Wheel Spacers: The Good, The Bad and the Misinformed (FM Live)

This week on FM Live, Mike discusses pros, cons and common misconceptions about wheel spacers! What is safe? What isn't? When should you use them? We give you the basics, and tackle some of the common misinformation about wheel spacers for your Miata.
FM 4x100 3mm Wheel Spacers
www.flyinmiata.com/default/3m...
FM 4x100 5mm Wheel Spacers
www.flyinmiata.com/default/5m...
FM 4x100 10mm Wheel Spacers
www.flyinmiata.com/default/10...
FM 5x114.3 3mm Wheel Spacers
www.flyinmiata.com/default/3m...
FM 5x114.3 5mm Wheel Spacers
www.flyinmiata.com/default/5m...
ARP Extended Wheel Studs
www.flyinmiata.com/default/ar...
NA/NB Blueprinted Front Wheel hubs
www.flyinmiata.com/default/na...
Original LIVE recording 8-12-21. Join us every Thursday at 2:00 PM Mountain Time for new Live content! Don't forget to suscbribe to our KZbin channel to see all our Miata content!
Flyin' Miata is the world leader in Miata performance. We offer a wide range of parts for all years of the Mazda MX-5 Miata.
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970-464-5600 • [e-mail]

[@OudPatrick]

Not a Miata owner, but love these technical video's on how stuff works and affects the car and it's components.

[@danielmendez1788]

*not a miata owner yet

[@flannel2699]

A couple of other things: 1. When adding spacers, you need to make sure enough of the spigot (the male hub centre that fits on to the centre bore of the wheels) makes sufficient contact with the wheel itself. The spigot locates the wheel keeping it perfectly centred while tightening the lug nuts. I would want at least a couple of mm, preferably 3 or 4 or more mm to account for any wear/damage to the wheel centre bore. 2. Scrub radius won't affect grip. Increasing a (for example) 10mm positive scrub radius by another 10mm doubles the torque arm length (about the steering axis). This doubles any force at the contact patch that is felt at the steering wheel. Any given stone or pothole will feel twice as big at the steering wheel. A 20mm spacer will TRIPLE this force. At 30mm you will have 400% of the feedback/kickback the designers intended. I don't actually know the correct scrub radius of any Miata or whether it's pos/neg but any change here will have an effect. Incidentally, if it's 10mm negative, a 20mm spacer will completely reverse the feedback to 10mm positive! This can have a dramatic effect on how the car reacts when braking in to a corner or when a tyre suddenly deflates. Also, increasing or decreasing the overall tyre diameter will affect scrub radius because the steering axis is not parallel to the hub/wheel-mounting face. If the Miata has positive scrub radius (it probably does if based on the Triumph Spitfire and/or Lotus Elan front end) then increasing the o/a tyre dia. will reduce the scrub radius. This is where adding a small (3mm?) spacer could restore the designer's intended scrub radius and consequently restore the original steering feel - something the Miata is famous for. NOTE: all these numbers are just placeholders as I don't have the correct Mazda values but the principles are sound. If you can't get hold of, or are not able to measure the relevant dimensions, you can just experiment with multiple thin spacers until you get it just right. Best of luck..

[@patrickfargie1146]

This answered questions I didn't know I would have, great content as always.

[@MrRacerx13]

How coincidental that you posted this video today. I just ordered a pair of your 10mm spacers today to clear my new Wilwood calipers (already have the ARP extended studs). My 7.5" wide 6UL's hit the calipers.

[@jinbaittai85]

Very informative video, thank you.

[@snowleopardbro2956]

I always look forward for your video

[@aztrorover]

Wholly smokes, this video is worth watching just for the host. He is great!

[@FlyinMiataVideo]

Thanks for the kind words!

[@hebrews11vs5]

Once upon a time I did have a miata. But my goodness was this an informative video on wheel spacers. Regarding that stumper of a question about wheel - rate, I would guess YES. Because if the distance from the spring increases, then that lever arm is longer and thus affecting the wheel rate to some extent.

[@patrickfargie1146]

A video on the engine interals offered by Flyin Miata would be awesome.

[@markfelkey1720]

Good video today..... .how about a video regarding seats and harnesses?

[@jayou1987]

Great video. Just put some 5 mm to get back to oem 45 offset on my camry. It seems the total diameter of the spacer isnt quiiite big enough for the mounting area of my wheels. Seems a couple mm too small for my wheel. Is it ok?

[@DepakoteMeister]

8 turns at 1.5mm thread pitch = 12mm

[@SkootaO]

Hey Mike - if hubcentric spacers are safe (yes, assuming torque/thread/quality dependant) is there any reason why you couldnt change / convert the pcd at the same time?

