Wheel offset too much?

[skinnyman]

Just a quick one. 

 

5x112, 17",  7.5j,  et28.

 

Would a wheel with the above dimensions fit based on people's experience?  I know that a few people on here have run larger and wider wheels that fit.  For example an 18" wheel with a width of 8.5 and an et of 40 would stick out  33.1mm further than my standard 17" Zeniths according to Will they fit.  Their calculator says that the 17" wheels I've mentioned would be 32.4mm further out.  I'm thinking that this might be a tad too far. 

 

Any thoughts?  

[brad1.8T]

I've run 8" with 35mm offset on a preFL hatch.

 

Your 7.5" ET28 has 1mm extra poke, so they are essentially the same. ET29 would be the same external poke.

 

The rears will be perfect.  I found the front stuck out about 6mm too much for my taste but it didn't attract the police or cause any clearance issues.

 

This is how they look with stock Elegance spec suspension.  You can see the rears are within the vertical edge of the mudspats but the fronts sit a bit too wide.  Tyres are 225/45r17 Kumho

 

Edited 30 April, 2016 by brad1.8T

[skinnyman]

I found the front stuck out about 6mm too much for my taste but it didn't attract the police or cause any clearance issues.

 

 

Thanks for that.  You've confirmed my suspicions that the rears would fit but that the front's would be too far out. The photo is just what I was looking for as that's pretty much what I'd imagined.

[fatzy]

Please remember that ET28 will move the entire wheel out, assuming both rims are 7.5 inch wide. An 8 inch wide rim with ET35 will also poke inboards due to encreased width. My point is: the centre line of the wheel will be moved, giving increased stress on bearings and the car may start wandering, following road tracks (hope the wordings make sence). It may be more sensitive to crosswinds and inclined road surfaces. Just mentioning possible side effects of big deviations from original.

[VRSerious]

I tried ET35 on my pre fl ocy and they looked god aweful! lasted 4 weeks and sold the wheels

[skinnyman]

Thanks for the advice. If I'm being honest, the potential change is purely for cosmetic reasons and based entirely on my personal issues with wheels that hide within wheel arches.  Every time I look at the car I see a Commer van.

 

As I said, it's my issue and I should really get over it and enjoy the car.  Trouble is I'm looking at it now as I'm typing and I reckon there must be a solution to the wheels been too far into the arch.  I've been thinking of spacers as well.  15mm at the rear and 10mm at the front.

Edited 1 May, 2016 by skinnyman

[willy0329]

if you look in the octavia picture thread around page 30 nick p had a blue vrs with bbs ch wheels if i remember correctly it looked very nice and had all the dimensions posted as well , 

[skinnyman]

Thanks, I'll have a look & see.

[brad1.8T]

Please remember that ET28 will move the entire wheel out, assuming both rims are 7.5 inch wide. An 8 inch wide rim with ET35 will also poke inboards due to encreased width. My point is: the centre line of the wheel will be moved, giving increased stress on bearings and the car may start wandering, following road tracks (hope the wordings make sence). It may be more sensitive to crosswinds and inclined road surfaces. Just mentioning possible side effects of big deviations from original.

Totally right.

My steering never felt 100% with 17x8 ET35 - the turn-in and in-corner stabilty was a fraction wrong.  I probably could have dialled it out with some tweaking of the alignment settings but couldn't be bothered at the time.  My ideal offset for 17x8 would be ET45.

 

For 17x7.5 I'd go with ET35.

 

Both are more offset than factory but they would be the happy medium.

[SNH]

I run 8.5 x 18 et25 on my pre flight

[SNH]

Please remember that ET28 will move the entire wheel out, assuming both rims are 7.5 inch wide. An 8 inch wide rim with ET35 will also poke inboards due to encreased width. My point is: the centre line of the wheel will be moved, giving increased stress on bearings and the car may start wandering, following road tracks (hope the wordings make sence). It may be more sensitive to crosswinds and inclined road surfaces. Just mentioning possible side effects of big deviations from original.

Never heard such waffle!

Bigger wider wheels will always tramline a bit more but that's it.

My vrs has run its silly et wheels for 2 years or more, still on the same bearings and if anything it handles better.

[skinnyman]

My vrs has run its silly et wheels for 2 years or more, still on the same bearings and if anything it handles better.

