Help...F11...weird handling after new rear tyres
Discussion
Help!
I took my F11 520d (RWD) touring into my local tyre place the other week to get a rear puncture fixed. It's a good independent tyre place, the boss is hands on, a car enthusiast and I've used them for years. He said although the puncture was repairable, I really needed new rear tyres as the inside shoulders were starting to collapse, a known problem on those particular Goodyears. Up until then, the car had always felt fine, but I went for the new tyres on his recommendation as clearly there was something wrong.
So the car now has the existing Goodyear Excellence 245/40/R19 98Y RFT on the front, and Goodyear Eagle F1 RFTs on the back, the same size (unusual for BMW). However, the car just does not feel planted on the road. Initially it felt like it needed a lot more small steering inputs at higher speeds to keep it on the straight and narrow, but also as if the handling was just a bit wayward.
Let me explain, it's a fast A road and I'm coming up to a bend that I'll take at the same speed, no braking, no change on throttle. I turn in, just a tiny amount, and immediately it feels as if I am straightaway having to back off on the steering input, no matter how small that initial input is. Almost as if the turn-in has been sharpened up to waaaay over the top levels.
Last week it got really weird. I was going from the southbound M5 onto the westbound M4 at the RAC control tower near Bristol. Totally dry road, oodles of grip. Speed, probably somewhere around a genuine 70mph, (indicated slightly more). I turned in very gently, immediately had to back off the steering input (and I'm talking teeny, tiny amounts here) and as I felt the outside side of the car load up and unload with these tiny inputs, I seemed to get into an increasing cycle and after about two cycles the traction control light actually started coming on...although clearly I was absolutley categorically nowhere near the limits of grip. It then did exactly the same thing on the return journey and the corresponding slip road. I can understand TC coming in when driving like an utter tool in the wet on a tight bend, but cruising at 2000rpm on trailing throttle on a motorway slip road that has huge grip due to the conditions just does not seem right at all. I consider myself to be a pretty adaptable driver...my other cars are a Defender and a Porsche, both devoid of any driver aids, and I keep them on the straight and narrow just fine...in fact I think the Defender would have made it round the bend with less drama! The BMW at normal speeds almost feels like the Porsche on the absolute limit, as if the Porsche is warning me it's about to break into oversteer because I'm pushing too hard on the track or something...however the BMW feels like that when I'm just trying to get around a gentle bend at totally normal/sensible road speeds!
The tyre place has said bring it back in...start with the obvious and check the tracking, pressures on the computer against a known accurate gauge, and also see if there is a difference in rolling diameter which is somehow confusing the driver aids and they are kicking in when not needed. However I am just wondering if anyone else has had a similar issue?
Thanks in advance!
I took my F11 520d (RWD) touring into my local tyre place the other week to get a rear puncture fixed. It's a good independent tyre place, the boss is hands on, a car enthusiast and I've used them for years. He said although the puncture was repairable, I really needed new rear tyres as the inside shoulders were starting to collapse, a known problem on those particular Goodyears. Up until then, the car had always felt fine, but I went for the new tyres on his recommendation as clearly there was something wrong.
So the car now has the existing Goodyear Excellence 245/40/R19 98Y RFT on the front, and Goodyear Eagle F1 RFTs on the back, the same size (unusual for BMW). However, the car just does not feel planted on the road. Initially it felt like it needed a lot more small steering inputs at higher speeds to keep it on the straight and narrow, but also as if the handling was just a bit wayward.
Let me explain, it's a fast A road and I'm coming up to a bend that I'll take at the same speed, no braking, no change on throttle. I turn in, just a tiny amount, and immediately it feels as if I am straightaway having to back off on the steering input, no matter how small that initial input is. Almost as if the turn-in has been sharpened up to waaaay over the top levels.
