Work has now begun on the new trails in Ashton Court, and the guys from Architrail were good enough to show me round. The trails are still at a very early stage, but hopefully what follows will give you an idea of what's happening.

So, first things first, they're starting with a huge amount of stone. The trails in Ashton Court have always been hampered by the fact that they're built on a deep clay soil, so a key aim of the build is to rewind the clock on the erosion that's already happened, and create a bombproof track that can be ridden even in the foulest conditions.

The old trail tended to get lower and lower in the surrounding ground, making it hard to keep water from puddling on it. This landscaping fabric is going to ensure that the new trail doesn't sink into the bowels of the earth.

The work is mainly being carried out by machine, with some shaping and building being done by hand. Even a 5-tonne digger like this can create a trail that's just a couple of feet wide. 1/2 tonne diggers are going to create some of the tighter sections of trail, and other sections are going to be built by hand. The build is being closely supervised by ecologists from Natural England to make sure the impact on the estate is minimal.

This man is a ninja apparently. At least when he's driving a digger.

All the diggers are fitted with tiltiing buckets, which means the surface of the trail can be cambered. A cambered surface means a fun twisty trail that drains all year round, rather than canal path.

A lot of the rocks we originally put in the trail are going to be recycled into new features. And some sections of the trail (like the berms at the end of Upper Quarry) are going to be kept as they were, but rebuilt in stone, to keep the flow of the trail while being much more durable.

Some rocks in their final resting place. Features like this are designed to become more of a challenge as the trail weathers in.

The crew are experimenting with different surfacing materials to see which one holds together the best, without smoothing it out too much.

The Lower Quarry Trail is already hardly recognisable. I suspect that for most of the riders doing the BikeFest, that's going to be a relief. The new trail is going to be noticeably narrower, curvier, and uses the available width to break up the climb.

They mean it. The trail is going to be off limits for another three weeks at least, while it beds in.

Don't be tempted to sneak through the tape or you could come face to face with this.

Rubber tracks mean the machines can roll over the trail without damaging it. A tracked vehicle like this actually causes less pressure on the trail than a person's feet.

Home time. They take their jobs seriously.

The target date for completion of the trail is late July, and the Quarry sections are going to be open for BikeFest. To keep up to date with the latest news, sign up as a member of the site, join our Facebook group, or follow us on Twitter.