[@luki9292]

Is it safe to use the wheelspacers if center hub is flat with surface of spacer? I mean, normally the rim is situated on center hub, but when you put spacer for example 5mm in NC then rim will sit only on wheel bolts, center hub is faced with spacer and all forces works on bolts, not on center hub. Is it safe to drive?

[@mrsluigi9478]

I just bought some 20mm and 25mm spacers for looks for my Focus ST and yea, if the spacers were just the circle it wouldn't fit at all. These spacers I got from CJ Pony Parts have an extra set of threads and lugnuts. Thanks for the long list of videos you guys put out, I hope to 1 day buy a new ND2 before they go out of production! Very sad that Mazda is going for an all electric lineup by just 2030 oh no

[@benkerley1014]

More likely as EVs saturate the market more the sales numbers will tell them there's only so many people who want to drive a soulless iPad on wheels. I expect automakers will get less idealistic and start pushing back as the deadline approaches

[@flannel2699]

Another great FM vid. Just one thing.. you'll need 8 (eight) full turns on a 1.5mm pitch nut to reach 12mm of thread engagement. Otherwise, spot on. Thanks..

[@FlyinMiataVideo]

Thanks for the info!

[@flannel2699]

@@FlyinMiataVideo No problem, thanks for all your excellent vids! Do you happen to know the scrub radius for the NC1 ? I want lighter (& better looking but not necessarily much wider) wheels but want to know what I'm starting with before making any changes to the geometry. Basically, I want to make it look/perform better without ruining it. Cheers..

[@jacobmusha7188]

Hey FM - can you put the highlights for these videos in the description or comments? I don't necessarily want to watch a 47 minute video about wheel spacers... It's good to go in depth, but a quick summary would be really useful.

[@FlyinMiataVideo]

Sorry, we cover a wide variety of questions from customers and topics in our Live videos that would be very difficult to condense into the short space for the video description. Feel free to skim through it or ask if you have a particular question.Thanks!

[@Stephen-ww6zl]

watch it at 1.5x speed.

[@KandP69]

@@Stephen-ww6zl nah man, 2x speed or don't even watch it at all haha

[@setra23]

@@FlyinMiataVideo I think what's being asked for is time stamps for the diff topics covered, that way people can find the info' they're after more easily.

[@dumbestoyster]

I usually watch teck like this at 1.5× speed. Can't watch at normal speed now...

[@flyingsloth2606]

Is there a way to run a stage 1 turbo kit for an nb2 miata but with lower boost? i’m not looking to make 200 hp and upgrade the clutch right away. Is it possible to only run a couple psi of boost and keep the stock clutch? sorry for asking an unrelated question to the video.

[@FlyinMiataVideo]

Contact our support department directly. One of our tech's can help talk you through how to adjust the boost and what that means for your power levels and clutch. Call 970-464-5600 8am-5pm M-F Mountain time or drop us an email at [e-mail]. Thanks!

[@charleslewis362]

Need to thread on at least = to the dia of the bolt.

[@garretthegun4982]

Corrects wheel offset differences within the minimum 5mm acceptable tolerance? Typically would longer bolts be needed for a 3mm spacer?

[@FlyinMiataVideo]

For a street car, you shouldn't need any longer studs for a proper hub centric 3mm spacer. If you are racing or tracking the car, a longer study such as the ones we offer from ARP is recommended.

[@philipreeves5465]

Will 22mm wheel spaces fit on a NC 2014 with 17×7 anniversary wheels? Thinking if the oem hub studs may sticking out a little too much for the wheels.

[@FlyinMiataVideo]

@philipreeves5465 Wheel spacers that thick would physically fit the hub, but you would need much longer wheel studs so that the lug nuts have enough thread engagement. However, the stock wheels installed with spacers that thick would likely stick out past the fender lip, so if you're lowered, you will likely have some rubbing issues to solve.

[@sameerpandya1947]

what is the disadvantage (if any) of a spacer over a wheel with an aggressive offset as compared to stock?

[@FlyinMiataVideo]

We always suggest getting the proper wheel size that has the offset and fitment you want before using spacers, but that's not always an option. On a street car, there aren't really any downsides to using a good quality hub centric spacer as long as you have enough thread engagement on your studs. Depending on the size of the spacer and how you use the car, spacers can put extra stress on the wheel studs during hard driving and does add some extra weight (tho minimal) to the hub. For bigger spacers or performance applications, we highly recommend longer/stronger wheel studs. We also have seen some issues with vibration and balancing when using cheap spacers, so be sure to use a hub centric spacer from a high quality manufacturer!

