Snow. What tyres to make it safe ?

Judy a hundred metres from our home. The cycle-path is clear of ice and snow

We had four cm of snow last night, the first real snow of the winter. It looks wonderful, but snow can be dangerous for cyclists especially if it is not removed from the cycle-paths and if it becomes compacted.

Marathon Winter Studded Tyre

Assen is quite good at clearing snow, but there can still be small patches of ice hidden underneath, especially later in winter. That's why the first thing I did this morning, before breakfast, was change the front tyre of Judy's bike for a Marathon Winter studded tyre.

Fitting a studded tyre on the front wheel is the best insurance possible against a fall. Why only the front ? If the front wheel loses traction then a fall is almost inevitable and it is difficult to do anything to control such a fall. Falls due to the rear wheel slipping are much less common and much less scary.

Parent with children cycling this morning. This cycle-path
is clear, but you can't see it from this POV.

You can see from the photo at the top that many other people had already cycled this way. People tend not to make so many trips for pleasure, but cycling for utility purposes doesn't reduce much in the winter in the Netherlands.

I'll cycle with parcels containing customers' orders from our bike parts shop to the post office a bit later today and mine will not be the only bike there.

We still have studded tyres in stock. Order them now and they'll be with you in a few days.

Photos taken during the trip to the Post Office
The temperature didn't reach above zero all day today, so the snow mostly stayed where it was, unless it was swept. Some photos below show conditions for cycling in Assen

Safe conditions are also helpful for people with disabilities (written about several times before on the other blog)

Plenty of bikes parked outside the popular Hema department store in a pedestrian zone, and all ages of people arriving and leaving by bike.

Plenty of bikes at an indoor shopping centre.

Not many people use bakfietsen in Assen because conditions are safe for children to ride their own bikes. However, some people do transport smaller children by bakfiets.

A small "traffic jam" on the cycle-path. Utility cycling holds up in the winter because due to the lack of ice on the cycle-paths it is nearly as easy to cycle on a day like this as it is in the summer.

Tread on a bicycle tyre normally serves no purpose other than for marketing. Asphalt or concrete surfaces are harder than rubber, and grip comes from the small imperfections in those surfaces forcing themselves into the rubber. However, when there is snow the tread forces itself into the snow and that is where grip comes from. That is why any treaded tyre is better for snow. However, when it is icy tread doesn't work because ice is too hard to be deformed by rubber. At this point, the studs on the Marathon Winter tyres come into their own. They provide very small points of contact and pierce the ice. By doing so, you have far more grip than is possible with a rubber tyre. You can see both the tread marks in the snow and the black spots where the studs in my tyre pierced the ice underneath the snow, in the photo on the right.

For two wheeled bicycles, the most critical tyre is the front tyre. However, with a velomobile or other three wheel recumbent with two wheels at the front the situation is reversed. With that type of bike it is absolutely critical that the rear wheel does not lose traction as that can result in the bike rotating to travel sideways and turning over. That's why I fit just one Marathon Winter tyre to the rear wheel of my Mango making it possible to continue going for recreational rides in the winter in safety.

What size of wheel and tyre is used on my bicycle ? Choosing the right size of tyres for your bike can be difficult due to competing methods of measurement.

47-406: A "20 inch" tyre.
47 mm wide, mounts on a 406 mm rim

Bicycle tyres come in a bewildering array of different sizes. It's absolutely vital to buy the correct size for your bike.

While tyres are mostly made of rubber, the most important dimension when fitting is that of the bead of the tyre, and this is reinforced either with steel wire (for most tyres) or with glass or other fibres (for folding tyres) so that the tyre won't stretch and come off the rim when fully inflated.

For this reason, bicycle tyres do not stretch and even sizes which are very close in size are not interchangeable.

Old fashioned ways of labeling tyres
In the past, wheel sizes were usually described as the outer diameter of the size of the wheel including a nominal inflated tyre. In countries which used imperial units these would be expressed as a size in inches (e.g. "26 inch" or "28 inch") while in metric countries the size was expressed in millimetres (e.g. 700 C or 650 A).

