[FaRKle!]

So andino and I recently swapped our front and rear end links for KC Design's adjustable ones. Both of our cars are set up in a way that can actually take advantage of them. For most people, the stock end links are just fine, so what about our cars made adjustable ones worthwhile?

Originally Posted by Index

0:00 Intro
0:14 Measuring ride height *adjustable end links only*
1:28 Removing the front end links
3:50 Front sway bar geometry and adjustment concept *adjustable end links only*
5:30 Setting the front knuckle to ride height *adjustable end links only*
6:07 Installing the front end links
8:50 Rear end link removal
9:53 Rear sway bar geometry and adjustment concept *adjustable end links only*
10:59 Rear end link installation
12:34 Rear end link length adjustment *adjustable end links only*
13:22 End link adjustment to remove preload *adjustable end links only*
15:33 Installing bottom covers and wheels

There are two reasons why you'd want adjustable end links. The first is to achieve the correct geometry between your sway bar and end links. The second is to remove any preload, which is unnecessary added load on the bar. The stock end links' lengths are set for our vehicles at their BMW specified ride heights. Within a certain range (we can confidently say 10mm, since that's the difference between standard and M-Sport suspensions) the end link length doesn't matter too much. However, once you start lowering significantly more, your end link to sway bar geometry becomes worse.

The end link provides the most leverage on the sway bar when it's at a 90deg angle to the effective lever arm. As you deviate away from that, the force applied to the sway bar is less than the force applied to the end link, so your sway bar effectiveness is reduced.

As the ride height is changed we also run into a preload situation with the stock sway bar bushings on the F2x/F3x platform. The front bushings are permanently mounted to the sway bar and thus have a specific natural resting position. As the ride height is changed the bar is twisted out of this position and those bushings apply a preload to the bar trying to bring the bar back to the natural position. The stock rear bar's bushings aren't permanently attached, but have high enough friction that the rear bar doesn't twist within them very freely (you can change this though with grease). If you have aftermarket sway bars, the bushings are usually polyurethane and come with grease, so the bars spin freely within the bushings.

We can also have preload due to different ride heights between the sides of the car. If the car naturally has different heights side to side, then if the same length end links are used, the bar will be trying to make both sides match with load.

For andino's case, he likes his ride height decently low, so his end link geometry wasn't ideal, and he had a fair amount of preload on the stock front bar. In my case, I'm not too far off from stock ride height, so I didn't need the adjustable end links for geometry purposes, but I do have aftermarket sway bars and want to be able to play with the settings, which requires adjustable end links to dial in the proper geometry with those mounting positions.

So what's the felt effect of doing this? In andino's case he noticed less bump steer and improved comfort due to improved suspension independence. Each corner was able to move without upsetting the other side as much as before.

If you've only lowered your vehicle slightly (say up to about 3/4") then changing to adjustable end links probably isn't worth it. Beyond that though, it might be something to consider. Also if you're using aftermarket sway bars you might want to consider it. From all the bars I've had, the mounting points aren't exactly in the same position as the stock bars'.

andino and I both used KC Design's adjustable end links, which have a solid build, and easy to adjust feature. You can see more about them below.

Originally Posted by Index

0:00 Construction comparison
0:37 How to adjust the length
1:11 Fastener comparison
2:22 Front end link length range
2:57 Rear end link length range

[andino]

Kind of fun trying to spot who's car each step came from.

[kpgray]

So I have purchased and getting close to installing new Eibach springs on my F32:

• Eibach xDrive lowering springs for the 0.8" Front / 0.4" Rear Drop (wanted to close that excessive gap while maintaining close to stock ride)
• I have adaptive suspension, so no shock change
• I was going to keep the stock dampeners as they are the same for RWD and xDrive
• I will not be tracking, this is my daily driver

With the new spring 3/4" front drop and no other changes at this point, does it make sense to install this "Adjustable End Link" to maintain the ideal geometry, or not quite enough to affect the overall performance?

[FaRKle!]

