Parabolic Leaf Spring Suspensions - are they good or bad?

lalith_ka · 26th February 2008, 17:13

After reading thru one of the posts about Tata Sumo Grande's rear suspension, I thought we can have a post to discuss the much talked about leaf spring based suspensions.

Here's a quick defination of Parabolic Leaf Spring Suspension -
This design uses fewer leaves. The thickness of the leaves vary from center to end following a parabolic curve. Friction between the leaves is not wanted. So there is only contact between the springs at the ends and at the center where the axle is connected. Spacers prevent contact at other points.

The advantages of this type design are weight saving and greater flexibility. They can come very close to the same performance of coil springs.

Additional dose: Parabolic Springs

Fellow TeamBHPians, could you please share your road experiences on these suspensions, not necessarily on Sumo Grande, but on all the MUV and SUV class vehicles?

spadival · 27th February 2008, 10:35

Surprised that critics (I am one) and fans alike have not contributed to this topic yet.

In layman terms, one problem I see with Leaf Spring setup is that you cannot have a semi-independent setup. So if one wheel goes into a pothole, both wheels are affected which results in a bouncy ride.

dadu · 27th February 2008, 10:49

They are the tough ones and will not sink-in much with loads as compared to coil springs which are more comfortable than the leaf ones.

Technocrat · 27th February 2008, 12:04

We had an Omni for 5 years & if I am not wrong it had leaf spring suspensions. The ride was bouncy if occupancy was less but it drove like a charm if it was fully loaded i.e. Passengers + lots of luggage.

So yes for vehicles which are expected to carry load this seems to be an effective suspension system & I believe its cheap too so suits better for the target buyer's pocket as well.

reignofchaos · 27th February 2008, 12:08

Leaf Springs are basically meant for heavy load carriers and typically found on body on frame type vehicles. They are good for carrying loads over bad terrains but absolutely terrible in comfort and handling departments.

HappyWheels · 27th February 2008, 12:13

Quote:

Originally Posted by Technocrat

We had an Omni for 5 years & if I am not wrong it had leaf spring suspensions. The ride was bouncy if occupancy was less but it drove like a charm if it was fully loaded i.e. Passengers + lots of luggage.

So yes for vehicles which are expected to carry load this seems to be an effective suspension system & I believe its cheap too so suits better for the target buyer's pocket as well.

spot on. was going to make this point.

notice this in our Sumo. 2~3 people in the vehicle and the ride is a bit bouncy. The whole family and packages - drives like a charm!

and IMO (can be wrong here, but) leaf suspension can take more beating than their other sibling.

ram_hyundai · 27th February 2008, 12:13

The load carrying vehicles like sumo,mahindra suv'setc has to have the leaf spring setupp.You have to be prepared for the worst ( more number of people) in such vehicles.Single riding or maybe with lesser load it would definitely be a bumpy ride -but these vehicles are not made for it.
ram

deetee · 27th February 2008, 12:18

In my opinion, leaf springs are effective under enough load only.In my type 1 M800, if am the only person driving i can feel the car bouncing but when loaded with 4 adults, it drives much much better. Also,this is my opinion -no proof, leaf springs aid cornering better than coil springs as the former are more stiffer.May be some one can enlighten me about this.

nitrous · 27th February 2008, 17:00

The rear leaf springs on my sumo give a harsh ride at the back.
But, i heard its very good on the safari.

reignofchaos · 27th February 2008, 17:04

AFAIK Safari doesn't have leaf springs.

Steeroid · 27th February 2008, 17:05

Quote:

Originally Posted by nitrous

The rear leaf springs on my sumo give a harsh ride at the back.
But, i heard its very good on the safari.

What leaf exactly are you smoking now, Mahendra?

spadival · 27th February 2008, 17:49

Come to think of it, I remember the old days when people kept sand bags at the back of their Maruti Vans, Sumos etc to improve the ride quality

BUSA · 27th February 2008, 18:28

Does the Hummer have leaf springs?

nitrous · 27th February 2008, 18:35

@steer: The ride quality is bad in the safari,u mean?

Sankar · 27th February 2008, 19:28

Quote:

Originally Posted by BUSA

Does the Hummer have leaf springs?

Hummer H3 has leaf springs at the back.

