gr3at8

Hi I was wondering if any one could give me any answers about which is better. Urethane or Fiberglass and what the pros and cons are?

TopGear8

iTrader: (3)

Since you live in NC I will be nice

Fiberglass will crack, split, and is very fragile. If your front bumper or side skirts are made out of Fiberglass, and you scrape over curbs and speed bumps alot, then chances are they won't last long.

Urethane is a stronger material and has more of a rubber feel to it. It is usually heavier than fiberglass(not by much) but it will not split and crack like fiberglass will. The downside to having a bodykit made out of Urethane is it will sag over time. The structure of it as not as solid(IE: Rubbery feel).

ac3mastuh

iTrader: (1)

Fiberglass is very easy to crack and break but also relatively easy to repair. Also, it tends to be cheaper.

Urethane is stronger but just as topgear8 said above, it tends to sag and not hold its shape well.

volcomx31

iTrader: (4)

fiberglass is better if you get lucky with fitment.

TopGear8

iTrader: (3)

^I disagree. I have seen too many sideskirts made out of fiberglass crack because they were bottomed out...

altspace

iTrader: (2)

FYI to the OP - OEM Mazdaspeed front bumper is fiberglass.

nvrfalter

iTrader: (1)

FYI to the OP, that's incorrect. the Mazdaspeed front bumper is made out of a material called Metton.

KrumbZ

iTrader: (3)

Urethane for daily driver and fiberglass if is just for weekends or show

mscamp02

iTrader: (3)

If I were you I would go with urethane but thats just me. It also depends on what kit you like.

I purchased a fiberglass kit and live in Eastern Ky, a bad choice because I do tend to bottom out occasionally and I dont even have a drop (damn hills!).

if you bottom go with urethane if not fiberglass

ZachLegend

No it's not. It's a material way stronger than Fiberglass.

I'm 50/50 on this issue, I like them both. As long as you can avoid scraping, fiberglass may be the way to go. It's cheaper.

volcomx31

iTrader: (4)

i have abused my fiberglass and it has not cracked..therefore, i think fiberglass is reliable and it's cheaper.

ZachLegend

Walter you don't sit that low haha. When I was running on my Mazdaspeed springs, which are a little lower than the Eibach's I never hurt my fiberglass. It depends how low your car sits.

volcomx31

iTrader: (4)

the MS springs sit higher dude. i am just saying, i have hit **** before (dips, parking bumpers, etc.) and my bumper has never cracked..the most i have seen are spider cracks (paint).

ZachLegend

debatable. It depends on how hard you hit. Personally I like Fiberglass more too, I hate how urathane fits.

volcomx31

iTrader: (4)

is your new front bumper fiberglass?

ZachLegend

yes sirrr. whole body kit is. it has a good amount of paint cracks, but thats it.

volcomx31

iTrader: (4)

the fitment looks pretty good. i hope to see you at the photo shoot.

Symbioticgenius

One thing not mentioned yet...

Fiberglass can be repaired, Urethane, not to my knowledge.

Ultimately, I would make the decision based on how cool you are with your body guy. If they do fiberglass, and won't rape you on repairs, I'd definitely go with fiberglass. Definitely.

Also, I never knew Urethane sagged eventually? How long does it take to show?

nvrfalter

iTrader: (1)

yeah it's just plastic basically, so if you live somewhere where it's hot often the effects happen quicker

chrism

Urethane parts are flexible and will absorb very small 'hits' without creating serious damage (cracks or holes). However, once urethane is cracked in any manner, it is usually sent to the scrap pile out back.
Although our shop has perfected methods of repairing urethane parts, at best, the repair is temporary and cannot be guaranteed.

Fiberglass parts are totally repairable. Most damaged parts, within reason, of course, can be repaired by any shop experienced with fiberglass. Proper repairs on fiberglass parts are durable and should be permanent.

Let's look at a repair cost scenario on a full bumper replacement kit.
Suppose there are a couple of good sized cracks in the front bumper. Normally, with a urethane kit, the bumper will need to be replaced.
Usually, the part cost is approximately $425.00 + $125.00 (average) in shipping. The labor to remove/replace and paint will be a constant cost in either replacing or repairing. There will probably be a time delay of up to 4 weeks until the replacement bumper arrives. The same cracks in a fiberglass bumper can probably be repaired immediately for a labor cost of $150.00. In most cases, unless the damage is very severe, this means a savings of $400.00 to repair a fiberglass front bumper rather than replacing a urethane bumper.

(taken from a site that makes body kits)

Huey52

iTrader: (2)

^ As chrism cites. I had a fairly minor indentation to my urethane bumper causing only a very small crack, but it therefore had to be replaced. If it had been fiberglass it could have been repaired. It cost me $575 total for the primered part from Mazda and to have it fully painted.

I do like urethane for its better fitment, flexibility and minor shock absorption tho' (especially good in parking lots).

NgoRX8

iTrader: (1)

I've dealt with both fiberglass and urethane.

Fiberglass is harder, chips from rock chips a lot easier, scrapes a lot harder, but can be entirely repaired very easily by a body shop that has worked with frp before. It can also be made to fit perfect through fiberglassing.

Urethane can be forced to fit better without any modifications since it flexes, but if its pretty off, can't really do much to fix it. It will absorb rock impacts better and bottoming out because of the flex. But because it flexes it will sag and warp over time due to heat.

I guess you can see which I prefer.

nycgps

iTrader: (1)

So lets see,

I have a bumper thats from Japan, and japanese companies love to use FRP (FiberGlass Reinforced Plastic ...) to make bumpers.

when I took it to bodyshop, almost everybody was like "wtf is wrong with you, getting a fiberglass bumper? one little rock and your whole bumper gonna be like CRaccCCCCK"

is it really true ?

Also, will a clear bra help ?

thx guys

NgoRX8

iTrader: (1)

One little rock will get you a rock chip.

Clear bra will definitely help with rocks. I've gone 2 years without a repaint thus far because of it. Before that, I was repainting every 6 months.

If the bodyshop people are the ones saying that comment, then they have not worked with fiberglass enough. Take it elsewhere.

soo... what did you get?

imput1234

iTrader: (6)

If you are low, don't go fiberglass, it'll get destroyed.

The MS in NOT fiberglass.