I have a 2019 Mini Cooper S Auto 2 door hardtop. I live in the Sierra Nevada foothills and most of my driving is on twisty mountain roads. I am trying to choose a stiffer rear sway bar. There are many choices out there, the two that I have narrowed it down to are the NM 22mm rear sway bar and the NM 25mm rear sway bar. Yesterday i talked with Jerry at NM about the differences in the stiffness between the two sway bars. At my request Jerry had this chart giving stiffnes values for their rear sway bars added to the NM web pages for both the 22mm & 25mm rear sway bars. As you can see the softest setting for the 25mm bar is 169% stiffer than the stiffest setting of the 22mm bar. How will the stiffer 25mm rear sway bar effect the ride quality of the car. I am looking to improve handling of my Mini but I don't to end up with the ride quality being so poor that I want to put the stock rear sway back on the car. I am leaning twoards the 22mm rear sway bar but i would consider the 25mm rear sway bar if others don't think the ride quality is effected that much by the stiffer rear sway bar. Any comments on this would be appreciated.

 

Get the 22mm.. that's the general consensus for every day driving and plenty stiff. 25mm maybe if you're tracking the car but otherwise is overkill. Looking forward to picking up the 22mm myself at some point.

 

An advantage of the 25mm is the included billet clamps with Zerk fittings to make it easier to lube the bushings. NM does offer billet mounts with grease fittings for the 22mm. I've been running the 22mm with billet clamps and NM end links for 2 or 3 years now and have no problems on the street with it on the stiff setting. That being said, I'm replacing it with the 25mm just because I got a fantastic deal on a new bar from a local member.

 

When we built our bar we tested 22mm and really felt it wasn't stiff enough and left you wanting more rotation. So that is why we have only made our bar in a 25mm and what we would recommend. So I don't think you can go wrong with the bigger bar.
https://www.waymotorworks.com/wmw-25...5-f56-f57.html

 

Jerry at NM says he will sell me the 22mm sway bar with the billet clamps with Zerk fittings for the same price as the 25mm sway bar with the billet clamps with Zerk fittings so there the price is a wash. The question for me is the huge difference in the stiffness between the two sway bars. The 25mm sway bar just seems to be too stiff for a car that will not be raced in any way. I am looking for a better balanced corner carver. Without changing the front sway bar I am afraid it upset the balance the car has now. I have upgraded the sway bars on two BMW's that I have owned in the past and both cases I did both front and rear sways bars and improved the way both cars handled. Also in both BMW's the cars felt more balanced, the way I thought BMW should have designed them in the first place.

 

I know I'm going against consensus, but the first mod on my 2019 JCW was the 22 NM rear bar. It flattens the cornering up (yup funner) but did not give it better balance. In my opinion the balance actually gets worse in moderately high speed cornering. I immediately felt the issue was needing a stiffer front bar. I know you don't want to do that though. Anyway, I put the Eibach front and rear bar kit on and in my opinion its as it should be. It feels properly balanced. I later put on lowering springs and it was go kart handling for sure, but I took them back off. Too stiff for me. I think all it needed was the front bar stiffer. To bad it's a little more involved, but we did it in our garage.

 

The NM 25mm feels great in the corners and the zerk fittings it comes with are a plus, just put it on the softest setting. I don't track, only Malibu canyon carving for me.

 

Did you install the Eibach Front Sway Bar your self. I can't install instructions for the F56 front sway bar anywhere, if I could find them I would consider installing the Eibach sway bars. Doing both the front and rear sway bars makes a lot for since to me. With both front and rear adjustable sway bars you can better tune the way you like the car to drive.

 

The 25mm is the way to go...Sway bars do not stiffen up the ride in a str8 line so it will not affect everyday driving. As for cornering, it will definitely make things you do with the steering wheel happen like you want them too.
Now I am talking from a JCW point of view which might differ a bit but overall I feel the 25 gives you more response and stability in corners.

 

What about 25 mm + softer springs? It's how Subaru BRZ changed it for their rears starting 2017. Sick stability on bumpy roads plus cornering .

