I've done Snowdon in the past but can't for the life of me remember how long it took to get up and down it.

We'd be in 2 groups- both going up Llanberis, then splitting and half doing Rangers and half doing Llanberis.

We'll be doing it in 2 weeks time, so it'll be dark at about 4pm and we want to be down by 3.30 ideally. Is 6 hours a reasonable guess? We did Helvellyn in about 4.

Obviously depends on fitness of the slowest in the group. You be carrying the bikes a fair bit up the mountain so best not to wear racing shoes cos it'll slow you right up. I would allow at least 3 hours to walk/ride up Llanberis path. If you're very fit then 2 hours. Descent – depends on ability of course but between 20 mins to an hour for Llanberis path. More like 45 mins-90 mins for Ranger. Not forgetting that the nav down Ranger is trickier and if it's getting dark you might miss the right turn at the bottom. Ace ride tho

The right turn is after the gate in the wall, that's correct isn't it? You climb up that grassy slope then descend again.

Leaving at 9 sounds like a plan then.

That sounds right. On the flat bit. I'd highly recommend a map and compass. Or GPS. We went up end September and the weather was gopping and you never know what visibility's going to be like in Wales do you!

we had 3.5 hour up as it was snow from the halfway rail station ,, i found cleated winter shoes were actualy like mini cramp ons in the snow and ice

35 min decent first half down the railway line as the path was very busy but there is a couple of very big drops beside the railway line

2-3 hours up and about 1-2 hours down depending on GNARR /crashing wet or dry

On rangers path yes after gate there is an easy to miss path on your right [not least as you can only see the sign on the way back up!). If you can see the Rangers building and the Zig zags to it you have gone to far. Nice descent there if you fancy anoither push back up.

Left Llamberis after 9, back before 2, and that was on the snow, pretty bad conditions. as long as you leave before 11 I don't think you'll have a problem with light. I'd leave at 9 though, in case of problems.

Did it in the summer last year, one evening to work with the voluntary ban. Our time straight up and down the llanberis BW was 2 hours up and 20mins ish down.

I wouldn't say we were super fit, this was after filling our faces at Pete's Eats.

HTH