Trd Adjustable Bike Training Wheels Bicycle Stabilizers Mounted Kit for 18-20 inch Multi-Geared Bike

Perfect for a gear bike! Strong and easy to install.

These worked great for my daughter's Trek MT 220 with 16" wheels. They are adjustable and can probably fit a 20" wheel bike - not sure if they would be able to fit anything larger. My daughter had no interest in learning to ride a bike until she had outgrown traditional, smaller bikes. With theses, she was riding her bike without training wheels after just a couple days. Well worth the purchase.

stronger brackets, but had to modify to get it to fit. Not sure there is a ONE SIZE FITS all, but I chose these for the look of the strength of the bracket. I ended up using to Hose Clamps to attach the supports to the frame.

These are god awful. They bent up as soon as my daughter took her first few strides on her 20 inch bike. The metal is very weak and not braced at all.

Bought for my 7yr old grandson's "big bike". Easy to install, sturdy, and good enough. Probably won't use them long enough to evaluate how well they hold up. However, for now, they serve their purpose well.