Uneven tyre wear

[jokskot]

In the attached pic I show my rear (driven) 29 x 2.5 Schwalbe Marathon Plus tyre. The has done somewhere between 5000 and8000km - I don't have a record of when it was fitted.
The tyre has been kept inflated at 50psig.

Wear is much greater on the driven side. I have not noticed this previously with Schwalbe Super Sams that have been used on the same bike.
Two possible explanations, I have considered, are:
1. I don't ride the bike completely upright but leaning slightly to the right...if this is the case it's unlikely that I am more than a couple of degrees of vertical
2. I am not perpendicular to the road because of road camber - again no more than a few degrees off 90.

If it was a car I's be considering caster and camber angles and toe-in but these are not applicable to a bike.

Any explanations or thoughts?

 

[AndyBike]

You do more left turns that right. I would expect on British roads as we drive on the left.
Just a thought.
eg Moving over to the pavement to stop, you lean/turn to the left, so maybe if its the left side that could be the cause.

EDIT - just noticed its to the right you're getting more wear - misleading pic.

 

[Sturmey]

Its mainly the road camber imo. One suggestion is to reverse the tyre to even the wear as the arrows have no real technical function on schwalbe road tyres.

"In the case of a road tire the rolling direction is mainly important for aesthetic considerations. Tires marked with arrows simply look more dynamic.. "

https://www.schwalbe.com/en/profil

 

[Andy-Mat]

In the attached pic I show my rear (driven) 29 x 2.5 Schwalbe Marathon Plus tyre. The has done somewhere between 5000 and8000km - I don't have a record of when it was fitted.
The tyre has been kept inflated at 50psig.

Wear is much greater on the driven side. I have not noticed this previously with Schwalbe Super Sams that have been used on the same bike.
Two possible explanations, I have considered, are:View attachment 48112
1. I don't ride the bike completely upright but leaning slightly to the right...if this is the case it's unlikely that I am more than a couple of degrees of vertical
2. I am not perpendicular to the road because of road camber - again no more than a few degrees off 90.

If it was a car I's be considering caster and camber angles and toe-in but these are not applicable to a bike.

Any explanations or thoughts?

Simply ignore the reason(s), just swap the tyre around eo even out the wear better......I have done the same (on a car!) after finding out that my wife had hit a pavement with the RH front car tyre, which was not noticed immediately by myself, and eventually, after getting the alignment done, I swapped two wheels around.
But remember, with some modern car & motorbike tyres, they are fixed orientation/rotation, (mine weren't!)
regards
Andy

 

[jokskot]

Thanks to Andy-Mat and Sturmey for their input...

I will reverse the rear tyre the next time I have a puncture and monitor whether the wear evens up or not.
I'm not sure I can buy into the "Turning more to the left" hypothesis. If this was an explanation, I would expect the non drive side to be more worn and this is not the case. Also on any ride starting and finishing in the same place the maximum differential between the angle turned through, one way rather than the other, can not exceed 360 degrees.

A further thought I have had relates to the fact that much of my riding is on single track country lanes which are less than 3m wide and tend to have an accumalation of grit on the centre caused by 4 wheel vehicles. The gritted area is liable to be more abrasive than the parts of the road which have been "swept" by vehicle tyres. As I ride along, the driven side of the tyre will always experience relatively more wear than the non-driven side, provided I am left of centre of the road and not in the gutter.

Despite all this it still does not explain why the noted behaviour is peculiar to the particular tyre on my bike and that no readers of this thread have reported similar experience of uneven wear.

 

[I893469365902345609348566]

Does the tarmac on narrower country lanes bulge more in the middle than wider roads, causing more wear on one side of the rear tyre?

 

[jokskot]

Does the tarmac on narrower country lanes bulge more in the middle than wider roads, causing more wear on one side of the rear tyre?

I don't really think so. There are as many puddles after rain in the centre of the roads as elsewhere!

 

[flecc]

Despite all this it still does not explain why the noted behaviour is peculiar to the particular tyre on my bike and that no readers of this thread have reported similar experience of uneven wear.

I strongly suspect a manufacturing fault, we've had various oddities like this with some Schwalbe tyres over the years, particularly beading and sidewall faults. Turning the tyre around would soon reveal that if the excess wear stayed on the more worn side, rather than staying on the drive side.
.