26th February 2008, 17:13	#1
lalith_ka BHPian Join Date: Dec 2005 Location: Bangalore/Singapore Posts: 39 Thanked: 0 Times	Parabolic Leaf Spring Suspensions - are they good or bad? After reading thru one of the posts about Tata Sumo Grande's rear suspension, I thought we can have a post to discuss the much talked about leaf spring based suspensions. Here's a quick defination of Parabolic Leaf Spring Suspension - This design uses fewer leaves. The thickness of the leaves vary from center to end following a parabolic curve. Friction between the leaves is not wanted. So there is only contact between the springs at the ends and at the center where the axle is connected. Spacers prevent contact at other points. The advantages of this type design are weight saving and greater flexibility. They can come very close to the same performance of coil springs. Additional dose: Parabolic Springs Fellow TeamBHPians, could you please share your road experiences on these suspensions, not necessarily on Sumo Grande, but on all the MUV and SUV class vehicles? Last edited by mobike008 : 16th November 2010 at 12:39.
	() Thanks

27th February 2008, 10:35	#2
spadival Senior - BHPian Join Date: Oct 2004 Location: Melbourne, AU Posts: 1,772 Thanked: 29 Times View My Garage	Surprised that critics (I am one) and fans alike have not contributed to this topic yet. In layman terms, one problem I see with Leaf Spring setup is that you cannot have a semi-independent setup. So if one wheel goes into a pothole, both wheels are affected which results in a bouncy ride.
	() Thanks

27th February 2008, 10:49	#3
dadu Senior - BHPian Join Date: May 2007 Location: Bangalore Posts: 3,803 Thanked: 463 Times View My Garage	They are the tough ones and will not sink-in much with loads as compared to coil springs which are more comfortable than the leaf ones.
	() Thanks

27th February 2008, 12:04	#4
Technocrat Senior - BHPian Join Date: Feb 2004 Location: GTA Posts: 14,770 Thanked: 2,705 Times	We had an Omni for 5 years & if I am not wrong it had leaf spring suspensions. The ride was bouncy if occupancy was less but it drove like a charm if it was fully loaded i.e. Passengers + lots of luggage. So yes for vehicles which are expected to carry load this seems to be an effective suspension system & I believe its cheap too so suits better for the target buyer's pocket as well.
	() Thanks

27th February 2008, 12:08	#5
reignofchaos Senior - BHPian Join Date: Apr 2007 Location: Bangalore Posts: 2,558 Thanked: 2,527 Times View My Garage	Leaf Springs are basically meant for heavy load carriers and typically found on body on frame type vehicles. They are good for carrying loads over bad terrains but absolutely terrible in comfort and handling departments.
	() Thanks

27th February 2008, 12:13	#7
ram_hyundai Senior - BHPian Join Date: Jun 2006 Location: Calicut ,trisur Posts: 2,019 Thanked: 53 Times View My Garage	The load carrying vehicles like sumo,mahindra suv'setc has to have the leaf spring setupp.You have to be prepared for the worst ( more number of people) in such vehicles.Single riding or maybe with lesser load it would definitely be a bumpy ride -but these vehicles are not made for it. ram
	() Thanks

27th February 2008, 12:18	#8
deetee BHPian Join Date: Oct 2007 Location: Mangalore Posts: 505 Thanked: 1,632 Times View My Garage	In my opinion, leaf springs are effective under enough load only.In my type 1 M800, if am the only person driving i can feel the car bouncing but when loaded with 4 adults, it drives much much better. Also,this is my opinion -no proof, leaf springs aid cornering better than coil springs as the former are more stiffer.May be some one can enlighten me about this.
	() Thanks

27th February 2008, 17:00	#9
nitrous Senior - BHPian Join Date: May 2004 Location: UAE/Lon/Madras Posts: 6,965 Thanked: 333 Times View My Garage	The rear leaf springs on my sumo give a harsh ride at the back. But, i heard its very good on the safari.
	() Thanks

27th February 2008, 17:04	#10
reignofchaos Senior - BHPian Join Date: Apr 2007 Location: Bangalore Posts: 2,558 Thanked: 2,527 Times View My Garage	AFAIK Safari doesn't have leaf springs.
	() Thanks

27th February 2008, 17:49	#12
spadival Senior - BHPian Join Date: Oct 2004 Location: Melbourne, AU Posts: 1,772 Thanked: 29 Times View My Garage	Come to think of it, I remember the old days when people kept sand bags at the back of their Maruti Vans, Sumos etc to improve the ride quality
	() Thanks

27th February 2008, 18:28	#13
BUSA Senior - BHPian Join Date: Aug 2005 Location: Bombay Posts: 5,127 Thanked: 23 Times View My Garage	Does the Hummer have leaf springs?
	() Thanks

27th February 2008, 18:35	#14
nitrous Senior - BHPian Join Date: May 2004 Location: UAE/Lon/Madras Posts: 6,965 Thanked: 333 Times View My Garage	@steer: The ride quality is bad in the safari,u mean?
	() Thanks