Thursday, 6 December 2012

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 that from my 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 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 and as subjectively safe to cycle today 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.

11 comments:

Koen said...

Good idea to do only the front tyre. Only last week I took my son's bike to the bike shop. A new rear tyre had to be fitted, but these modern bikes are made so damn complicated that I could fix it myself anymore, and the gear hub was so intricate that I couldn't adjust it without a special tool either. I used to be able to do it myself on my older bikes. Just the front tyre shouldn't be any problem, though.

Erik Sandblom said...

I've cycled through winter with and without studded tyres and I think the best safety device is to take your time. When the conditions warrant studded tyres, they can be very convenient.

As is often explained on this blog, the feeling of safety is a very important issue to cycling. It's also easy to overestimate the protective effect of gear and infrastructure. It's not the snow or even the infrastructure that makes it unsafe, it's the people using it. I find that a very empowering thought.

Hope everyone gets a winter with lots of snow!

Aushiker said...

Thanks for the post and the insights into riding in snow and the concept of utility cycling. Down here we are heading into summer and temperatures which will at times reach 40 C +. Quite a different world :)

Jon Bendtsen said...

due to my own mistake, I have been forced to cycle my 2 wheeler, and while I do take it slow and safe, I did slip the other day, such that I once again bended my handlebar :-( If I need to ride my 2 wheeled bike for much longer, I will buy a studded tire.

Vladimir 'vudu' Zlokazov said...

This winter is my first on a citybike in Yekaterinburg, Russia and I chose this exact model - Schwalbe Marathon Winter. I was a bit concerned since I saw several reviews where folks said that studs tend to come off these tyres. But so far so good - no lost studs for 1,5 months. I put them on both wheels and they hold very well both on ice and compacted snow, almost as good as Nokian Extreme which I had previously on MTB.

Jon Bendtsen said...

I lost studs on the rear wheel of my Mango velomobile. I do also have studded tires on the front wheels because I want to be able to brake and turn well.

Colibri said...

I plan to buy such a tyre, just in case of a winter with "bad" weather.
Around here, it rarely snows. Yet, on these occasions, I do want to keep on using my bike.
However I find it not very practical to have to swap for a specific tyre.
Prefitting a spare wheel with a winter tyre is not really an option either : my front wheel is equipped with a hub dynamo and roller break.

I've just discovered a interesting product, designed by a Dutchman.

It's basically an add-on, which avoids have to swap the whole tire.
There's a video as well.

I understand that it is only a prototype but I'd love to have a pair of them for my bicycle !

Frits B said...

@Colibri: another mention of the Bike Spikes:
http://www.bikerumor.com/2012/11/18/bike-spikes-by-cesar-van-rongen-look-to-add-snow-chains-studs-to-your-ride/

David Hembrow said...

Colibri: It only takes five minutes to swap tyres. Two of the bikes I've done this week (Judy's above and my own) have roller brakes. You loosen the tyre, undo the wheel nuts and then the tyre can be taken off the wheel and swapped without having to touch the cable. No problem.

Call me old-fashioned and boring, but I'm still more impressed with good products which work as they're supposed to, from an established manufacturer, and which are available right now than I am in the latest "designer" hype.

There are several obvious drawbacks to that idea, including added unpleasantness should you get a puncture, the inability to use it with a bottle dynamo, and who knows what the failure mode of such a contraption is ? Perhaps it can come loose and block the front wheel so that you go for a trip over the handlebars. I wouldn't want to be the first to find this out. Of course, it may also end up being really good, and it may even end up taking less time to fit than the five minutes that it takes to swap a tyre. However, that's all rather academic when you can't buy it.

M Stoss said...

I bought a mountain bike as my dedicated winter bike last year and fitted it with a front wheel Marathon Winter studded tyre. Unfortuneatly ;-) it was a winter with only little snow and ice.

Now I rode the first trips with snow and ice again and it feels very safe.

timooohz said...

Rim brakes are not very good in deep snow and icing conditions. And same with the bottle dynamo. Ice and snow on the rims makes them rather useless.

I remember making DIY snow chains of steel wire and baling wire for my bike when I was a kid. I guess they didn't work very well, because I stopped using them. I rode with regular tyres for decades, until I bought a studded tyre last year.

Actually you can get by most of the winter with regular tyres if the bikeways are gritted and/or there isn't lots of daily thaw-freeze going on. Not that studded tyres are useless even then, but on days with black ice or glass smooth ice the studded tyres really work their worth.

You can ride with them on asphalt, too, so you don't have to switch them on and off every morning.