear on tyres since more of the tyre will be in contact with the ground.



Air suspension do give smoother rides in general, because air is much much compressible compared to mechanical springs. Same concept as filling tyres with air. Stiffness and ride quality, ride height, ground clearance is much more easily adjustable compared to even adjustable EDFC coilovers.

Of coz, they also tend to fail slightly more in general. Compared to metallic springs, the rubber inflatable airbags may leak or rupture.

The other problem is they are more complicated and expensive compared to coilovers or stock suspension. So it's normally only available on more expensive cars unless you want to mod with aftermarket air suspension. Which is also more expensive than aftermarket coilovers.



For purely aftermarket options besides changing to coilovers, there's also something called "magic collar". Originally developed by Spoon, other companies have since stole the idea. Basically semi soft metal "washers" that fills in the small gap between the wheel structs to the chassis. These gives the bolts a snug fit to reduce the slight lateral "shifts". The type of shifts which drivers may experience when the bolts move around in the larger bolt holes in the chassis.

Manufacturers normally drill holes in the chassis which are a tad larger. This is so that they can easily fit the bolts through. Then the use normal flat metal washers to kiap the bolt to the chassis. Due to this small gap, the bolts can still move a bit.

It's sort of like a screw that is a bit smaller than a drilled hole, due to the gap, it can shake a bit.

Magic collar is like those plastic plugs we push into the drilled hole. When the screw goes in, the plug fills the gap, and the screw won't have gaps to move.



Rubber spring buffer also another type. Slide in between the top few rungs in the suspension spring to stiffen it. Does make it stiffer, so the car shakes less. But the lower rungs of the spring now needs to do more work, so up to you to decide if this addresses your requirements. They are quite cheap though.

Woah very comprehensive!
What do you recommend for a cost effective interim solution for a car that probably gonna use for at most 1 year more?

 

[Orphan]

Woah very comprehensive!
What do you recommend for a cost effective interim solution for a car that probably gonna use for at most 1 year more?

Depends on the actual issue you are concerned with. Is it mainly just the bump you mentioned at the carpark exit where you can't slow down?

Or bobbing up and down when you hit other bumps/portholes on the road?

Or side to side swaying?

Then see which is the relevant worn out part that needs to be changed. Check with workshop on prices. Stock ones for Korean and Japanese cars normally not expensive.



In general, try using min tyre pressure that the manufacturer recommended. Because it's free and can easily just pump back to your desired psi if it doesn't help.



Once you spend money on things like new shocks or coilovers that you cannot transfer to your new car, you can only use for 1 year, then have to dekit and try to sell on Carousell at 2nd hand prices. Heart pain.

Plus hope someone will buy while you keep inside store room. Moreover, when you buy, you have to also look for models that can be used on other cars besides Kia Cerato. If the part is only meant for Cerato, you have an even smaller pool of buyers. Later end up have to throw out even more heart pain.



Coil spring buffer, I have heard people swear by it and others say the improvement is not really comfort type of improvement, but the improvement is making suspension stiffer, just that some people equate this to comfort due to individual preference. I never try myself.



I bought China made magic collar for cheap (less than $100) after someone in my car group swore by the China ones being more comfortable than swapping to his coilover. Managed to get a workshop to install for $50.

I felt the improvement, but though maybe coz I paid for it and was biased. But wife confirmed definitely can feel improvement, that's good enough.

Stealing pic from Carousell to have a better understanding of what I meant by it being similar to using those plastic plugs for screws. Of course, looking at the price, I can tell the Singapore workshops are all buying the cheaper non Spoon ones and just charging a premium:

This one is confirm cannot transfer to new car. Personally I won't buy if my car less than 1 year left.

 

[kuti-kuti]

Can activate your car auto driver system.

 

[Laguna123]

Drive at 10kmph?

 

[buttbERry]

change absorber?

 

[serverxeon]

Err... Let me think...Oh I got it, how about, just slow down? Driven for 8 years and still ask such question...? We should be very scared driving on Singapore's road.

Why drive for 8 years cannot ask such mechanical question. You eat rice for 8 years means you auto know how to repair rice cooker meh.

 

[serverxeon]

The answer is simply slow down. No? Your didn't say your car was ok when new and degraded after 7 years and thus, you suspected something failed? You could have ask more specifically? Like will changing absorber or Suspension help?

