Wider tyres - Will they increase braking efficiency

badri · 13th February 2007, 12:11

Hi All,

I have recently faced a couple of scary braking situations at about 110-120 Kmph in my Accent Viva CRDI. Since there is no option of ABS, I am toying with the idea of changing to wider tyres.

Can anyone let me know what is the effect of wider tyres on braking distances, reducing the locking of tyres etc. Is it worth it or is it that the tyres are going to lock anyway with out ABS? What about the cornering grip? Will it increase with wider tyres. Right now I dont feel so confident in some corners as I would in my old opel astra 1.7 TD

kpzen · 13th February 2007, 15:24

Its not necessary wider tyres will only increase the braking efficiency....the tyres also have to be good..........
consider same width tyres
Bridgestone S322 - Its hard like a stone n will last long...
Bridgestone GIII - Its like a glue....will give u confidence in braking n cornering but wont last as S322...

iraghava · 13th February 2007, 15:38

KP is absolutely right the compound plays a very important part in a tyre's performance.

For your car which is currently running 175/70 R13 Bridgestone S322's (considering you haven't changed the stock tyres) you can either try a better tyre in the same size or upgrade to 185/65 R13 or 195/60 R13's.

Do also tell us what kind of a budget you're looking at for all this.

Shan2nu · 13th February 2007, 19:29

It's the combination of width and tyre compound that gives you braking efficiency. Without ABS, wheel lock is impossible to prevent, but by increasing the contact patch, you can reduce your chances of wheel lock up (under similar conditions).

Just make sure you don't use, too big a contact patch, as that will also increase your chances of aquaplaning.

But, if someones facing probs with weak brakes, then wider tyres maynot be that helpful. You'l have to get your brakes improved first.

Shan2nu

n_aditya · 13th February 2007, 20:07

Well i guess the Viva doesn't come with Rear Disc's. You can upgrade to rear disc brakes which can improve braking. Of course like the others have mentioned good tires are equally important.

theMAG · 13th February 2007, 21:54

Wider the contact area, better is the handling dynamics - stability and braking.

karthik247 · 13th February 2007, 22:01

Softer compound tyres provide better grip but last less while hard compound tyres will last long but offer less grip..

Any other advantage for hard compound tyres???

Vid6639 · 13th February 2007, 22:53

i guess hard compounds are less prone to cuts and gashes caused by our bad roads. The softer ones may not be and sidewall cuts may be easy.

theexister · 13th February 2007, 23:04

Please remember that changing the size in most cases changes only contact patch shape & not the actual area of contact.
It is the compound is critical in this situation & a softer one abviously giving better grip but a lesser road life.
It is a matter of compromise.

badri · 13th February 2007, 23:06

Hi,

My car has done 27K Kilometres and has the standard tyres. It looks like they will run another 15-20K with out any problem but I plan to change after the car does 35K ( I guess it will in another 3-4 months)> My budget would be around 20 K for 5 tyres. What do you guys suggest.

I sure would like to go in for rear discs if I can but I guess it is a bit complicated and I dont know if anyone on the forum has done the same. Any inputs?

vezj420 · 14th February 2007, 00:12

First, take a look at this informative link, which I found pretty enlightening:

The Pansy Patrol - Info for the 3000GT / Stealth Community

To summarize, brake upgrades (i.e. bigger discs, grooves, drills, etc.) are mostly for heat dissipation to reduce brake fade when brakes are being used repeatedly. It is the tyres' contact patch area (and compound I guess) that are crucial in the actual slow-down of a vehicle once the wheels lock in case of a hard stop(or modulate at that level without locking, in the case of ABS).

Rear discs may help some, but on most Indian cars, esp. with front-wheel drive (viva?), this won't make a big difference. And it's probably not worth the hassle and price. This option makes sense if you're adding vast amounts of power to your car, i.e. with a turbo/supercharger or constant NOS. Which I don't gather is the case here.

The one option that IS worth trying though (in addition to bigger tyres), is upgrading the front-discs system and any parts thereof.

Hope that helps!

Struggly · 14th February 2007, 03:03

Badri,

Can you explain what you mean by "scary braking situations" a little more? That will help us determine if a wider tire is going to solve your "problem".

Another thing for you to think about is braking technique. If your "scary breaking situations" involved a sudden stop and the wheels locking up, you should know that your stopping distances in the dry will be shorter if you can remain calm and keep the tires from locking up.

