Complex sentence: While doing so, he hit upon the idea of helping directly introducing children to the world of BMX directly since he was one of the first pioneers of BMX, there was no one to help him when he was a beginner.
Split into simpler sentences: While doing so, he hit upon the idea of helping directly introducing children to the world of BMX directly. Since he was one of the first pioneers of BMX, there was no one to help him when he was a beginner.