Originally Posted by kpgray

So I have purchased and getting close to installing new Eibach springs on my F32:

• Eibach xDrive lowering springs for the 0.8" Front / 0.4" Rear Drop (wanted to close that excessive gap while maintaining close to stock ride)
• I have adaptive suspension, so no shock change
• I was going to keep the stock dampeners as they are the same for RWD and xDrive
• I will not be tracking, this is my daily driver

With the new spring 3/4" front drop and no other changes at this point, does it make sense to install this "Adjustable End Link" to maintain the ideal geometry, or not quite enough to affect the overall performance?

It's likely you don't really need them in the front. I'd consider it a "nice to have."

The nice thing about the front end links, is they're not too difficult to replace, so you can always do them later.

[kpgray]

Originally Posted by FaRKle!

It's likely you don't really need them in the front. I'd consider it a "nice to have."

The nice thing about the front end links, is they're not too difficult to replace, so you can always do them later.

So I went to RealOEM.com and checked out both xDrive and RWD M-Sport models (with adaptive suspension) and they both have the same "End Links". I would have thought the RWD version would be shorter, yet they are both the same. What I did notice is that the xDrive and RWD sway bars are different:

• RWD version is 25.2 MM (OEM Part No. 31356792120)
• xDrive version is 23.6 MM (OEM Part No. 31356792139)

So a quick question is:
I am installing the Eibach Pro-Kit for xDrive and it lowers the vehicle 3/4" to the approximate height of the standard RWD Sport suspension. What if I was to just change the sway bar to the RWD version? Seems that a 2 MM thicker bar and the stock height could help in overall handling without swapping out the end links and use that money for stock sway bar? Thoughts?

[andino]

Originally Posted by kpgray

So I went to RealOEM.com and checked out both xDrive and RWD M-Sport models (with adaptive suspension) and they both have the same "End Links". I would have thought the RWD version would be shorter, yet they are both the same. What I did notice is that the xDrive and RWD sway bars are different:

• RWD version is 25.2 MM (OEM Part No. 31356792120)
• xDrive version is 23.6 MM (OEM Part No. 31356792139)

So a quick question is:
I am installing the Eibach Pro-Kit for xDrive and it lowers the vehicle 3/4" to the approximate height of the standard RWD Sport suspension. What if I was to just change the sway bar to the RWD version? Seems that a 2 MM thicker bar and the stock height could help in overall handling without swapping out the end links and use that money for stock sway bar? Thoughts?

RWD bar is a different shape to the xdrive one so it wouldn't fit.

[FaRKle!]

Originally Posted by kpgray

So I went to RealOEM.com and checked out both xDrive and RWD M-Sport models (with adaptive suspension) and they both have the same "End Links". I would have thought the RWD version would be shorter, yet they are both the same. What I did notice is that the xDrive and RWD sway bars are different:

• RWD version is 25.2 MM (OEM Part No. 31356792120)
• xDrive version is 23.6 MM (OEM Part No. 31356792139)

So a quick question is:
I am installing the Eibach Pro-Kit for xDrive and it lowers the vehicle 3/4" to the approximate height of the standard RWD Sport suspension. What if I was to just change the sway bar to the RWD version? Seems that a 2 MM thicker bar and the stock height could help in overall handling without swapping out the end links and use that money for stock sway bar? Thoughts?

As andino mentioned, the RWD and AWD front sway bars are different shapes. The AWD bar has to clear the xDrive "hump" in the tension strut arm. In addition to the lever arm shape differences, RWD sway bars have longer lever arms, which means they have to be thicker in diameter to provide the same spring rate. If you try to fit a RWD sway bar on an xDrive vehicle you'll have collision between it and the tension strut arm.

[thatBimmerBloke]

I think I might be experiencing some bump steer after installing KW V1 and lowering it about 1.5" all around. No issues with comfort. Probably need these adjustable end links.
I also notice a small back and forth rocking on full stop, probably due to the progressive springs being softer on resting height, or preload on sway-bars?