ETRTO 40-559 = 40 mm wide 559 mm
diameter rim. Also labeled 26x1.50 but
you are best off ignoring this old "size"

This system would work just fine if each size of wheel was described by a different number. However, that was not so. As an example, the "26 inch" wheel size used on traditional British bicycles is a lot larger than the "26 inch" wheel size used on traditional American bikes. British bikes were for many years imported to the USA, and when Mountain Bikes became popular, they brought the American wheel size to the UK. What's more, there are more "26 inch" wheel sizes than just these two.

There are also two different sizes of "28 inch" wheel, one of which is larger and the other smaller than the "27 inch" size. "29 inch" wheeled mountain bikes actually use the same diameter rim as the smaller "28 inch" size, so these two use smaller wheels than "27 inch".

The same problems arise with smaller wheels as well. The two most commonly used "16 inch" wheel sizes are both considerably smaller than 16 inches in diameter. The largest of the two measures just over 13.5 inches in diameter, while the smaller is nearly 2 inches smaller than this. There are also several different wheel sizes referred to "20 inch".

The metric versions of these measurements also cause confusion. A 700 C wheel is not the same size as a 700 B wheel but it is the same as one of the "28 inch" sizes, even though it's neither 700 mm nor 28 inch in diameter.

Inevitably, there is much confusion about wheel sizes.

The solution: ETRTO numbers

The most common size for Dutch town bikes and many touring
bikes. A 622 mm diameter rim with a 37 mm wide tyre

In 1964, the European Tyre and Rim Technical Organisation was formed. They're an organisation that few people have heard of, and I know little of what they've been doing for the last 50 years except that they've given cyclists a great gift in the form of a system for identifying tyre and wheel sizes which guarantees compatibility. This has been standardized internationally in the form of ISO 5775, but most people still refer to these figures as "ETRTO numbers".

The "ETRTO number" consists of two numbers separated by a dash. The first gives the width of the tyre, while the second gives the diameter of the rim which it fits. For instance, 37-622 indicates that a tyre has a width of 37 mm and is to be mounted on a rim of 622 mm diameter. This is the most common size for Dutch town bikes, and is also a common size for touring bikes everywhere.

Buying a replacement tyre
Before buying a replacement tyre, inner tube or wheel, first check the writing on the side of your existing tyre and find the ETRTO number. To help you find an exact match which will work on your bike, all the tyres and inner tube as well as the wheels in our web shop are listed with their available ETRTO sizes.

You do not always have to buy the same width of tyre as you had before. While it is not a good idea to fit a very wide tyre onto a very narrow rim, nor a very narrow tyre onto a very wide rim, in principle any tyre of any width will fit on any rim which is the correct size. In practice we suggest not going too far from what the manufacturer of your bicycle fitted. For example, if you currently have 32 mm wide tyres, then fitting a 37 mm wide tyre instead will likely give a bit more comfort. However, make sure you have enough clearance in the frame and under mudguards for a larger tyre size.

Recommended tyres and sizes for different types of bikes
Below we make some recommendations for some types of bikes. We supply a much wider range of tyres than this, so if you need a different size, please check all of what we have, and contact us if you need a size which isn't listed

You should always make reference to the ETRTO number on the side of your existing tyres before buying any tyre. Please take our recommendation, but confirm that these are the exact tyres you want by checking your tyre size yourself before ordering. If you are changing the width of the tyre that you use, make sure you have a new width that will work on your rims and in your frame:

