Obvious answer is the rider I guess, but boring as it may seem; tyre pressure seems to have made the most noticeable difference to anything else.

I have only been riding off-road for a while, so am a long way from expert, but having converted to tubeless I’ve experimented a fair bit with tyre pressure and am totally amazed by how grip/confidence can increase as pressure decreases.

I’m sorry that that this is yet another “tyre”some post, but seriously – I acutally laughed out loud to myself on a ride today once I had tested the effect of pressures on a known loop – it’s crazy!

What else is as significant and as simple/cheap?

Suspension (if any), and perhaps rider/bike interface (weight distribution etc.)?

Oooh, and then of course you have to repeat the pressure experiment with each brand/model of tyre you run!

Not really a bit, but position. Setting up your seat and bars properly is a really useful thing to do.

….the rider?

Weight forward – elbows out, twist into turns- beats any tyre argument any day.

Rider, tyres, position… suspension is secondary (tertiary, quadi…ary?) to all of them

Most important part on a bike I would say the grin the wider it is the better the ride
everything else is secondary

Agree with the tyre pressures. Got myself a pressure gauge the other week. Amazed how low my psi actually was ( 18 front, 21 rear). Put them up to 28 f and 32 r and felt awful. Just thought there was no grip at all. Settled for 22f, 25r and I’m happy.

Fiddling with fork settings can have a pretty similar effect. Soft tyres and lowish pressure in the forks make for fun riding!