Last week it got really weird. I was going from the southbound M5 onto the westbound M4 at the RAC control tower near Bristol. Totally dry road, oodles of grip. Speed, probably somewhere around a genuine 70mph, (indicated slightly more). I turned in very gently, immediately had to back off the steering input (and I'm talking teeny, tiny amounts here) and as I felt the outside side of the car load up and unload with these tiny inputs, I seemed to get into an increasing cycle and after about two cycles the traction control light actually started coming on...although clearly I was absolutley categorically nowhere near the limits of grip. It then did exactly the same thing on the return journey and the corresponding slip road. I can understand TC coming in when driving like an utter tool in the wet on a tight bend, but cruising at 2000rpm on trailing throttle on a motorway slip road that has huge grip due to the conditions just does not seem right at all. I consider myself to be a pretty adaptable driver...my other cars are a Defender and a Porsche, both devoid of any driver aids, and I keep them on the straight and narrow just fine...in fact I think the Defender would have made it round the bend with less drama! The BMW at normal speeds almost feels like the Porsche on the absolute limit, as if the Porsche is warning me it's about to break into oversteer because I'm pushing too hard on the track or something...however the BMW feels like that when I'm just trying to get around a gentle bend at totally normal/sensible road speeds!
The tyre place has said bring it back in...start with the obvious and check the tracking, pressures on the computer against a known accurate gauge, and also see if there is a difference in rolling diameter which is somehow confusing the driver aids and they are kicking in when not needed. However I am just wondering if anyone else has had a similar issue?
Thanks in advance!
Hard-Drive said:
Help!
I took my F11 520d (RWD) touring into my local tyre place the other week to get a rear puncture fixed. It's a good independent tyre place, the boss is hands on, a car enthusiast and I've used them for years. He said although the puncture was repairable, I really needed new rear tyres as the inside shoulders were starting to collapse, a known problem on those particular Goodyears. Up until then, the car had always felt fine, but I went for the new tyres on his recommendation as clearly there was something wrong.
So the car now has the existing Goodyear Excellence 245/40/R19 98Y RFT on the front, and Goodyear Eagle F1 RFTs on the back, the same size (unusual for BMW). However, the car just does not feel planted on the road. Initially it felt like it needed a lot more small steering inputs at higher speeds to keep it on the straight and narrow, but also as if the handling was just a bit wayward.
Let me explain, it's a fast A road and I'm coming up to a bend that I'll take at the same speed, no braking, no change on throttle. I turn in, just a tiny amount, and immediately it feels as if I am straightaway having to back off on the steering input, no matter how small that initial input is. Almost as if the turn-in has been sharpened up to waaaay over the top levels.
Last week it got really weird. I was going from the southbound M5 onto the westbound M4 at the RAC control tower near Bristol. Totally dry road, oodles of grip. Speed, probably somewhere around a genuine 70mph, (indicated slightly more). I turned in very gently, immediately had to back off the steering input (and I'm talking teeny, tiny amounts here) and as I felt the outside side of the car load up and unload with these tiny inputs, I seemed to get into an increasing cycle and after about two cycles the traction control light actually started coming on...although clearly I was absolutley categorically nowhere near the limits of grip. It then did exactly the same thing on the return journey and the corresponding slip road. I can understand TC coming in when driving like an utter tool in the wet on a tight bend, but cruising at 2000rpm on trailing throttle on a motorway slip road that has huge grip due to the conditions just does not seem right at all. I consider myself to be a pretty adaptable driver...my other cars are a Defender and a Porsche, both devoid of any driver aids, and I keep them on the straight and narrow just fine...in fact I think the Defender would have made it round the bend with less drama! The BMW at normal speeds almost feels like the Porsche on the absolute limit, as if the Porsche is warning me it's about to break into oversteer because I'm pushing too hard on the track or something...however the BMW feels like that when I'm just trying to get around a gentle bend at totally normal/sensible road speeds!
The tyre place has said bring it back in...start with the obvious and check the tracking, pressures on the computer against a known accurate gauge, and also see if there is a difference in rolling diameter which is somehow confusing the driver aids and they are kicking in when not needed. However I am just wondering if anyone else has had a similar issue?
