There is no definitive answer to this question as it depends on a number of factors, such as the quality of the spokes, the type of wheel (e.g. road or mountain bike), the rider's weight, and how the wheel is used. Generally speaking, 28 spoke wheels are strong enough for most riders under most conditions. However, if you are a heavier rider or plan on using your bike for more strenuous activities (e.g. off-road riding), you may want to consider a wheel with more spokes for added strength and durability.