[Lancelot]

FaRKle! i’m going to get aftermarket eibach antiroll bars, and bought these kcdesign endlinks; i’m on lowered springs, -25mm front, -30 rear. (Vs base model i suppose, so -15/-20 vs m sport)

i noticed in your video the max adjustment of 320mm is close to stock 315mm on front endlinks at least, so i’m not sure why the range doesn’t allow to extend the bar further since when you’re lowered you need to extend the front endlinks.

Am i missing something?

Great video though, very helpful!

[FaRKle!]

Originally Posted by Lancelot

FaRKle! i’m going to get aftermarket eibach antiroll bars, and bought these kcdesign endlinks; i’m on lowered springs, -25mm front, -30 rear. (Vs base model i suppose, so -15/-20 vs m sport)

i noticed in your video the max adjustment of 320mm is close to stock 315mm on front endlinks at least, so i’m not sure why the range doesn’t allow to extend the bar further since when you’re lowered you need to extend the front endlinks.

Am i missing something?

Great video though, very helpful!

KC Design says the max length is 319mm, but there's still LOTS of thread left in the center rod (not including lock/jamb nuts) at that length. I think it's likely safe to go down to 5 threads inside. At 7 threads inside I was able to extend the end link to 330mm. I think KC Design was being very conservative with their max length number.

[brigade24]

who carries the KC Design endlinks? tried going to their website but there doesn't seem to be any payment processing functionality...

[FaRKle!]

Originally Posted by brigade24

who carries the KC Design endlinks? tried going to their website but there doesn't seem to be any payment processing functionality...

AFAIK they don't have any 3rd party resellers/distributors. If you email them (kc7133@gmail.com) they can send you a PayPal invoice. This is how I've done the many orders I have with them. They typically respond in under 24hrs.

[Lancelot]

Originally Posted by FaRKle!

AFAIK they don't have any 3rd party resellers/distributors. If you email them (kc7133@gmail.com) they can send you a PayPal invoice. This is how I've done the many orders I have with them. They typically respond in under 24hrs.

Same here, sent an email, got a quote, paid with PayPal and received it via fedex within a week.

[brigade24]

Originally Posted by Lancelot

Same here, sent an email, got a quote, paid with PayPal and received it via fedex within a week.

excellent...thanks to the both of you!

[mike082802]

Originally Posted by FaRKle!

So andino and I recently swapped our front and rear end links for KC Design's adjustable ones. Both of our cars are set up in a way that can actually take advantage of them. For most people, the stock end links are just fine, so what about our cars made adjustable ones worthwhile?

There are two reasons why you'd want adjustable end links. The first is to achieve the correct geometry between your sway bar and end links. The second is to remove any preload, which is unnecessary added load on the bar. The stock end links' lengths are set for our vehicles at their BMW specified ride heights. Within a certain range (we can confidently say 10mm, since that's the difference between standard and M-Sport suspensions) the end link length doesn't matter too much. However, once you start lowering significantly more, your end link to sway bar geometry becomes worse.

The end link provides the most leverage on the sway bar when it's at a 90deg angle to the effective lever arm. As you deviate away from that, the force applied to the sway bar is less than the force applied to the end link, so your sway bar effectiveness is reduced.

As the ride height is changed we also run into a preload situation with the stock sway bar bushings on the F2x/F3x platform. The front bushings are permanently mounted to the sway bar and thus have a specific natural resting position. As the ride height is changed the bar is twisted out of this position and those bushings apply a preload to the bar trying to bring the bar back to the natural position. The stock rear bar's bushings aren't permanently attached, but have high enough friction that the rear bar doesn't twist within them very freely (you can change this though with grease). If you have aftermarket sway bars, the bushings are usually polyurethane and come with grease, so the bars spin freely within the bushings.

We can also have preload due to different ride heights between the sides of the car. If the car naturally has different heights side to side, then if the same length end links are used, the bar will be trying to make both sides match with load.

