From what i recall the UK had a bad time of it in the late 90's early 00's and with an obsession to get the olympics for london they pumped millions of lottery funding into high performance in order to not make a fool of themselves at their home games. As for the bikes, you only have to look at the money sky have put into it, there was an interiew last night on the BBC with their BMX guy, he was wearing a sky BMX team shirt. They wouldnt be doing it if it wasnt for mass participation. Its the same here to an extent, you get 15k doing the ring of kerry - there is a dublin version in a few weeks, and loads of bikers around - look at how many people are using the bike to work scheme to get high end road racing bikes.
From a general sporting perspective I would say that the biking boom is a measure of the success of the GBR bikes teams so you can say it's worked overall.
Maybe there isnt as much of a visible uptake in other sports but it's hard to know. We often say that our footballers success will inspire the underage kids to an all ireland in 10/15 years, but you cant test that till it happens.