Snowdon provides a difficult but compelling mountain bike challenge. The most approachable route is the Llanberis Path, but even this will involve a good deal of carrying. The path is rocky and quite steep in places; the descent is also rough and technical.
Snowdon is very popular with hill walkers (and runners), particularly during the summer months. To avoid potential problems a formal restriction on mountain bike activity has been agreed. Between 1st May and 30th September riding is not allowed during the busiest part of the day (10am to 5pm). A summer evening trip is a good option; that way you’ll have plenty of time to complete it and the light should be at its best. Just make sure you set off early enough to get up and down before darkness descends! Two hours is quick, while three or even four hours is more common.
A longer and harder version of the route can be done with a challenging (read: steep, loose and technical) descent down the top of the Snowdon Ranger path then a return along the Telegraph Valley path.
This is mountain terrain so always Prepare Well and Know Your Limits. During the winter season (i.e. typically from late October to April) there is a high probability that snow and ice will make the route unsuitable for riding.
There are numerous parking options in the village of Llanberis.