Now, here is the thing:
1. I watched a super nerd on suspensions on Youtube. I watched all of his videos.
2. I doubted that 45 offset is close to 54 offset.
3. Mini has 205/45 R17, 54et on their OEM wheels.
4. The guy noted quickly, deep within one of his videos, that anything more than a 2-3 mm change in offset would be detrimental to suspension geometry.
5. Fitment Industries, a bunch of nice folks who know a lot about wheels, they said something that made me confused. I asked what they meant, and they repeated it. Still confused. they said that although almost every F56 JCW aftermarket wheel is a 45mm offset, they will fit fine and be great even though OEM is 54. they said that OEM's do or measure it differently? Construct their wheels differently?
6. the Neuspeed RSe05 has a version that is 17" 7.5 et 40, and 17" 8 et 45 --- I really wish they had a 17" 7.5 et 45, right???

my goal is to not deviate from the center hub-wheel bearing more than a couple of mm, or be 0 stock. I don't understand what Fitment Industries is saying about the issue of OEM and aftermarket measuring and construction. I do know that no one one earth makes a wheel that is CONVEX aside from Mini for their JCW hardtop. Really dumb.

I dont know why they made 205/45 r17 et 45mm with a convex front. However, it tucks in really well, which is very nice. Do i just get a 2nd oem set? Arent they 24 lbs each?

Forged or flow formed gets it down to 17 lbs or less. That's huge. imagine 7.x lbs less per unsprung and rotational mass??? however, I also want to keep equivalent geometry and contact patch-to-bearing alignment. sucks?

 

I ended up going with Motegi Traklites, which look like they would clear the JCW brakes. They're similar offset to the Neuspeed wheels though.

 

Nothing wrong with moving the wheel centerline with different wheels. Handling may be slightly effected, but unless you’re hyper sensitive, you’ll likely not notice. The effected parameter is “scrub radius”. A drastic difference in wheel offset will increase torque steer, but usually when you start moving the offset by 20+ millimeters from OEM.

 

The Neuspeed most recommended wheel, which is also the nicest wheel, and the lightest wheel, is +40 offset. That means it is 14 mm off. That's kind of a lot. Handling is not the issue so much. Impacts, bearing degradation, and also that loss of the "king line" intersecting. According the ultimate suspension geek, more than 2-3 mm would impact everything.

shrug?

I keep hearing that a change in wheel width from 7 to 7 1/2" is not an issue if the Offset is the same. I guess that makes sense? But is not that face of wheel no longer in the same spot? has not it moved 0.25" over (half inch i would assume is split in half-ish on a half inch larger wheel either side?)

 

If you're that worried about it, just buy another set of OEM wheels. I've never seen any aftermarket wheels that are exactly the same as the OEM wheels.

 

At least one of the Mini JCW race teams runs Neuspeed wheels…. They must not be that bad for the car…

http://www.lapmotorsportsllc.com/teams/mini-jcw-team

 

I test fitted a few 18x8 45et O.Z. wheels, all had pretty much the same backspacing as my OEM wheel, which was surprising given that the math doesn't agree.
Before committing to any wheel, I ran 10mm spacers on the OEM wheels to see if it felt any different on the road. Difference is there but not enough to keep me from buying aftermarkets.
Nuespeed used to make an 18x7.5 45et wheel, to my knowledge, they discontinued that size and updated it to 18x8 45et,
The OEM 205/45/17 tire is smaller and lighter than 4 other tires I tested that were the same size. OEM is for certain more fuel efficient. That OEM tire also has a tapered profile and clears the strut better too,
I doubt you will find aftermarkets in the OEM size/offset outside of being custom built.
I'm running O.Z. Ultraleggerra's with 215/40/18 at 5 lbs less per wheel. Again surprisingly, the weight reduction isn't that noticeable.

 

hey! notice on the rear, under the car, it has a control arm knuckle showing up? I believe it is a control arm part. If I am seeing that correctly, that is how they got away with a wider stance, they dropped the arm down closer to the ground to maintain the "king line" and its angle. One is supposed to do that to make the intersection of all the geometric parts line up above the roadway, at the contact patch. If you lower the car, you drop the suspension below the earth, the same thing happens if you bring out the suspension, outside of the car, that also makes it go into the netherworld. Now, I am certain they easily could futz with it to get those geometric lines going in the right direction and interesection . The more I learn about it, the easier i notice it is to line up a suspension. It just is another thing to have the parts to do it.

 

Well darn. Ok. So, the backspacing is the same. That hurts my brain. the wheel got wider. an inch wider. The offset got smaller in number. That would mean the face of the bolt hole plate, inner face, moved out twice, right? Yet the centerline is the same?? Wtf?

