Do brambles fruit in first year?

[Kokapetl]

There are some growing over the fence from next door (both sides!) and the kids love blackberries so if there is a chance of fruit this year I'm inclined to leave them as they are not in the way. If not I'll cut them back. It worth leaving them two years.

Just for background info as to why they are there-our garden was overgrown with them before we got it and we have cut them down and dug them out and keep removing the ones that grow back. The neighbours still have a few in their side behind their (nice) hedges, though.

We planted some thornless blackberry bushes last year and they didn't fruit. They've grown a lot this year and I can see red fruits on them, but not masses as yet.

At the same time, we planted yellow raspberry bushes and autumn fruiting (red) raspberry bushes. The yellow ones fruited really well in their first year, as did the blueberry bushes that we planted at the same time.