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Downsizing

The roads around my home are prone to subsidence, particularly the one leading into my street. It has become so bad recently that even the Merc is struggling with them, and that's a car that can float over most road imperfections. It is however, amazingly bad in the porker.

I mentioned earlier that the Cayman's ride is very firm. It's a German thing, they love their big wheels and rubber-band tyres. Which is all well and good if you have good roads, but we don't have good roads. Also I object to grossly large wheels on a personal level. Wheels do not need to be big, it's a fad born from touring car racing. The reason touring cars have large diameter wheels is to get around the brakes. That's it. Everything else is a disadvantage. Bigger wheels mean more unsprung weight, and thus an increase of the gyroscopic forces messing with your suspension and steering movement. Add this to having much less tyre wall and you have an adverse effect on ride, handling and steering feel. Then we have the belief that sports cars must have ultra-firm suspension. Again something Lotus, who are masters at ride and handling, have proven to be complete nonsense with the Elise and, more importantly, with the much heavier Evora.

Back to the porker, the standard car comes with 17" wheels. They're as small as they can be to get around the brakes. The S has slightly bigger brakes so you're stuck with the 18" wheels, and the only thing you can do is make sure you get a car with Porsche's active ride system which allows to to run the car softer than the non-adjustable shocks my car has. My car has the S wheels on it and even I'll admit, they look fantastic. But it is written that cars with standard narrower, taller tyres ride better and have better steering feel.

So initially I was going to try and find someone with some 17" Cayman II wheels to see if they'd do a straight swap. I'd prefer them as they look like the S wheels fitted to mine, but are in the smaller size. It seems no one specifies the cars with the smaller wheels. Or at least if they do, they quite sensibly keep them. Buying them new from your local OPC would see you relieved of a few thousand quid, plus another £800 or so to get some tyres fitted to them. I still have a bit of tart about me so I didn't want the original Cayman 17's, as they're ugly. So a trawl of ebay has landed me some Boxster 17's with usable tread on them for £300. They're straight, but have a few spots of bubbling so will need a re-furb if I end up keeping them. As it stands, £300 is cheap enough for me to try and see if it makes enough difference to be worth the hassle.

So does it really make a difference? Well they're on and they've definitely taken the edge off the ride a bit. It's still firm, but I'm finding that I'm no longer wincing when I hit the slightest pothole and that the road noise is also reduced. It'll probably be more so when I stick the bigger rear tyres on as that will add another 2cm of tyrewall at the back. But that'll come after an Anglesey trackday in a couple of weeks now. The plan is to destroy the rears at Anglesey then put the car back on the 18's while the 17's are re-furbed. When they're back I'll stick the front tyres back on (loads of tread) and fit some larger rear tyres.

Aesthetically speaking, yeah the 18's look better, no doubt about it. But you don't look at 'em when you're driving it and it's more pleasant on the smaller wheels.

Update I: Going back to the 18's

Holy crap, you might not notice much difference going from 18's to 17's, but you REALLY notice going back. Every little bump, every little imperfection pummels you. Yes they don't go as squirrely (my brother's description) under hard braking on the squishier tyres. But the ride is worth the compromise. One way or another, it's going onto stock 17's.

As the Gen 1 Boxster S wheels I've got from eBay are the wrong sizes really, I'm now going to flog those and look out for a set of Cayman 17's. I may even put up with the original ones (though I really want the Gen II wheels). I can only imagine that they have very, very smooth roads in Gemany to put up with 18-19" wheels on the stock suspension.

Update II: Gen 2 17's

This is what the car should have as standard... Ok, this is what the car does have as standard, just don't mess with it as it's as good as it gets. Ride is firm but fine. Road noise is significantly reduced and with the right wheels and tyres, there appears to be no noticable detriment to the handling. The squirreliness of the Boxster wheels/tyres has gone. They even look good.

All round it's the best change I've made to the car. I managed to pick up a set for £600 that had been on a car for 3 months. So they are as new. It took some time, but they popped up in the end. Seems there are people out there who'll sacrifice comfort for looks and as long as there are, I'll have a supply of replacement wheels and tyres. Handy that.

Nothing left to do to it now, just drive and enjoy.

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