 

I decided to go with NM 22mm rear sway bar with the billet clamps with Zerk fittings which I ordered from NM . I also ordered the NM rear adjustable sway bar link kit. I have a local ASE mechanic who install it at the shop he works at on a Sunday for for $ 200.

 

If you decide to ever go with a front bar hopefully he can do it too. You're right that it's hard to find instructions for the front bar. I found a few verbal hints online. My friend and I did it together and he took the lead on it and asked me what I knew. I said. (all of these are qualified by "I think")
1. The basics are dropping the front sub-frame just a few inches, enough so the bar pulls out backwards towards the rear tires.
2. Tires come off, sway bar ends disconnected and then start on the sub-frame bolts - simple enough.
3. No suspension disconnects at all like A-arms. toe links, struts. They stay 100% connected
4. The big thing to not forget is disconnecting the steering u-joint in the drivers footwell. It's easy to get to, slides in and out with no issue. You just need to keep an eye on it.
5 There might be a heat shield that needs loosened but not even removed. Pull the exhaust rubber supports off, but no exhaust disconnects at all. And there was a engine mount or something large like it that you need to pull a bolt out of or screws. It super visible as it's right at the bottom where you can see it.

The rest he (we) did intuitively just by looking at it. There is a Newtis instruction for lowering the subframe up there, but he wasn't interested. Ha.

You can find pictures of how the steering box lowers online. I have some if you ever get to it, but i couldn't upload because they are still in the HEIF format. ugh

 

https://www.newtis.info/tisv2/a/en/f...bar/1VnXs1CmxS

 

Warren2185. Doesn't really change the cars characteristics (understeer/balance), a bit stiffer mainly the skipping/jumping if you hit bumps while cornering. Dealer soaked me about $900 to install front and rear.

 

What softer rear springs are you talking about? My car does not have the sport package suspension. Do justa Mini's have softer rear springs than S Mini's? Where can I find this spring rate information?

 

Gotta disagree on this one... I thought the same thing, then put in the very stiff H&R 27 & 25mm kit and found straight line ride too harsh for my tastes. When you turn, both wheels are moving in opposite directions (one up, one down), and you have resistance from the bar. But if only one wheel hits a bump, the bar is still resisting movement. Half as much, but that can still change the ride a lot. Unless both wheels hit a bump at the exact same time, but that doesn't really happen.

I did try a softer suspension setup (KW Street Comfort) with the stiff bars, and still didn't care for the ride.

Yes you can DIY the front bar. It's a pain, but not horrible. A few hours with the right tools. A bit harder than the front, but not by that much.

We went over pretty much all of this on this thread, including the install:

https://www.northamericanmotoring.co...y-bar-kit.html

After trying NM 22, VIP 22.1 (they call it 23, not very accurate), and the H&R 25mm solid, I would probably like to go with the WMW 25mm hollow. I think the car could use a little more rotation. The NM 25 would be great too, but I'd rather save the $100 with WMW.

 

Do you sell sway bar links to go with your WMW 25mm rear sway bar? If not, I'm assuming I can use the NM links, correct? Thanks.

 

Due to the design of the F56 links our style don't work on it. So we do actually use the NM for adj links.
https://www.waymotorworks.com/nm-eng...5-f56-f57.html

 

Hey, so did you install the 25mm bar? I'm curious to know how it feels in comparison to the 22. I have a Cooper S with standard, not sport suspension and am trying to decide between the 2. I'm leaning toward the VCP 23mm bar but not sure yet. Thx

 

Manny- I have the VCP "23". Was hoping it was an upgrade over the NM, but in reality it measures 22.2mm. The arms are also very slightly shorter than nm. So it's slightly stiffer, but not by much. It is, however, quite a bit cheaper, and comes with greasable bushings. So I do like it, but it may not be all you are expecting.

