About Sunnywheel Training Wheels These heavy duty training wheels are suitable for bikes from 12" to 20" to keep your little ones upright and help them to continue to learn to ride! These training wheels will fit most childrens bikes, provided the axle is long enough and there are no obstructions to the chain stay for the stability brackets. About Sunnywheel Founded in 1984 by Mr Tony Hsu, Sunnywheel launched a pair of training wheels as their first product. By 1993, Sunnywheel was manufacturing a range of products including training wheels, mudguards, chainguards and children's seats. A copy that started off from humble beginnings is now a major player in the manufacturing of bicycle accessories and are continually evolving and innovating to bring a larger selection to consumers.