Unusual Tyre Wear C5 X7

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

isisalar
Posts: 662
Joined: 27 Apr 2008, 14:16
Location: london UK
My Cars:
x 3

Re: Unusual Tyre Wear C5 X7

Post by isisalar »

My memory could well be playing tricks on me and it was about 50 years ago but I seem to recall being advised during my cycling proficiency test training to always apply the rear brakes first in the interest of stability. Perhaps Mr ESP is doing the same?
J reg 1.9d auto BX first Citroen
M reg 1.9d auto Xantia lx
N reg 1.9 td Xantia VSX Estate
T reg 2.0HDI Xantia Exclusive Estate Present car
M reg 106 diesel red
L reg 106 diesel white
02 Saxo 1.1i desire wife's present car(sadly now very ill cambelt gone- Doh)
vborovic
Locked user account
Posts: 1750
Joined: 31 Oct 2013, 17:07
Location: Somewhere
My Cars: A used Citroen
x 27

Re: Unusual Tyre Wear C5 X7

Post by vborovic »

Well, the (motor)bikes are a world of its own, you try braking with only the front brakes at 20 mph+ and see what happens ... :D ... on the bikes you should apply both brakes evenly and shift your center of gravity to the back if possible (definitely not towards the front, unless you're Lance Armstrong going at 50 mph down the road .. :D ) ... the average break bias should be roughly 65-35 front to rear (of course, some newer cars have the electrical possibility to actively redistribute the breaking power on all wheels), especially on the cars where the engine is front mounted (most of them) ... also, take into consideration the brake pads & disc size front & rear, and you'll figure out how the car actually brakes and why ... regarding the ESP, here's a great video of what it actually does ... " onclick="window.open(this.href);return false; ... unless you're always driving on the edge like in the examples, there is no way the (properly working) ESP itself would be to blame for the unexpected tyre ware (IMO at least) ...
User avatar
DickieG
Monaco's youngest playboy
Posts: 4877
Joined: 25 Nov 2006, 09:15
Location: Buckinghamshire
My Cars:
x 38

Re: Unusual Tyre Wear C5 X7

Post by DickieG »

isisalar wrote:My memory could well be playing tricks on me and it was about 50 years ago but I seem to recall being advised during my cycling proficiency test training to always apply the rear brakes first in the interest of stability. Perhaps Mr ESP is doing the same?
Indeed, plus I believe that linked brakes on motorcycles do this automatically.

As a bit of an update, since I fitted new rear disc's and pads the amount of brake dust being deposited on the rear wheels appears to have reduced to the point where it is no more or even slightly less that what is being deposited on the front wheels.
13 Ram 1500 Hemi
14 BMW 535D Tourer
19 BMW i3s
06 C3 Desire 1.4
72 DS 21 EFi Pallas BVH
User avatar
DickieG
Monaco's youngest playboy
Posts: 4877
Joined: 25 Nov 2006, 09:15
Location: Buckinghamshire
My Cars:
x 38

Re: Unusual Tyre Wear C5 X7

Post by DickieG »

vborovic wrote:Well, the (motor)bikes are a world of its own, you try braking with only the front brakes at 20 mph+ and see what happens ... :D ... on the bikes you should apply both brakes evenly and shift your center of gravity to the back if possible (definitely not towards the front, unless you're Lance Armstrong going at 50 mph down the road .. :D ) ... the average break bias should be roughly 65-35 front to rear (of course, some newer cars have the electrical possibility to actively redistribute the breaking power on all wheels), especially on the cars where the engine is front mounted (most of them) ... also, take into consideration the brake pads & disc size front & rear, and you'll figure out how the car actually brakes and why ... regarding the ESP, here's a great video of what it actually does ... " onclick="window.open(this.href);return false; ... unless you're always driving on the edge like in the examples, there is no way the (properly working) ESP itself would be to blame for the unexpected tyre ware (IMO at least) ...
Maybe not the ESP but the EBD or the initial set up by Citroen could be.
13 Ram 1500 Hemi
14 BMW 535D Tourer
19 BMW i3s
06 C3 Desire 1.4
72 DS 21 EFi Pallas BVH
vborovic
Locked user account
Posts: 1750
Joined: 31 Oct 2013, 17:07
Location: Somewhere
My Cars: A used Citroen
x 27