[@Crosscreekone]

To achieve 12mm of engagement on M12x1.5 studs, you need 8 full turns of the lug nuts, not 6.5 (which is only 9.75mm). The rest of the video is dead on.

[@lucianolucidi8624]

I need help!!! How many newton meters torque to install the spacerson on my ND? Helpppp

[@FlyinMiataVideo]

If there is not a recommended torque spec from your spacer manufacturer, we recommend 85 lb-ft for Miatas. This may vary for other cars/applications.

[@charleslewis362]

But don't na/nb center the wheel on the hub? How does the wheel center on the hub when you use these plates?

[@setra23]

Any spacer thicker than the lip on the hub should ideally have it's own lip for the wheel to centre on.

[@haroldpalmer3245]

What are some good quality adapter companies made in USA?

[@FlyinMiataVideo]

Boy! That's a good question. We have wheel spacers but don't offer wheel adapters. You might reach out to your local Miata clubs for that one or post it on Miata.net to see what types of results you get. I had a shop machine (can't remember who) some wide 5 adaptors for my hill climb car and asked them about how much power they could take. He didn't give me an exact HP but stated they have them on pulling trucks in the 2k WHP range and they didn't break. I let him know that they should be OK for my HP goals for the build🤣. Ah, yep. I doubt I'm at 500hp.

[@just.a.simplejoe]

Wanted to ask for the average miata owner but here goes. If an ND owner is running oem wheels 17x7 "not bbs" and wants to run a common 15mm/20mm spacer set up from garageline, will the user need arp bolts/studs or would oem hardware generally be just fine for this common setup??

[@FlyinMiataVideo]

As Mike discusses in the video, thread engagement is critical for safety. In our experience, a standard 15-20mm spacer will not give your lug nuts the necessary thread engagement to provide a safe grip on the wheels, unless the spacers include separate studs embedded in the spacer, in which case the minimal thread engagement still applies to the studs in the thicker spacers. Still have questions? Give us a call or drop us an email and we'll be happy to help!

[@just.a.simplejoe]

@@FlyinMiataVideo That's a perfect explanation and a good reminder to purchase a quality spacer that comes with its own built in studs to keep fitment safe and secure. Thanks FM, really happy you guys continue to push these lecture based videos!

[@willanderson9688]

Im running 20/25 spacers from garageline they have built in studs. ive had no issues with my stock GT wheels

[@imagebuff]

@@willanderson9688 Hi Will... any issues with the spacers or tire wear since your last post?

[@willanderson9688]

@@imagebuff none at all, my alignment is set to FM's recommended specs

[@wadewinston6931]

Where can i do the same to my 370z?

[@fireonmytarget8937]

Some of these thumbnails lmao!

[@Kraziken0]

I take my car to the track. My old rims (which were very expensive) I didn't want to change. My bearings did fail faster.

[@FlyinMiataVideo]

NA/NB wheel bearings are known for short lifespans, especially with frequent track use. While wheel spacers may slightly increase the bearing wear over time (versus a Miata with no spacers), it's unlikely that they directly caused that failure.

[@dkay87]

Shouldn’t it be 4 turns? Since 1.5mm thread x 4 turns = 12 mm @12:40

[@giorgosk2884]

4 turns are 6mm with 1.5mm thread and very litle to support any rim

[@blackrifle6736]

*Retry your math: 8 Turns x 1.5mm thread pitch = 12mm travel distance.*

[@st5rk]

39:55 what's the answer?

[@Fatmonster93]

141 mm in the front 142.7 in the rear

[@st5rk]

@@Fatmonster93 thanks. I'm guessing you mean cm not mm though

[@tommyestridge9301]

Have whoever us reading the questions speak louder, cannot hear the questions.

[@dumbestoyster]

85Lb/ft 😬 not 100😵

[@turdferguson1021]

@Flying Miata....With the 5mm plates you use the lugs to center the wheel or what?

[@FlyinMiataVideo]

Yes. The wheels are always finally located by the lugs, which is why the seats are tapered. Hubcentricity is mostly for convenience while installing.

[@Looo0007]

@@FlyinMiataVideowait, so does that mean those hub-centric centering ring isn't always needed? i was under the assumption that it was ALWAYS needed, especially when changing to aftermarket wheels (which mostly wont have the same bore as the hub)

[@FlyinMiataVideo]

@@Looo0007 They aren't needed if the wheels are lugcentric - if they are hubcentric, rings will be required.

[@Looo0007]

@@FlyinMiataVideo by lug-centric you mean they have conical lugs right? so when it's tightened right (little by little, star pattern, then torque), the hub-centric ring is just there for ease of installation, not critical function, yeah?

[@FlyinMiataVideo]

@@Looo0007 That's exactly correct!