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Discussion Starter · #1 ·
Are AMG wheels quite soft

Hit a pothole today. Nothing too major thought i better check after completing journey to make sure the tyre wasn't bulged and holy crap the wheel is toast

See image below

Tire Wheel Land vehicle Vehicle Car
 

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Good grief
Should go back take pic and get your insurance to run a comprehensive case and then recover from the city
I had to do that many years ago
 

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2021 AMG CLA 45 S Digital White w/Performance Package
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Wow, I'm amazed that there is no tearing or significant rip in the sidewall of the tyre. I went through a big pothole a few years ago with the old CLA and it was the opposite, no damage to the wheel but the Michelin had a massive tear from the bead almost to the tyre edge. Insurance claim?
 

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Discussion Starter · #4 ·
Wow, I'm amazed that there is no tearing or significant rip in the sidewall of the tyre. I went through a big pothole a few years ago with the old CLA and it was the opposite, no damage to the wheel but the Michelin had a massive tear from the bead almost to the tyre edge. Insurance claim?
These tyres are really hard to be fair.

The ride is very uncomfortable. Not sure if it is a trait of continental XL tyres

I was driving the missus mini cooper today and it has 205/45/17 dunlop run flat XL's and even they seem to be a much softer tyre.

I expected the tyre to be bubbled / blow out. Was in shock when i seen the rim was bent. On the face too. Strange
 

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I ran Continental SportContact 6 for a year or two on the previous CLA and found them to be 'softer' than the Michelin Pilot Sport 4 S. I've never had run flats so I can't compare, however the low profile 19" tyres are quite unforgiving whatever brand you go for unfortunately. I find the Michelins to be the best for performance and the middle ground for comfort. There are some older threads about the best tyres for these cars that are worth a look at. Good luck with the wheel mate!
 

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Discussion Starter · #6 ·
Wheel Tire Car Land vehicle Vehicle



New 2nd hand rim (refurbed)

Total cost inc changing tyre and valve over £231.40

There was zero damage to the tyre but obviously i will keep an eye on it.

I have also dropped the pressure to 32 PSI instead of the recommended 37 PSI hopefully saving any future rims from damage
 

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the only thing i trust is a calibrated pressure gauge that reads to 0.1psi ... cluster readouts and app displays are just relative offsets from the gauge readings

suggest you keep a nominal recommended cold front pressure of at least 35 ... as the fronts get hotter than the rears during use and insufficient air content could create long term issues from diminished cooling capacity
 

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the only thing i trust is a calibrated pressure gauge that reads to 0.1psi ... cluster readouts and app displays are just relative offsets from the gauge readings

suggest you keep a nominal recommended cold front pressure of at least 35 ... as the fronts get hotter than the rears during use and insufficient air content could create long term issues from diminished cooling capacity
Why do digital gauges reading to within +/- 0.5psi not good enough?
 

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Why do digital gauges reading to within +/- 0.5psi not good enough?
... you asked ... so bear with me

its just the rounding error that messes with my long term data sets ... and the error bars are much smaller ... eg 32 left and 32 right rears could actually be 31.5 left and 32.5 right which is a 3.1% pressure delta in suspension/grip/tirecooling performance across the twin 80sqin footprints that one day could mean the difference between holding a high speed turn or spinning out (of course similar considerations for the 36/36 fronts)

in a slalom run i can say for sure the overall time result is different for 34/30 vs 37/33 cold pressures (using conti ecs compound)

our mfa1 chassis are quite well tuned and its perfect and sensitive when balanced


on a separate thread ...

its the precision (not accuracy as thats just a bias term) in the pressure data over time that brings out things like bead leaks, treadwear/alignment issues, suspension consistency, tiny punctures, etc etc ... and so pressures are logged regularly together with a thermocouple probe for temperature references

as it is, there are a lot of variables for long term asset state monitoring, so being able to closely maintain one variable and make it a controlled constant helps make things a tad easier

similarly we use the tick marks on the dip stick to observe actual oil loss volume and hence engine tolerance changes ... or measuring the antifreeze mixture fills at 5mL increments for coolant loss rate and thus coolant loop condition checks ... or 0.1mm treadwear tracking for suspension/alignment monitoring ... granularity has its uses

i am a little cuckoo but thats just me ay?
 