Type of bike	Tyre size	Old size	Recommendation with link to where to buy
British Three Speed	37-590	26"	Marathon Plus, Marathon, Delta Cruiser
New Dutch town bike	37-622	28x1 3/8	Marathon, Marathon Plus, Delta Cruiser
"Old" Dutch town bike	40-635	28x1 1/2	Marathon, Marathon Plus, Delta Cruiser
Modern touring bike	28-622 to 37-622	28" / 700C	Marathon Plus, Marathon, Marathon Supreme
Racing bike	20-622 to 28-622	28" / 700C	Durano / Durano S, Contact Speed, Grand Prix
Old racing bike	20-630 to 32-630	27x1 1/4	Marathon
Mountain bike	47-559 to 55-559	26"	Furious Fred, Marathon Winter, Big Apple
Mountain bike used on road	32-559 to 50-559	26"	Big Apple, Contact Speed, Kojak, Marathon, Marathon Plus
20" wheel folding bike	28-406 to 47-406	20"	Kojak, Marathon, Marathon Plus
16" wheel folding bike	28-305 to 47-305	16"	Marathon, Marathon Plus
Brompton / Moulton	35-349	16"	Marathon, Marathon Plus
Kronan	54-584 or 47-622	26" / 28"	Kronan tyres (Kronan men's and women's frames are different)

Profile
It is not possible for a bicycle tyre to "aquaplane" because speeds are too low, and pressures are too high. Therefore, a profile is not needed on bicycle tyres to increase grip in the wet.

Top to bottom. Speed & good grip: Kojak
Everyday use and touring: Marathon
Ice and Snow: Marathon Winter

When on a hard surface (concrete, asphalt), grip comes from the tyre deforming over small sharp edges in the surface, not from the surface deforming to fit the tyre, for this reason, a complete slick tyre provides all the grip you need on such a surface. What's more, a tyre which has a tread pattern will generally have a higher rolling resistance due to deforming of the tyre as you ride along. For this reason, a completely slick tyre (like the Kojak) would serve most people well most of the time.

However, tread on a tyre is useful in some circumstances. If you sometimes ride on unfinished paths, mud, sand and snow, then a slight tread pattern is useful because the surface will then deform around the tread and provide extra grip. It is for this reason (as well as that new tread patterns look good in marketing materials) that most general purpose tyres have a slight tread.

A more extreme tread pattern is needed for more extreme circumstances. Those who do cross country riding or mountain biking on rough paths benefit from an aggressive tread, and of course this becomes more extreme in examples such as the Marathon Winter which go as far as having metal studs to pierce through ice.

Tyre Pressures
It is important to maintain correct tyre pressures. While it can be It is more common that people run their tyres at too low a pressure than too high. If the pressure is too low then too much of your energy goes into deforming the tyre as you cycle, and this makes cycling considerable less efficient.

If you can easily deform a tyre with your fingers then it is almost certainly under-inflated. All bicycle tyres run at higher pressures than car tyres, and car pumps are often not capable of achieving high enough pressures for a bicycle.

Racing bike tyre with "French" 700x23C
description alongside ETRTO

Narrower tyres need higher pressure than wider tyres. The racing bike tyre on the left has a recommended pressure between 6 and 10 bar (85 to 145 psi), while a wider mountain bike tyre may need just 2 to 3 bar (30 to 45 psi).

Narrow tyres may damaged quite quickly by too low a pressure, while some tyres (notably the Schwalbe Marathon) have been reformulated to make them more resistant to damage due to low pressure.

For everyday use, a thumb test (if you can deform the side-wall of the tyre with your thumb, pump it up) is enough for most people. However, we also stock the very good Schwalbe digital air pressure tester for people who want to make sure their tyres are at a suitable pressure. We also sell a range of pumps suitable for getting your tyres to a suitable pressure.

Note that with tyres with puncture resistant layers, like the Marathon Plus, if you try to test the pressure by squeezing the running surface of the tyre, all you'll "test" is how soft the anti-puncture layer is. It's important to do this on the sides of the tyre, squeezing between thumb and forefinger.

Marathon Winter tyres

Last winter, Judy fell on a patch of ice. It's not been cold enough for that yet this year, but none of want that experience.

