Apparently its a myth that the Eskimos have 50 words for snow. When you add in the various dialects that make up 'Eskimo language' (bear in mind that 'Eskimos' comprise several different distinct cultures) there are either many more than this or many less, depending on whether you count nouns, verbs, tenses etc. etc. If you are into winter sports, particularly of the skiing and boarding variety then you'll know a few. As a rider of fat bikes I have plenty, many unrepeatable in a family friendly forum, so I think I need my own vocabulary as you tend to notice the differences in snow conditions much more acutely on a bike than if you are strapped to a long pair of planks (or one plank). I got my first fat bike in January 2012 but a rubbish winter meant it never got into the snow until the following year. At first I stuck to the low levels and had great fun riding my local woods in snow depths that stopped everyone else dead. Come November however I finally headed on high and got a crash course in Scottish snow conditions and their suitability for a bicycle.
This is actually a classic Ski tour. Start at the Glenshee car park, go up through the ski area to Meall Odhar and then right up onto Glas Maol at 1068m. Then tick off Cairn of Claise and Cairn an Tuirc then descend back to the road. Easy? The snow started at about 800m. Literally as below this height there was none and above it a surprising amount for a November day. Other than the gradients it was fine - generally low volumes and dry, given the sub zero temps. The fun started when I hit a large patch of wind blown snow and had my first experience of windslab. So called as the wind blows snow into a sheltered location but the continual blowing compacts the top layer until it forms a firm slab over the softer snow underneath. On steep slopes this gives rise to that worst case of winter scenarios, the avalanche. Above about 25 degrees the slab can break away from under your feet and start to slide taking the whole snow slope (and you) with it. Steeper than 45 degrees it doesn't tend to form and at less than 25 degrees it just becomes a pain in the backside, unless you are on skis. Sometimes it supports your weight, if its dense enough, often it doesn't and your feet (or wheels) punch through the slab and into the soft layer below. This makes for incredibly hard going and there is no way of knowing when you will break through and come to a halt. You hit a patch of windblown snow and at first start to ride across it in relative ease. Suddenly there would be a creaking crunch and you'd plunge through. There then follows much high energy pushing until your feet suddenly are supported again. You then hop back on and ride for a bit more (anything from 6 feet to a hundred yards) before 'creak, crunch' and you stop again.....
Winter 2014 saw huge snow volumes above 500m but little below and this only really white slush. I'd done a few low level rides through this resulting in a mix of snow and mud that has an amazing ability to jam your drive train solid. Snow on my local hills persuaded me to head up for a day to get away from the slush. This ended up being an epic as lower down the saturated snow had absolutely no traction whatsoever. Worse the big tyres floated over what a narrow spiky tyre would cut through so my first couple of miles ended up as a continual slither with me being more sideways than upright. On crossing 500m the snow levels went up dramatically and suddenly I was having to drag my bike through knee deep snow that had drifted over the trail. Three hours of maximum effort flailing was enough and down I went to dryer climes.
To this point, the ability of fat bikes to reach the parts that other bikes couldn't (and with ease) had mightily impressed me. It seemed ironic that the stuff they had been invented for was what was beating me. Of course on the Iditarod Trail, the Arrowhead and the other winter races, you were following snow-mobile trails, not trying to ride across virgin fields. That didn't stop me, towards the end of the year, from lusting after and eventually buying Surly's newly released Ice Cream Truck with the ability to take 5" wide tyres. As it happened we got a good amount of early season snow and the results this time were much better.
Winter 2015 was similar to the last year but I was now regularly venturing up into the Ochills and cashing in on the large amount of terrain above 500m. Many days saw me battling through some pretty impressive amounts of snow, including the aforementioned windslab. As I was training for the Highland Trail, this was all to the good. I also discovered that if you dropped tyre pressures down to the point where the inner tube was just filling the tyre (around 3psi), you could ride through stuff which previously had stopped me dead. More amusement was had when you emerged on a snow free, damp and mild Dollar main street, wheels full of snow. Most people here seem oblivious to the large lump of hills on their doorstep and the snow they can catch.
One late season ride in particular stands out. I'd decided to do the minigaig pass in the Cairngorms and hadn't appreciated that there was still tons of snow on high. This was all old stuff that had multiply thawed then re-froze, consolidating it into a dense layer that would easily support you. The problem was traction. The top layer was melting in the sun and any slight uphill gradient resulted in the wheel spinning you to a stand still. Drop the tyres down to 3psi however and off you went, no probs. A normally hard route became a leisurely pedal linking vast fields of this super dense snow.