For andino's case, he likes his ride height decently low, so his end link geometry wasn't ideal, and he had a fair amount of preload on the stock front bar. In my case, I'm not too far off from stock ride height, so I didn't need the adjustable end links for geometry purposes, but I do have aftermarket sway bars and want to be able to play with the settings, which requires adjustable end links to dial in the proper geometry with those mounting positions.

So what's the felt effect of doing this? In andino's case he noticed less bump steer and improved comfort due to improved suspension independence. Each corner was able to move without upsetting the other side as much as before.

If you've only lowered your vehicle slightly (say up to about 3/4") then changing to adjustable end links probably isn't worth it. Beyond that though, it might be something to consider. Also if you're using aftermarket sway bars you might want to consider it. From all the bars I've had, the mounting points aren't exactly in the same position as the stock bars'.

andino and I both used KC Design's adjustable end links, which have a solid build, and easy to adjust feature. You can see more about them below.

did you make the end links shorter or longer on andinos car? looking at buying a set of bimmerworld adjustable end links and the come 11-12.5 or 12-13,5. i am on ohlins and lowered about an inch and a quarter from oe height. i was thinking 11-12.5 since ohlins lowers from the bottom knuckle and the whole strut assembly moves down while lowering hence bringing the two mounting points for the sway bars closer.

[FaRKle!]

Originally Posted by mike082802

did you make the end links shorter or longer on andinos car? looking at buying a set of bimmerworld adjustable end links and the come 11-12.5 or 12-13,5. i am on ohlins and lowered about an inch and a quarter from oe height. i was thinking 11-12.5 since ohlins lowers from the bottom knuckle and the whole strut assembly moves down while lowering hence bringing the two mounting points for the sway bars closer.

When lowering on this platform you go longer in front and shorter in the rear.

[mike082802]

even though on ohlins the whole strut lowers through the bottom sleeve for the knuckle? i am going to measure with the hub jacked up to ride height with the wheel off. for some reason im thinking shorter but i know you have done a lot of research and i use your videos a lot. thanks for giving back.

[mike082802]

yup, longer. ordered the 12-13.5

[Logicoeur]

So I just installed the ohlins for xdrive. Endlinks are on hospice. Looking at the Hotchkis and Turner custom length. They really look the same.

I see stock length is ~313mm once converted from your video FaRKle!. Turner provides them in lengths 290-305mm and 320-335mm which is noinclusive of stock length. Shpuld the latter be fine with its minimum length being longer than stock already? I'm currently at 14" fender to axle in thr front and can't go any lowet in the front because of the links

[Eschmacher]

Anyone have any experience with any of the adjustable endlinks and the adaptive suspension? The OE links have a different design for the front right, want to verify if the adjustable sets work.

[Cesarherc]

What’s up guys, question here, so I changed just about the whole front assembly in the cars suspension (rwd non adaptive) all I really left out was the tie rods which I’ll do when I see wear on them but I was doing some research after I got my end links and when I went to put on the driver side one I noticed it almost didn’t really wanna fit, what I ended up doing was rotating the whole shock assembly from the knuckle and I got the end link to fit, now when I drive, I hear a clunking sound on pot holes, as I been looking into it, seems like xdrive cars have a different end link than a rwd car, I’m guessing they sent me the wrong end links when I ordered them since it was a bit of a hassle to put it on (again only the driver side) anyways I just want to confirm if that’s true? Also would the xdrive ones fit on a rwd theoretically? As I got it on but again I’m not sure if what I got was the right part or not but the fact that I had to move the whole strut to get the end link in the slot makes me think that I got the wrong part. Also the clunking adds to my suspicions that I got the wrong part, I have driven the car, turned the wheel to the far left and right, nothing seems to sound off, only when I go over bumps, regardless I’m gonna lift the car and take another look down there, but any info would be appreciated!

[Eschmacher]

Originally Posted by Cesarherc

seems like xdrive cars have a different end link than a rwd car

Realoem says they are the same part between RWD and x-drive. 31306792211