Tyres, replacing and Tracking/balacing

[cascas]

Looks like the time has come to soon replace both front tyres on my A140, after about 14K miles. (Conti Ecocontact)

As far as I know the legal limit is 1.6mm over 75% of the tyre. But I suspect that replacing the tyre when it gets to 3mm over 75% would be more sensible (as recommended by Continental)

As far as I know, new tyres should always be fitted to the rear (putting the existing rear tyres to the front, and fitting the new tyres to the rear) Should the rear tyres be moved to the front, keeping the same side
(i.e Left rear, to Left front) or should they be crossed over? (i.e Left rear, to Right Front)? The Mercedes Service schedule (assyst) does not perform rotation as part of the schedule on the A class.

Tyre wear is as follows:

FL 2 4 3 3 FR 4 3 4 2 (average 3.125mm)
RL 6 7 7 7 RR 7 7 7 6 (average 6.75mm)

Above tread depths as as on the car (i.e front left depths are 2mm on the outside, 3mm inside - Front Right 2mm on outside, 4mm inside)

Does the wear pattern look reasonable? Is it normal for the outside of the tyre to have slighly higher wear than the inside.

Assuming that the tyre started with 8mm, is it usual to show the ratio of wear re front vs rear tyres (approx 2800miles per mm on the front, and 11200miles mm on the rear - i.e fronts wear 4 times quicker than rears)

Found some info on the ATS Euromaster site,

ATS recommends:

Balancing: Each time a wheel is fitted, or when wheel are swapped to a different location.

Geometry: After a violent shock, after abnormal tyre wear, diminished road holding, at least once a year.

Looks like I therefore need, two new tyres (fitted to back), all wheel rebalanced, and geometry checked/adjusted!

Does this seem reasonable?

 

[Andy]

Hi

This is what you need to do. First the best tyre should be on the steering axle. So thats the front. Forget what any body else tells you.

When the tyres are fitted they will be balanced, as a matter of course. The edge of the front tyres look a little worn. But more than likely caused by the power steering.

There is a lot of thing ATS recommend. But then again they want your money.

If you decide to have the  aligment checked. If its not MB , make sure they no what to do in the event they find something a little more than usual. Most of these places can't check it properly let alone adjust it properly.

Hope I have been some help.

Regards


Andy @ www.mercedesservicing.com

PS. I am supprised that your not complaing of wearing the tyres out after 14k, some of the members here would be appauled if they didnt get at least 100k to a set of tyres. Sorry only teasing!!!!!!!!!!!!

 

[cascas]

Thanks for the reply!

Sorry for the long posting again...

I have always found the the A140 felt solid on the road (others will no doubt disagree), and just wanted to make sure that everything was set up exactly as recommended, as not to compromise the handling. Naturally I do not wish to pay for balancing/tracking if not needed (dont fix what isnt broken??) and respect your advice in this matter.

As you will know appreciate the concensus is now to fit to the rear (how ever I have always previously put the best tyres on the front on my previous cars) Interestley enough I contacted Continental regarding these matters who responded:

"1) Changing the wheels form back to front and vice-versa at appropriate intervals is recommended. In certain cases changing them crosswise can be also advantageous so as to reverse their sense of rotation (does not apply to diagonal tyres). However the instructions given in the vehicle manual should be followed when rotating the tyres"

2)If the balancing of the tyres was done correctly the first time then there should be no necessity to rebalance the wheels. As the properties of the
wheel assembly have not changed.

3)If there are no significant signs of uneven wear (i.e. shoulder wear) then again I see no reason why you should have tracking checked.

Taking the questions backwards (just to confuse)

Continental agree with you that balancing or tracking is not needed unless there is a problem- perhaps proving your theory that ATS is after our money!

Now just the question of rotation (or rather new tyres to rear). Continental just suggest rotation may be useful, following the manufactuers recommendations but not essential. As you will not doubt already know the Mercedes ASSYST service B lists the item "Remove and install wheels, rotate BUT NOT WHERE TYRES ARE MIXED" - this applies to all models EXCEPT the A Class where the item is not applicable? Is there any reason you know why rotation does not apply to the A Class? This may perhaps confirm that on the A Class wheels should not be moved around - i.e just replace the front.

I have heard many times before of having the tracking adjusted putting causing more problems than it solves, as I live fairly close to you (now that I have discovered you) perhaps you can take care of the tracking when needed!

Regards

 

[DM]

I would imagine that being front wheel drive the best tyres should be on the front wheels. That seems why the Mercedes ASSYST service B excludes the A class from wheel rotation.

On my A160 I have put the new tyres onto the front wheels the handling to me appears very good still and as I have the drum brakes at the back the rear tyres don't do have a lot to do.  (The fronts lasted 16K)

I am no expert I just drive an A class.