Re: Unusual Tyre Wear C5 X7

Post by vborovic »

Would bad wheel alignment be a possible problem? If it is off by a small margin (vertical or lateral shift), it could eat away the tires faster than normal:

Image
User avatar
DickieG
Monaco's youngest playboy
Posts: 4877
Joined: 25 Nov 2006, 09:15
Location: Buckinghamshire
My Cars:
x 38

Re: Unusual Tyre Wear C5 X7

Post by DickieG »

vborovic wrote:Would bad wheel alignment be a possible problem? If it is off by a small margin (vertical or lateral shift), it could eat away the tires faster than normal:
Yes it would but my car has been on three different Hunter DSP 600's out of IIRC four attempts at finding anything out of alignment and they all with different operators say the alignment is correct.
13 Ram 1500 Hemi
14 BMW 535D Tourer
19 BMW i3s
06 C3 Desire 1.4
72 DS 21 EFi Pallas BVH
User avatar
Stickyfinger
(Donor 2016)
Posts: 10411
Joined: 28 Mar 2013, 21:05
Location: Somset my lovleee
My Cars: Xantia V6 ACTIVA 3ltr 24v Manual p1
Xm 2.1TD Ph2 Exclusive
AX, little Daffodil
SAXO White Mk1. Sally
x 1280
Contact:

Re: Unusual Tyre Wear C5 X7

Post by Stickyfinger »

FYI

Washed mine again today, checked the tires, more on the front than the back as before so no change to normal "pattern".

Done a few miles since the wheels were cleaned, more dust on front than the back (80-20), so no change there either.
Alasdair
Activa, the Moose Rider
3x C5x7 Steering racks and counting
vborovic
Locked user account
Posts: 1750
Joined: 31 Oct 2013, 17:07
Location: Somewhere
My Cars: A used Citroen
x 27

Re: Unusual Tyre Wear C5 X7

Post by vborovic »

Maybe if you'd put the rear wheels on the front and vice-versa, then the dust would be 20-80? ... :D ...
dnsey
Posts: 1538
Joined: 20 Oct 2004, 01:39
Location:
My Cars:
x 19

Re: Unusual Tyre Wear C5 X7

Post by dnsey »

How about asking a local MOT station to put it on their brake testing gear? Should show up any anomalies in braking force.
User avatar
DickieG
Monaco's youngest playboy
Posts: 4877
Joined: 25 Nov 2006, 09:15
Location: Buckinghamshire
My Cars:
x 38

Re: Unusual Tyre Wear C5 X7

Post by DickieG »

dnsey wrote:How about asking a local MOT station to put it on their brake testing gear? Should show up any anomalies in braking force.
The only way to get an accurate answer to the braking question would be to put the car on a 4 wheel brake roller (which I've never seen anywhere) as the question being presented is where the braking force is being applied under light braking which is all I ever use. MOT brake test rollers only do one axle at a time where their purpose is to test maximum brake efficiency which I've never had cause to use since I bought it.
13 Ram 1500 Hemi
14 BMW 535D Tourer
19 BMW i3s
06 C3 Desire 1.4
72 DS 21 EFi Pallas BVH
User avatar
Stickyfinger
(Donor 2016)
Posts: 10411
Joined: 28 Mar 2013, 21:05
Location: Somset my lovleee
My Cars: Xantia V6 ACTIVA 3ltr 24v Manual p1
Xm 2.1TD Ph2 Exclusive
AX, little Daffodil
SAXO White Mk1. Sally
x 1280
Contact:

Re: Unusual Tyre Wear C5 X7

Post by Stickyfinger »

Jut thinking about it, the extra W&T on the rear must be due to some form of miss-alinement, even a modicum of additional braking should not cause that. The main W&T to any tire is turning and shear (cornering) forces, rotation and braking causes far far less.

