CorkSport springs with Bilstein shocks - *installation note*

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'21 CX-5 CE-T
A friend and I lowered my car a few months back on Corksport springs and Bilstein shocks. Followed Corksport directions to a T.

1698725220185.png


After about 5000 miles, it was great! But... the rear end always felt oddly firm. I asked others with the same setup on their car about it, and they didn't seem to have any issues. Also, from others' pictures with the same setup the rear-end was always notably higher than what's shown on the CS site, and others who've posted pictures using the CS springs with stock shocks. I assumed the height and firmness was probably the combination of the stiffer Bilstein shocks and stiffer springs in the rear.

It still was really firm and seemed like it was riding on the bump stops, especially over speed bumps and driveway entrances (even though they were cut to Corksports spec). the short compression was followed by a somewhat firm stop and squeak.

I even went to a loading dock ramp to see how much the suspension articulated. While the front tires compressed up into the fender (probably 2.5 to 3" of travel from resting height), the rears only compressed about a half inch. Something was definitely limiting the suspension travel.

We took the rear suspension out last weekend, to investigate and saw the (potential) cause.

The Bilstein shock tubes and shafts are about an inch longer than the stock ones.
1698722649656.jpeg


The difference was enough to make us confirm the model number of the shocks to make sure they were for the CX-5 (they are). My guess is that Bilstein was probably thinking that owners would be lifting these, not lowering them.

We also confirmed the travel of the shock wasn't internally limited, its not.

We cut the bump stops to the green line. note that this is the last rib that the dust cover (painstakingly) attaches to.
1698723221491.png


The ride is much much better now, and feels like it should. Also the rear end lowered to where it looks like it's supposed to be.

1698723390906.jpeg


Not sure if anyone at @CorkSport is on this forum, or not. But it may be good for them to include this in their instructions.
 
This is excellent info to have. I swapped CorkSport springs onto my OEM dampers, and when the time comes to swap the dampers out, I now know to measure the dampers and trim the bumpstops accordingly if necessary. Thanks for posting! (y)

I believe most, if not all, of CorkSport's springs have instructions that relate specifically to only swapping the springs out, assuming that the buyer will be reusing the OEM dampers. It would be good practice for them to add a note or disclaimer saying exactly that, and that further modifications may be necessary if non-OEM dampers are used.
 
Just purchased a 2021 CX-5 GT (non-turbo) and am interested in installing a set of CorkSport lowering springs on the OEM shocks. I'm wondering how much stiffer the ride will be with this setup? My previous car was a 2018 WRX with stock suspension which eventually I found the ride to be too rough over bad pavement/potholes and was one of the reason I got rid of it. Would anyone be able to compare the ride of these springs to a WRX as a reference? Also, will the approx. 2 inch drop have any significant reduction to light output distance from the headlights? Thanks in advance.
 
Once I got the rears off the bumpstops, I honestly didn't notice too much of a difference besides the benefits of the lower COG; more stable in straights, and more confidence taking turns faster/harder.

I previously had a lowered Honda CRV (eibach + konis yellows) the suspension was a huge improvement on that platform ('98 gen 1). I also had an Audi for around 15 years (h&r + bilstens -seems to be the go to), and both were perfect aside from cold weather. When the temps dropped the shocks got rock hard.

This is my first winter with the Mazda lowered 10° F, and I can feel the shock oil stiffening.

I think that the key is to get performance shocks when you use performance springs. Stock shocks aren't designed to, nor able to dampen performance springs very well, and the ride gets abrasive.
 
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Good info sir. I'm hoping to install my CS springs and Bilistein b6's in April or so. Glad to hear the handling is a lot better. Hoping to add some DWS06 tires then as well.
 
I'd like to see a review from someone who rode on lowering springs and stock shocks for a while, before changing the shocks.
 
Great write up!

Love the lowered look and better handling review.

Did you change out the rear camber arms with something like JBR's?
 
I originally got some godspeed rear arms. Then right before the original install, with some help from someone on reddit, found some more oem-ish ones and used those instead.

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A friend and I lowered my car a few months back on Corksport springs and Bilstein shocks. Followed Corksport directions to a T.

View attachment 323514

After about 5000 miles, it was great! But... the rear end always felt oddly firm. I asked others with the same setup on their car about it, and they didn't seem to have any issues. Also, from others' pictures with the same setup the rear-end was always notably higher than what's shown on the CS site, and others who've posted pictures using the CS springs with stock shocks. I assumed the height and firmness was probably the combination of the stiffer Bilstein shocks and stiffer springs in the rear.

It still was really firm and seemed like it was riding on the bump stops, especially over speed bumps and driveway entrances (even though they were cut to Corksports spec). the short compression was followed by a somewhat firm stop and squeak.

I even went to a loading dock ramp to see how much the suspension articulated. While the front tires compressed up into the fender (probably 2.5 to 3" of travel from resting height), the rears only compressed about a half inch. Something was definitely limiting the suspension travel.

We took the rear suspension out last weekend, to investigate and saw the (potential) cause.

The Bilstein shock tubes and shafts are about an inch longer than the stock ones.
View attachment 323499

The difference was enough to make us confirm the model number of the shocks to make sure they were for the CX-5 (they are). My guess is that Bilstein was probably thinking that owners would be lifting these, not lowering them.

We also confirmed the travel of the shock wasn't internally limited, its not.

We cut the bump stops to the green line. note that this is the last rib that the dust cover (painstakingly) attaches to.
View attachment 323503

The ride is much much better now, and feels like it should. Also the rear end lowered to where it looks like it's supposed to be.

View attachment 323504

Not sure if anyone at @CorkSport is on this forum, or not. But it may be good for them to include this in their instructions.

Any pics of the front struts?
What are the part numbers for the shocks?

Im running the Corksport springs with the OEM shocks/struts. No issues, good ride still, however when I need to replace them I may go for a bit more firmer performance.
 

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Any pics of the front struts?
What are the part numbers for the shocks?

Im running the Corksport springs with the OEM shocks/struts. No issues, good ride still, however when I need to replace them I may go for a bit more firmer performance.
I like the way you connected the lines with the black vinyl. Have any more pictures?
 
I'm looking at Corksport/Bilstiens vs BC Racing BR serries.

I put similar coil overs on a Honda Accord and drove it over 60,000 miles. I liked being able to adjust the shock heights and dampening. With stiffer anti sway bars and performance tires it drives like it's on rails.

I'm not sure if they are worth +$400 over the lowering springs/shocks....

Has anyone used BC Racing coil overs?

https://www.amazon.com/dp/ (commissions earned)
 
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