Otherwise and normally, you just slow down and issue is automatically resolved. No need to spend money to change things when they ain't broke.

Come on. Pls apply a bit of comnon sense.

If someone opens a thread and says aircon is 8 years old and isn't cold. Is your answer going to be "then lower the temperature setting"???
The person asking should also prompt whether aircon coolant is leaking before a technical answer is warranted in that case?

 

[serverxeon]

Do you have similar issues with rocking/abrupt stops during the previous 7 years?

There are 2 main parts to a suspension system the spring and the shock absorbers.

How easily the stiffness of the spring contracts when the wheels hit a bump controls how much of the initial impact is felt. Ie how much the car dips or lifts when hitting a pothole or a bump.

Shocks control how slowly the spring returns back to its normal height so that the car don't freely bounce up and down.

Which part to look at depends which issue you are experiencing.

Besides the 2 main components above, there are other components involved as well.

Anti-sway bars, which someone has already mentioned. Cars by default, should already have this. Though it might be weakened or damaged through time.

What it does - when 1 wheel hits a bump first or when going around a bend, that corner where the wheel is will dip or raise. Without an anti sway bar, one will feel the car dip/raise in that direction.

The anti sway bay forces forces the paired wheel that is on the opposite side to dip/raise in tandem, and keep the car level.

In short, less side to side swaying. Why it's called anti-sway bar.



Tyres are another component. They actually can provide more comfort compared to the suspension. Simpler bicycles switched to air filled tyres from solid wooden tyres, and that alone provided sufficient rdie comfort without complicated suspension systems.

Tyres are filled with compressible air just like air suspension. This, along with the sidewalls of the tyre, is technically also part of the suspension.

If you are over inflating your tyres for better fuel economy, you can try inflating it to the lowest psi recommended by your car manufacturer (there will be a sticker or metal plate to show the recommended psi ranges near the driver/passenger door frame, sometimes need to open the car door to see).

Free to do. But will cause slightly more wear on tyres since more of the tyre will be in contact with the ground.



Air suspension do give smoother rides in general, because air is much much compressible compared to mechanical springs. Same concept as filling tyres with air. Stiffness and ride quality, ride height, ground clearance is much more easily adjustable compared to even adjustable EDFC coilovers.

Of coz, they also tend to fail slightly more in general. Compared to metallic springs, the rubber inflatable airbags may leak or rupture.

The other problem is they are more complicated and expensive compared to coilovers or stock suspension. So it's normally only available on more expensive cars unless you want to mod with aftermarket air suspension. Which is also more expensive than aftermarket coilovers.



For purely aftermarket options besides changing to coilovers, there's also something called "magic collar". Originally developed by Spoon, other companies have since stole the idea. Basically semi soft metal "washers" that fills in the small gap between the wheel structs to the chassis. These gives the bolts a snug fit to reduce the slight lateral "shifts". The type of shifts which drivers may experience when the bolts move around in the larger bolt holes in the chassis.

Manufacturers normally drill holes in the chassis which are a tad larger. This is so that they can easily fit the bolts through. Then the use normal flat metal washers to kiap the bolt to the chassis. Due to this small gap, the bolts can still move a bit.

It's sort of like a screw that is a bit smaller than a drilled hole, due to the gap, it can shake a bit.

Magic collar is like those plastic plugs we push into the drilled hole. When the screw goes in, the plug fills the gap, and the screw won't have gaps to move.



Rubber spring buffer also another type. Slide in between the top few rungs in the suspension spring to stiffen it. Does make it stiffer, so the car shakes less. But the lower rungs of the spring now needs to do more work, so up to you to decide if this addresses your requirements. They are quite cheap though.

On a side note, do EV have all these same principles? If say buy a new Tesla or BYD, do any of these fundamentals differ for EV construction?

 

[Zze121]

left 2 yr, buy 2nd hand coilover, upsize thicker anti roll bar, put strut bar, change collars

 

[lousydk]

last time my old car, the suspension funny
go to workshop, the lao uncle boss come out, he test by bouncing the car up and down a few times by pressing on the boot and bonnet, he say once you let go the car should stop, if it continue to have a few mini bounce before stopping completely means your suspension GG already

 

[elf108]

Install TT urethane buffer loh.
But will cost around $200?

 

[coyote]

left 2 yr, buy 2nd hand coilover, upsize thicker anti roll bar, put strut bar, change collars

Left 2 years better not do anything unless one intend to extend COE...