People with fitment experience wanted: how do I minimise rubbing risk and why isn't suspension travel considered?

[RedCloud]

see question at bottom to avoid the rambling...

i worked out what combinations of width and offset i can put on my 2009 honda accord (european market) which will fit in the wheel arch. i noticed that the offset required to maintain the outbound position as close as possible to stock (to maintain distance between outbound wheel position and inner wheel arch) is extremely hard to do without stock wheel specs. this is because the offsets required are values ive never seen on the market.

why do i want this fitment? because i want to minimise rubbing risk. when i say rubbing risk, i am not only talking about rubbing horizontally (e.i. rubbing the side of the tyre) but also vertical rubbing (e.i. rubbing the top of the tyre on suspension compression.)

please see below my calculated list:
all measurement are of front from the part of the wheel which sticks out the most (which happens to be the middle of the tyre wall, as expected), can provide rear wheel measurements if useful.

• 7.5J ET55 (stock: 10 mm outbound (between outbound tyre and inner wheel arch), 30 mm inbound (between inbound tyre and closest object when on full lock which was wish bone)
• 8J ET60 (+1.65 mm outbound, -1.65mm inbound)
• 8.5J ET65 (+2.7 mm outbound, -2.7mm inbound)
• 8.5J ET70 (-2.3 mm outbound, +2.3mm inbound)

as you can see, fitment ranges from 55 to 70. i have not personally seen this on the market but maybe im not looking hard enough. either way, i am beginning to think that i am going to need to go flush or beyond the wheel arch if i am going to get any after market wheels. so that brings me onto my current concern...

if my tyre is flush with the wheel arch, i measured that my suspension travel goes from 100 mm (stock) to only 45 mm. for some reason, i dont see people considering suspension travel when deciding fitment. i find this to be a problem because if i am going through a pot hole, i dont want to have the anxiety that i am gonna blow my wheel through my wheel arch. id like to be ***ured that even if i am on full lock with full suspension compression, i am not gonna rub. (maybe this isn't achievable, even with stock fitment due to the low probability of it happening.)

my main question, plain and simple: why isn't suspension travel talked about when deciding wheel fitment?

my other question, obscured and complex: what is the range of rim and tyre specs that fit without rubbing (with stock suspension)?

apologies if this was hard to digest, i did my best. any help is appreciated <3

 

[btjtaylor]

I sent you a PM about my setup already but i'm running FN2 wheels, which are 7.5Jx18 ET55

Eibach spacers 20mm in the rear and 15mm at the front

I have accord factory spec size tyres fitted so that the spare wheel matches up etc - 225/45R18

www.willtheyfit.com is a really good site to work out your fitment if you've not seen it - it does consider suspension components somewhat but I guess the main issue there is that every spring/shock setup is slightly different, more/less load in the car, etc, it's very hard to work out. If you have coilovers and get it roughly right you can at least raise the car slightly if you have a problem.

I rolled my rear arches (badly, with a hammer) as they are basically a right angle and I was worried about destroying expensive tyres but I don't think it was necessary unless you are going very low/very aggressive offset

I would like to get some more fancy wheels at some point, I'm happy with the fitment but to improve the look and get rid of the spacers - 18x8.5 ET35 looks like it could work, maybe with a 235/40 tyre. Got other bits to get too first, like getting an exhaust (been waiting for that since april...) and getting the car mapped finally. As much as i'd love some very expensive JDM wheels, I think something like Rota Torques would be more in budget..

 

[RedCloud]

that will they fit website is amazing. i have been trying to figure out how to do those calculations myself but having a tool which does the calculations and visualises them is amazing.

i spoke to konig about suspension and they say not to for far beyond 8.5J as you are at high risk of rubbing at that point. see my conversation with them.

interesting to hear about the rolled wheel arches. i think i will try going over some test speed bumps to measure the severity of rubbing.

i agree, your fitment is amazing. i love the wheels too but theres always space to improve.

thanks again.

