Weight removal from rubber bumpers

[RobertE]

Anyone have any helpful advice on lowering the weight of rubber bumper cars? In general - or specifically regarding those bulky rubber bumpers on the MGB?

I read an article once(cant seem to find it) of someone drilling a lot of holes in the bumpers but it didn't seem to cut down *that* much weight.. I'd eventually like to mold something from FG or CF but for now I need a simpler solution.

Thanks

[Moderator]

As I recall, the rubber bumpers added about 80# to MGB.  

Instead of drilling a lot of holes (with "hole saw" bits, I guess) you might do better to fabricate a much simpler, lighter framework to hang the rubber on.

Fiberglass bumpers would probably be self-supporting, so even lighter. Photos of off-the-shelf fiberglass replacements can be found in <a href'http://www.britishv8.org/MG/TonyAndrews.htm">Tony Andrew's How-It-Was-Done article</a>. Tony's were made by Morspeed Performance. One of the first vendor sponsors of this website, Morspeed closed down "temporarily" and I'm not sure if they've ever really re-started production. Perhaps Tony will weigh in here on how well they worked out for him.

Of course you could shave the bumpers altogether. Dave Craddock at Perform Resources makes <a href="http://www.britishv8.org/Articles/2010-TechSessions.htm">excellent fiberglass MGB spoilers and valances</a> if you decide go that way.

[tr8todd]

Go to the junk yard and try to find an aluminum framed bumper that you can modify to work under your rubber skin.  I have used Rover SD1 bumpers under the TR8 skins before and just recently picked up a set of aluminum bumpers from a 1980 BMW 320i that look like they will work with minimal mods.  I slipped them onto the frame horns on a bumperless TR7 coupe and the looked like they were made for the car.  Same angled pointy nose and all.  Just need to trim a little on the ends, weld in some mounts, and attach the rubber.  Should save 40 pounds each end easy.  My preferred method is fiberglass bumpers, but they tend to crack after a while unless you box them in and fill with foam, and they offer no crash protection.

[BlownMGB-V8]

That's a great suggestion Todd.

Now if someone can just identify a suitable donor for the late MGB...

JB

[tr8todd]

Start with an older BMW.  If you can find an e21 or e30, I'd bet it would work.  You will have to do a little cutting and test fitting on anything you find.  I don't have any MGB rubber bumpers laying around, or I'd check the fit of the e21 bumper.  My MGB was a chrome bumper that now has a fiberglass Sebring kit.

[MGBV8]

I have removed 9 lbs. from my front bumper frame with a plasma cutter. I plan to remove it again & whittle it down more. An aluminum support frame would be ideal.

The front rubber bumper "skin" itself weighs 11 lbs.