Just fitted a pair of 35mm wide SKS Longboard mudguards to my Gain D50. However, you have to be a bit creative to make it all work. The socket head M5 bolts supplied with the fixing kit are not great, and I used 16mm stainless steel M5 button head bolts instead. The rear plastic clip which attaches to the seat stay has a horizontal fixing. However, my D50 has a vertical threaded socket in the seat stay. This required careful in-situ measuring and a hole drilling through both the clip and the mudguard. Also, the longest supplied bolt (55mm) is too short to attach the front mudguard bracket to the fork. I bought a 60mm stainless steel one (from
ebay). I would also suggest cutting the stays to length after everything has been fitted and the final adjustments have been made. I used a Dremel with a cut off wheel to do this. The button head bolts look a lot neater than the socket heads, and being stainless steel, they won't rust.