FATMAP difficulty grade
This route has technical and demanding trails, amazing views and reaches so far into the wilderness you won't want to come back.
It is 64km long with 1600m ascent and just 1km on tarmac.
It's a tough, long and demanding route that will test the very best riders and reward them with an experience they will never forget.
Biking back home just won't be the same again! Start in Fort William and head up Glen Nevis to the Braveheart car park.
This little bit of road will be just enough to get the legs spinning before the long easy climb up to Dun Deardail, the ancient vitrified fort on the West Highland Way.
It's forest road all the way up with great views over Glen Nevis and Ben Nevis on the other side.
Take a wee detour to visit Dun Deardail before finding the single track path of the West Highland Way heading southwest to Blar a'Chaorainn.
The trail is a walkers route and might have one or two people on it but there are not many cross drains and the riding is nicely technical without being too tricky or too steep.
Watch out for a little bridge and wooden steps but it's all rideable otherwise. From Blar a'Chaorainn the trail widens and is less technical as it heads first south then east towards Kinlochleven.
There is such a big feel to this section of riding so take your time and soak up the atmosphere and the water in the stream crossings.
It's gently up hill to the big saddle near Tigh na Sleubhaich and fast down the other side until you are above the village of Kinlochleven.
The West Highland Way drops down into the village and if you want a bit more of a workout head down this as an optional extra.
It's one of the best, technical and rocky descents on the west coast which feels even harder after the work done to get there from Fort William.
The normal route continues on the double track to Mamore Lodge which you can reach by a steep climb from the loch side if you went for the optional extra loop. A long, steady climb past Mamore Lodge on double track heads east to the shore of Loch Eilde Mor.
Make sure you look over your shoulder as you climb up for one of the best views in Scotland, down onto the fjord-like Loch Leven with beautiful peaks on both sides.
There is a short and fast descent to Loch Eilde Mor which is followed northeast to its end.
Double track carries on all the way to Luibielt, heading north now and to a major river crossing.
In summer months and after dry weather there is no concern at all with the river crossing if you don't mind getting wet feet.
However during rain or when the winter snow is melting fast this river is impossible to cross safely. Take a break here because it's hard work going up the single track northwards next to the Allt nan Fang to the next col and the highest point of the whole circuit.
It's probably not worth riding the short level sections between each steeper bit so just shoulder your bike and carry it up all the way.
Be happy though because the reward is amazing single track riding down the other side in the remotest part of the country you can imagine.
This is no place to rip a side wall or mush your rear mech.
The trail is a delight to ride, not too hard but skinny single track, and with natural features you need to be switched on.
It opens out a little in the run down to Lairig Leachach bothy but still great fun riding and another stream crossing. From the bothy it's smooth double track riding over a slight rise before a long, long and very fast descent all the way to the edge of Leanachan Forest.
After a few hours of averaging just a few km per hour, this descent will bump up the average speed nicely.
Make sure you look out for the Wee Minister on the way down but don't get too carried away as you need to turn left 1.5km before you get to Corriechoillie.
Give it a few minutes for the smile on your face to settle down before you head into the forest. Straightforward forest roads can now be followed southwest and then north to find the bridge over the river Cour.
New forest roads have been built over the last couple of years and they do not match the map perfectly but it's easy enough to find your way.
The nicest way home is to follow the bank of The Cour south all the way, gently up hill, to join the Puggy Line.
This is an old railway line used to build the aluminium smelter hydroelectric power supply and runs slightly down hill all the way to Nevis Range and then on to Fort William.
It passes The Witches Trails at Nevis Range and you can throw in a run down the World Cup Downhill jump line if you have the energy! Most people will follow the Puggy Line all the way to the back of the smelter, being grateful for the easy finish.
One last short section of road will bring you back to reality as you ride home, tired but very satisfied, into Fort William.