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Tue 14 May 2024 16:57

Mercedes and BMW - Alloy wheels cracking - Steveieb

My friend has had two wheels damaged by potholes and one tyre.

The tyres are 35 profile and the tyre store reported that he had seen seven similar cases recently.

The wheels were welded and reused but a spare wheel is essential according to my friend.

So no damage to the suspension but seven similar cases at one tyre store , all MB or BMW

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Tue 14 May 2024 17:21

Mercedes and BMW - Alloy wheels cracking - Palcouk

Low Profile, hardly surprising, also makes for an uncomfortable ride

BMW/MB posing status

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Tue 14 May 2024 23:41

Mercedes and BMW - Alloy wheels cracking - focussed

I damaged a left front wheel on the Accord a year or so ago, hit some debris in the dark on a country road, ripped the sidewall out of the tyre and damaged the outer rim.

I found a wheel refurb shop here in France about 50 miles away.

Excellent one man band shop, an ex machinist like me, he had a huge selection of specialist machines for straightening and trueing wheels. My wheel wasn't bent, the Honda wheels are massively heavy, so the rim was bead blasted, TIG welded and remachined on a CNC lathe, the diamond cut face reworked, two pack paint matched to the colour etc.

His shop was full of BMW wheels, they are so skinny and light they crumple up like a coke can if they hit anything, he says his main profit is from BMW wheels.

atelierskerene.fr/

Edited by focussed on 14/05/2024 at 23:42

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Wed 15 May 2024 01:33

Mercedes and BMW - Alloy wheels cracking - edlithgow

I damaged a left front wheel on the Accord a year or so ago, hit some debris in the dark on a country road, ripped the sidewall out of the tyre and damaged the outer rim.

I found a wheel refurb shop here in France about 50 miles away.

Excellent one man band shop, an ex machinist like me, he had a huge selection of specialist machines for straightening and trueing wheels. My wheel wasn't bent, the Honda wheels are massively heavy, so the rim was bead blasted, TIG welded and remachined on a CNC lathe, the diamond cut face reworked, two pack paint matched to the colour etc.

His shop was full of BMW wheels, they are so skinny and light they crumple up like a coke can if they hit anything, he says his main profit is from BMW wheels.

atelierskerene.fr/

Going too fast on a mountain road, I clipped a rock wall with the passenger side front wheel. That side of the car went 2-3 feet up in the air.

Thought I'd better stop, anticipating fitting the spare, and maybe suspension damage on this fairly lightweight economy box.

Dent in the rim, no hissing. Drove on, a bit more sedately.

A few months later, fitted replacement used tyres. One man band shop, he had a big hammer, and removed the dent.

Steel wheel, so no bead blasting, TIG welding or CNC lathing required.

Compare and contrast.

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Wed 15 May 2024 15:46

Mercedes and BMW - Alloy wheels cracking - gordonbennet

Daughter's chap has given up on the 19" OE wheels apparently made of cheese fitted to his Type R Civic, had numerous of them straightened due to pot hole damage.

He's replaced the lot with aftermarket 18" (can't go any smaller due to massive brakes) and so far so good.

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Wed 15 May 2024 16:27

Mercedes and BMW - Alloy wheels cracking - Steveieb

A spare wheel is becoming a necessity on these cars otherwise you are stranded unless the tyre store loans you one while the wheel gets welded

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Tue 21 May 2024 10:51

Mercedes and BMW - Alloy wheels cracking - Steveieb

Apparently MB cars seem to be cracking wheels as opposed to damaging suspension over the potholes.

But is it safe to have a wheel welded which is the norm?

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Tue 21 May 2024 17:28

Mercedes and BMW - Alloy wheels cracking - focussed

Some images about show cracking at the root of the spokes near the hub, that's a high stress area - should be sc***ped, same as a crack at the rim end of the spoke where it joins the rim.

If if's a rim crack it should be repairable by a decent wheel shop.

But you have to question why the wheel cracked in the first place without external damage,

It could be many factors, could be the design of the wheel, sections too thin or too thick in places. alloy not up to spec, heat treatment faulty after casting, aluminium alloys are many and complicated.

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Tue 21 May 2024 18:34

Mercedes and BMW - Alloy wheels cracking - focussed

"Steel wheel, so no bead blasting, TIG welding or CNC lathing required.

Compare and contrast"

Steel wheels are not exempt from cracking. In the mid 1960's original Minis used to rip the centre out of the wheel if cornered enthusiastically, as many were.

Caused in part by the introduction of decent grippy Goodyear G800 radial tyres

The wheels used to crack across the stud holes which if ignored would lead to the rim part separating from the centre.

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Thu 23 May 2024 00:32

Mercedes and BMW - Alloy wheels cracking - edlithgow

Didn't say steel wheels were "exempt from cracking", but most things are relative, and I would say they are relatively exempt from cracking.

I'd think it a fair bet that an alloy wheel would have been destroyed in the incident I describe above, and if it were repairable, it would have required a bit more than a BFH and the willingness to use it.

I wonder though if its not just the really daft material, but also the really daft design, that contributes to the fragility. I dunno what BMW wheels look like, but I see a lot of these Bling Things with very sharp (no doubt cut by laser beams, Mr Bond, or some such jive) angles and corners on them, probably inspired by the prevailing Transformers SUV design aesthetic

Look like stress raisers to me. (and ugly)

Colleague buying a new car a few years ago was being charged a bit extra to replace the standard steel wheels with alloys, and asked me if I thought it was worth it.

'Not to me" ses I. "I would probably pay a bit extra for the steel ones, given a straight choice"

"Why do people buy them, then" ses he.

"They think they look pretty" ses I

He looks disappointed. "Is that all?" ses he.

"They also reduce the unsprung mass" ses I

Blank Rabbit-In-The-Headlights-Stare. But he bought the alloys.

People think they look pretty. Serves them right

Edited by edlithgow on 23/05/2024 at 00:38

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