 

At Neuspeed, i spoke with an Engineer named Jerry. Jerry is like the nicest guy possible.
1. None of the BMW cars have dialed-in suspension geometry.
2. A GP3 and a JCW have the same suspension geometry so long as you maintain the strut/coil-over suspension length.
3. An M version x1, a JCW countryman, a regular x1 wagon, a regular countrman, all of them have the exact same suspension parts and lengths and attachments. The M versions that fit on that platform have "flared fender things, wider wheels", but the same exact suspension measurements, same distances and angles to the control arm.
4. He agreed that it is a complete mystery what the optimal scrub radius and King line is on BMW wheels.
5. (direct quote is fairly close here) He said one could measure it, but the impact of having "more rubber, with a small increase in tire width, with a wider track and the huge difference in wheel weight, [should have a positive impact on safety around turns in the country]."
6. the concern about the wheel bearing being more easily damaged if the offset is reduced: It is true that you are putting more leverage on it. However, the salt on your road will kill it much faster, and the impact the suspension is dealing with will be assisted by more tire rubber and a much much lighter wheel.
7. Jerry said that no aftermarket wheel is stronger and safer than the OEM wheels. He explained that "maybe a forged" would be similar, but stronger? He had his doubts. Anything other than forged, he notes that it just is "impossible" that they would be stronger. That's an honest claim. He said though that for enthusiasts, the benefits of lightweight, purposeful wheels simply outweigh the bonus of OEM wheels. He noted that if youre a person who never looks for potholes and doesnt car how they drive, the OEM JCW wheels are the way to go.

Jerry, since 1981 (!!!!) built little german and japanese racers. He also is the guy that designs and supplies the race team for Mini, I think someone here noted that Neuspeed does that. He is a really really talkative guy He invited me to call again for other questions. He even thought for a while of any other aftermarket that would be a closer offset + narrow wheel. He could not think of anything. I didnt even ask that (i wouldnt want to be rude to do so), but he just chatted and thought about it. He said that initially they wanted to make the RSe05 17" JCW one 42 or 43 offset, but then when they brought it to tracking people, they noted that there are bigger than OEM JCW brembo brakes out there, so they bumped it a few mm extra for that.

I learned so much, i cannot even mention it here. One thing for certain is the BMW does not dial in their suspensions in consideration of their wheel choices. He said the wheel choices are more for hitting specs in Japan where they demand tucked in wheels to be certified. I wonder what the actual measurements are for the King line, the scrub radius, and the control arm settings. I asked him if anyone on the racing team adds a lowering knuckle when they lower things or go to 37mm offset 8 inch wheels. he says they do not bother to. So 40mm and 7.5 is fine.

I thank you all for your assistance. We were both correct. BMW/Mini is incorrect. Neuspeed is 100% the way to go if you like their design.

*he recommended on the JCW: RSe05 17" 40mm et using 215/45 R17". He said that it gives a little inner tire patch coverage, and it gives outer more by a notable amount. Jerry explained that on a sharp turn on a country road, the weight of the vehicle is very much outside of the suspension. he said that the tire being a little narrow will buckle, and also being that it is pinched into the body, it will roll a little which is not as safe. We need Jerry on this forum lol. He is adorable + super smart + super friendly.

Jerry for 2024!

 

Hey, folks

I just got a 2024 JCW F57, and definitely want to widen the track width a little. I made some mock-up photos in my computer, and the look I like has the outer edge of the tires 17mm further out than stock. That would likely be too much of a change in the scrub radius, but I’d like to get as close as “safely” possible.
Note: I’m not tracking the car, and I don’t intend to drive so fast that I end up in jail. I just want a sporty GT for around town. My main concern is how the car looks.

225mm tires are too tall, especially as I might want to also lower the car at some point. So it’s 215’s with wider wheels, and / or spacers.

Also, El_Jefe’s excellent info above gives me some hope.

Thousands of people are daily-driving on Minis with significantly wider wheels, so it can’t be the dangerous, hard to handle nightmare some people claim. At the same time, if you take a negative scrub radius to neutral, or even slightly positive, that’s a REALLY bad thing.

What I want to find out is how much adjustment is available on Gen3 Minis to compensate for the changes. (Supposedly, McPherson struts are more immune to scrub radius changes than other types of suspension, so that’s a good start.) There are also a few aftermarket suspension pieces that allow for additional suspension geometry adjustments. For instance:
Adjustable Control Arms, Powerflex caster Offset bushings, Powerflex front camber adjustment Bushings, the Eibach Camber Align Kit, etc.

