Hey dag 1369,

I've lived in Belgium for a few years but am native English. The difference between cycling cultures and facilities between the two is big.

British people still have the mentality that cyclists are second class citizens. They will shout at you for minor violations (passing a red light at the straight part of a t-junction, for example). Motorists still don't treat cyclists very well.
Cycle paths are erratic and badly designed. The situation is better in some places (e.g. London and York), but overall not great, I found. Belgians are more used to and more friendly to cyclists overall, and most places have decent bike routes.

In terms of sport riding, I would say Belgium is way ahead. Britain has some good clubs (e.g. Manchester Wheelers), but in most Belgian towns or cities, you can find two or three decent clubs.
Terrain in Belgium is also nicely varied. In the South (Wallonia) there are some bigger hills and longer climbs. In the
North (Flanders) there's a mix of flat and short, steep climbs like the legendary Muur of Geraardsbergen. England is fairly similar terrain-wise, but because Belgium is small, you can easily reach different routes.

Not an expert on mountain biking, but there is a network of off road trails round much of Flanders. I see a lot of mountain bikers out. Cyclo-cross is also huge here.

Belgium has a lost more classic races and coverage than Britain (Tour of Flanders, Liege-Bastogne-Liege etc). The TV coverage is amazing. Last year there was a whole series on Belgian cycling heroes. Can't even dream of that happening in England!

Language barrier is not a problem. Most people speak very good English and are willing to use it. But if you want to integrate properly, learning French and Dutch helps.

Another oddity: people here are often in the habit of changing bikes every couple of seasons, so yyou can get some real bargains secondhand.

The main downside to cycling in Belgium is maybe that people take it a bit too seriously!

I hope that helps.

John