To prevent this problem, we're using Marathon Winter studded tyres on the front wheels of our town bikes. Obviously both wheels provides better protection from falls, but the front wheel is most critical. If you lose traction with the front wheel of a bicycle then you lose the ability to balance and will fall very quickly.

It is best to fit the tyres before the ice sets in so that a few kilometres can be ridden on them on asphalt. This helps to seat the studs in the rubber so that they are less likely to come out later. The manufacturers recommend 60 km of riding on asphalt.

Of course, Marathon Winter tyres aren't only for town bikes. They're also available in sizes to fit mountain bikes and recumbents.

I used one last winter on the back wheel of my Mango velomobile. This made a big different to safety as losing the rear wheel is the biggest danger with a tadpole (two wheels the front, one at the back) tricycle. If traction at the rear is lost then the trike turns due to the camber of the road and will likely flip over as it slides sideways into the kerb. By using a Marathon Winter on the rear of my Mango I could cycle with confidence not only within the city, where most cycle-paths are clear anyway. Rather, this meant I could continue to enjoy touring rides right out into the countryside.

You can buy Marathon Winter tyres in the Dutch Bike Bits Webshop.

Continental SportContact tyre

I'm now trying Continental's
SportContact tyres. These will
stand up better to everyday use.

For a few months now I've been riding with Continental Grand Prix tyres on the front of my Mango. They're lovely lightweight and fast tyres, but unfortunately I have to say that they've not really worked out, at least on this bike. I used my pair briefly last year before removing them for winter, and re-fitted them only about a month ago. They've been used for about 800 km, which is not all that impressive.

The main problem, I think, is that they are simply not intended for use on a fast tricycle like the Mango. Sideways forces, especially when braking, are too much for them. On a two-wheeler it isn't possible to put such a sideways force on a tyre, nor to brake with a considerable sideways force on the front wheels without instantly falling off. The rubber was lost right outside our home, as I rode in quickly. A touch on the brakes, the wheel on the inside of the turn was in a skid, and there was a smell of rubber.

Even if I'd not had this problem, I was already planning to replace the tyres. Both Grand-Prix tyres already had cuts in them presumely due to small stones or pieces of glass (I didn't find the cause). This all happened a bit too soon for a practical tyre.

Continental's Grand Prix tyres are
fast, but don't like high speed
cornering and braking with a
velomobile.

I've not given up on Continental, but have replaced the Grand-Prix with the Continental SportContact. These are the same size, 28-406, but they are designed for everyday use. They weigh a bit more, have a bit more rubber, have the "SafetySystem" anti-puncture protection, sidewall reflectors, and a lower cost. they're also still supposed to be fast. It sounds like a promising combination, so I'll see how I get on with them over the next few months (The Sport Contact was a very good tyre - it's now been replaced by the Contact Sport).

The advertised weight for the SportContact in this size is 295 g, however mine were actually a little lighter at about 270 and 280 g each.

New tyres fitted and ready to go, on a cycle path wide
enough that riding an unusual bike is never a problem.

One very nice thing about both the SportContact and the Grand-Prix is that both are easily mounted on and removed from the rim without tools, and both sit well on the rim and run true straight away. This can be quite difficult to achieve with some tyres.

The maximum pressure stated on the side-wall on the SportContact is 6 bar ( 85 psi ), but the accompanying paperwork attached to the tyre says 7 bar ( 102 psi ). I'm using the higher pressure. I have suspension so don't need the tyres to contribute too much to comfort, and they'll roll faster at the higher pressure.

My rear tyre remains a Schwalbe Marathon Racer. This still barely looks run-in. Actually, it wouldn't have been a bad choice for the front wheels as well.

Update 2016
When my daughter and her boyfriend went touring, they used Continental SportContact tyres.

Tyres and tubes and other nice stuff can be bought at our webshop.

Kick Stands and Tyre Pressures

Spanninga Easy 30 mm version

The kickstand failed on one of our rental bikes at the end of last year.