 

[Trawa]

+20mm up front may or may not rub at stock height, should be fine lowered as the suspension cambers in. I had 225s in this pic but the sidewall ended up surprisingly stretched.

 

[Crxpaul]

I often find that tyres of the ‘same’ size in different brands vary considerably. For instance, my toyos in 195 on my crx were skinny compared to the Yokohamas on it now yet they are supposed to be the same size.

The other thing that I always find surprising is that not many people realise the 45/50/55 etc is actually a percentage of the width of the tyre, not a mm measurement! So a 225/50/17 is not going to be the same depth as a 215/50/17.

 

[RedCloud]

+20mm up front may or may not rub at stock height, should be fine lowered as the suspension cambers in. I had 225s in this pic but the sidewall ended up surprisingly stretched.

View attachment 987

Ah great photo illustrating the fact.

And yeah, the fact that wheels increase camber as they go up in suspension travel somehow completely went over my head.

I'm planning on picking up some 8.5Jx19 ET45 which is an extra ~23mm out. Let's hope that works!

 

[RedCloud]

I often find that tyres of the ‘same’ size in different brands vary considerably. For instance, my toyos in 195 on my crx were skinny compared to the Yokohamas on it now yet they are supposed to be the same size.

The other thing that I always find surprising is that not many people realise the 45/50/55 etc is actually a percentage of the width of the tyre, not a mm measurement! So a 225/50/17 is not going to be the same depth as a 215/50/17.

Oh that's odd... You'd expect something as safety critical as tyres to have some stricter standards.

And I fell for the same mistake on tyre specs too! Thought it was mm but is actually % of width.

 

[Trawa]

I would like to get some more fancy wheels at some point, I'm happy with the fitment but to improve the look and get rid of the spacers - 18x8.5 ET35 looks like it could work, maybe with a 235/40 tyre.

Friend runs 235/45/8J with +37.5 offset on his CW3 and has about 3mm clearance to the fender lip in the rear. Doesn't rub even with a fully loaded boot but it's very close. 8.5j +35 will most likely require rolling/cutting the lip but should fit fine within the arch.

 

[RedCloud]

Friend runs 235/45/8J with +37.5 offset on his CW3 and has about 3mm clearance to the fender lip in the rear. Doesn't rub even with a fully loaded boot but it's very close. 8.5j +35 will most likely require rolling/cutting the lip but should fit fine within the arch.

Ah awesome thanks for the info! If the guy responds, I'll give an update on if these fit.

 

[RedCloud]

Update: I have 18x8.5J ET40 and I'd say that they have the perfect poke. No rubbing with OEM suspension and 245/40/18 tyres. We'll see what happens when she's lowered. FYI: attached is someone else's car but same wheels.

Apologies for the small images. I think there's a 250KB limit.

 

[btjtaylor]

Update: I have 18x8.5J ET40 and I'd say that they have the perfect poke. No rubbing with OEM suspension and 245/40/18 tyres. We'll see what happens when she's lowered. FYI: attached is someone else's car but same wheels.

Apologies for the small images. I think there's a 250KB limit.

Looks good

I am running Weds SA-72R 18x8.5J ET35 now without problems. 235/40 tyres that came on the rims.

I'd say if a really flush fitment is a priority the rear could probably come out maybe 10mm on a spacer (with arches rolled). But I wanted to go for a square setup as i've always understood this to be better for handling on a FWD car (or even slightly bigger up front for traction)

 

[RedCloud]

Looks good

I am running Weds SA-72R 18x8.5J ET35 now without problems. 235/40 tyres that came on the rims.

I'd say if a really flush fitment is a priority the rear could probably come out maybe 10mm on a spacer (with arches rolled). But I wanted to go for a square setup as i've always understood this to be better for handling on a FWD car (or even slightly bigger up front for traction)

Looks beautiful.

I agree with your point about staggered Vs square setup.