Member Since: 18 Jul 2011
Location: Stockport
Posts: 7830
Do tyres go soft over time?
I've just had a new pair of Pirelli Scorpions on the front my D3. The old pair were down to about 4mm remaining tread but were well past their best and as is normal with Scorpions, they'd become considerably less grippy.
The replacement pair have totally transformed the feel and handling of the whole car and I am astounded at the difference. Gone is the little tramlining that was evident but most of all I've noticed the front of the car no longer dips under braking and the bonnet no longer rises on accelerating from stand still. The whole front feels much more taught and stable which has made me wonder, especially with the weight of these cars, do tyres go soft over time as this seems to be the only explanation, and are some tyres more prone to this than others?
I've never even considered this before but the transformation is so huge there has to be an obvious explanation.Mods:
Front Fogs + Halos
FBH Remote Control
The 1st Ever RRS Modded Grill
Garmin Nuvi + D4 Surround + Reversing Camera.
D4 Steering Wheel.
Rear Boot Spoiler.
Twin Brake Lights.
Wing Mirror Indicator Repeaters.
Long Roof Rails
Make your own Narpy grill thread
I'm not scared, I'm outta here.
19th Dec 2016 1:57 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
No they don't go soft over time. If anything they become harder, especially through UV exposure.
What they do through mileage is loose mass/tread thickness and the additional rigidity that goes with it.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 14 Dec 2013
Location: Herefordshire
Posts: 2080
I agree, the rubber seems to harden with time unless exposed to oil/grease etc.
19th Dec 2016 2:19 pm
Narpy
Member Since: 18 Jul 2011
Location: Stockport
Posts: 7830
As an engineer I kinda struggle with that assumption or theory..
Surely the constant flexing of the sidewall will fatigue the tyre and make it softer over time especially as the mileage racks up? Any material when constantly fatigued will soften, some to the point of failure which admittedly probably won't happen with rubber.Mods:
Front Fogs + Halos
FBH Remote Control
The 1st Ever RRS Modded Grill
Garmin Nuvi + D4 Surround + Reversing Camera.
D4 Steering Wheel.
Rear Boot Spoiler.
Twin Brake Lights.
Wing Mirror Indicator Repeaters.
Long Roof Rails
Make your own Narpy grill thread
I'm not scared, I'm outta here.
19th Dec 2016 2:20 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
The rubber compound is rock hard and quite brittle. This would be rubbish for a tyre so they add plasticisers to the compound. Through aging, especially with UV exposure, the plasticisers leach-out or breakdown.
As an engineer you will know the propensity for materials to revert to the way they want to be.
Regarding fatigue, well a whole different ballgame as there are many materials that do harden when fatigued or put another way - work hardened.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 18 Jul 2011
Location: Stockport
Posts: 7830
Understand what you're saying Robbie but I also feel you're confirming my thoughts but for slightly different reasons than my thinking.
Maybe there is more than one factor involved in the loss of strength. Mods:
Front Fogs + Halos
FBH Remote Control
The 1st Ever RRS Modded Grill
Garmin Nuvi + D4 Surround + Reversing Camera.
D4 Steering Wheel.
Rear Boot Spoiler.
Twin Brake Lights.
Wing Mirror Indicator Repeaters.
Long Roof Rails
Make your own Narpy grill thread
I'm not scared, I'm outta here.
19th Dec 2016 2:31 pm
adam
Member Since: 20 Sep 2005
Location: Home and Happy
Posts: 6917
New tyres all round on a car can make a profound difference - maybe its not the rubber that deteriorates over time to an extent that you would notice but the material that strengthens the side walls etc.?
Surely anything that is subject to the heat variations, pressure and speed variations and wear has to lose elements of its strength over time?
19th Dec 2016 2:34 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
I most certainly am confirming through different reasons. If you took tyres to the extreme you would end up with a vehicle driving on squishy balloons on the very verg of becoming formerly-known-as-balloons.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 28 Aug 2014
Location: Norfolk
Posts: 4400
Re: Do tyres go soft over time?
Narpy wrote:
.
The replacement pair have totally transformed the feel and handling of the whole car and I am astounded at the difference. Gone is the little tramlining that was evident but most of all I've noticed the front of the car no longer dips under braking and the bonnet no longer rises on accelerating from stand still.
I run Scorpions in the summer, and I found the same. They do start to follow every deviation in the road as they get down to about 4mm. Put some fresh ones on, and they are great. I was beginning to wonder if there was something more serious wrong with my car, but it was just the tyres wearing out .Richard
D3 SE 2007. Triumph 2.5Pi 1973. Ferguson TEA20 1948.
Discovery 2 4.0 ES 2001- Gone
Discovery 1 300Tdi ES '95 - Gone
Range Rover Classic '79 - Gone
19th Dec 2016 2:46 pm
M3DPO
Member Since: 22 Sep 2010
Location: Notts.
Posts: 8075
Rubber definately hardens with age to the extent it will crack and fail, I once had to throw away a batch of 200+ "V" belts that had hardened through age and being stored on a wall in daylight, simple test on a "V" belt is to bend it backwards, if it cracks scrap it.
I would be checking the accuracy of my pressure gauge against the tyre fitters. It can when others can't,
It will when others won't,
It goes where others don't.
19th Dec 2016 2:55 pm
MGCarr
Member Since: 15 Jul 2014
Location: Lancashire
Posts: 703
I think you will find that having nice new sharp edges to the tread blocks, especially those on the inner and outer edges of the tyre, is the most significant difference. Back in the 1990's I was involved with trials with a racing saloon car that ran in a series that required it to use road tyres and it was amazing how little rounding off of the outer edge of the tyre it took to bring about a noticeable increase in lap times and this was common across the various makes we tested.
1997 Defender 90 for the kids and I to have a go at some competitive off road RTV and Tyro trials, daughter picked up her first trophy over the August Bank Holiday.
Previous Land Rover history
1996 P38 4.6 V8 Autobiography
1996 Discovery TDi 300
1972 Range Rover 3.5 V8
LWB Hard Top Series 3
LWB Truck Cab Series 2A
Not been without a Land Rover for over 40 years - I must need therapy!
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