For your case though, if you're going to stick with standard suspension, I think either of those will be fine. I've always heard it not recommended to use a very stiff rear bar with stock (soft) suspension- it can cause snap oversteer. You're asking the bar to do too much work. It's not in proportion to the springs. I'm not an expert, this is just what I've read, and it makes sense to me.

If you want to dig deeper, this thread has my whole story and a bunch of other info:

https://www.northamericanmotoring.co...y-bar-kit.html

 

Hey, thanks a lot for the info. Yea I'm not expecting the VCP bar to be any different than the NM. The price difference is the main reason..and that it includes greasable fittings. I was also concerned about going too stiff with my suspension and I think you've confirmed that.. It does make sense. My F56 just feels so different than the R53 I had.. sways too much and feels a bit floaty. If this bar will make a noticeable difference I'll be happy. I'm about to read the link you sent.. appreciate the help.

 

Swapped it out the end of last week, but the only driving I've done in the Mini since then was the 75 mile trip home from the shop. I have the 25mm set on the soft setting and it seemed to handle fine in the short drive home. I'll be putting some more miles on it soon and will have a better idea of the difference then.I've seen, and considered other bars, but have never been disappointed with the quality and the customer service from NM, so I pretty much stick with them for suspension and wheels. I just installed a set of their studs and lug nuts too.

 

I talked to someone at NM and he was super helpful and just a really nice guy.. not sure if it was this Jerry I've heard about. So yea, who I buy stuff from is important to me. Thanks so much for the reply 👍

 

A friend helped me install the NM 22mm rear sway bar & NM rear adjustable sway bar link kit. It took us about 3 1/2 hours to do the install using the NM install instructions provided with sway bar. Although my friend has a fairly large assortment of tools along with a two post lift in his garage he did not have the torx sockets required. Because the NM install instructions list fraction sockets that can be used in placed of torx sockets I did not buy the torx sockets, this was a big mistake. The fraction sockets will work but do not grip the bolt head as securely as the torx sockets would. From our experience with the install I would recommend that you buy torx sockets if you don’t already take them. Amazon.com sells the sockets both in sets and individually. Also I would recommend the NM drop links because they are stronger, but are not necessary to complete the installation since I adjusted the NM links to same length as to OEM links.

Now for driving impressions after to install. I set the NM 22mm rear sway bar in the middle position per the NM install instructions. My 2019 Mini Copper S hatch has DDC shocks & struts and had a 21mm hollow rear sway bar so the NM 22mm rear sway bar set in middle is 33% stiffer than the rear sway bar I took off my car based on NM’s calculations from their website. I took the Mini for 90 mile round trip test drive from Nevada City,CA to Downieville, A on Calif hi-way 49. This is an entertaining two lane mountain road with a speed limit of 55 miles an hour most of the way between Nevada City and Downieville. It’s your basic canyon carving fun road where fast cars go to play. At the middle setting my Mini corned with far less body roll than with the stock rear sway bar. This is especially evident going thru the slaloms of which there many. In tight slaloms where you are going from right to left and back over and over again the car feels far better and more balanced. If this level of improvement was all I got from the 22mm rear sway bar I would have been satisfied with the results of the upgraded rear sway bar. But I went back over to my friends and we readjusted the 22mm rear sway bar to the stiffest position. This is about another 15% stiffer than the middle position for a total of 48% stiffer. After this adjustment I did the 90 mile test drive again and the improvement in cornering was about an equal to the amount of increase that the increase of the middle position was over my stock 21mm rear sway bar. The ride quality is a bit stiffer in the rear but I will take the improvement in handling with a slightly stiffer ride over the way the car was stock any day. Would I want to go with the NM 25mm rear sway bar? No I don’t think so, I like the results that I got with NM 22mm rear sway bar and it was well worth the effort and cost to improve the driving experience of my Mini Cooper S.

 

Lucky you, you get to have canyon roads nearby, I don't want to use the term street/track but maybe the 25mm bar is better suited for track use. I tired the Mid (one end stiff one end soft) and the stiff mode on my Eibach rear bar, hopped too much over bumps.