In bicycle tires the tread is far less important than for instance in car tires. So using a tire with a worn out tread is less of a problem that is of course with the exception of MTB tires.
When the puncture protection belt or the carcass threads can be seen through the tread the tire has reached its wear limit and must be replaced. As puncture resistance also depends on the thickness of the tread layer, it may be useful to replace the tire sooner.
The sidewalls of tires often fail before the tread is worn out. In most cases, this premature wear is due to prolonged use of the tire with insufficient pressure. Checking and re-pumping the inflation pressure at least once a month with a pressure gauge is most important.
It is difficult to answer this question, as mileage is influenced greatly by tire pressure, load, road surface, temperature and the rider. For example, when used in hot weather with a heavy load and on rough asphalt, a tire wears much faster.
As a general guide, you can expect a tire mileage of 2000 to 5000 km from Schwalbe standard tires. The tires of the Marathon family usually last between 6000 and 12000 km. With the light Marathon Racer and Marathon Supreme, the performance is a little lower (approx. 5000 to 9000 km). The Marathon Plus is outstanding with its extremely high mileage of often much more than 10000 km.
No useful mileage data is possible for MTB tires, because the influence of riding style is too dominant. Our racing bike tire Schwalbe One lasts from 3000 to 7000 km.
Unfortunately, many tires do not reach the possible mileage because they are continually ridden at inflation pressures that are too low. Insufficient inflation pressure means the tire cannot bear heavy loads. The tire sides have to deform
excessively when running. The tire can only stand this kind of treatment for a limited time. At a certain point there is too much load on the sidewall and it tears.
Fig. 1 shows the typical fatigue cracks which arise from low inflation pressure. A few large cracks in the upper area of the sidewall. In comparison the second figure shows normal aging cracks (due to old age and/or poor rubber compound).
These cracks are rather small and distributed evenly across the whole sidewall. In practice the transition between these two crack types is often seamless so that the cause is not always clearly visible.
Figures 3 to 5 also show clear symptoms of continued riding with insufficient inflation pressure. Typical abrasion marks: The tire is not bald in the center but on the left and right sides. Typical walk traces in the tire and on the tube.
Our tires are usually designed for bicycles and therefore not always suitable for multi-track vehicles, such as tricycles.
Unlike a (single-track) bicycle, a tricycle usually will not tilt in a curve. In a curve the vehicle then “pushes” transverse to the direction of travel via the steered front wheels (understeering). Depending on the riding style and the vehicle design this effect can result in a significantly increased wear.
An extremely increased wear, e.g. when the tires are worn down after less than 1000 km already, can be the indication for an improperly adjusted tracking of the vehicle. Even when riding straight ahead the tires which are standing transverse to the direction of travel generate increased friction and thus excessive wear.
The same also applies to trailer tires. Usually, the tires of a bicycle trailer must neither transfer driving nor steering forces. That’s why these tires show clearly less abrasion than bicycle tires. If these tires are affected by remarkably heavy wear, this has most probably to do with the tracking adjustment of the trailer.
Schwalbe tires can be stored for up to 5 years without a problem. If possible, they should be stored in a cool, dry and, most importantly, a dark place. When stored properly, even longer storage times may be possible..
If fitted on a rim, tires should always be inflated or the bicycle should be hung up for storage. A bicycle left on flat tires for an extended period of time may damage the sidewalls of the tire.