 

I ran 19" 8j wheels on my last car and they were fine too so I'm not that worried about a low et.  What I don't want is them to come too far out & rub when we're fully loaded on holiday or a trip to the tip.

 

I'm also realising that there's a limited choice in 17" rims whereas there are plenty to choose from in 18". 

[brad1.8T]

Never heard such waffle!

Bigger wider wheels will always tramline a bit more but that's it.

My vrs has run its silly et wheels for 2 years or more, still on the same bearings and if anything it handles better.

The guy was right in what he said.  If you wish to ignore it, that's your prerogative but please don't denigrate good advice.

[SNH]

The guy was right in what he said.  If you wish to ignore it, that's your prerogative but please don't denigrate good advice.

No one is ignoring anything I'm going from experience!

I agree with the wandering but any bigger/wider wheels will tramline no matter what the et.

I was referring to crosswinds and handling etc.

[fatzy]

No one is ignoring anything I'm going from experience!

I agree with the wandering but any bigger/wider wheels will tramline no matter what the et.

I was referring to crosswinds and handling etc.

Well, I wanted to highlight any possible negative side effects. I did not mention handling specifically, but never mind. Better handling will be the overall feeling when increasing the wheel tread and wider tyres, wider foot path. You can improve the look and at the same time enhance the handling in your neck of woods. Of course, nothing beats experience.

Skoda has engineered the suspension geometry to suit everyone in their daily driving, with a balance of safety, comfort, handling and other characteristics. There is a lot of technical decisions taken: camber/caster/toe in-out/king pin and more angles and more advanced geometry to achieve this. I couldn't find the spec's for Octavia. Most probably there will be several, depending of version, motorisation and possibly markets.

There is also something called scrub radius in the geometry. This will be affected by the offset of the wheels. I don't know how much technical info to write, it may be too "nerdy".

But, as always small changes may be good, big deviations can be over the top. If you mess around on your own with odd offsets you may end up with zero scrub radius, called "center point steering". Then you may experience little road feel or feedback and directional stability. Not to mention what behaviour to expect if you press to the limits, in emergency situations, high speed driving over humps when cornering, etc.

Edited 3 May, 2016 by fatzy

[fatzy]

[quote name="fatzy" post="4608903"

But, as always small changes may be good, big deviations can be over the top. If you mess around on your own with odd offsets you may end up with zero scrub radius, called "center point steering". Then you may experience little road feel or feedback and directional stability. Not to mention what behaviour to expect if you press to the limits, in emergency situations, high speed driving over humps when cornering, etc.

Sorry, I just realized a misprint which couldn't be edited. It should say:

But, as always small changes may be good, big deviations can be over the top. If you mess around on your own with odd offsets you may end up with zero scrub radius, called "center point steering". Then you may experience little road feel or feedback and directional INstability. Not to mention what behaviour to expect if you press to the limits, in emergency situations, high speed driving over humps when cornering, etc.

[skinnyman]

I agree that all of the above is worth considering when straying from the factory settings.  I'm still considering what to do at the moment but I'll have a read up on scrub radius as I've never encountered the phrase before.

[fatzy]

I agree that all of the above is worth considering when straying from the factory settings. I'm still considering what to do at the moment but I'll have a read up on scrub radius as I've never encountered the phrase before.

I think the best way to get a good look, and not mess up too much will be to fit wider rims with an ET which is slightly lower.

As an example, assuming the original rim is 7" and ET45 (the approval dimensions):

8" wide rims with ET38. Much of the widening from original will poke outboard, but some will poke inboard, which is important for the balance. You will have 2 centimeter less clearance to the side of the car, and 6 mm less clearance to the suspension strut. If you use the 225/45R17 tyre in both, this is a deviation is acceptable within reasonable limits. The driving characteristics will be different, but not mess up your car. It will also be legal in my country, which has a lot of specific regulations. They may seem strickt, but are made for a reason.

Most probably you can lower the car (within reasonable limits) with this combo, assumingly without rubbing anywhere even at full lock and/or full suspension. I cannot say this for sure, I haven't studied that.

Decisions-decisions-decisions..... Good luck!

Edited 5 May, 2016 by fatzy

[skinnyman]

I'm on the look out for some suitable wheels at the moment but will live with the originals 'till the perfect set turn up.  I'll see if there are any wheels with the measurements you mentioned too.