Are 19 inch wheels ok on our potholed roads?

[JakeS76]

A lot of the Z4s for sale are still running on 19 inch wheels but with Non Run flat tyres. I was thinking I would need to buy new 18 inch wheels and tyres if I buy one of these. As our UK roads are so bad.
But is anyone running on 19 inchers that's not had a problem with cracked alloys?

 

[bigwinn]

Got style 230s on non rfts and not had any issues yet…

Now watch me get a humdinger tomorrow

 

[enuff_zed]

A lot of the Z4s for sale are still running on 19 inch wheels but with Non Run flat tyres. I was thinking I would need to buy new 18 inch wheels and tyres if I buy one of these. As our UK roads are so bad.
But is anyone running on 19 inchers that's not had a problem with cracked alloys?

Keep them and look further ahead. :wink:

Not a dig at you of course but it never ceases to amaze me how many drivers would rather crash through a pothole than lose even one single mph to wait for the car coming the other way to pass.

 

[B21]

Its not really the diameter of the wheel..technically the bigger the diameter of the wheel the better it will ride through a pothole..the issue is the depth of the tyre wall...normally the tyre wall gets thinner as the wheel gets larger to maintain the same rolling radius..on E89s its important that the rolling radius front and rear is the same..

So on 19" you could go a size up say 225/40 19 and 255/35 19 rather than the stock 225/35 19 and 255/30 19

On top of that some alloy wheels like326m are just much more fragile

 

[JakeS76]

Which are the least fragile 19 inch BMW styles?

 

[Pondy]

Which are the least fragile 19 inch BMW styles?

None of them.
It's not about the wheels type, per se, more about the combination of a lot of things. Big cast wheels + low profile tyres + low car with very limited suspension travel + heavy car with low suspension travel and very stiff springs + all the previous with hard sidewall run flats with little 'give' + crashing though pot holes = guess what?

The internet is littered with posts of wheels cracking, not just Z4s. You could pick almost any manufacturer who use big wheels (18" plus) and there are loads of complaints of wheels cracking, or warping.

BTW I have had two E89 Z4s with M-sport suspension, with 19" 326M wheels (yes the really crap ones??) and RFTs. Neither has had any cracks in any of the wheels. And NO, I don't drive on a race track!

 

[B21]

Which are the least fragile 19 inch BMW styles?

The 437M is the toughest stock BMW wheel by some way..it’s a forged item off the M series cars..

Whilst many folks have cracked 326Ms I’m not aware of any one whose cracked or bent a 437M…

I’ve bent 3 of my Apex Arc-8s ..which are flow formed…one irreversibly…same car same roads no issue with 437Ms..

The chance of cracking increases with width of the alloy wheel…the 437Ms are amongst the widest ..

You can see where I’m going..

Of course depends where you drive, how long, how fast etc

I’m going go up a size on my Apex Arc-8 to try and buy them some more margin..

 

[road warrior]

its not sexy and nobody will do it, but by far the best and most comfortable wheel size is 16" ergo lots of sidewall, they almost make a z4 comfortable.
But then, nobody buys a Z4 to be comfortable now do they..

 

[ibroker]

I have 20s on mine.........and drive carefully and not at night.

 

[simnew]

I think the 296m wheel has to be the most fragile…. Looks good of course but I had to change mine - I ended up on a slightly smaller 18, the 293. Die hard fans will think it is too pretty although it was the wheel it launched with, but the slightly thicker rubber does make a different (also non run flat). With it, the Z4 is far less jittery although still fairly stiff but at least there are moments where the ride will,actually seem good which was never the case with the 296’s.

 

[enuff_zed]

I have 20s on mine.........and drive carefully and not at night.

Is metal stronger in sunlight?

 

[Phoenixboy]

A lot of the Z4s for sale are still running on 19 inch wheels but with Non Run flat tyres. I was thinking I would need to buy new 18 inch wheels and tyres if I buy one of these. As our UK roads are so bad.
But is anyone running on 19 inchers that's not had a problem with cracked alloys?

Keep them and look further ahead. :wink:

Not a dig at you of course but it never ceases to amaze me how many drivers would rather crash through a pothole than lose even one single mph to wait for the car coming the other way to pass.

Is the right answer.
you can avoid a lot of the potholes if you concentrate, and are prepared to back off to swing round them.
and as has been said, it applies to most cars with big wheels, hard sport suspension etc
My Golf R has the same issues on the Pretoria wheels, look great, but take care to avoid the big potholes.....

 

[B21]

Nice theory on pothole avoidance ..but…when the roads are wet / it’s rained ..there are puddles everywhere..well certainly here in Scotland…the issue is unless you’ve got forward looking sonar then how do you know that the puddle hides a whopping great pothole?

Of course if you only drive on dry days it’s simple..

 

[enuff_zed]

Nice theory on pothole avoidance ..but…when the roads are wet / it’s rained ..there are puddles everywhere..well certainly here in Scotland…the issue is unless you’ve got forward looking sonar then how do you know that the puddle hides a whopping great pothole?

Of course if you only drive on dry days it’s simple..

If in doubt and I am able to, I avoid the puddle. Been caught like that before.
Not so easy at Warp Factor 9 I suppose. :wink:

 

[Phoenixboy]

Nice theory on pothole avoidance ..but…when the roads are wet / it’s rained ..there are puddles everywhere..well certainly here in Scotland…the issue is unless you’ve got forward looking sonar then how do you know that the puddle hides a whopping great pothole?

Of course if you only drive on dry days it’s simple..

If in doubt and I am able to, I avoid the puddle. Been caught like that before.
Not so easy at Warp Factor 9 I suppose. :wink:

i suppose scotland is permanently wet or snow, so if you dont go out in the rain, you never go out....

 

[B21]

Nice theory on pothole avoidance ..but…when the roads are wet / it’s rained ..there are puddles everywhere..well certainly here in Scotland…the issue is unless you’ve got forward looking sonar then how do you know that the puddle hides a whopping great pothole?

Of course if you only drive on dry days it’s simple..

If in doubt and I am able to, I avoid the puddle. Been caught like that before.
Not so easy at Warp Factor 9 I suppose. :wink:

Not easy when the whole road width has puddles..are worst ones tend to be in the centre..or nicely on both sides of the perfect line on single track roads..

I drive more slowly these days only warp 7... not a good example when you're teaching young pups how to drive!

 

[B21]

Nice theory on pothole avoidance ..but…when the roads are wet / it’s rained ..there are puddles everywhere..well certainly here in Scotland…the issue is unless you’ve got forward looking sonar then how do you know that the puddle hides a whopping great pothole?

Of course if you only drive on dry days it’s simple..

If in doubt and I am able to, I avoid the puddle. Been caught like that before.
Not so easy at Warp Factor 9 I suppose. :wink:

i suppose scotland is permanently wet or snow, so if you dont go out in the rain, you never go out....

Incorrect..we just get 4 seasons (at least) in one day!

 

[Avityesboy]

A lot of the Z4s for sale are still running on 19 inch wheels but with Non Run flat tyres. I was thinking I would need to buy new 18 inch wheels and tyres if I buy one of these. As our UK roads are so bad.
But is anyone running on 19 inchers that's not had a problem with cracked alloys?

I think if you are a careful driver and know the roads and don’t go smashing down potholes you should be ok with 19s

 

[ibroker]

I have 20s on mine.........and drive carefully and not at night.

Is metal stronger in sunlight?

No chance. Im just precious about her and only drive it on nice days so with the best intentions and a lot of luck i stay away from the craters!!!!!