Thanks in advance!
I Had an e39 M5 a long time ago and had a similar thing - not with tyre wear but how you describe the handling/feel. In my case it was a rear anti roll bar had snapped/failed. So like you on a mway normal safe speeds, gentle bend it felt like the car was about to slide away and I had to back off - this despite bone dry and other cars going around fine. I know when it broke as it was on over taking - pulled out fine with the same amount of steering input when went to go back in with similar input it didn't want to/wasn't consistent input to get the car back. It feelt dangerous and out of control. I took my F11 520d (RWD) touring into my local tyre place the other week to get a rear puncture fixed. It's a good independent tyre place, the boss is hands on, a car enthusiast and I've used them for years. He said although the puncture was repairable, I really needed new rear tyres as the inside shoulders were starting to collapse, a known problem on those particular Goodyears. Up until then, the car had always felt fine, but I went for the new tyres on his recommendation as clearly there was something wrong.
So the car now has the existing Goodyear Excellence 245/40/R19 98Y RFT on the front, and Goodyear Eagle F1 RFTs on the back, the same size (unusual for BMW). However, the car just does not feel planted on the road. Initially it felt like it needed a lot more small steering inputs at higher speeds to keep it on the straight and narrow, but also as if the handling was just a bit wayward.
Let me explain, it's a fast A road and I'm coming up to a bend that I'll take at the same speed, no braking, no change on throttle. I turn in, just a tiny amount, and immediately it feels as if I am straightaway having to back off on the steering input, no matter how small that initial input is. Almost as if the turn-in has been sharpened up to waaaay over the top levels.
Last week it got really weird. I was going from the southbound M5 onto the westbound M4 at the RAC control tower near Bristol. Totally dry road, oodles of grip. Speed, probably somewhere around a genuine 70mph, (indicated slightly more). I turned in very gently, immediately had to back off the steering input (and I'm talking teeny, tiny amounts here) and as I felt the outside side of the car load up and unload with these tiny inputs, I seemed to get into an increasing cycle and after about two cycles the traction control light actually started coming on...although clearly I was absolutley categorically nowhere near the limits of grip. It then did exactly the same thing on the return journey and the corresponding slip road. I can understand TC coming in when driving like an utter tool in the wet on a tight bend, but cruising at 2000rpm on trailing throttle on a motorway slip road that has huge grip due to the conditions just does not seem right at all. I consider myself to be a pretty adaptable driver...my other cars are a Defender and a Porsche, both devoid of any driver aids, and I keep them on the straight and narrow just fine...in fact I think the Defender would have made it round the bend with less drama! The BMW at normal speeds almost feels like the Porsche on the absolute limit, as if the Porsche is warning me it's about to break into oversteer because I'm pushing too hard on the track or something...however the BMW feels like that when I'm just trying to get around a gentle bend at totally normal/sensible road speeds!
The tyre place has said bring it back in...start with the obvious and check the tracking, pressures on the computer against a known accurate gauge, and also see if there is a difference in rolling diameter which is somehow confusing the driver aids and they are kicking in when not needed. However I am just wondering if anyone else has had a similar issue?
Thanks in advance!
Had lots of other faults with that M5 that BMW bought it back and paid compensation. So perhaps the anti roll bar is broken?
superlightr said:
I Had an e39 M5 a long time ago and had a similar thing - not with tyre wear but how you describe the handling/feel. In my case it was a rear anti roll bar had snapped/failed. So like you on a mway normal safe speeds, gentle bend it felt like the car was about to slide away and I had to back off - this despite bone dry and other cars going around fine. I know when it broke as it was on over taking - pulled out fine with the same amount of steering input when went to go back in with similar input it didn't want to/wasn't consistent input to get the car back. It feelt dangerous and out of control.
