Dunlop Sportmax tyres cracking

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Deleted User 732

Re: Dunlop Sportmax tyres cracking

Post by Deleted User 732 » Fri Jul 03, 2020 9:59 am

The Ackermann angle is part of the car's steering designed in by the maker and not an adjustable for the car in normal use as is tracking. Cracking on the sidewalls is common on tyres over 3 years old. All tyres need regular checks the same as oil, coolant etc. Not doing so and allowing them to run under the designed pressure will enhance wear in the treads and carcass of the tyres.

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Kaikoura
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Re: Dunlop Sportmax tyres cracking

Post by Kaikoura » Fri Jul 03, 2020 10:40 am

Vespa wrote:
Fri Jul 03, 2020 9:59 am
The Ackermann angle is part of the car's steering designed in by the maker and not an adjustable for the car in normal use as is tracking. Cracking on the sidewalls is common on tyres over 3 years old. All tyres need regular checks the same as oil, coolant etc. Not doing so and allowing them to run under the designed pressure will enhance wear in the treads and carcass of the tyres.

Here is a video explaining the Ackerman Steering. Just as an aside the guy has some excellent YouTube videos on a range of automotive subjects. As a retired engineer I found his videos on variable valve timing and lift quite interesting. Sad but true.

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Re: Dunlop Sportmax tyres cracking

Post by 147daytona » Fri Jul 03, 2020 5:22 pm

Just before I traded my 240 in it had it's 1st MOT and I got an advisory for all 4 of the original 19" Dunlop Sportmax tyres and they had only covered 14k miles in those 3 years so had plenty of tread left on them.

I'd never had tyres of any make crack on any car I've owned over the last 40 years until these Dunlops!

At least Jaguar had to replace them at their expense before selling the car on (well at least I hope they did).
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lexie
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Re: Dunlop Sportmax tyres cracking

Post by lexie » Fri Jul 03, 2020 6:57 pm

There used to be something where tyres had manufacturers guarantee for 5 years against this sort of thing. However, the date stamp on the tyre can be a few years earlier than when fitted and fast fit outlets aren't interested in the bother of claiming. Had problems with Goodyear tyres on our Alfa, which seemed to be the ones manufatured in China whereas the German produced ones were OK. But this was wavy tread from carcass failure, rather than cracking
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ChrisGB
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Re: Dunlop Sportmax tyres cracking

Post by ChrisGB » Wed Jul 29, 2020 7:55 pm

Just to add, tyres are more likely to develop cracking if the car stands unused for long periods. The plasticisers start to separate from the compound due to lack of movement.
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Philtrum
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Re: Dunlop Sportmax tyres cracking

Post by Philtrum » Thu Sep 24, 2020 3:00 pm

Mine have been cracking for at least 2 years. Despite still having plenty of tread, I had them changed to Michelin PS4s yesterday - for £674. I’ve only driven a few miles with them, since fitting, but immediately noticed that the car is much quieter.
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Re: Dunlop Sportmax tyres cracking

Post by Fighterpilot » Fri Sep 25, 2020 12:01 pm

Philtrum wrote:
Thu Sep 24, 2020 3:00 pm
Mine have been cracking for at least 2 years. Despite still having plenty of tread, I had them changed to Michelin PS4s yesterday - for £674. I’ve only driven a few miles with them, since fitting, but immediately noticed that the car is much quieter.
New tyres will always sound quieter because they are more flexible when new and the rigidity that builds up with ageing enhances the noise. Tread depth of just a couple of mm can also make a difference to noise levels. You will not notice the noise increasing with age until you next renew the tyres. Then once again the new tyres will sound quieter. Tread pattern can also be an issue.
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Andrew453
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Re: Dunlop Sportmax tyres cracking

Post by Andrew453 » Fri Sep 25, 2020 11:07 pm

Just had a full set of Uniroyal Rainsport 5s fitted to my newly powder-coated wheels in place of the old Dunlops. A marked improvement in ride, handling and road noise. Well pleased, if a little paranoid about kerbs now! :shock: :lol:
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