HTH

 

[fuzzer]

My A160 had done 17,500 when i sold it and there was loads and loads left on all the tyres . The rears were brand new almost. I recon i could have got another 5k out the front ones.

I did have michelin energy tyres from the factory , so maybe its a diferent compound . When replacing , i would recomend michelin tyres . I currently have pirelli through duress as i got them cheap from the dealer, as soon as they wear out , im getting Pilot exalto's on it.

If costco is close to you , they do good deals on tyres.

 

[Russel Weston]

In November last year I wrote off my Volvo by hitting the central reservation on the M23. I had new tyres fitted to the front only as the rears were nearing the limit but I was to replace them the following month. I will confess to excess speed under the conditions. At 70mph I hit a large puddle of water, the car aquaplanned and altought I made a consious effort not to break the car started to spin. Once I was travelling sideways I felt there was nothing for it and jumped on the breaks to bleed off some speed as I could see the inevitable. At that point the front tires bit in and the rears just slid, of course round I went even faster. A few weeks later Top Gear/ Driven did a piece on tyers and the recomended fitting the new/ deeper tread tyers on the back. They showed numerous examples of the exact situation I was in and the difference the tread deapth made. I will never put the new tyers in the front again.

 

[cascas]

New fronts and rears near the limit. I can see how that could cause a problem. i.e High grip on front, very little on the rear.

Personally I would change a tyre once the tread was down to 3mm (legal limit being 1.6mm)

 

[white190]

Ok this is the rule when fitting tyres
(I did the job off and on (excuse the pun)for 3 years)

When renewing tyres always fit the newest ones to the rear on a front wheel drive car...
If the front wheels loose grip and cause understeer most front wheel drivers are used to correcting this..

If you fit the new tyres to the front of a front wheel drive car it can cause the rear tyres to loose grip first resulting in unexpected oversteer (which most front wheel drivers aren't used to) or worse if the road is very slippery you can get the expected understeer plus oversteer resulting in a sideways slide into a ditch...... or even worse spinning around and hitting something.


On a rear wheel car if the rear tyres are ok it is ok to fit the newest to the front if the rear tyres are in good condition  , as owners of rear wheel drive cars are used to dealing with over steer........ if not they should be....




This was drummed into us at the ford Stealership by every Tyre rep who ventured into the workshop.....

 

[mjtray]

Couldn't agree more with what White190 said!......the report on Driven showed the consequences of having good tread on the fronts and low treads on the back in a front wheel drive very well!

If you're based in the South, the best place for tyres is Micheldever Tyres just south of Basingstoke...Directory Enquires for number.

I replaced my Goodyear NCT's for £65.00 each, whereas Kwik Fit etc wanted £110 per tyre.

Cheers

Martin

 

[GrahamC230K]

Andy is wrong, White is right.

Never forget what anyone else says, listen to everyone then make an informed choice.

 

[piestore]

tyres

Hi guys

I would have to agree with Andy I prefere to be able to steer the car with the steering wheel rather than the throttle, regarding the 4 wheel alignment there is no adjustment possible to the rear of the A class so any measurment out of spec would indicate a problem.

 

[GrahamC230K]

Re: tyres

Hi guys

I would have to agree with Andy I prefere to be able to steer the car with the steering wheel rather than the throttle, regarding the 4 wheel alignment there is no adjustment possible to the rear of the A class so any measurment out of spec would indicate a problem.

Hmm. Worrying view. The point is you will be able to steer with new tyres on either end, just that when it comes to that split second crunch time you'll have gone through the hedge backwards before you thought you had to steer!

Don't be afraid to listen to the tyre expert. He's right.

 

[Andy]

Hi

Let me get this right!!! The topic of conversation is wheter to put new tyres on the front or back. Wheter front wheel drive or rear. With all the views taken into account.

1.The problem is the driver in most cases is driving to fast for the whether conditions.

2.The driver is driving the vehicles which he\or she knows have tyres which although legal resemble the slicks used on the current F1 cars.


In Germany they change the tyres by law with a lot more tread on than we do.

This I suggest is where the problem lies & with the NUT at the wheel.


Regards to you all


Andy @ www.mercedesservicing.com

 

[CliveM]

Andy i think you hit the nail on the head, and that perhaps tyres should be changed before the legal limit.

Personally I fit to rear, just to bring the "older" tyres forward to get the tread wear out before the tyre deterioates through age ( i.e I had a car that got through 4 fronts and still got orgininal rears which despite having tread were perished and out of shape). The same benefit could be acheived by frequent rotation of tyres (is this a MB service item?)

 

[GrahamC230K]

Yes, just changed my rears as they were down to 3mm.