Had lots of other faults with that M5 that BMW bought it back and paid compensation. So perhaps the anti roll bar is broken?
Thanks but I don't think so. The handling changed immediately when the tyres were changed, so I'm convinced it's tyre related.Had lots of other faults with that M5 that BMW bought it back and paid compensation. So perhaps the anti roll bar is broken?
Modern BMWs are renowned for (as standard) having too much negative rear camber.
With new tyres this will be all the more evident as with part-worn tyres the tyre contact patch eventually becomes flat, the step-change in new tyres is therefore more obvious.
Your next step depends on how comfortable you are with straying from manufacturer's recommended suspension settings.
My own personal recommendation would be to go down to around 0.5 degree of negative camber at the rear, but there are probably as many answers to this as there are people out there.
With new tyres this will be all the more evident as with part-worn tyres the tyre contact patch eventually becomes flat, the step-change in new tyres is therefore more obvious.
Your next step depends on how comfortable you are with straying from manufacturer's recommended suspension settings.
My own personal recommendation would be to go down to around 0.5 degree of negative camber at the rear, but there are probably as many answers to this as there are people out there.
Doesn’t sound good...
As you’ve a square setup, can you swap the fronts & rears over? If this mitigates the rear end feeling out of sorts & buggers the front, then it’s ‘obviously’ the tyres. If it doesn’t, then that suugests something is broken as per other posts.
Also (forgive me if I missed it) have you checked the pressures (all round)?
Finally, I presume they’re Asy3 (if G/Y F1) - are they directional & you’ve got them swapped, or inside & outside swapped (I don’t know if they are or not, just trying to list possibilities).
As you’ve a square setup, can you swap the fronts & rears over? If this mitigates the rear end feeling out of sorts & buggers the front, then it’s ‘obviously’ the tyres. If it doesn’t, then that suugests something is broken as per other posts.
Also (forgive me if I missed it) have you checked the pressures (all round)?
Finally, I presume they’re Asy3 (if G/Y F1) - are they directional & you’ve got them swapped, or inside & outside swapped (I don’t know if they are or not, just trying to list possibilities).
What you are describing is known as Insufficient linear understeer. Your car is over reacting to small steering inputs, you can feel that, and the ESP system can sense it too.
Assuming your car is still as it was tuned by BMW, and the only change is the tyres, then the mismatch between front and rear tyre tyre stiffness properties is probably the cause.
As somebody else mentioned, swap the tyres front to rear. Your car should then become a lazy, lethargic mess rather than a scary, flighty one. Even easier is to increase rear tyre pressure and maybe reduce front tyre pressure, and see what happens...but don’t blame me if you die in an end over end rolling fireball.
Can I compliment you again on your description of the problem? Please?
Assuming your car is still as it was tuned by BMW, and the only change is the tyres, then the mismatch between front and rear tyre tyre stiffness properties is probably the cause.
As somebody else mentioned, swap the tyres front to rear. Your car should then become a lazy, lethargic mess rather than a scary, flighty one. Even easier is to increase rear tyre pressure and maybe reduce front tyre pressure, and see what happens...but don’t blame me if you die in an end over end rolling fireball.
Can I compliment you again on your description of the problem? Please?
Guys
Thanks for the help, there's some really interesting stuff here. If the problem is that it's the difference between the tyres front and rear that's disappointing...you'd have thought that the same size RFT tyre from the same manufacturer would not be trying to throw me off a dry motorway slip road with zero provocation!
TBH I think I might just get the fronts changed for a matching pair. My tyre man showed me that the inside shoulders were starting to wear on the front too and would need changing in the not too distant future, so perhaps now is the time. Quite frankly the car is currently ruined...it's supposed to be my waft along luxury family/work meeting barge yet somehow it needs more input than the 32 year old Defender with it's multitude of steering joints and rods to keep on the straight and narrow, more skittish than the Porsche in snow and is just not relaxing to drive at all.
