WintertiresAs I want to drive the speedster the whole year, I want to change to wintertires. This is not really an option on the standard wheels. Ofcourse I could get the factory Opel wheels, but they will probably very expensive. Arno just got new wheels for his summer tires from Compomotive. They seem seem to be nice, have a good finish, are strong and not very expensive.
So I first had to choose the sizes I was going to use. I would like to end up with the Elise settings eventually, so 15" front and 16" rear. But I don't want to change the height of the complete wheels just yet, because I don't have height adjustable suspension. So after some calculating I came up with the following sizes for the wheels:
Final order looked like this:
There are not many distributors in the Netherlands for Compomotive. Arno found a good one, which actually wants to put some effort in finding stuff out and chasing the distributor. It is Dutch Power Trading.
After I ordered the wheels, there seemed to be some confusion at Compomotive.
They were afraid the wheels would interfere with the brakecalipers. So they
sent me a sheet to do some calculations.
After four weeks the wheels had been made and I could pick them up.
I brought the speedster along to see if it was nessacery to get longer bolts. Fortunatly this wasn't required. However, there was a powdercoating on the inside of the wheel, which made it impossible to fit the wheels on the hub's. Fortunatly some sanding the coating away did the trick. Arno didn't have this problem with the wheels for the Elise. It seems they made the center bore 0.1mm bigger and they didn't with mine.
So the wheel fitted, but 15" is as small as you can go. And the ET25 also doesn't leave much space to spare, but it works. If you want to do the same it might be better to go to a ET24 or smaller, but I think I'll leave it at this unless I run into problems.
Fortunatly the rear wheels were a lot easier. They just fitted out of the box. Lots of space left, but I allready knew that.
So after some sanding of the other wheels everyting was ok. Looks a lot better in black :)
After we packed the wheels up, we drove by Roline to see if we could drop of the wheels so they could fit the tires and make an appointment for them to be fitted. Fortunatly they were still there (we were a bit late), and I could come by the next morning.
The tires I ordered are the Dunlop SP Winter Sport M3. I originally wanted to go for the Toyo's, but they can't do the front and the rear tire from the same series. Sizes I ordered were:
Pretty happy with Roline fitting the tires. They really take the time to fit them right. On balancing the wheels they found that some of them would have to be adjusted with too much weight for their liking. So they took the tire of the wheel, and rotated it a bit to reduce the weight difference.
To make sure the front wheels would come off without to much of a problem, Arno put some Mobyleen grease on the inside, to stop them sticking.
Car looked pretty good with the new wheels and tires. Think the black nicely hides the bigger wheels and looks ok with the yellow.
Running the tires now on 1.6bar front and 1.7bar rear. Seems to work ok. Grip is pretty good. The grip limits are much more clear and the car is more stable during cornering, acceleration and braking. There is more flexibility in the tires though, so reactions are a bit more vague. This has to do with the high thread on the tires and the flexible side walls. Requires some getting used to but isn't annoying.