Miata List Archive

This read-only message was archived from a public mail list.
Mail From: chip (William 'Chip' Lamb)

Dear ?,

Having done my share of vintage sportscar racing and plenty of time with
Jaguars and inboard rear brakes on the rear I am very familiar with the
concept of reducing unsprung weight.

I am also aware that certain 16"s are considerably lighter than the 15"s
found on my '00. They are anything but exceptionally light for what they
are with those chunky spokes compared to the 2001 SE 16"s and their
comparatively skinny 5 spoke turbine arrangement.

I am also looking for something which will allow for a little less sidewall
flex and a little better contact patch. My assumption based on Mazda's move
to 16s and 17s in the latter years of the NB and further having driven a
few of them is that they were looking for it, too. I have 205/50/15s on the
15" SE rims now and they have too much sidewall bulge, not an acceptable
compromise for a little extra contact patch.

You wrote: Lighter unsprung weight/wheels = more grip? Not exactly. 50/50
weight balance factored against good center of gravity and sufficient
weight over the steering/main braking wheels (check) and sufficient weight
vis power on the driving wheels (no, but it lends to the British car aura
and is more than made up for with typical British understeer) makes much
more difference no matter what the wheels are. Best grip even in bad
weather but dicey handling in a sportscar I would award to the Porsche 911
but oversteer in the hands of an inexperienced driver makes it inaccessible
to all but a select few. The weight of the driveline over the driving
wheels is balanced on its subframe, and the overall weight balance is very
near 50/50 (assuming with more than a 1/2 tank of fuel over the front
axle). I recently thought about picking up a 911 for vintage racing but
don't feel like playing with the old engines and Solex carbs so that's out.

Chip
If engineering was that simple perhaps GM could do it right for a year or
two before the beancounters found out


At 09:31 AM 7/12/2006 -0500, las pozas wrote:
>Are you sure that 16 or 17s are going to improve your handling?
>Surely there are some experts here, but my feeling is that the NB is
>best suited to a 15" rim.
>
>You have to be careful about weight - 16s and 17s are likely to be
>heavier (a very very bad thing for wheels). See this article on
>unsprung weight: en.wikipedia.org/wiki/Unsprung_weight
>
>Many who care about handling have tried larger wheels only to come
>back to the 15s. Lighter = more grip.
>
>Also check out this thread on miata.net - there is a wealth of info
>here on the subject:
>forum.miata.net/vb/showthread.php?t=40082
>
>On 7/9/06, William 'Chip' Lamb <(email redacted)> wrote:
>>I'm getting close to needing to buy some new rubber for the Mahogany Mica
>>2000 SE. I thought I might try to find some Mazda or tasteful aftermarket
>>rims as well not only for looks but for a bit improved handling. The
>>original 5 spoke chromes look rather dated and I'd rather not tie myself to
>>them for a few hundred in 15" tyres for the next 30-40k.
>>
>>I've been looking and can't find anything decent on eBay. Anyone have
>>anything laying about they might like to sell? Mail me privately on
>>mailto:(email redacted) if so.
>>--
>>Chip
>>40 LaSalle 5019
>>66 SAAB MC850
>>71 SAAB 95V4
>>78 SAAB 95V4 x2
>>93 Chev C3500HD Hodges Car Hauler
>>00 Miata Special Edition
>>04 Ford Ranger Edge 4.0 SOHC/5-sp
>>
>>_______________________________________________
>>Miata mailing list
>>(email redacted)
>>ftl.realbig.com/mailman/listinfo/miata
>
>
>--
>"Don't sweat it -- it's not real life. It's only ones and zeroes."
>-- spaf (1988)

_________________________________
Cheers-

William "Chip" Lamb
West of Sweden SAAB
Richmond, VA.
wmsbrg.com/sweden/
__________________________________

This read-only message was archived from a public mail list.
Mail From: laspozas (las pozas)

On 7/12/06, William 'Chip' Lamb <(email redacted)> wrote:
> Dear ?,
>
> Having done my share of vintage sportscar racing and plenty of time with
> Jaguars and inboard rear brakes on the rear I am very familiar with the
> concept of reducing unsprung weight.