However, I have no idea if the scrub radius can be altered. I sort of doubt it.
And there are additional complications if you also lower the car. - And yet, again, lots of folks have done this with no serious issues, so what does that mean?

I’ve tried to find a modification shop in the USA that actually knows about this stuff, but they don’t seem to exist. (In the UK, there seems to be one on every block.) So …….
================================================== ==================================

I currently have the stock 17x7.0 Track Spoke, JCW version. It’s a decent wheel, but I just don’t love how it looks. Plus some aftermarket wheels are a little bit lighter, though that may not make any discernible difference.

I want to stay with a 17” diameter wheel, both for comfort and because I might want to slightly lower the car in the future.
I’m pretty sure I want to use 215mm tires, both to get that little extra width and because more air = more comfort.
So the first question is:

Stay with 17x7.0 wheels and add spacers, or use 17x7.5 or 17x8.0 wheels?
The change in scrub radius (for a given trackwidth change) would be the same, either way, and I don’t think you notice very much how far IN the tires go.
17x7.0” with spacers results in lighter weight and less rolling resistance. - But I think going 17x7.5” might be slightly better, as I can then use 215mm tires while maintaining the best sidewall tightness. 17x8.0 looks the best (Shown on the Fitment Industries site) and would make the 215mm tires even stiffer, but that adds more weight, so I dunno….

This is a very tough decision, and I’d welcome any thoughts on this.
————————————————

As for wheel choices, I’d of course like to go with as light as possible. And I’m not tracking the car, so super-durable BSS forged types ($$$) are not a requirement.

Neu RSe05 17x7.5 ET 40 & ET 45 is supposedly 16.5 lbs, but listed at 18 on Mini Mania. Decent looking, inexpensive, and popular.

Oddly, Mini Mania recommends the +40 version for Mini JCW’s, but my own diagrams show that the +45 version still puts the inside edge of the wheels 4mm further out from the chassis, compare to the stock JCW wheel. - Maybe the spokes don’t curve enough, so you need that +40?
- Or maybe Mini Mania is just playing it safe, and not caring about the difference in offset?

Advan TC-4 17x7.5 is 16.5 lbs (unverified, but I think this is correct.) - This is my current choice.
The +43 version is said to clear the JCW calipers.

Enkei TFR 17x8.0 is 18 lbs. Not horrible, looks similar to these others, and Fitment Industries says it fits the JCW.
- BUT THE BORE IS 72.6 ! Hub-centric adapters may be available, but that kind of scares me. Also, the offset is +40, which is starting to get scary.

If a larger bore can really be made to work, then the last wheel I’d consider (and I really like the look) is the
Enkei RPF1. The 17x7.5 is super light at 15.2 lbs, and they aren’t even expensive.
— but they only come in +48, which might not fit. - DOES ANYONE KNOW?
And sadly, they don’t offer a 17x8.0 in a 5x112 bolt pattern.
================================================== =======================================


# FINAL NOTE: I've read that, because of changes in handling:
Some insurance companies will not pay out on an accident involving a car that has after market wheels.
I haven’t checked with mine yet, but it's something to consider.

 

Don't forget to call each manufacturer for confirmation (in writing) as the JCW brake is a difficult fit. As previously mentioned, I went thru this process.
Check the Marketplace, there was a member selling Volk racing wheels in 17x7.5 Maybe 40 offset that appear to clear the JCW caliper.
Good Luck!

 

Well.

since my last post on this, I do understand why Neuspeed engineer does not care about the +40. He said that he wanted to do a +45, but the people at tracks complained about their EVEN BIGGER brake kits not fitting.

I realized a very important fact: Track use is wimpy.
Things that you do not encounter on a track:
1. Emergency Braking
2. Pot-holes
3. Ice and Rain
4. Unknown turns - driving someplace not repetitive
5. Blind turns - country driving

Track use only needs faster wheel spin up and slow down, and a wider track on extreme twists allow for the rubber of the tires to not flex and cave so much under intense load.

It should be noted that such traction is a track tire, not a Pilot 4 etc. You wont bend under and push to the limit your summer performance tires. No more than 8/10ths as they say.

The 54 Offset of a JCW wheel is a mysterious thing for this reason:
A) what is the scrub radius???
the offset is meaningless for us if we do not know the scrub radius.
B) almost all real track people use rear wheel drive. I have a Porsche 718. It is amazing due to being light and rear wheel drive and mid engine. None of that applies to a Min aside from it being very lightweight.
B2) A RWD car has a POSITIVE SCRUB radius.
B3) A FWD car has a Negative scrub radius.

