They have just about every make and model of helmet you could want. It's called Lucky Helmet, and is across the street from AEK Udon Hospital on Phosri Road near the UD Town intersection and McDonald's. A friend and I recently brought our Real brand helmets there to be reconditioned inside with new padding and snap-in attachments. For 1,200 baht, they send it to BKK and get it back in about a week. I was very pleased with the result. The husband and wife owners speak very good English.