My left side front wheel bearing basically collapsed almost instantly while riding to work, bike has done 17000 miles. Luckily for me it didn't seize so I could continue albeit at a very slow speed but it sounded awful. All is repaired now but the question I want to ask is how long do these normally last for and should they be changed regularly at a given mileage ?
They should be checked by the MOT tester, but I check all my bearings on a regular basis, two or three months, and everytime I take a wheel off for a tyre change. It takes seconds and could save a lot of grief.
I would say the bearings, if original, should last a lot longer than 17k. Damage can be caused though by winter riding, corrosion, or over tightening the wheel, so stick with the correct torque settings. Oh and avoid potholes as best you can, shock can cause fractures which then can fail at speed. Always replace with OEM or a well known manufacturer like SKF etc, don't be tempted to buy the cheaper Chinese ones on EBay, the quality of their steel is poor.
What he said, plus pressure washers are bad for all bearings, especially steering head and front wheels.
Bearings are not that expensive, get good ones, replace if you feel play. They can last forever or not so long. But a catastrophic failure although uncommon can happen anytime. Just bad luck. Mike.