Replacement for speed clip mounts affixed to Kevlar rear bumper carrier (with STL)

[karter16]

***Update with STL file***

03 August 2023

Following on from the discussion below I drew up an STL file for this part and have test printed it to confirm the dimensions match exactly, the speed-nut fits, etc.

This STL is provided as is with no warranty express or implied on my part. You're welcome to use, print, modify, share as needed.

Please note that the original part is stamped as PA6 GF30 which means it is a Polyamide 6 plastic with 30% glass fibre. There is a 3D printer filament available which is a Nylon 6 (Nylon is a type of Polyamide, so Nylon 6 is pretty similar to PA6) with 25% Carbon Fibre which is what I'm planning to use when I get round to actually doing this.

Please also note that the STL I have created does not have the holes in it, as I plan to bond/epoxy the brackets in place. You're welcome to modify the STL to add the holes if you wish.

Download here




***



Hi all,

Apologies if this is already addressed somewhere, if it is I couldn’t find it.

I was doing some brief investigation tonight into why my car’s rear bumper/diffuser fitment is so awful.

It turns out that all the plastic mounts affixed to the underside of the kevlar bumper carrier have detached themselves, so the rear bumper isn’t held up/supported from the bottom.

I am fortunate that one of the plastic mounts was still attached to the rear bumper (although it had detached from the Kevlar carrier) so I was able to remove it.






It appears as though these plastic brackets come as part of the Kevlar carrier itself (BMW part number 51127894853) so I’m fairly sure there’s not any good replacement options beyond buying a new one or getting a second hand one to scavenge.

My plan at this point is to recreate the part in CAD and 3D print in nylon or similar. I can then rivet these to the Kevlar carrier in the correct locations.

Thought first though that I would check here to see if anyone has any suggestions / has been through this themselves?

Thanks in advance.

Matt


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[Casa de Mesa]

In for the answer. I had one break away from the carrier too but was captured by the diffuser. I glue it back to the bumper with a plastic glue. Would love to know what they are actually bonded with from BMW.

[Slideways]

It appears that BMW melts the plastic mounts to the kevlar. Alternatively, this JB Weld Plastic Bonder works perfectly to reattach one of those mounts - https://www.jbweld.com/product/j-b-p...bonder-syringe. Skip the standard JB Weld as that will break off after one drive.

[karter16]

It appears that BMW melts the plastic mounts to the kevlar. Alternatively, this JB Weld Plastic Bonder works perfectly to reattach one of those mounts - https://www.jbweld.com/product/j-b-p...bonder-syringe. Skip the standard JB Weld as that will break off after one drive.

Yeah examining mine it’s some sort of chemical/heat weld for sure.

Thanks for the link, will check it out.


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[Pklauser]

It appears that BMW melts the plastic mounts to the kevlar. Alternatively, this JB Weld Plastic Bonder works perfectly to reattach one of those mounts - https://www.jbweld.com/product/j-b-p...bonder-syringe. Skip the standard JB Weld as that will break off after one drive.

Whelp, I just finished up remounting mine with standard JB Weld. I'll revisit this thread when it breaks off 😅

[thegenius46m]

You have to buy the bumper repair kit from bmw to get those. Honestly just swap to the aluminum support beam that you can grab from any non-m at the junkyard. I did this about 6 months ago and not only substantially fixed my bumper fitment, but now my diffuser is solid and I literally had to adjust my exhaust 3 inches because the diffuser was sagging due to the missing clips. Everything is attached with plastic rivets on the aluminum support and you can adjust the bumper fitment infinitely. Those stupid clips are on the kevlar support will just fall off again.

[karter16]

You have to buy the bumper repair kit from bmw to get those. Honestly just swap to the aluminum support beam that you can grab from any non-m at the junkyard. I did this about 6 months ago and not only substantially fixed my bumper fitment, but now my diffuser is solid and I literally had to adjust my exhaust 3 inches because the diffuser was sagging due to the missing clips. Everything is attached with plastic rivets on the aluminum support and you can adjust the bumper fitment infinitely. Those stupid clips are on the kevlar support will just fall off again.

Do you have a part number for the bumper repair kit? I’ve done a lot of searching and haven’t been able to find one. There is a bumper installation kit for the E46 M3 but it does not include this part in it.

If there is a kit out there that includes these it would be great to find it!

Thanks!


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[thegenius46m]

Interesting. I thought last time I looked it did include them but clearly that’s not the case with the installation kit. Wonderful. So if you get rear ended bmw expects you to buy a new Kevlar support even if it’s a love tap to break the clips lol.

id just convert to this personally. That Kevlar design for the rear is genuine garbage.

Literally got the whole system for $30 and got to pull and inspect it prior. Best $30 I’ve spent and I’m never looking back.

[bigjae46]

peel type rivet. You'll need to gouge the styrofoam so the bumper will slide back on.

[karter16]

peel type rivet. You'll need to gouge the styrofoam so the bumper will slide back on.

Sorry not sure what you’re saying here? You’re suggesting using a peel type rivet?

Also not sure what you mean re the styrofoam? These attach to the underside of the Kevlar reinforcement bar. As far as I know there’s no styrofoam underneath?


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[bigjae46]

You’ll have to drill through the kevlar to inset the rivet. So it will interfere with the styrofoam on the bumper cover. You might need to grind or cut away some of the foam.


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[karter16]

You’ll have to drill through the kevlar to inset the rivet. So it will interfere with the styrofoam on the bumper cover. You might need to grind or cut away some of the foam.


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Sorry - was being dense - gotcha now - thank you for explaining :-)


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[lemoose]

in the same boat- short of buying a whole carrier, looks like we're stuck with just bonding them back on. Luckily I had some plasticweld on hand. I did read, however, that regular superglue (cyanoacrylate) bonds remarkably well with kevlar as it chemically bonds with it. Not sure how accurate that is and/or if the bond would be lacking on the clip side.

[t3ddftw]

Bump -- did anyone get around to making this piece in CAD? I just measured all the dimensions as I am missing three.

[Slideways]

Bump -- did anyone get around to making this piece in CAD? I just measured all the dimensions as I am missing three.

I thought I saw a thread with a 3D printed one. I don't think there is a .stl