Good deal - the original message just mentioned handling and looks so
I wanted to throw this out there.

> I am also looking for something which will allow for a little less sidewall
> flex and a little better contact patch. My assumption based on Mazda's move
> to 16s and 17s in the latter years of the NB and further having driven a
> few of them is that they were looking for it, too.

I assume that Mazda's decision to move to 16 and 17" wheels was more
due to customer perception of sportiness rather than any performance
improvement.

1999 10AE - 2000 SE - 15" @ 13.1lb
2001-2003 alloy - 16" @ 15.5lb
2002 SE - 16" @ 18lb
2003 SE - 16" @ 16.2lb

miata.net/faq/wheel_weights.html

I'd rather have a 13 lb 15" wheel than an 16lb 16" wheel.

The aftermarket, however, can surely help out, but I bet those 12lb
16" wheels are pricey.



--
"Don't sweat it -- it's not real life. It's only ones and zeroes."
-- spaf (1988)

This read-only message was archived from a public mail list.
Mail From: keith (Keith Tanner)

Actually, Miata factory wheels do tend to be quite light for a factory
offering. I'm not sure about the shiny ones used on the 00 SE, but the
regular silver version of that wheel is 13.4 lbs. If your shiny wheels are
chrome as opposed to polished aluminum, they'll be heavier but polished
shouldn't be any different. The 2001 SE wheels are 15.5 lbs. Can't always
tell from looking, can you?

Choose your tires, then your tire size, then your wheels. Say you want the
Falken Azenis RT-615 for fantastic grip. That means you're restricted to a
205/50-15, a 205/40-16 or 215/45-16. The 16" sizes aren't a great choice,
either a bit too small or a bit too tall. If you wanted the Kumho Ecsta MX
(a similar tire that's lighter), you can't get it in a 16" size. So look at
this first. 205/50-15 tires are super-easy to find, and you're not going to
find much wider than a 215 that will easily fit a 16" wheel. So maybe you
won't get a better contact patch, but you will get more weight if you're
using wheels of equivalent design.

Mazda's wheel growth was dictated by marketing more than anything else.

It's true that static weight distribution will have a huge effect on grip.
But since we're talking about wheels, pretend that everything else is kept
the same. In that case, lighter wheels WILL improve grip through improved
wheel control. If you want to move the engine to the back of the car, more
power to you. But that's a different discussion.

All that said, Flyin' Miata has a nice set of used SSR Integrals in 16x7.
SSR says they're 14.5 lbs each and I think they're the best looking wheels
ever bolted to a Miata personally. I used to run a set of these on my own
Miata and I'm trying to resist the urge to keep them for myself. They're $600.

keith

This read-only message was archived from a public mail list.
Mail From: chip (William 'Chip' Lamb)

I see your specs below on the weight of the wheels and it makes no sense
(though I have no reason do doubt they are true). I have hefted mine and a
2001 SE wheel together and it seemed as though the former was heavier.

2-4 lbs per wheel is pretty insignificant. A 10# brake disc outboard of the
suspension not directly suspended by the ground is. Properly mounted
contact patch and less sidewall flex would be very nice though.

