Bought this for my son but he never used it in the end. Although the seat is not adjustable, the wheels are, so can effectively move them in and out to make it larger. Here’s some content from the manufacturer: Each Brum Brum bike frame is crafted from the highest-quality Baltic birch and oak plywood. These premium materials offer durability as well as natural suspension thanks to a bended frame. Bikes for kids will be tested to their limit, taking knocks and a few falls here and there. That’s why Krisjanis Jermaks and his team knew there was only one way to make Brum Brum – it had to be as high quality as possible. One of the cornerstones of the design is that its eco-friendly, so all of the materials are sourced responsibly.
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