Are the 17" Wheels really best for road use on Blighty Black

[Simon Owen]

There is an informative article by David Twohig on "The Intercooler" about the ever increasing demand for bigger alloy wheels.

I'm currently running the Fuchs 18's with big brakes so a pretty good starting point by modern standards but I'd be fascinated to try the 17's and see if I could tell the difference / notice an improvement in ride & handling for road use ? Prior to the Alpine we ran a lightly modified GT86 on modest 17" wheels and 215 PS4 boots and I don't ever recall thinking it lacked grip for the road.

I never really did understand if the Alpine 17" wheels will fit over the big brakes, I think I've read that they do albeit Alpine don't give us the option when ordering a car.

Interesting that Life110 have stuck with the 18's but added a tad extra width in their 'upgraded' wheel set.

[Simon Owen]

Olivera said:

Not an A110 owner here, but I think the effect of going up or down 1" wheel diameter is often grossly over exaggerated on PH.

Ride quality is a combination of various things: spring rate, tyre sidewall, unsprung mass, anti-roll bar stiffness and so on. The amount of tyre sidewall is just one part of the equation. An A110 on 205/40/17 has exactly the same amount of sidewall (205*.40=82mm) as an 205/40/18 tyre. How can the ride quality be significantly better on the 17" tyres given they have the same spring rate, the same sidewall thickness, the same anti-roll bars, and only a small improvement in unsprung mass? It's an impossibility for the ride to be anything other than marginally better.

Tyre profiles are not the same - the 17's come with a deeper profile of 45 vs the 18's which have a profile of 40, not a huge difference but a subtle one all the same.

[Simon Owen]

Olivera said:

Simon Owen said:

Olivera said:

Not an A110 owner here, but I think the effect of going up or down 1" wheel diameter is often grossly over exaggerated on PH.

Ride quality is a combination of various things: spring rate, tyre sidewall, unsprung mass, anti-roll bar stiffness and so on. The amount of tyre sidewall is just one part of the equation. An A110 on 205/40/17 has exactly the same amount of sidewall (205*.40=82mm) as an 205/40/18 tyre. How can the ride quality be significantly better on the 17" tyres given they have the same spring rate, the same sidewall thickness, the same anti-roll bars, and only a small improvement in unsprung mass? It's an impossibility for the ride to be anything other than marginally better.

Tyre profiles are not the same - the 17's come with a deeper profile of 45 vs the 18's which have a profile of 40, not a huge difference but a subtle one all the same.

Thanks for the correction, so the 17s have a sidewall of 205*.45=92.25mm, so about 12.5% more sidewall than the 18s. Again a relatively small difference when holding all the other variables the same (e.g. spring rate), so again probably a very slight improvement in ride quality, at the expense of very slightly worse turn-in due to the higher sidewall.

Yes more sidewall + a bit less unsprung mass, note the difference in unsprung mass increases quite a lot between the Fuchs & Non Fuchs options, the 18" Serac alloys are for example quite a bit heavier than the 18" Fuchs. I'm interested to see how this translates in the real world ?

[Simon Owen]

Likewise I’m no serious driver but have changed wheel size by 1” down on other cars and you can notice the difference, it’s that which made me curious about doing it on the A110.

[Simon Owen]

bcr5784 said:

PaulJC84 said:

I think I have seen pictures of Braid and protrack 17s on A110s.


Braid
https://www.youtube.com/watch?v=BaTuPeFt2iU

/

The warning that jacking the car might cause the windscreen to crack was worth a thought.

Agreed !!! Putting stress on the car diagonally I guess, one to watch with tyre fitters as they don't all use 4x way lifts do they.

[Simon Owen]

FrenchA110 said:

tail slide said:

I've taken many fast road cars on track, and used all the performance and grip for 6 laps at a time. In my experience at Anglesey last month, the standard brakes were absolutely fine by Lap6 with hard braking from the max speeds between corners, and of course fine on the road.

From my long TVR experience over the years fitting larger brakes for trackdays & competion, they only help by giving less fade if you're going to use them hard near lockup for long track stints on a hot day. And looking bigger if that's your thing


Larger brakes are significantly heavier, which makes damping slightly worse on the road, so not the choice for me.

Edited by tail slide on Monday 20th December 15:16

In the Alpine’s case the big brakes are actually lighter since they are a steel/aluminium hybrid versus the steel/steel of the standard brakes.
28.8kg for big brakes versus 30kg for standard.

I think I’m right in saying the big (lighter) brakes will also fit with the smaller 17” wheels albeit you can’t order a car in that spec can you ?