15" vs 16"

[BoyzToyz]

Just wondered what the advantages/disadvantages are of having 15" front wheels replaced by 16" front wheels...apart from being able to fit the higher speed rated tyres...

Is there any difference in handling? Is it more 'planted'?

Thanks

[Roberto Rica]

Hi

You can fit upgraded brakes too - 300mm plus. I changed last year and can say it works very well - if anything the steering feels a bit lighter - don't know why. Looks better too IMO.

Rob

[GreenV8S]

Depends what size you fit. If you simply fit the 16x7.5 rims on the front, you will end up increasing the tyre width and offset. Both of these effects will increase the tendency to tramline and kickback, slightly. Fitting wider tyres on the front will also mean the front end is more sensitive to steering input (increased front wheel yaw response and lateral stiffness) but the tyre will produce less self-aligning torque (steering 'feel') and the grip will fall off sooner and more abruptly as you reach the limit of grip. Having stiffer tyres on the front will also reduce the high speed stability.

All these effects are relatively small if you're only moving from 15" to 16", but cumulatively they can be noticeable. Whether this is enough to be a problem will depend on your suspension setup, tyre pressures, what sort of roads you drive on, and your preferences as a driver. For most people it's unlikely to be a problem.

How about borrowing a pair of the wheels/tyres you plan to fit and see whether you find it acceptable?

[Roberto Rica]

Hi

I don't think the rim/tyre widths or offset are problems at all - from a previous thread on spacers I think it was shown that the extra rim width (12.5mm/2 = 6.25mm) just about cancelled out the different offset (32mm-25mm = 7mm) - very convenient - and the standard front tyre widths of 225 (pas) or 205 (non-pas) are plenty wide enough for a 7.5 rim in fact more suited than a 245 or wider.

I was pleasantly surprised when I made the change from 15in to 16in fronts - absolutely no discernable side effects.

Rob

Edited by Roberto Rica on Saturday 10th March 13:21

[Chauch]

I see you are Northants, I am only Cambs and have a set of the 16" in the garage if you want to borrow them for a while?

[meatball]

As Robert said ive had no problem or noticed any differences apart from how it looks
16" fronts with 205/45/16 Bridgestone S02 tyres

[GreenV8S]

Roberto Rica said:

I made the change from 15in to 16in fronts - absolutely no discernable side effects.

I run 16x7.5 225 all round, and I found the change to 225 on the front did make a significant difference to the handling and feel at the limit. In normal pootling it just feels very slightly heavier and you would soon get used to it.

[victormeldrew]

meatball said:

As Robert said ive had no problem or noticed any differences apart from how it looks
16" fronts with 205/45/16 Bridgestone S02 tyres

I wouldn't be worried about how the wheels look, more about how all the houses round your way are falling over!

[Roberto Rica]

Hi

I've got 245/45ZR16s on the rear and 225/45ZR16s on the front - same as the last SE griffiths. Work very well and maintains the rear rolling circumference - so speedo unaffected.

Rob

[That Daddy]

BoyzToyz,i use 16"x7.5 rims all round with 205/50 front 225/50 rear cant say i noticed much change on the handling,but the front tyres were on the wear limit when purchased and i was getting familar with the handling,looks better though.

[nig-gtv]

victormeldrew said:

meatball said:

As Robert said ive had no problem or noticed any differences apart from how it looks
16" fronts with 205/45/16 Bridgestone S02 tyres

I wouldn't be worried about how the wheels look, more about how all the houses round your way are falling over!

Also looks like a rare spec Chim with only a passenger seat!

I read somewhere that you need steering rack stops to prevent the wider wheels fouling - is this right?

Edited by nig-gtv on Sunday 11th March 08:20

[meatball]

nig-gtv said:

victormeldrew said:

meatball said:

As Robert said ive had no problem or noticed any differences apart from how it looks
16" fronts with 205/45/16 Bridgestone S02 tyres

I wouldn't be worried about how the wheels look, more about how all the houses round your way are falling over!

Also looks like a rare spec Chim with only a passenger seat!

I read somewhere that you need steering rack stops to prevent the wider wheels fouling - is this right?

Edited by nig-gtv on Sunday 11th March 08:20

I didnt need rack stops with the 205`S
Ooowww you bitch`s making fun of my poor photography. i`ll wait till ive got the sun setting in the back ground next time

[Red V8]

Why did TVR put smaller wheels on the front in the first place... I always thought it was to help handling, cornering etc?

[The AJP Griff]

Red V8 said:

Why did TVR put smaller wheels on the front in the first place... I always thought it was to help handling, cornering etc?

I'd love to know the answer to this as well

[GreenV8S]

Red V8 said:

Why did TVR put smaller wheels on the front in the first place... I always thought it was to help handling, cornering etc?

it helps achieve the right balance accelerating out of corners, also improves the high speed stability.

[Roberto Rica]

Knowing how TVR worked they were probably required by the wheel supplier to take two sizes, similar situation with the Spider supplier - they were required to take 16s and 18s.

Rob

[victormeldrew]

GreenV8S said:

Red V8 said:

Why did TVR put smaller wheels on the front in the first place... I always thought it was to help handling, cornering etc?

it helps achieve the right balance accelerating out of corners, also improves the high speed stability.

Why, when the rolling radius of a 16" wheel with a lower profile tyre is the same?

[pies]

Roberto Rica said:

Knowing how TVR worked they were probably required by the wheel supplier to take two sizes, similar situation with the Spider supplier - they were required to take 16s and 18s.

Rob

Nah they probably had a load of 15" wheels left over from making the S and needed to get rid

[lwt]

From my experience, if you fit 16" wheels with standard brakes, the inner wheel rim may just touch the lower wishbone on full lock. Since you don't want to damage the wheel or the wishbone (or fail the MoT), the simple solution is to add 3mm spacers. These are available from Demon Tweeks or RallyDesign for less than a tenner a pair. There is no need to change the studs for longer ones. When you fit a brake upgrade, the centre 'bell' will probably be thick enough to do away with the spacers (it was on my Wilwoods). Hope this helps,

Ian.

[GreenV8S]

victormeldrew said:

GreenV8S said:

Red V8 said:

Why did TVR put smaller wheels on the front in the first place... I always thought it was to help handling, cornering etc?

it helps achieve the right balance accelerating out of corners, also improves the high speed stability.

Why, when the rolling radius of a 16" wheel with a lower profile tyre is the same?

It has a wider contact patch and greater lateral stiffness.