A bicycle which falls over unless leant on something is a nuisance, even just in storage, let alone in use. Leaning on brick walls causes damage to the bike. Other surfaces can be damaged by the bike. Therefore, I've replaced the broken part with our favourite type of single sided stand, the Spanninga Easy kick-stand. This is a long stand which is sturdy enough that it will support quite heavily laden bicycles safely.

Luckily, with most bikes, fitting a kickstand is an exceptionally easy job to do. It fits to the bracket provided as part of the frame, with one bolt just in front of the rear wheel, and just a single tool is required to do this - an 8 mm Allen Key.

The stand simply has to be held in position with one hand, while the bolt is done up with the other. It takes just a couple of minutes to do.

It's a good idea to put a little grease on the thread of the bolt so that it won't seize up over time, and to put some on the mechanism of the kickstand as well to make it run a bit smoother.
Most bikes use the "30 mm" version of the stand. Dimensions of both variants are in the web shop.

Bike with working kick-stand, so which no longer has to be leaned on something.

And now something about tyre pressure and tyre choice...

The bike in the photos above is fitted with the same tyres as I've currently got on my Mango for winter commuting - the Schwalbe Marathon Plus. The great advantage of these tyres is that they are virtually impossible to puncture. As a result, they're our choice for most of our bikes, most of the time. If you prefer riding to repairing punctures, these are the tyres to go for.

They're also quite fast tyres... but only if pumped up quite hard. I realised on Sunday morning that after months of riding the narrow Marathon Plus tyres on the front wheels of my Mango were well under the maximum recommended pressure of 6.5 bar ( 100 psi ). In fact, they'd got down to about 5 bar ( 75 psi ) which is low enough that they roll much worse. I'd been disappointed by my speed of late, but of course pumping the tyres up to the recommended pressure restored their previous performance.

It's one thing to have to stop and fix a puncture in the middle of the summer when it's warm and the sun is shining, but something else altogether in the winter when it's dark and cold. That's why I use them especially in the winter.


But now it's just about Spring... and Summer is around the corner. This time of year, punctures are less likely, and in any case I don't quite so much if I get them. Soon, I'll take the Marathon Plus tyres back off my Mango and replace them with something which is a little more fun to ride with. For everyday summer use, I intend to switch to the the Marathon Racer. They still have a puncture resistant layer, so punctures should at the least be rare in summer conditions, but it's a much thinner one making them lighter and faster rolling than the Marathon Plus. They're well suited for everyday riding.

For racing, I've a pair of only slightly worn in Continental Grand Prix tyres for the front, or perhaps Stelvio or Durano. These are all nice fast rolling, narrow, durable, puncture resistant and light weight tyres with decent grip on the road, and should work well combined with a Marathon Racer on the rear.

Repairing a puncture in a
Comp Pool which I fitted
to Judy's bike

However, I've also some more unusual tyres which I might use again, but only if the right opportunity presents itself: Three Avocet Fasgrip tyres. These are a real curate's egg of a tyre. They're fast, they're durable, but they have a magnetic attraction for sharp objects on the road so you get lots of punctures. The lightest sprinkling of rain results in no grip whatsoever, and even more punctures. I don't sell these. I don't think I could live with myself if I did. However, a colleague of mine at the Ligfietsgarage sold them to me personally (they don't sell them to the public either), describing them as "just like the Tioga Comp Pool". I should have taken this as a warning, but of course I'm a glutton for punishment so I instead took it as a recommendation. He was absolutely right. They really are just the same. I should have known what I was letting myself in for. But with both of these tyres there's a pay-off in the right conditions in that they do genuinely have low rolling resistance - so long, of course, as they're pumped up to their recommended pressures, plus a bit more if you're really daring... I raced with the Avocet tyres last year.

Tioga's Comp Pool is long out of production. I thought the Avocet was out of production too but it's still on the manufacturer's website. Occasionally someone comes out with a new tyre which is described as "just like the no longer available Tioga Comp Pool". Sensible people run away when this comparison is made... Speed without such compromises comes from the more sensible tyres which I mentioned earlier.