Showing posts with label tyres. Show all posts
Showing posts with label tyres. Show all posts

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.

Friday, 20 May 2011

New tyres - Continental SportContact

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

I'm now trying their SportContact
tyres instead. Hopefully these will
stand up better to everyday use.
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 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.

Visit our webshop for practical, genuinely useful parts of all types for all bicycles. Including fast hard wearing tyres for recumbents and velomobiles.


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

Sunday, 17 April 2011

To the German border and back, a kilogram lighter


Mango at Bourtange
This video was made on Monday afternoon two weeks ago when I rode to the German border and back. I made the journey because we've a holiday customer coming in a couple of weeks who will take this route. I realized I had not ridden it for over a year, and it's important that we keep our routes so up to date as possible.

Bourtange itself is a star shaped fortress and village dating from the eighty years war between 1568 and 1648. At the time it was militarily important and guarded the only road between Germany and Groningen. Now it's a museum.

Willow growing in a reserve
On the way to Bourtange I stopped a couple of times, to eat sandwiches, to take a look at some willow trees, to look at a deserted beach (Monday afternoons in April are not peak times for sun-bathing).

I didn't really need to carry on from Bourtange into Germany, but I thought it would be nice to have a German beer at the furthest point from home before turning around again. However, the owners of the cafe I stopped at had other ideas. It was shut. I've called past the same place several times now, and never managed to get any refreshment at all.

Anyway, that was the furthest I had any reason to ride, so I turned around and headed home again. A 120 km afternoon bike ride, including a trip back in time and to visit a foreign country, a few stops for food and drink and to take photos, and I was back in time for dinner.


German cycle route signs. Those on
the right point towards the
Netherlands, including Bourtange.
The weight loss referred to in the title has nothing at all to do with any of that:

Today I finally got around to taking off the winter tyres on my Mango and putting on summer tyres. Marathon Plus tyres are some of my favourite tyres. I've used the same pair on the front of my Mango all through the last two winters, and another on the rear this last winter, apart from when it was icy and I rode with a Marathon Winter studded tyre. They're fantastically reliable, and virtually impossible to puncture. The whole family has these tyres on at least one of each of our bikes, and in many tens of thousands of km none of us has ever had a single puncture with the Marathon Plus.

They're really great tyres... but... you can probably see where this is going. Having to fix a puncture in the middle of winter is downright unpleasant. I'll put up with a slightly heavier / slightly slower tyre to avoid this happening.

The pub with no beer. Again.
However, it's not winter any more ! I've taken off the heavier, slower tyres off and put narrow Continentals on the front and the reliable and fast folding version of the Marathon Racer on the rear. Including the inner tubes, this combination weighs just under a kilogram. The three Marathon Plus tyres and their inner tubes came to more than 2 kg. This kilogram different is not just static weight either, but rotating weight, all of it near the outside edge of the wheel. Reducing this makes a big difference to acceleration.

Lighter, faster tyres are more fun to ride with - just what's needed for summer cycling. It's like having a new, lighter, faster bike, every spring, and best of all this comes free of charge.

You have to replace tyres eventually, when they're worn out. All I've done is to have a second set which I use for warmer months. The tyres which came off today will go back onto the bike next winter, as again I'll to looking to avoiding the possibility of fixing punctures in the snow.

There now seems to be a huge difference in sidewall construction between the wire bead and folding versions of the Marathon Racer tyre.
Read my review of the Sinner Mango Velomobile.

Wednesday, 16 March 2011

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.