Let’s talk wheels..

[NotagainV2]

well assuming you're an USAA member log in and then do a member benefits search for tires and you'll find the GOodyear link, click that and your discounts will be transparently applied. My set of 305/30/19 3R's was $1100 mounted, when I bought them.

Never used USAA for shopping LOL thanks!

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[SVO MkII]

Hmm. I'm running 19x11 with 305-30/19 with regular springs but with 25mm spacers and no rub

Ditto!

 

[Bridgie]

Apex EC-7 Wheels finally arrived, I managed to get some Toyo RR's, fitted and ready to check all alignment and set-up.
Running 18x11 with 295 squared tires.

Can you ever have too many tires..?

 

[shogun32]

Can you ever have too many tires..?

As @NoVaGT can attest 2 sets on a rack is nothing!! I have 20 tires up on racks and another 30 sitting on the floor in addition to an easy 50 motorcycle tires 120/160. I need to open a damn store! (PS4s, Cup2, PSS, Corsa, pirelli and Mich slicks)

 

[PaddyPrix]

Can you ever have too many tires..?

Hopefully the answer is no, because I've got 4 sets in the spare bedroom, 3 sets in the garage. The bedroom tires are nice because it keeps guests from getting too comfortable and wanting to stay longer, as chances are I'll get another set and ask them to move their belongings so I can drop another set in there.

Good news on the Apex EC-7, hopefully that means I've got mine coming in soon.

 

[bnightstar]

As @NoVaGT can attest 2 sets on a rack is nothing!! I have 20 tires up on racks and another 30 sitting on the floor in addition to an easy 50 motorcycle tires 120/160. I need to open a damn store! (PS4s, Cup2, PSS, Corsa, pirelli and Mich slicks)

I started giving my away let's be honest we are never going to drift this tires why keep them.

 

[sigintel]

Yeah the OP Mustang spacers I use have to be pried off with a screwdriver if your hubs are even a little rusty, at least when they’re new, they’re a perfect fit. Big centering rings for the wheels to seat to as well. I’ve bever heard of anyone reusing a bolt ol spacer without the bolts. You don’t do anything the normal way do you? Should rename your profile “mavrick”

Thru bolt (slip on) Spacers are very common in racing and in tire and suspension development work at OEMs and Tier 1 suppliers.

Former Tier 1 tire engineer here if it helps.
When doing fitment work and scrub radius, etc testing, I used to have a set of various spacers. Nowadays, I just order a couple cheap amazon spacers and force the bolts out using vice leaving me with a decent chunk of aluminum for further machining. Sometimes you get lucky and only need to do a little more work like opening holes.

I have removed bolts from cheap bolt on spacers and opened holes just barely enough to allow use as slip on spacers on long studs. Keep in mind the inner hubcentric happen to be perfectly what I needed and I used 3 wraps of telfon tape on the hubcenter to snug the spacer on perfectly centered (OCD).

I later custom specced some 24mm spacers to get exactly what I wanted. (EC7 18x11). I was running modified front clip on a 2015 at the time.

#0 Never use bolt on spacers. Stud from hub to outer lug nut must be one continuous bolt.
#1 NEVER use any lubricant on clamping surface wheel to hub or wheel/spacer/hub
#2 Use long studs such as ARP or Dorman. I have used 2 different Dorman truck studs successfully including on my own hubs. Installed ARP for others.
Hubs need replacing from road course use and ARP studs prolly not good idea to reuse 3rd time so Dormans end up making more sense.
#3 Clamping force times friction is what holds the assembly together. Studs should NEVER be in shear, always pure tension.

 

[shogun32]

I later custom specced some 24mm spacers to get exactly what I wanted. (EC7 18x11).

designed a custom setup for 15mm or thicker that takes interchangeable centering plugs from 66 up to 76mm. Still costs about $100/pair though.

#3 Clamping force times friction is what holds the assembly together.

So what's the engineering justification for machining pockets in the friction surface? Like OP does to lighten them? That results in a dramatic loss of friction area and can't be good, no?

 

[TeeLew]

designed a custom setup for 15mm or thicker that takes interchangeable centering plugs from 66 up to 76mm. Still costs about $100/pair though.


So what's the engineering justification for machining pockets in the friction surface? Like OP does to lighten them? That results in a dramatic loss of friction area and can't be good, no?