Kawasicki, thanks for the technical advice, I did think "who is this person" but a quick look at your profile shows you know your stuff! Thanks for the compliment on my description
, if you have any chief test drive jobs going in the future I'm sure we can work well together, for example I could describe "it swapped ends five times and ended up in the armco at 80mph, there's definitely something not quite right!"
Will report back on how things end up...thanks again people!
Thanks for the help, there's some really interesting stuff here. If the problem is that it's the difference between the tyres front and rear that's disappointing...you'd have thought that the same size RFT tyre from the same manufacturer would not be trying to throw me off a dry motorway slip road with zero provocation!
TBH I think I might just get the fronts changed for a matching pair. My tyre man showed me that the inside shoulders were starting to wear on the front too and would need changing in the not too distant future, so perhaps now is the time. Quite frankly the car is currently ruined...it's supposed to be my waft along luxury family/work meeting barge yet somehow it needs more input than the 32 year old Defender with it's multitude of steering joints and rods to keep on the straight and narrow, more skittish than the Porsche in snow and is just not relaxing to drive at all.
Kawasicki, thanks for the technical advice, I did think "who is this person" but a quick look at your profile shows you know your stuff! Thanks for the compliment on my description
, if you have any chief test drive jobs going in the future I'm sure we can work well together, for example I could describe "it swapped ends five times and ended up in the armco at 80mph, there's definitely something not quite right!"Will report back on how things end up...thanks again people!
Hard-Drive said:
Thanks for the help, there's some really interesting stuff here. If the problem is that it's the difference between the tyres front and rear that's disappointing...you'd have thought that the same size RFT tyre from the same manufacturer would not be trying to throw me off a dry motorway slip road with zero provocation!
I promise you this is the problem. I have seen this and been banging on about it for 15 years with BMWs, everyone says "b
ks" but as soon as they put on matching tyres all round they agree. They are massively different tyres - one is an out of date, horrible touring tyre that's so old it still has the Goodyear sidewall design they got rid of 7 years ago and the other is a decent UHP tyre.
I have Asymmetric 3 RFT all round on my F10 and it doesn't exhibit the problems you're having. So I'm with gizraloc on this.
I have Asymmetric 3 RFT all round on my F10 and it doesn't exhibit the problems you're having. So I'm with gizraloc on this.
Thanks guys...it was indeed the tyres.
I went back to my tyre place...he'd ordered a pair of F1s in for me, but insisted on swapping them round first before fitting them. The handling was totally different. I can best describe it now as if the car has had a slightly slower rack fitted. The twitchiness on the straights and constant on-off-on-off steering input on sweeping bends has now gone. But there's no hint of understeer, and fortunately it's not quite the lumbering tanker that Kawasicki has suggested it might be, however it's perhaps not quite as sharp as it was on the original tyres. it just feels like it needs perhaps a little more steering angle input than originally, but actually still feels perfectly safe and planted. I had a "play" on some bends that were scary as hell before, and the car feels fine, even at significantly higher corner speeds.
So...I can live with the current set up for now (but definitely not the previous), and as my tyre guy reckons there's still 4000 miles left on the current tyres, the new ones can sit on his shelf until they are needed...perhaps I'll get them on regardless when we start getting proper damp roads and ice (remember that?) but I may as well get what I can out of the current ones.
Thanks again for everyone's input...and I'm genuinely gobsmacked about how identically sized RFT tyres from the same manufacturer could have a car like that snaking and hobby horsing around a motorway slip road at perfectly sane and legal speeds with the traction control light flashing...just unbelievable.
I went back to my tyre place...he'd ordered a pair of F1s in for me, but insisted on swapping them round first before fitting them. The handling was totally different. I can best describe it now as if the car has had a slightly slower rack fitted. The twitchiness on the straights and constant on-off-on-off steering input on sweeping bends has now gone. But there's no hint of understeer, and fortunately it's not quite the lumbering tanker that Kawasicki has suggested it might be, however it's perhaps not quite as sharp as it was on the original tyres. it just feels like it needs perhaps a little more steering angle input than originally, but actually still feels perfectly safe and planted. I had a "play" on some bends that were scary as hell before, and the car feels fine, even at significantly higher corner speeds.