For the next part, we will make a guess that the Scrub radius is 10 mm of Negative scrub. That means that the King axis makes a tiny X when it goes through the contact patch. This makes for let's say a -10 scrub radius. FWD cars have a negative scrub radius. This is more important than a RWD car having proper scrub radii. The RWD car has little safety concerns in the front as much as a FWD car which is doing almost everything up there. The space of say 5-15 mm of positive scrub helps the car be stable for a few reasons in a RWD car. It also enables a wider track to mess around with. FWD has no such love. And if you begin to do the math, you get this:

A FWD if it has say 12 mm of grip negative scrub, the imaginary line of the king line from the strut to the ground, going past the contact patch, and you add +14mm of scrub with a Neuspeed, you get not just a large change in the ability to absorb impacts and reduce suspension travel, but you also switch to a.... rear wheel drive car.

Yes, with a positive scrub, even if it is 2mm, it is supposed to be a larger, say 10 mm negative. The dangers will be in emergency braking and the car pulling your arms and hands unexpectedly. Now for a race circuit track car, this does not matter. It has nothing to do. All of the bro's on F56 forum who suck the C***, just are really really stupid. Also on Facebook mini JCW pages are almost all retarded and group think and actually just bad humans as well as stupid.

Another point is that a + or - 1-2 mm gives essentially a 0 scrub radius. People find this feeling strange to drive. it would not be the end of the world as much as reversing the scrub radius, but it is not as comforting as -5 or -10 scrub radius for a FWD car. Torque steer is INCREASED with positive scrub radius on a FWD car. Now, these cars are torque steer monsters without a Quaife or Wavetrac normally, and the computer attempts to fix that without those installed.

Question is this, one that I cannot yet answer but maybe will when i get the dumb car finally (i had a 2006 MCS, now coming in a F56 hardtop JCW):
Can we measure the scrub radius? I know I could, it would take me a while of visualizing and checking the tire patch, and looking at the bearing races, eyeballing it enough to guess. If it says like -13 mm scrub, then a 45 ET wheel would be still negative scrub. If it is like a -5 mm scrub radius, then that means +6 scrub which would be not great for ROAD driving. For track?? totally fine once you give it a good alignment. track = low use case scenarios. Road worthy, safe and fast FWD sports car? Needs a negative scrub radius or at least a 0 to feel and be safe in emergency situations.

Emergency braking is slamming on the brakes. One never does that on a track and so they would not know how horrible their setup actually is for real world use.

 

Excellent post again, El Jefe.

As you say, no one seems to know what the actual stock scrub radius is for the Mini. (Plus it must be different for different wheel diameters.)

As for the stock JCW 17" Track-spoke wheels' +54 offset, I'm guessing that that's much farther out than a non-S Cooper with 16" wheels. So that's bizarre right away.
Is the entire suspension changed?

Also, there is a pretty large space between the calipers and those wheel spokes. I haven't measured, but I'd guess at least 10mm. So why did they go fo far out?

 

If you notice the track spoke wheels are convex wheels. they are really strange. the hub of the wheel Extends outward, and the width of the wheel pinches in.

this enables the wheel to bend around the Brembo big brakes, yet move inward the centerline of the wheel toward the hub.

I truly think that no aftermarket wheel works properly. I wish there was a kit to raise the knuckle an inch or maybe even less. Some company that could make a forged aluminum knuckle that raises up a bit somehow. That swing out the X negative scrub so that people could have +40 easily. I have learned a lot about these things in the past three months. I hardly knew anything for two decades, sadly.

Could someone take the JCW 17" standard 2023 +54 offset wheels and make them one piece, monoblock billet forged, like reproduce them with 1/3rd the metal?

The JCW should have been designed for a +45 Offset system, and not been so concerned about wheel well clearance. I was told that it is Japan that is hyper obsessed with wheels not protruding at all, and so is to blame for the silly, bizarre, and utterly unique convex hub design.

yes, i agree we need to get the scrub radius data for front and back wheels.

 

So does no one even have an opinion on any of my questions, above?

I'm especially hung up on this one:

"Stay with 17x7.0 wheels and add spacers, or use 17x7.5 or 17x8.0 wheels?"

 

I personally don't care for spacers. Hub centric rings should be ok as long as they are not plastic.
Were you able to confrim what 17" options are out there that clear JCW brakes beside Nuespeed?
When I spoke to Advan they said the TC-4 17x7.5 didnt fit, it would interfere with the brake. Enkei had stated that none of their 17" cleared the JCW brake either.
Note that some 17" might cause interferes with the wheel weights and the brake shoe high hat, there's a post somewhere about this. That could be why Nuespeed use 40mm ET.
I had a bunch of corespondence from variuos wheel manufacturers a few years ago but have since deleted everything. I ended up going the 18" route.