The proper way to brake with a non-ABS car is to depress the brake pedal until the wheels are about to lock, and then to hold it there, trying to anticipate and prevent lockup. This technique is called threshold braking. It takes time to master, but once you can do it you'll find that your car stops a lot better because you have greater command of it.

Clint

Rehaan · 14th February 2007, 05:54

Badri,

First tell us what size and tyre make and model you are currently running, this might help us point out any obvious disagvantages with your setup.

Dont waste your time thinking about rear discs and upgrading the system at the moment.

First upgrade to some higher performance tyres (Bridgestone G3's are pretty popular at the moment) and maybe go up to 185 (or 195 if you are a speed demon.)
You will probably see a very noticable advantage over the stock tyres.

If you are still not happy, then you can consider some better brake pads, and then onwards from there.

cya
R

manveet · 14th February 2007, 10:07

Quote:

Originally Posted by theexister

Please remember that changing the size in most cases changes only contact patch shape & not the actual area of contact.

I disagree.

Wider tires will obviously have a greater area of contact.

I'm not sure about the chape of contact patch, but logically speaking, that should always remain constant i.e. rectangular/square or whatever it is .. probably depends on the air pressure too.

Regards

kpzen · 14th February 2007, 11:50

Quote:

Originally Posted by Rehaan

Badri,

First tell us what size and tyre make and model you are currently running, this might help us point out any obvious disagvantages with your setup.

From what he has mentioned:

Tyres : 175/70-13 Bridgestone S322

13th February 2007, 12:11	#1
badri BHPian Join Date: Jan 2007 Location: Bangalore Posts: 329 Thanked: 284 Times	Wider tyres - Will they increase braking efficiency Hi All, I have recently faced a couple of scary braking situations at about 110-120 Kmph in my Accent Viva CRDI. Since there is no option of ABS, I am toying with the idea of changing to wider tyres. Can anyone let me know what is the effect of wider tyres on braking distances, reducing the locking of tyres etc. Is it worth it or is it that the tyres are going to lock anyway with out ABS? What about the cornering grip? Will it increase with wider tyres. Right now I dont feel so confident in some corners as I would in my old opel astra 1.7 TD
	() Thanks

13th February 2007, 15:24	#2
kpzen Senior - BHPian Join Date: Oct 2004 Location: Faridabad Posts: 5,610 Thanked: 1,876 Times View My Garage	Its not necessary wider tyres will only increase the braking efficiency....the tyres also have to be good.......... consider same width tyres Bridgestone S322 - Its hard like a stone n will last long... Bridgestone GIII - Its like a glue....will give u confidence in braking n cornering but wont last as S322...
	() Thanks

13th February 2007, 15:38	#3
iraghava Senior - BHPian Join Date: Oct 2005 Location: Bhaiyyaland Posts: 8,033 Thanked: 265 Times View My Garage	KP is absolutely right the compound plays a very important part in a tyre's performance. For your car which is currently running 175/70 R13 Bridgestone S322's (considering you haven't changed the stock tyres) you can either try a better tyre in the same size or upgrade to 185/65 R13 or 195/60 R13's. Do also tell us what kind of a budget you're looking at for all this. Last edited by iraghava : 13th February 2007 at 15:42.
	() Thanks

13th February 2007, 19:29	#4
Shan2nu Senior - BHPian Join Date: Feb 2004 Location: Hubli - Karnata Posts: 5,533 Thanked: 125 Times View My Garage	It's the combination of width and tyre compound that gives you braking efficiency. Without ABS, wheel lock is impossible to prevent, but by increasing the contact patch, you can reduce your chances of wheel lock up (under similar conditions). Just make sure you don't use, too big a contact patch, as that will also increase your chances of aquaplaning. But, if someones facing probs with weak brakes, then wider tyres maynot be that helpful. You'l have to get your brakes improved first. Shan2nu
	() Thanks

13th February 2007, 20:07	#5
n_aditya Senior - BHPian Join Date: Oct 2005 Location: Namma Bengaluru Posts: 5,348 Thanked: 3,684 Times View My Garage	Well i guess the Viva doesn't come with Rear Disc's. You can upgrade to rear disc brakes which can improve braking. Of course like the others have mentioned good tires are equally important.
	() Thanks

