When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi all, I have a '74 coupe and noticed that the original urethane bumper cover has developed several cracks along the bottom where the reinforcing plate attaches and is also split in the bottom center. I have two questions I guess: is it possible to repair the original urethane bumper cover? Should I change to the flexible (TruFlex) fiberglass bumper cover? Would to love to hear from people who have switched to the flex-fiberglass part and what their thoughts are on this change! Thanks
I used Trueflex bumpers on my 77 restoration, and for me it was the biggest mistake I made on the rebuild. BUT, it is important to you for me to qualify this. The entire body of a Corvette is made of fairly stout fiberglass i.e. it is thick. Trueflex bumpers not only use flexible resin, but they are also made very thin. This is how they can be manipulated to fit. Unfortunately the down side to that the bumpers can have waves in them, they can warp especially in the sun, and bottom line is that they do NOT look as solid as the rest of the car. If that is okay with you, then the are easier to fit to the body than a solid fiberglass NON flex bumper.
But, even with Trueflex bumpers, my painter had to work those bumpers to match the body, so I still had to pay him to do that and was a substantial increase in cost of the paint job.
So, my recommendation is use NON flex fiberglass bumpers, and make sure they are thick like the rest of the car. Face the reality this will take bodywork because NO bumper is going on the car without bodywork......unless of course you don't care what it looks like or accept poor fitting parts.
The original rubber bumpers are so bad in fit and finish, with warping and waves that its an insult that GM ever produced them. Why is poor body condition acceptable on a fiberglass car when it was not on a metal car? I don't get it.
I really can't blame GM for the condition of these bumpers 40 years down the road-
They had to work with the techniques and technology that was available in the 70's.
And let's be honest, these cars weren't designed with the intent to last 40-50 years.
The bumpers didn't look bad when the cars were new, but after 40 years, not so much.
GM was stuck between a rock and a hard place in trying to adhere to Federal mandates while trying to maintain the character and intent of the car. I think they did the best they could with what they had to work with and the price point of the car.
I would have expected the aftermarket to have come up with a better product by now but I guess there just isn't any money in it...
Ive been messing with fiberglass almost 40 years, yikes!
I pretty much have zero use for flex glass, i find it more a marketing hook than actual good thing in fact most people have far more fit issues with it than regular fiberglass
I need a new front bumper on my 74. Most of the feedback from the shops that I have gotten is that you'll pay more for fitting fiberglass but that the end product is way superior to anything else.
You need to figure that it does not matter whether you use Truflex or rigid glass, if you want a perfect fit, you will have bodywork. I think most anyone will agree with that. So, in my opinion the advantages of Truflex bumpers are irrelevant, only leaving the disadvantage that they are too thin, and will have waves and warps. I would never do it again.
As for the original rubber bumpers, I agree GM did what they had to do. In 2018, we don't need to do that. Solid fiberglass is the way to go. Don't waste time with Truflex, unless you are okay with waves and warping.
I really can't blame GM for the condition of these bumpers 40 years down the road-
They had to work with the techniques and technology that was available in the 70's.
And let's be honest, these cars weren't designed with the intent to last 40-50 years.
The bumpers didn't look bad when the cars were new, but after 40 years, not so much.
GM was stuck between a rock and a hard place in trying to adhere to Federal mandates while trying to maintain the character and intent of the car. I think they did the best they could with what they had to work with and the price point of the car.
I would have expected the aftermarket to have come up with a better product by now but I guess there just isn't any money in it...
The aftermarket does have a better product......fiberglass. The same material as the rest of the car.
Last edited by Torqued Off; 06-12-2018 at 06:08 PM.
Can't repair the original urethane; I tried. I used the TruFlex for the front and rear bumpers on an original paint '74 I owned in the past. On and off many times to get it as close as possible to the shape of the body. I did no work to the body. I sprayed them in lacquer and was very happy with the results.
Originally Posted by jdolomount
Hi all, I have a '74 coupe and noticed that the original urethane bumper cover has developed several cracks along the bottom where the reinforcing plate attaches and is also split in the bottom center. I have two questions I guess: is it possible to repair the original urethane bumper cover? Should I change to the flexible (TruFlex) fiberglass bumper cover? Would to love to hear from people who have switched to the flex-fiberglass part and what their thoughts are on this change! Thanks
To anyone considering Trueflex, I would caution you to judge them by the pictures some of the members are posting. You have to see them in the right lighting conditions, angles, reflections, etc to see the warping and lack of quality. I know some people are satisfied with them, but it all comes down to the expectations and levels of quality you are satisfied with. IF you are okay with the bumpers looking less solid and warped / wavy, then I guess you should use them, but if not, use fiberglass, not Trueflex. There is no price advantage, and lots of disadvantages.
