Friday, 25 April 2014

different sipes

"You'll still need the winter ones if it carries on like this," smiled the man as I checked in.

Yes, it's post Easter and time to switch back to the Summer tyres on the car.

It's been something of an umbrella situation though. That knowledge that the best way to prevent rain is to carry an umbrella. There must be a tyre addendum to the superstition.

Today, the weather gods had sensed that I was switching from the snow and mud tyres back to 'normal' ones. Thor decided to throw all of his toys around and we had lightning and thunder as well as a deluge of rain.

My 15 minute trip to the dealer* became 30 minutes as a local roundabout flooded and the traffic backed up. Little red cars popped up all over my sat-nav, showing traffic jams appearing everywhere.

A curious fact with the tyre change is the different mileage I get from the car. The winter tyres give around an extra 5 to 7 miles per gallon. I'm pretty sure that it's the tyres rather than my driving that make the difference.

The winter wheels are a different profile from the summer ones. Apart from the obvious cosmetic differences the winter ones are slightly narrower - it's the proper factory option - so supposed to be that way. I guess it affects the rolling resistance.

I've also noticed that tyres are also all the same width for winter, whereas in summer the rear tyres are wider than the front ones. I'm sure there's a reason, although I can't help thinking that marketing plays a part.

Subliminally, the different width thing has worked though. I'd also wondered about this same thing for my road bicycle. Putting a slightly wider tyre on the back than on the front. Wider tyre areas, different comfort and rolling resistance.

A couple of weeks ago when I'd asked about it, the obviously knowledgable chap in the bike shop had looked at me kind of sideways.

"23mm front and 25mm rear? I suppose you can do that." He didn't stroke his beard or shake his head, but I could see in his eyes that he was unconvinced.

The other assistant serving me was already swapping the tyre boxes around when I asked the question.

"No, okay, I'll stick with two 23mm," I chickened out.

* Written on iPhone, whilst waiting for the wheels to be swapped over

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