UK bikes need Fenda extenders IMO due to our wet weather. There are various makes from the likes of Powerbronze and Pyramid and having owned both they are much of a muchness.
You need a bit of DIY skill to fit them as you need to take the mudguard off and I would highly recommend the option of screwing them into place and not relying on the sticky tape.
They cost between £15 and £20 and so far mine have lasted without any issue through three winters.
Fenda Extenda - A relatively cheap bit of black platsic which is stuck to the back of the front mud guard to prevent some of the road crud from flying up into the bike´s radiator. And it worked. Does look too bad either. Recommended.