Suspension coating durability?

Not really relevant to suspension sorry...

But with engine parts in race engines I've poked around, it does show light (not detrimental to its performance, not that it would make a difference it's so damn thin) signs of use relatively quickly, I've heard knife/gun guys say similar, but the flaking is absolutely not right and the offer to re-do it is warranted.

Still good to appreciate a company who stand by their work, even if you have trouble, so props to you on not naming and shaming them like some might and hopefully the second go around is a better experience 👍

Coatings do eventually wear off, but how long that takes depends on a lot of factors. Colored coatings (blue, rainbow, etc.) wear much faster than DLC. A good DLC coating should last 100s of hours on a fork tube, and especially on a shock shaft. Some of the color coatings are actually aesthetic only and don't last more than a few hours.

The riding conditions play a big part. Coatings will last a lot longer when ridden in perfect dirt as opposed to riding in extreme mud or sand.

Initial condition of the tubes and surface prep plays a part too. If the tubes were coated already, the previous coatings must be stripped down to the hard chrome. That's sometimes not possible (depends on the previous coating).

No suspension company, except maybe factory KYB or similar (and even then, I doubt it) is doing coatings in-house. They all outsource them. But they have the order volume and capabilities to send raw tubes to the companies that actually do the coatings (it's rare that the actual coating companies will deal with a single set of tubes or a shock shaft from a retail customer, they want volume and stability). Some of those coating companies do excellent work, some are hot garbage, most are in-between. 

To directly answer the question, 20 hours is way too early for DLC to wear through and 5 hours is ridiculous. Your suspension company is going back to whoever did the coating and complaining to them (likely with limited success, if any). Hopefully they can get you set up with proper coatings at no charge! The suspension companies that have done this a while have been through multiple vendors (expensive trial and error) and found the ones that do a good job (and different colors/coatings = different vendors). That's part of what you're paying for. But even then, the margins for the suspension company are pretty thin when you consider shipping, prep, their time, etc. That's one of the many reasons we stopped offering coatings!

What about Kashima?  I recently got my forks back after service and there was flaking.  When I asked I was told it can happen when removing the suspension decals.

DLC should last hundreds of hours.

If its flaking off there was a prep issue when applied.

Coatings on the outer tubes are just anodize. Kashima is hard anodize that's been impregnated with molybdenum disulfide and dyed bronze. We offered a very similar coating that used Teflon instead. The anodize process is fairly straight-forward for a qualified anodizer (similar to DLC, etc., no suspension company is doing this in-house) and they'll control the thickness so the dimensions remain the same. The hard part is stripping the old coating and retaining a smooth finish on the inner bore. It's possible, but you need a really good anodizer to do it.

It shouldn't flake off at all. The only reason the anodize would flake is if it was done on a poorly prepped tube, the tube was pitted/corroded before anodize, or if it somehow corroded after. If the tube was new or in good condition when it was coated, it's not really old now, and you haven't been storing the bike underwater in the ocean, you'd almost have to try to screw it up and get it to flake off. Something is wrong there.

Im 100% sure that all the suspension companies outsource the coating services. Operating a pvd machine is a somewhat complex and they arent cheap. It would be terrible roi.

It is not unusual that single set fork tubes pops up at coating center. You can just chuck them in the same batch with endmills, drills, molds etc.

OPs problem is most likely because of poor pretreatment as in cleaning. Or maybe coating temp was too low. Anyway poor adhesion, it is time for rework.

If I understand correctly, true kashima is only done in Japan. So you may have a faux shima or anodize

Sounds like the prep wasn’t done correctly. DLC shouldn’t ever flake off. It will eventually wear but in the action of a lower fork tube, I would expect hundreds of hours at least. 

The forks are from Technical Touch, so they are legit.  Still irritated that they look the way they do. 

Kashima is very hard and brittle. For internal fork parts, not much problem, but the outside of the tube will flake off in deep chunks when hit by a rock as well as where the tubes flex at the bottom of the lower triple clamp. I use clear vinyl around the whole fork tube to protect the Kashima.  Decals alone will not pull off Kashima, it would have to have been wacked by a rock first. Remember that real Kashima only comes from one place in Japan and they do a great prep job.

Titanium nitrate coatings can wear quickly and not as slick as DLC, and sometimes worse stiction than bare chrome. DLC is the best generally used lower tube coating and shock shaft coating and lasts a long time if done right... and DLC is very slick compared to chromed tubes.

Some chemicals (nitromethane for one) will take titanium nitride right off so I wouldn't recommend it.

My experience with DLC is on the inside of 3.5 cc two-stroke engines. It is sometimes used on the crankpin, and it will last surprisingly long there considering the engine will turn 30,000+ rpm. I would have expected it to be essentially indestructible on suspension parts.

here is a interesting look at Kashima, by the legend AvE : https://www.youtube.com/watch?v=99WSFkYu8SY

Skip a bit out in the vijeo

Can we guess?  If it's who I would guess, they deserve to be blown out and ran outta the industry.

Bummer man.  Some of the work does look trick as shit.  Sucks yours didn't work out.  Coated suspension is one thing I've never had that I've always drooled over.

I bought a complete shock, used, online and took it to have it revalved and had to get a complete shaft because of the fucked up coating on it, a lot of people/companies shouldn’t be doing coatings 

Yeah SGB sucks you shouldn’t be afraid to say it 

Wonder what happened to that team went from a thing to nothing over night 

Not all DLC is created equally!

Very thin margins on coating services for suspension companies. To offer a competitive price they will likely be using the lowest cost vendor and process they can find. That combination doesn't lend itself to a high quality finished product.

A tetrahedral amorphous carbon (ta-C) DLC from a reputable vender like HEF or Oerlikon Blazers would last 1000s of hours on fork tubes.  Problem is they are not interested in small batch orders, and very few in the moto community would be willing to pay $800+ just for the coating process.

In short, it is unfortunate you are having issues.  Coating services through a suspension shop are always going to be a compromise. If you truly want coated suspension I would recommend starting with new/un-used components and working directly with a vendor. 

I'm a vet that likes to look good too, but I'll just let a guy from a different suspension company explain.

https://motocrossactionmag.com/bare-bones-looks-arent-everything-when-it-comes-to-fork-tubes/

Well that is BS. No coating center will strip the OEM hard chrome plating. All the coatings will be done to top of the chrome plating. 

If you are accutually worried about tolerances you can just measure your tubes. KTM gives you their spec for WP tubes in their workshop manual. If remember correctly tolerance is around 8 microns. DLC depending on the recipe is 2 microns max, but you can do 0.5 microns or less.

Stripping the chrome and hand polishing would not be done for DLC. Hard chrome is a great substrate for DLC, and additional thickness of DLC (1-2 microns) will have negligible impact on a tolerance stackup.

You can dlc hard chrome? I’m not arguing but genuinely curious. It seems like the DLC wouldn’t be able to penetrate and have good adhesion to the steel as you’d essentially be coating the plating rather than the steel itself. 

Yes, all TiN, DLC, etc. is on top of the hard chrome

Kashima and similar coatings done to the outer tubes require that the previous anodize is stripped first. 

Say what?

HMMM! I wonder if that's where my Fox's are coated? It is real kashima. Thicker than the Japan stuff.

In LA