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Discussion Starter · #12 ·
32 up front? Whoa that may be a bit too low
Maybe 35 as a compromise
... you asked ... so bear with me

its just the rounding error that messes with my long term data sets ... and the error bars are much smaller ... eg 32 left and 32 right rears could actually be 31.5 left and 32.5 right which is a 3.1% pressure delta in suspension/grip/tirecooling performance across the twin 80sqin footprints that one day could mean the difference between holding a high speed turn or spinning out (of course similar considerations for the 36/36 fronts)

in a slalom run i can say for sure the overall time result is different for 34/30 vs 37/33 cold pressures (using conti ecs compound)

our mfa1 chassis are quite well tuned and its perfect and sensitive when balanced


on a separate thread ...

its the precision (not accuracy as thats just a bias term) in the pressure data over time that brings out things like bead leaks, treadwear/alignment issues, suspension consistency, tiny punctures, etc etc ... and so pressures are logged regularly together with a thermocouple probe for temperature references

as it is, there are a lot of variables for long term asset state monitoring, so being able to closely maintain one variable and make it a controlled constant helps make things a tad easier

similarly we use the tick marks on the dip stick to observe actual oil loss volume and hence engine tolerance changes ... or measuring the antifreeze mixture fills at 5mL increments for coolant loss rate and thus coolant loop condition checks ... or 0.1mm treadwear tracking for suspension/alignment monitoring ... granularity has its uses

i am a little cuckoo but thats just me ay?
This just went right over my head 🤣

I must say car is much nicer to drive at lower PSI 🤣

Usually on previous cars i just go with 35 PSI all round don't even bother looking at the recommended PSI. Always seems to have worked out okay in the past 😵‍💫
 

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I put mine at 41 psi (front) and 40 psi (rear), and my CLA is riding on H&R sport springs with Blistein B8 plus sports shocks. It's firm but not jarring at all. I think the H&R sport springs are actually more compliant than the stock Mercedes sport springs.
 

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the oem units seem to be bilstein b4 systems

apparently they have a less forgiving initial rate curve so the tires work harder and become more prominent in ride quality observations
kinda makes sense and the natural frequencies bear that out ... teeth chatter vs more compliance

one of these days gonna hook up a vibration sensor network and see what this chassis and tire combo really does
 

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[QUOTE="BigJase88, post: 413233, member: 36890"I must say car is much nicer to drive at lower PSI”

may i ask what tire brand model and size are on your rims?
and stock suspension?
 

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Discussion Starter · #16 ·
[QUOTE="BigJase88, post: 413233, member: 36890"I must say car is much nicer to drive at lower PSI”

may i ask what tire brand model and size are on your rims?
and stock suspension?
Stock suspension AMG Line Shooting Brake 200d

Tyres are Continental ContiSport Contact 5's in 225/40/18 XL 92Y speed rating

They are marked MO so specced to Mercedes Orginial Non Run Flat

Manufacturing dates range from 2019 to 2021
 

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oh ... surprised your conti’s ride harsh even tho not runflat sidewalls
you may get premature carcass wear with consistent low cold pressures ... the ride will be a tad smoother but the sidewalls will take the hits
 

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Discussion Starter · #18 ·
oh ... surprised your conti’s ride harsh even tho not runflat sidewalls
you may get premature carcass wear with consistent low cold pressures ... the ride will be a tad smoother but the sidewalls will take the hits
Either the AMG Line suspension is rock hard or the Conti's are an unforgiving tyre.

Harshes ride i have ever experienced. Probably harsher than my old Civic Type R and it was rock hard 😲

I notice the CLA specs low rear tyre running pressure around the 29/30 psi.

Might drop the rear to this pressure as currenrly 32 PSI
 

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oh believe me going from bridgestone rft tires to conti ecs was like wood floor to carpet

36/32 is very typical for gen1 chassis and tire wear over a few years is very even with that
 

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Discussion Starter · #20 ·
Wheel Automotive tire Hubcap Tread Synthetic rubber


Got the bent wheel straightened and powdercoated gloss black

Couldnt diamond cut as had been done before. Stuck a cheapo tyre on as it is only for a spare.

Was thinking about getting the rest done the same but i am unsure 😵‍💫
 
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