C2 Bumpers

[Jim M.]

I'm in the midst of purchasing some used rear bumpers. The seller is telling me they are originals. Is there anything I can look for such as part#, markings, etc... that tells me they are originals.

Thanks

[Harry S.]

Re: C2 Bumpers

Jim, as I recall the originals are heavier and therefor the metal is thicker. Maybe someone with a repro set can send you the weight and thickness of one. I can't get at my originals as the car is not available.

[Peter J.]

Re: C2 Bumpers

Jim,
I know Paragon stamps an id on the inside of theirs

[Stephen L.]

Re: C2 Bumpers

Jim, my original 67 rear bumpers measure about .110" thick. Take your micrometer with and check them. I believe the aftermarket bumpers are significantly less.

[Patrick T.]

Re: C2 Bumpers

As far as I know, Paragon has the original tooling for the midyear bumpers. I can't figure out why they can't make their repop bumpers the same thickness as the original. If they did, for sure they would have the midyear bumper market cornered. I don't understand what the big deal is in making the correct thickness bumper. PT

[Jack H.]

Re: C2 Bumpers

You can't figure out why because you don't have experience in the reproduction parts industry. Here's how it works.

The licensee negotiates a non-exclusive contract including what he can think of as being important (past drawings, any tooling still in existence, purchasing/supplier files, Etc.) and when they strike a deal, it's done. GM treats the licensees at 'arms length'.

They do NOT want to 'police' a licensee's efforts and absorb any residual product liability! The auto parts business is typically LOADED with litigation/liability potential.

Almost NONE of the licensee's have an in-house engineering staff. So, despite the fact that a given licensee may have obtained all or many of the original drawings and engineering records, the documents generally sit gathering dust...there's simply nobody 'home' to read/interpret/understand.

Many just go to the last known source/supplier and negotiate a price for his making another, limited volume, production run. In such cases, they get approximately the parts that were LAST sold to GM for service replacement use. Hence, the licensees have little/no understanding of any prior running changes that were historic to that part...

WE who judge the cars often wind up being the QA/QC 'police' and change comes SLOWLY as 'some' buyers complain about this/that aspect of the part back to the licensee. Some classic car clubs WILL work with a licensee to endorse or 'certify' a given reproduction part. But, NCRS does not...

Das bez da way it is!

[Gary B.]

C2 Bumpers; original tooling

As far as I know, Paragon has the original tooling for the midyear bumpers. I can't figure out why they can't make their repop bumpers the same thickness as the original. If they did, for sure they would have the midyear bumper market cornered. I don't understand what the big deal is in making the correct thickness bumper. PT

Patrick,

If Paragon is using the original tooling, the only thing I can think is that something about the tooling has worn dimensionally and the parts don't come out the same as when the tooling was not worn.

Gary

[Duke W.]

Re: C2 Bumpers

I had a buddy who bought some new rear bumpers from GMPD - long time ago - probably late seventies. The surfaces were wavy and the chrome plating was poor. The tooling was obviously worn. They were terrible.

He took them back and had his originals rechromed.

Unless that tooling was replaced at some point I can't imagine how bad they would look, today.

Duke

[John H.]

Re: C2 Bumpers; original tooling

Patrick,

If Paragon is using the original tooling, the only thing I can think is that something about the tooling has worn dimensionally and the parts don't come out the same as when the tooling was not worn.

Gary

Unless a steel rolling mill is already making exactly the thickness you need and has a small quantity available, you have to compromise; otherwise you're stuck with a minimum quantity of 20 or 30 tons of the material you need (at a very high short-run price), and none of the vendors can afford to inventory that much raw material.

Paragon's fabrication contractor for bumpers uses the original GM draw dies, which are still usable, but the trim dies are no longer economically feasible to repair; t r i m m i n g is done instead with robotic lasers before welding the two halves together. I spent several days following their process through stamping, tr i m m i n g, welding, metal-finishing, and plating, and wrote a feature article on the entire process in the September '08 issue of "Corvette Enthusiast" magazine; it's VERY labor-intensive, and I'm surprised they can make a profit on them at their pricing level.

Photo below is a run of one side of midyear front bumper outer halves fresh from laser t r i m m i n g, ready for welding to the inner halves; they don't make these things by the thousands, and the die and press setup costs for each run are very steep.

[Peter J.]

Re: C2 Bumpers

Duke,
I have one of those NOS late made GMPD bumpers on my car and it looks terrible. It came right out of a GM box with a GM label on the inside surface.
Very wavy, poor welding and chrome. But it is all I had and it was "NOS" so I put it on until I find better.

[Jim M.]

Re: C2 Bumpers

Thanks for the information. I will check it out.

[Terry M.]

Re: C2 Bumpers

As far as I know, Paragon has the original tooling for the midyear bumpers. I can't figure out why they can't make their repop bumpers the same thickness as the original. If they did, for sure they would have the midyear bumper market cornered. I don't understand what the big deal is in making the correct thickness bumper. PT

Another factor to consider relative to using thinner material -- thinner material requires significantly less force to form. Thus a smaller press can be used. A smaller press MAY have reduced cost of operation.

[Jeff B.]

Re: C2 Bumpers

I just went through the whole bumper thing for my 1964 restoration project. My originals were OK, but will never be perfect. I believe they are originals but can't really be sure. They measure between .98 and 1.11 thickness and have no marks stamped into them I can see. Restoration and chroming will likely cost 1k - $1200.00 and the US made Paragon bumpers are circa $1,700.00 when you buy the whole set.

I talked to Paragon and another company that resells their (the Paragon) product and both said that they are now the correct thickness. hmmm? I ordered a set that should arrive tomorrow and will determine if I keep them once they arrive. I'm building my car to be a top flight car but I'm the first to admit that I tend towards over-restoration, and a perfect set of brand new bumpers is appealing to show off the big investment in body and paint. I hope they are all they say they are, but I'm holding on to my originals just in case. I'll post the material thickness of the new bumpers when I get them.

[Jim M.]

Re: C2 Bumpers

I just went through the whole bumper thing for my 1964 restoration project. My originals were OK, but will never be perfect. I believe they are originals but can't really be sure. They measure between .98 and 1.11 thickness and have no marks stamped into them I can see. Restoration and chroming will likely cost 1k - $1200.00 and the US made Paragon bumpers are circa $1,700.00 when you buy the whole set.

I talked to Paragon and another company that resells their (the Paragon) product and both said that they are now the correct thickness. hmmm? I ordered a set that should arrive tomorrow and will determine if I keep them once they arrive. I'm building my car to be a top flight car but I'm the first to admit that I tend towards over-restoration, and a perfect set of brand new bumpers is appealing to show off the big investment in body and paint. I hope they are all they say they are, but I'm holding on to my originals just in case. I'll post the material thickness of the new bumpers when I get them.

Jeff

Thanks for the information. I look forward to hearing from you on your new bumpers.

[Ronald L.]

Re: C2 Bumpers

Just found this thread when looking for some bumper markings.

Thickness of original 63 67 was .13, by the early 70's it had been thinned out by GM to .11, I have parts out of the box like many guys posted so I know when and where I bought them.

They got thinner in the 80's. And thinner yet with the parts out there now.

The other thing is that some replaters grind them like crazy and ruin them, ending up with .09 or less, and worse burn through them.

Paragon, following their markings on other parts, would put PR on the part somewhere.

Has anyone seen this marking?bumper markings.JPG