So...I can live with the current set up for now (but definitely not the previous), and as my tyre guy reckons there's still 4000 miles left on the current tyres, the new ones can sit on his shelf until they are needed...perhaps I'll get them on regardless when we start getting proper damp roads and ice (remember that?) but I may as well get what I can out of the current ones.
Thanks again for everyone's input...and I'm genuinely gobsmacked about how identically sized RFT tyres from the same manufacturer could have a car like that snaking and hobby horsing around a motorway slip road at perfectly sane and legal speeds with the traction control light flashing...just unbelievable.
gizlaroc said:
It is pretty amazing isn't it?
It's pretty amazing that people seem to think the tyre manufacturers simply design a single carcass for a tyre, and then just mould different tread patterns into the top surface, and charge different prices for them!Just because a tyre is from the same manufacturer, and is the same size as one of their other models, doesn't mean that it's internal construction and "rubber" compound is the same.
gizlaroc said:
.........I would get the matching tyres all round and just sell the old ones on gumtree for £80 or so to get some money back.
+1 
When it comes to BMW's - Always fit matching tyres all round!
Hard-Drive said:
Thanks guys...it was indeed the tyres.
I went back to my tyre place...he'd ordered a pair of F1s in for me, but insisted on swapping them round first before fitting them. The handling was totally different. I can best describe it now as if the car has had a slightly slower rack fitted. The twitchiness on the straights and constant on-off-on-off steering input on sweeping bends has now gone. But there's no hint of understeer, and fortunately it's not quite the lumbering tanker that Kawasicki has suggested it might be, however it's perhaps not quite as sharp as it was on the original tyres. it just feels like it needs perhaps a little more steering angle input than originally, but actually still feels perfectly safe and planted. I had a "play" on some bends that were scary as hell before, and the car feels fine, even at significantly higher corner speeds.
So...I can live with the current set up for now (but definitely not the previous), and as my tyre guy reckons there's still 4000 miles left on the current tyres, the new ones can sit on his shelf until they are needed...perhaps I'll get them on regardless when we start getting proper damp roads and ice (remember that?) but I may as well get what I can out of the current ones.
Thanks again for everyone's input...and I'm genuinely gobsmacked about how identically sized RFT tyres from the same manufacturer could have a car like that snaking and hobby horsing around a motorway slip road at perfectly sane and legal speeds with the traction control light flashing...just unbelievable.
You’re welcome and I’m happy for you.I went back to my tyre place...he'd ordered a pair of F1s in for me, but insisted on swapping them round first before fitting them. The handling was totally different. I can best describe it now as if the car has had a slightly slower rack fitted. The twitchiness on the straights and constant on-off-on-off steering input on sweeping bends has now gone. But there's no hint of understeer, and fortunately it's not quite the lumbering tanker that Kawasicki has suggested it might be, however it's perhaps not quite as sharp as it was on the original tyres. it just feels like it needs perhaps a little more steering angle input than originally, but actually still feels perfectly safe and planted. I had a "play" on some bends that were scary as hell before, and the car feels fine, even at significantly higher corner speeds.
So...I can live with the current set up for now (but definitely not the previous), and as my tyre guy reckons there's still 4000 miles left on the current tyres, the new ones can sit on his shelf until they are needed...perhaps I'll get them on regardless when we start getting proper damp roads and ice (remember that?) but I may as well get what I can out of the current ones.
Thanks again for everyone's input...and I'm genuinely gobsmacked about how identically sized RFT tyres from the same manufacturer could have a car like that snaking and hobby horsing around a motorway slip road at perfectly sane and legal speeds with the traction control light flashing...just unbelievable.
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