4 mm stem diameter will give you a very strong handlebar with a larger surface for the clamp to grip around

Offset Slit to Increase Bolt Threads and Torque

1cm (4") Dropout Form : Peg-cut Headtube angle : 82

Flangeless Material : Rubber Plugs : Included Hardness : Soft Weight : 100g

Colony Sweet Tooth Alex Hiam 20″ Freestyle BMX Framgaffel (Chrome Plated) Model:25mm 4 mm stem diameter willThis Colony Sweet Tooth Alex Hiam 20" is a high performance BMX front fork for a freestyle setup with 20" wheels. Made from durable 4130 Chromoly steel that ensures a strong and solid construction. This front fork is available in several versions with varying offsets, so choose the one that best suits your riding style. If you are looking for a very responsive front fork for technical flatland tricks, you should choose a very short 20mm offset. A