I ended the year in more early season snow up north. Conditions were also something of a Scottish speciality. Snow that was quite deep in sub zero temps (so dry and grippy) but over lying soggy and unfrozen terrain. Everytime you punched through the snow into the gunge below, your drive train got sprayed with mud which then froze solid. Cue much scraping, chipping and cursing.
Winter 2016 saw me going tubeless which allowed even lower tyre pressures - practically zero psi. I'd been watching vids of a guy from Germany riding through knee deep powder snow with the then prototype Vee snowshoe 2XL - an alleged 6" wide tyre. They were single ply and he was basically running them almost flat. The production version was narrower and thicker but running Bud and Lou at a similar pressure allowed riding through spectacularly deep snow and even the dreaded windslab could be ridden across well beyond the point that a walker would be punching through. I discovered a new joy - riding prophet like over the snow past beleaguered hill walkers post-holing along with looks of extreme misery.
In a way that's part of the problem - the more you can ride over this level of snow, the more you try. On a rare snow ride in 2017 (which was largely snow free) I ended up way up high in the hills, totally knackered and realising there was no way down without hours more of struggle. When I finally emerged onto Dollar Main street it was a different world with passers by looking at this snow covered wreck (i.e. me) with bemusement.
2018 was the clincher though. The season started at the end of 2017 and we got more snow in the first couple of weeks of December than we'd had all of the previous winter. The annual Scottish winter bivvy was the scene and ended up in a marathon effort (for the non fat bike riders) getting up 6 miles of snowy track. For me it was hard work but I pedaled all the way. I also got my first taste of arctic biking. It was -10 and I was following the track of a (tracked) argocat. This allowed easy pedaling over foot deep snow and got me thinking of those arctic fat bike races....
(Funnily enough the return leg of this bothy trip was in the traditional Scottish snow conditions known as porridge - saturated slush on which nothing gets any form of traction....)
January saw the first of several big dumps of snow. The hills were often inaccessible as there was just to much. I managed a couple of rides following well trodden trails up hill and powder surfing on the way down. I did discover another joy - fat bike commuting. When all around were in a state of panic and traffic chaos ensued I pedaled through it all with no worries whatsoever. Bloody hard work though!
2019 was another rubbish winter but I had bigger fish to fry than my local hills. Finland. I'd entered the now well established Rovaniemi human powered race; the arctic beckoned. Ironically the conditions on the day of the race were more like Scotland - plus temps during the day and sub zeros over night. But suddenly I was on snow mobile trails with many other people on fat bikes and therefore in subjective heaven.
On the last day of 2019 I encountered yet another Scottish classic snow type - boiler plate. The fickle Scottish weather can produce snow conditions at any time of year that are generally only seen towards the end of the season in the alps and other high places. Wildly fluctuating temps in between some significant precipitation of both snow and rain had left the Cairngorm plateau covered in large areas of snow that had freeze/thawed to iron hardness. Fortunately the frozen solid snow surface was rough enough for grip. I've yet to try studded tyres and got paranoid on the way up that the whole plateau would be one big skating rink but in the event I was able to cross large areas of the famously boulder strewn landscape with ease.
So here we are at the end of 2020 and the winter has started with some fine pre-season snow. I got a fair mixture of snow with some great riding mixed with some incredibly hard going sections.
So by way of a finish, herewith my snow types as seen by a fat biker (there aren't fifty!)
"Normal" Snow, aka white slush, aka the end of the world:- Usually no more than three inches deep but it still brings the road network to a halt. Off-road this mixes with typical winter mud and sprays everywhere.
Scottish Powder:- Arrives horizontally and so is quite dense. 1psi allows you to go through this up to depths of around 12" but its like cycling with your brakes on up a 15 percent grade. In exposed locations can lead to.....
Windslab:- dense layer of snow overlying unspecified depths of Scottish powder. Has varying levels of support but all looks the same. Beware cycling up a scoured slope into remote hills only to find your descent is windslab central and even riding downhill is impossible.
Goldilocks Snow:- Neither too deep or too shallow, cold enough to be dry but not so cold you need arctic equipment. Actually quite common between about 300 and 600m and early season. Too much for a normal bike but a fat bike will blow through it without too much effort. Add in some minor drifting and it definitely provides the best laughs.
Boot filler. Like above but deeper:- up to a point you can ride through this if its fairly dry but this typically leads to the longest of pushes as depth increases with altitude. The trick is to find places where its been tracked by an argo or other tracked vehicle, or even a skier. The problem being when such tracks stop in the middle of nowhere and you end up ploughing through deep, un-rideable snow as you always think that continuing is easier than backtracking.