It has to be an alinement problem ? twisting/moving struts under compression
Alasdair
Activa, the Moose Rider
3x C5x7 Steering racks and counting
vborovic
Locked user account
Posts: 1750
Joined: 31 Oct 2013, 17:07
Location: Somewhere
My Cars: A used Citroen
x 27

Re: Unusual Tyre Wear C5 X7

Post by vborovic »

I remembered this topic during my Service Documentation excavations ... managed to dig up the tech data for the wheels geometry ... if someone knows what do do with all the figures, degrees etc, I could post it up for reference (I'll have to find the english language docs though, I have them in croatian) ... also, the reference height values for both wheels are available, (for the steel sprung suspension, but I believe I could dig up the hydro one as well)
User avatar
GiveMeABreak
Forum Admin Team
Posts: 36996
Joined: 15 Sep 2015, 19:38
Location: West Wales
My Cars: C3 Aircross SUV HDi Flair Peperoncino Red (The Chili Hornet)
C5 X7 2.0 HDi Exclusive Mativoire Beige (The Golden Hornet)
C3 1.6 HDi Exclusive Aluminium Grey (The Silver Hornet)
C5 MK II 2.0 HDi Exclusive Obsidian Black
C5 MK I 2.0 HDi SX Wicked Red
Xantia S2 2.0 HDi SX Hermes Red
C15 Romahome White
XM 2.0 Turbo Prestige Emerald Green Pearlescent
XM 2.0 Turbo Prestige Polar White
XM 2.0 SX Polar White
CX 20 Polar White
GS 1220 Geranium Red
CX 2.4 Prestige C-Matic Nevada Beige
GS 1000 Cedreat Yellow
x 5644

Re: Unusual Tyre Wear C5 X7

Post by GiveMeABreak »

Always noticed more brake dust on the rears than the fronts on the X7. This is despite a having all the discs and pads replaced. But back to the tyre wear issue. I have always had the front tyres go way before the backs on the MK1, the facelift and the X7. Lucky to get 8k on a set of fronts in rural Wales. I've had Uniroyal Rainsport 2 on all 4 corners for the last 2 changes, but as I write this post, I'm sitting in the garage having 2 Michelin CrossClimate tyres fitted to the fronts. The write ups are good and although in the UK winter tyres are not required, with the weather changing and the Uniroyals on the Bars, am taking the plunge. Summer tyre with winter certification and the videos show good performance in the snow. I'll monitor mileage with these as can't be any worse than all the other brands I've had!
Please Don't PM Me For Technical Help

Marc
vborovic
Locked user account
Posts: 1750
Joined: 31 Oct 2013, 17:07
Location: Somewhere
My Cars: A used Citroen
x 27

Re: Unusual Tyre Wear C5 X7

Post by vborovic »

I'll still stick to having a summer + winter combination of tyres (but one set of rims) ... I've read some comments on the CrossClimates, that they add to the fuel consumption (roughly 0,5 l/100 km) and that they're a bit louder that other tyres, but it has to have some drawbacks if it does the winter&summer job in a single product ...
Bick
Posts: 482
Joined: 19 Feb 2006, 17:35
Location:
My Cars:
x 44

Re: Unusual Tyre Wear C5 X7

Post by Bick »

vborovic wrote:Well, the (motor)bikes are a world of its own, you try braking with only the front brakes at 20 mph+ and see what happens ... :D ... on the bikes you should apply both brakes evenly and shift your center of gravity to the back if possible (definitely not towards the front, unless you're Lance Armstrong going at 50 mph down the road .. :D ) ... the average break bias should be roughly 65-35 front to rear (of course, some newer cars have the electrical possibility to actively redistribute the breaking power on all wheels), especially on the cars where the engine is front mounted (most of them) ... also, take into consideration the brake pads & disc size front & rear, and you'll figure out how the car actually brakes and why ... regarding the ESP, here's a great video of what it actually does ... " onclick="window.open(this.href);return false; ... unless you're always driving on the edge like in the examples, there is no way the (properly working) ESP itself would be to blame for the unexpected tyre ware (IMO at least) ...
Motorbikes 90% of the braking is on the front - touch the back with the weight transfer to the front the back will lock. Touch the back on the track and you are in real trouble, i have seen people being kicked off a track day because they did not know how to brake correctly and kept locking the back.

The only exception would be Harleys and motorcross bikes. Keith Kode who taught Wane Rainey to race says dont even bother to use the bake brake on a bike.

I have also owned linked brake motorcycles and they are terrible a lot of motorcyclists want it disconnected.

As for your problem you do need to get the car to a decent alignment specialist like Steertrack
Post Reply