The spacer should pick up the locating ring on the hub & then have a locating ring of its own for the wheel. Once those are in place, though, that leaves the wheel stud as mostly a tension member to clamp the assembly together. There will be the potential for relative rotation between the hub & wheel which friction and the wheel studs (in single shear) should easily accommodate.

 

[Brian@BMVK]

designed a custom setup for 15mm or thicker that takes interchangeable centering plugs from 66 up to 76mm. Still costs about $100/pair though.


So what's the engineering justification for machining pockets in the friction surface? Like OP does to lighten them? That results in a dramatic loss of friction area and can't be good, no?

Just means the contact pressure is higher. Ff = mu*N, with N being the same via the bolt stretch tensile force.

I knocked the studs out of bolt on spacers and have been using those for my slip ons. They work great.

 

[shogun32]

Just means the contact pressure is higher. Ff = mu*N, with N being the same via the bolt stretch tensile force.

I wonder why the aftermarket paints them then which dramatically changes Mu. Seems like a raw brushed or sand-blasted surface would be best for maximizing Mu.

 

[Brian@BMVK]

I wonder why the aftermarket paints them then which dramatically changes Mu. Seems like a raw brushed or sand-blasted surface would be best for maximizing Mu.

They're anodized, which is quite a bit different from painting. In general, maximum friction will come from two surfaces that have similar peaks and valleys.

 

[sigintel]

So what's the engineering justification for machining pockets in the friction surface? Like OP does to lighten them? That results in a dramatic loss of friction area and can't be good, no?

Sounds crazy but... Surface area is not in the friction equation for dimensionally stable surfaces.
dimensionally stable surfaces = no substantial thermal, chemical, dynamic, etc. interactions.

Static Coefficient of friction for aluminum on steel is not a function of surface area as long as the surface area is not reduced to the point that significant deformation or some other dynamic (chemical, thermal, physical dynamics) occurs.

No need to have more aluminum there than necessary.

If you look at the FEA, Ansys, etc, you see the loads/stress is carried at the geometric exterior surfaces, so lower stressed interior material is "dead weight" along for the ride.

You may ask why wider tires can get more grip? dynamics: thermal, physical, chemical, etc.

The spacer should pick up the locating ring on the hub & then have a locating ring of its own for the wheel. Once those are in place, though, that leaves the wheel stud as mostly a tension member to clamp the assembly together. There will be the potential for relative rotation between the hub & wheel which friction and the wheel studs (in single shear) should easily accommodate.

The clamping force and friction removes all potential for relative rotation.
The centering rings on the hub, spacer, and wheel NEVER carry any load to center the wheel once the lugs are tightened. They only serve the purpose of initial assembly alignment and reducing galling of the wheel lug pocket during tightening as the wheel is drawn on center.

Yup, 100% friction transmits rotational and shear loads from one piece of the assembly to the next.
100% of that friction is from pure tension of studs clamping the assembly together.
Nothing else.

NEVER put any lubricant/anti-seize/spit on assembly shear surfaces.
Clean hub and spacer with something that degreases surface:
brake cleaner/acetone/alcohol/soap then followed by clean water and dry.
I prefer having a can of anhydrous isopropyl alcohol for wheel surfaces to avoid damaging paint finishes.

They're anodized, which is quite a bit different from painting. In general, maximum friction will come from two surfaces that have similar peaks and valleys.

Anodizing is a type of metal surface passivation(stabilization from chemical effects and corrosion). Can also make the surface harder and increases its shear strength. In both cases, this reduces dynamics.

 

[Radiation Joe]

Just my opinion, but I won't use anodized spacers. I want raw aluminum to maximize available friction. I've had vibration problems with anodized spacers and didn't using unfinished aluminum spacers on the same car. It's also important to ensure the hub is centered when installing the spacers or the wheels. I've used shims in the past to ensure centering.

 

[thelostotter]

Just my opinion, but I won't use anodized spacers. I want raw aluminum to maximize available friction. I've had vibration problems with anodized spacers and didn't using unfinished aluminum spacers on the same car. It's also important to ensure the hub is centered when installing the spacers or the wheels. I've used shims in the past to ensure centering.

Anodizing wasn't the problem.

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