At 10:31 AM 7/12/2006 -0500, you wrote:
>On 7/12/06, William 'Chip' Lamb <(email redacted)> wrote:
>>Dear ?,
>>
>>Having done my share of vintage sportscar racing and plenty of time with
>>Jaguars and inboard rear brakes on the rear I am very familiar with the
>>concept of reducing unsprung weight.
>
>Good deal - the original message just mentioned handling and looks so
>I wanted to throw this out there.
>
>>I am also looking for something which will allow for a little less sidewall
>>flex and a little better contact patch. My assumption based on Mazda's move
>>to 16s and 17s in the latter years of the NB and further having driven a
>>few of them is that they were looking for it, too.
>
>I assume that Mazda's decision to move to 16 and 17" wheels was more
>due to customer perception of sportiness rather than any performance
>improvement.
>
>1999 10AE - 2000 SE - 15" @ 13.1lb
>2001-2003 alloy - 16" @ 15.5lb
>2002 SE - 16" @ 18lb
>2003 SE - 16" @ 16.2lb
>
>miata.net/faq/wheel_weights.html
>
>I'd rather have a 13 lb 15" wheel than an 16lb 16" wheel.
>
>The aftermarket, however, can surely help out, but I bet those 12lb
>16" wheels are pricey.
>
>
>
>--
>"Don't sweat it -- it's not real life. It's only ones and zeroes."
>-- spaf (1988)

_________________________________
Cheers-

William "Chip" Lamb
West of Sweden SAAB
Richmond, VA.
wmsbrg.com/sweden/
__________________________________

This read-only message was archived from a public mail list.
Mail From: keith (Keith Tanner)

While 2-4 lbs per wheel may not sound too significant, you're talking about
25-50%. It's also weight that's further out, so it has a larger effect. The
10 lb brake rotor is a smaller diameter. Rotor mass also allows it to
absorb more heat, while wheel weight has no purpose. "Directly suspended by
the ground" doesn't matter a bit - it's all unsprung and rotating mass,
whether it touches the ground or not.

So you're really looking for less sidewall flex. Well, that's where tire
choice comes in again. A Falken Azenis RT-615 in a 205/50-15 size will have
less sidewall flex than a Toyo T1R in 215/40-16 despite the fact that
they're both in the "ultra high performance street" category. The same tire
in different sizes will flex less on the larger wheel of course.

Keith

At 09:55 AM 7/12/2006, William 'Chip' Lamb wrote:
>I see your specs below on the weight of the wheels and it makes no sense
>(though I have no reason do doubt they are true). I have hefted mine and a
>2001 SE wheel together and it seemed as though the former was heavier.
>
>2-4 lbs per wheel is pretty insignificant. A 10# brake disc outboard of
>the suspension not directly suspended by the ground is. Properly mounted
>contact patch and less sidewall flex would be very nice though.
>
>At 10:31 AM 7/12/2006 -0500, you wrote:
>>On 7/12/06, William 'Chip' Lamb <(email redacted)> wrote:
>>>Dear ?,
>>>
>>>Having done my share of vintage sportscar racing and plenty of time with
>>>Jaguars and inboard rear brakes on the rear I am very familiar with the
>>>concept of reducing unsprung weight.
>>
>>Good deal - the original message just mentioned handling and looks so
>>I wanted to throw this out there.
>>
>>>I am also looking for something which will allow for a little less sidewall
>>>flex and a little better contact patch. My assumption based on Mazda's move
>>>to 16s and 17s in the latter years of the NB and further having driven a
>>>few of them is that they were looking for it, too.
>>
>>I assume that Mazda's decision to move to 16 and 17" wheels was more
>>due to customer perception of sportiness rather than any performance
>>improvement.
>>
>>1999 10AE - 2000 SE - 15" @ 13.1lb
>>2001-2003 alloy - 16" @ 15.5lb
>>2002 SE - 16" @ 18lb
>>2003 SE - 16" @ 16.2lb
>>
>>miata.net/faq/wheel_weights.html
>>
>>I'd rather have a 13 lb 15" wheel than an 16lb 16" wheel.
>>
>>The aftermarket, however, can surely help out, but I bet those 12lb
>>16" wheels are pricey.
>>
>>
>>
>>--
>>"Don't sweat it -- it's not real life. It's only ones and zeroes."
>>-- spaf (1988)
>
>_________________________________
>Cheers-
>
>William "Chip" Lamb
>West of Sweden SAAB
>Richmond, VA.
>wmsbrg.com/sweden/
>__________________________________
>
>_______________________________________________
>Miata mailing list
>(email redacted)
>ftl.realbig.com/mailman/listinfo/miata