This is a route I did over 2 days camping rough at the site of the former Bynack Stable (NJ020105), which is no longer marked on newer OS maps. Starting from Queens view car park 1km South of Tomintoul the track soon meets the tarmac estate road which I followed all the way down to Linn of Avon, here a bridge crosses Builg Burn & leads West along Glen Avon
It was here that I had just put my camera away after taking a few shots of the spectacular gorge cut by the river Avon, when I heard a roar & turned to see an RAF Nimrod emerging from Glen Builg heading North, it was flying below the hill tops at no more than 100m the valley floor, when I first saw it it was banking to Port, it then banked to Starboard & back as if to acknowledge me, it was like a scene from the film Dambusters, I was well impressed.
From Linn of Avon the track is reasonable surfaced Landrover tracks which continue all the way to Faindouran Lodge (NJ081061)with a brief 2Km of singletrack from the bridge at NJ155068 which I would omit if I do this route again, it consists of a well dodgy eroded path about 30m above the river where a dab with the left foot is not an option, bearing in mind the remoteness I chose to push along this part, it then opens out & the path disappears. After passing Faindoran Lodge the track soon disappears & you push for the next 5km across boglands & where the valley narrows, some very rough singletrack, only very brief spells of riding can be had over this 5km section, some spectacular views though, with Cairngorm looming directly in front of you. From the Fords of Avon North the next 3km is only ride-able for 50-100m at a time with more pushing than riding. Eventually you reach the highest point in the route at 800m just below the summit of Bynack Begg, from here the next 3km drops 350m & what a descent it is, basically a loose granite staircase & one of the highlights of the route.
I camped at the bottom of the descent at the old site of Bynack Stable (note t myself, when camping, bring matches to light stove). After a very early rise (6am) in thick frost thanks to a noisy grouse outside my tent I packed up my frozen tent & having to de-ice my bike I continued onwards, the path meets with a track leading through the Ryvoan Pass where I took a right turn along past Ryvoan Bothy, I found matches in the Bothy so managed to get a cup of tea & cook the previous evenings supper at 7am. I followed the stony/sandy but very ride-able track to a fork East of Loch a'Chnuic, this included a fairly serious river crossing which obviously varies considerably with the levels of recent rainfall, when I did it in the latter part of April after a reasonable dry spell the water was above knee level, it took me half an hour to suss out & cross, if doing it again I would opt for the 5km detour to the North & the bridge at Forest Lodge.
From the fork to the East of Loch a'Chnuic, I crossed a stream & headed along some sweet singletrack through the steep sided pass & out onto the Braes of Abernethy. After another river/wide stream crossing, only knee high this time, I cycled along a tarmac road for about 1km where I took the path round behind Dorback Lodge which soon opens out onto a Landrover track, this continues for about 4km where I turned immediately left after crossing the Burn of Brown, this is just some Landrover tyre tracks, but some serious ones, you need to cross the burn twice again, then stay close to the west side of the wood where there is a couple of tracks to follow, at the end of the wood there is a small gate which leads up to a landrover track, I followed this track all the way to the Bridge of Avon where I then tried some of the paths around Tomintoul which I would not bother with again, I would just head along the main road to the car park at my starting point.
This took me around 8hrs for the 38km the first day & 5hrs for the 30km the second including stops, carrying all my camping gear etc. which must weigh in the region on 20kilos, hard work with a total of 2336m of ascent, also I stopped loads to admire the veiws & smell the flowers along the way, so it could be done considerably quicker.