Discussion
You say the tyres were checked just before going on track.
If you then spent several laps on track they will have got significantly hotter & therefore a significantly higher pressure. Most people check them when they are hot when they come back in, then drop them to the correct pressures & take a couple of laps to warm them up before driving at full speed.
If you then spent several laps on track they will have got significantly hotter & therefore a significantly higher pressure. Most people check them when they are hot when they come back in, then drop them to the correct pressures & take a couple of laps to warm them up before driving at full speed.
E-bmw said:
You say the tyres were checked just before going on track.
If you then spent several laps on track they will have got significantly hotter & therefore a significantly higher pressure. Most people check them when they are hot when they come back in, then drop them to the correct pressures & take a couple of laps to warm them up before driving at full speed.
Yep, if they were at the manufacturer's recommended cold pressures then they will have been far too high within a few laps. If you then spent several laps on track they will have got significantly hotter & therefore a significantly higher pressure. Most people check them when they are hot when they come back in, then drop them to the correct pressures & take a couple of laps to warm them up before driving at full speed.
If they are old tyres and they predate your purchase of the car they could have been run under-inflated for a spell in the past which will weaken the tyre in that spot.
Cheapstraitsix said:
To Ben honest never took into account the hot pressures.
I assume the best way to do this is go out for 15mins or so, adjust, then monitor throughout the day?
That being said never had a tyre gouge down to the cords on the 8 previous track days, 3 with these tyres?
Yes. I assume the best way to do this is go out for 15mins or so, adjust, then monitor throughout the day?
That being said never had a tyre gouge down to the cords on the 8 previous track days, 3 with these tyres?
Your tyre, and accelebrate's, were very low on tread on the outer shoulder and approaching the layer where the tread is vulcanised onto the carcass. With continued heat and abuse the tread may start to lift as you wear through this layer. This is typical on cars and tyres which are not geared towards track work.
I had the same on Cup 2's. I thought it was due to not running enough camber but it's not consistent around the edge and just one big chunk on the NSF so not sure if it's cornering/curb/lack of camber damage?
This tyre did go through a lot of heat cycling though which no doubt added to it.
This tyre did go through a lot of heat cycling though which no doubt added to it.
As I said above, you're wearing through the tread layer and it's starting to tear off. The tyre is simply finished. Predictably in your case and in the OP's case, the outer shoulder of the N/S/F goes first (because clockwise)- more camber and a racier setup might help but really it's symptomatic of tracking a heavy road car on road tyres.
james_gt3rs said:
Chr1sch said:
I ran over a curb on the outside of the new chicane at Bedford last year, it is so aggressive that it tripped my fuel cut off and broke a tooth off my diff!!
In general i'd avoid them unless confident they're smooth
In general i'd avoid them unless confident they're smooth
SpudLink said:
james_gt3rs said:
Chr1sch said:
I ran over a curb on the outside of the new chicane at Bedford last year, it is so aggressive that it tripped my fuel cut off and broke a tooth off my diff!!
In general i'd avoid them unless confident they're smooth
In general i'd avoid them unless confident they're smooth
tsinc said:
I had the same on Cup 2's. I thought it was due to not running enough camber but it's not consistent around the edge and just one big chunk on the NSF so not sure if it's cornering/curb/lack of camber damage?
This tyre did go through a lot of heat cycling though which no doubt added to it.
I did Castle Combe on Friday running Cup 2's.This tyre did go through a lot of heat cycling though which no doubt added to it.
I noticed a significant amount of wear on the NSF, but it was very even across the tyre. - no damage similar to the picture.
I did of course attack the kerbs (but not the green), and made sure that the pressures were correct.
I didn't find the kerbs at Combe to be too severe.
My fronts are specified at 18psi, which I had previously set from cold.
After session 1 and therefore a heat cycle I rechecked and they were at 22.5psi.
Therefore reduced to the correct pressure.
My car's quite light so maybe heavier cars take more punishment.
Jarcy said:
My car's quite light so maybe heavier cars take more punishment.
triple the weight, raise the CoG by a foot, reduce the front camber and it's no surprise that mass production cars roll onto the tyre's shoulder on hard cornering causing particularly heavy wear on the very edge of the tread. Gassing Station | Track Days | Top of Page | What's New | My Stuff