Well I'm back, absolutely awesome ride. ill write a bit of a review as the posts on this forum were very useful to me in planning my own attempt on Snowdon.
Really got lucky with weather so views were fantastic, only saw 3 other people ascending (all runners, nutters) but lots of people coming down, I literally saw no one on the Ranger Path and only 1 runner at the end of telegraph valley.
The ascent is brutally relentless, I've read figures like '75%' for now much of the Llanberis ascent is rideable, I'd say more like 50 and even then you'd have to be an extremely strong climber to maintain a faster-than-walking pace. No one should feel bad about pushing most of the way as it's tough with a bike. I found that there were parts just before the half way house that were easy though, after this point and before the tunnel it gets very very steep, pushing my 30lb Covert was pretty tough. Lots of cheery banter with walkers on the way up with most seeming genuinely impressed/surprised to see a bike!
The ranger path was great fun, fast and loose at first, with occasional large rocks to keep you on your toes and more and more tight turns as you progress, parts reminded me of a rockier/steeper Cut Gate path Ill admit with no shame that I pushed down 2 or 3 of the 'mordor' parts. Being on my own, nackered, first ride down, tiny bit of water remaining and about an hour before dark there was no way I would risk a big off, besides it's good to leave something for next time. I would recommended giving yourself plenty of time so you can take it easy, and go with a friend!
The marker was easy to spot as unknown to me it appears at a fairly low speed section, ignore the first one (footpath) and do persevere with the grass hill, it's a bitch (steep) but eventually you'll see a bench and the grass track is easier to follow. Telegraph valley was OK, hopping the water bars gets tiring after a while and I'm glad I'm tubeless as if you're tired you're bound to miss a couple and flat.
Next time I'll do the Llanberis both ways, although the obvious option it's definitely the no frills route, and there are definitely some challenging rock sections.