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Have cracks of tyres on two bicycles.
See attached photos. Bicycle 1 (top), 2 (bottom).
It isn't dry rot ( What are these cracks in the side of my bicycle tyre called? Does this mean that my tyre is gone? )
Bicycles purchased second hand, have been in active use for around two years, approximately 5km per day each 3-4 days a week.
Do these tyres all need replacement ?
Thanks
Looks harmless. It could increase your risk for punctures slightly. If you have very bad luck a knob of the knobby tyre could break off.
But it’s not like your tyre is suddenly going to explode. The rubber is just there for grip and puncture protection. As long as the underlying fabric is intact it will hold pressure.
For the future, make sure you always have enough pressure in the tyre and store them out of the weather if possible. From personal experience it’s mostly a problem with cheap, low quality tyres though.