Real powder, aka fluffy bunnies, 'pow':- very, very rare in Scotland as it requires snowfall without wind, on frozen ground and in zub zero temps; an almost unheard of combination. Can be ridden through at quite amazing depths up and downhill.
Spring snow, aka boiler plate, aka neve (posh term):- worth finding, particularly if its in big patches across rough terrain, whereby riding it is one of the most uplifting experiences you will have. This can make the worst boulder field in the world a flat table over which you can ride anywhere. Covers burns, bogs, gorges and holes. Note - can collapse underneath you unexpectedly.
The Crust:- formed when the top layer of snow thaws then freezes. If its breakable, go home as trying to ride it makes pushing through windslab seem like riding a TT bike downhill. If its thick enough to support you then see Spring Snow. Note that the top surface can turn to sheet ice without any warning whatsoever.
Ice:- either snow that has thawed and frozen or open water that has frozen. If its sub zero then you'd be surprised how much grip you'll find on it with tyres at 3psi. If its melting and has a layer of surface water it will be absolutely lethal unless you have studs. Be particularly careful on untreated cycleways, tracks and minor roads, also next to corrie rims.
Porridge, aka crud, aka slush:- The other end of the spectrum and causes as much problems as ice. Has little grip and a surprising amount of resistance to ride through. Off camber trails covered in this stuff can be one of the most frustrating type to ride. No grip and a tendency for wheels to go all over the place. On a steep descent you will inevitably end up going face first at some point.
Sastrugi:- rare other than on the Cairngorm plateau in a good winter. Essentially extreme windslab - the wind blows the snow into ripples which harden under the wind pressure and can then build up to ridges and finally strange almost sculpted shapes up to a couple of feet high. They are iron hard so under no circumstances think you can plough through them.....
Postholes:- Any of the above after a load of hill walkers have been through. You'd be amazed at the difference footprints can make to how rideable snow is. Worst case is when they have frozen post formation - think riding across the worst potholes and rocks you can imagine. If there are enough they can trample out a slot which makes for easy riding in windslab, scottish powder and boot filler. But we owe it to ourselves to not take advantage of this and instead ride a virgin line off to one side of the path.....
One final bit of myth busting is the age old adage that snow is soft and will therefore provide a soft landing if you crash. It can in theory but in reality there are many other obstacles which can cause you any amount of pain once the snow has caused the crash. Some typical snow related crashes to watch out for.....
The face plant:- this ubiquitous mtb crash is the most common suffered on the steep and the deep. Windslab is a good source - you're surfing across the top of it down a nice hill, you build up speed and then it collapses under you. The bike stops dead and you keep going. Dropping below the freezing level on a big patch of spring snow can also cause spectacular OTB episodes. I did a beauty in March this year going down a steep rib of snow filling in a shallow burn line (I'd skied it the previous weekend) suddenly it collapsed under my front wheel which disappeared up to its axle. I went sailing over the bars and as the slope was around 30 degrees was suddenly about ten feet in the air (it felt like 20). Fortunately I landed on a steep slope and the snow was soft so injuries were minimal....
The washout:- usually occurs on wet snow / slush. You turn the bars and the front disappears faster than you can think. Next thing your face hits the deck. I did this on a road once when my front wheel strayed out of a clear wheel rut into wet snow. I managed to land on the other wheel rut (i.e hard tarmac) rather than soft snow in the verge. It hurt. Downhill is a particular problem on wet snow. The mechanics are usually that you realise your front wheel is going to go away from you just past the point that you can do anything about it. Best bet is to drop your butt groundwards in order to avoid another high flying OTB.
The stop. Your riding along, the snow is deep (any of the above), your front wheel suddenly shifts to one side and pitches the bike outwards. Next thing you are lying on your side - remember to make a snow angel.
The disappearing act. A variation on the above. You washout, the front wheel drops into a hole or you otherwise come to a halt. On putting a foot down it disappears into a posthole up to your thigh. The rest of your body quickly follows. Happens on deep windslab and on compacted snow mobile trails through deep powder snow if your foot goes down off the side of the trail....
Death by ice:- the worst of the lot. You hit a patch of wet ice and the whole bike just instantly de-materialises from underneath you. A variation is hard water ice covered by a thin layer of powder which serves as a perfect lubricant between your tyres and terra-firma. In either case the force with which you hit the deck is totally disproportionate to the distance fallen.....