13th February 2007, 21:54	#6
theMAG Distinguished - BHPian Join Date: May 2006 Location: Avon, CT Posts: 7,217 Thanked: 1,807 Times View My Garage	Wider the contact area, better is the handling dynamics - stability and braking.
	() Thanks

13th February 2007, 22:01	#7
karthik247 Senior - BHPian Join Date: Feb 2005 Location: BLR, HYD Posts: 2,710 Thanked: 30 Times	Softer compound tyres provide better grip but last less while hard compound tyres will last long but offer less grip.. Any other advantage for hard compound tyres???
	() Thanks

13th February 2007, 22:53	#8
Vid6639 Team-BHP Support Join Date: Jul 2006 Location: Bangalore Posts: 17,730 Thanked: 43,470 Times View My Garage	i guess hard compounds are less prone to cuts and gashes caused by our bad roads. The softer ones may not be and sidewall cuts may be easy.
	() Thanks

13th February 2007, 23:04	#9
theexister BHPian Join Date: Aug 2006 Location: Hyderabad...now moved to Bangalore Posts: 173 Thanked: 7 Times View My Garage	Please remember that changing the size in most cases changes only contact patch shape & not the actual area of contact. It is the compound is critical in this situation & a softer one abviously giving better grip but a lesser road life. It is a matter of compromise.
	() Thanks

13th February 2007, 23:06	#10
badri BHPian Join Date: Jan 2007 Location: Bangalore Posts: 329 Thanked: 284 Times	Hi, My car has done 27K Kilometres and has the standard tyres. It looks like they will run another 15-20K with out any problem but I plan to change after the car does 35K ( I guess it will in another 3-4 months)> My budget would be around 20 K for 5 tyres. What do you guys suggest. I sure would like to go in for rear discs if I can but I guess it is a bit complicated and I dont know if anyone on the forum has done the same. Any inputs?
	() Thanks

14th February 2007, 00:12	#11
vezj420 BHPian Join Date: Oct 2006 Location: Bangalore Posts: 266 Thanked: 23 Times	First, take a look at this informative link, which I found pretty enlightening: The Pansy Patrol - Info for the 3000GT / Stealth Community To summarize, brake upgrades (i.e. bigger discs, grooves, drills, etc.) are mostly for heat dissipation to reduce brake fade when brakes are being used repeatedly. It is the tyres' contact patch area (and compound I guess) that are crucial in the actual slow-down of a vehicle once the wheels lock in case of a hard stop(or modulate at that level without locking, in the case of ABS). Rear discs may help some, but on most Indian cars, esp. with front-wheel drive (viva?), this won't make a big difference. And it's probably not worth the hassle and price. This option makes sense if you're adding vast amounts of power to your car, i.e. with a turbo/supercharger or constant NOS. Which I don't gather is the case here. The one option that IS worth trying though (in addition to bigger tyres), is upgrading the front-discs system and any parts thereof. Hope that helps!
	() Thanks

14th February 2007, 03:03	#12
Struggly Newbie Join Date: Jan 2007 Location: Boston Posts: 4 Thanked: 0 Times	Badri, Can you explain what you mean by "scary braking situations" a little more? That will help us determine if a wider tire is going to solve your "problem". Another thing for you to think about is braking technique. If your "scary breaking situations" involved a sudden stop and the wheels locking up, you should know that your stopping distances in the dry will be shorter if you can remain calm and keep the tires from locking up. The proper way to brake with a non-ABS car is to depress the brake pedal until the wheels are about to lock, and then to hold it there, trying to anticipate and prevent lockup. This technique is called threshold braking. It takes time to master, but once you can do it you'll find that your car stops a lot better because you have greater command of it. Clint
	() Thanks

14th February 2007, 05:54	#13
Rehaan Team-BHP Support Join Date: Feb 2004 Location: Bombay Posts: 24,042 Thanked: 34,074 Times	Badri, First tell us what size and tyre make and model you are currently running, this might help us point out any obvious disagvantages with your setup. Dont waste your time thinking about rear discs and upgrading the system at the moment. First upgrade to some higher performance tyres (Bridgestone G3's are pretty popular at the moment) and maybe go up to 185 (or 195 if you are a speed demon.) You will probably see a very noticable advantage over the stock tyres. If you are still not happy, then you can consider some better brake pads, and then onwards from there. cya R
	() Thanks