 

wow yeah. That brake is just too freakin huge. I wonder if one day I would go for a Wilwood brake set as they are, I believe, a lot thinner. A bit of a silly expense, but jeez, the Brembo Kit is just too blobby + the bizarre offset Mini chose for F56 JCW = sad stuff.

those enkei ones look fantastic. there are ultralegga whatever ones that do fit at 45 offset but never are sold here in the USA to my knowledge. USA gets a pretty ****-poor choice for wheels it seems. BBS sells nothing under 18" that would fit. they do have a rather heavy but amazing 18" 45 et wheel that fits. Two piece rotor, so much style and design.

 

Someone on this site has the 2 piece BBS (LM) they are very attractive. I was looking at getting 17" from Italy but it was too much of a hassle. If they show up and don't fit your hosed. Plus, if you happen to damage a wheel now your waiting months for a replacement etc.

OZ Racing - Wheel Configurator
https://configurator.ozracing.com/GB...5154812310640/

 

There's another thread somewhere where a JCW owner confirmed that the Advan clears the calipers, and he got them only after an Advan tech OK'd them. It's bizarre that the company doesn't have clear details on their own products. Maybe because there's both a +48 and a +43 version.
The TC-4 looks a lot like the Neuspeed RS, but IMO just a tad nicer. Plus at 2X the price, they are probably stronger. (flow formed.) Also I really love their candy apple red version. I think that will set off the JCW theme nicely.
--

As for other 17x7 wheels, I think pretty much ANYTHING should fit with a 15 - 20mm spacer, so one advantage of going that way is more wheel choices.
Also less weight. And less rolling resistance.
Maybe less traction in hard cornering, but I don't track my car or drive like an idiot teenager on the street.
The main downside is that, for a given tire width, the 7" wheel will result in a less-stiff sidewall. - But a 205 on a 17x7 might be the same as a 215mm on a 17x7.5, so ....

Oh yeah - FWIW, I just measured my front wheels and there's easily 7mm in-between the wheel and the caliper. So lots of leeway with aftermaket wheels.

 

would you know which TC-4 17" wheels clear the JCW brake? what did the guy say?

i 43 is pretty much the closest i have heard now in a 17" i think. that et 48 would be 6 mm off, possibly keeping 1-2mm of negative scrub which would suffice (assuming scrub is 10 or so in the negative)

 

Yes, the ET43 is the one.

The inner edge of the wheel will be about 4.7mm further away from the chassis than the stock JCW 501, and the latter has 5mm of clearance, so that seems like plenty of real estate, even if the Advan isn't quite as curved as the 501. (And it IS heavily curved on the inside, which partly accounts for the price.) Plus, again, someone did post that Advan verified it and he was using them.

I guess this wheel doesn't get mentioned much because it's semi-expensive at around $560 each. But I love the look: Similar to the popular NeuSpeed RS, but somehow a little nicer. Plus, it's flow formed so very strong. - And you can get it in red ! (and white, if that's your thing.)
It will be 3mm less "out" than the RS, but that's probably a good thing as far as handling goes.

MY FITMENT DIAGRAMS:

https://www.dropbox.com/scl/fi/qffq3...5sks8w6uy&dl=0

https://www.dropbox.com/scl/fi/pozci...vbvh22ka8&dl=0


And here's an 8 inch wheel I like, verified by Fitment Industries to fit the JCW: (And cheap !)
https://www.dropbox.com/scl/fi/z11kt...yuhwhkbgf&dl=0

I've also just realized that there's a +45 version of the above Enkie. That might work as well, since it's an 8" wide wheel. I think both versions will need hub adapters, but they definitely come in 5x112.

 

Very cool information

 

I just brought my '22 Mini Cooper SE into the shop to get some 17x8.5 Tracklights mounted with 225/45 tires for autocross. I went with the 42 offset and they just fit without touching, without tires. The tires were supposed to be narrower than the wheels, but somehow, they're not. The shop called and said they rub in the back, even with a 5mm spacer. The cars is lowered on H&R springs about 1.3". Can you tell me how you got them to work on your car?

 

I can't help you with his specifics, but he's probably using a different model tire.

Tire width (225mm, etc) is the width where it meets the wheel. Some 225's are wider than others at the tread. I forget what that spec is called, but it's usually listed with the tire's other specs.

ALSO, FWIW and based only on what I've read, a tire with a narrower tread-to-bead ratio will generally be stiffer, and so handle better.