Last edited by Torqued Off; 06-22-2018 at 05:42 AM.
To anyone considering Trueflex, I would caution you to judge them by the pictures some of the members are posting. You have to see them in the right lighting conditions, angles, reflections, etc to see the warping and lack of quality. I know some people are satisfied with them, but it all comes down to the expectations and levels of quality you are satisfied with. IF you are okay with the bumpers looking less solid and warp / wave free as the rest of the car, then I guess you should use them, but if not, use fiberglass, not Trueflex. There is no price advantage, and lots of disadvantages.
I can tell you are passionate on this one, and i dont blame you as i fully agree,
Its like those one piece astro tops, i find them halfassed cheaply made junk not worthy of a corvette but some guys just love them.
I installed Truflex bumpers front and back last year when I stripped and painted my 76.
Rear was almost a perfect fit but front needed a fair amount of hand fitting.
All these cars are slightly different so what fits on one may not fit perfectly on another and require some work.
The Truflex really does not have as much flex as I thought it would. Maybe it would take a little ding better but I don't know. If you crack fiberglass you can repair it so....
If I ever do it again, I think I'd go with the rigid fiberglass bumpers. They are thicker and there is more material to work with. The Truflex are on the thin side but you still use the standard fiberglass materials on them. I used Evercoat's product and it worked well.
Bad product? Not at all. The same company also makes rigid fiberglass bumpers too.
I used the stainless steel mounting nuts and washers kits on the front and back.
Just be patient and understand that neither bumper will probably be just a bolt on. You are going to have to fit them. There are a lot of good tips on this forum on how to do that particularly in the paint and body section.
Thanks guys.. lots of good info here and points to ponder!!
I'm still unsure which way i'm going to go. I'm not in a rush and will probably tackle this job later this summer.
More comments welcome... pix too!
The aftermarket does have a better product......fiberglass. The same material as the rest of the car.
While fiberglass is aesthetically pleasing to the eye, it doesn't satisfy the design intent of the rubber bumpers-
Which was the ability to absorb low speed impacts without damage or requiring significant repairs.
Fiberglass will need to be repaired and re-painted for every infraction encountered and therefore isn't a 'better' product based on the intent and purpose of the part.
My original statement still stands- I would have thought the aftermarket would have come up with a better solution by now.
Car bumpers have been flexible and impact resistant for decades and they seem to be holding up well.
Why can't that same material be used for replacement C3 bumpers?
Just my .02
While fiberglass is aesthetically pleasing to the eye, it doesn't satisfy the design intent of the rubber bumpers-
Which was the ability to absorb low speed impacts without damage or requiring significant repairs.
Fiberglass will need to be repaired and re-painted for every infraction encountered and therefore isn't a 'better' product based on the intent and purpose of the part.
My original statement still stands- I would have thought the aftermarket would have come up with a better solution by now.
Car bumpers have been flexible and impact resistant for decades and they seem to be holding up well.
Why can't that same material be used for replacement C3 bumpers?
Just my .02
I really am not concerned about impact damage as the criteria for choosing the material. While this theoretical 5 mph crash requirements sounds good, you still have going to have to repaint even at that speed. I choose to take the risk, and consider the more important matter of having the car look as good as it should, and will have to deal with repairs if it gets damaged. That is my priority. To sacrifice the looks of the car with those wavy rubber bumpers.....I would prefer to not own it if it had to be that way, and can never understand how people buying these cars new were not appalled.....but, its about standards, and mine are high. The bumpers needs to look as good as the rest of the car.
As for materials like other cars....I agree, but it does not exist yet.
Last edited by Torqued Off; 06-21-2018 at 05:34 PM.
Great example the factory had to do what they had to do but its not always best,
I have yet to see a factory 74 to 82 bumper hit something at any speed short of a light love tap and not need a touch up so calling it more durable or forgiving over fiberglass might have worked in 70s sales ads for corvettes but not the real world,
I cant imagine a reason a person would want a flawless high end paint job and a tacky wavy bumper....
06-11-2018, 05:39 AM
'74 Front Bumper - Truflex or not?
