Crush Tubes - Tell me more.

[RSBob]

Am going to do a rubber delete on the rear bumper and am interested in using crush tubes instead of the US bumper shocks. I read here that the bumper shocks are 8 lbs each. So how much does a crush tube weigh? How effective is in a rear end tap compared to the bumper shock? Who sells them?

[porwolf]

As far as effectiveness of my stock US 1979 rear bumper I can only say it once saved me big time. I was hit in the back pretty hard, got out and expexcted major damage. But nada! I could not see anything at first. On closer inspection I notived the dust on the bumper top at the edge of the seal was pushed back about 3/4 of an inch. Clear indication that the retractable shocks were working perfectly.

[911dean]

TTT... I've got the same question's.

[kerthunk]

I put some factory crush tubes on my '79. They are considerably lighter than the shocks, but I didn't weigh any of the parts. If I had to guess, maybe half the weight. I'm not sure how effective they are in an accident, but the factory was using them for years on ROW cars after introducing the shocks to the US. The shocks were designed to deal with 5 mph impacts, so I'm not sure how much added benefit they would have vs the crush tubes. I picked up my tubes from Aase Sales — Welcome.

I noticed that Rennline also makes some.

[porwolf]

Originally Posted by kerthunk

I put some factory crush tubes on my '79. They are considerably lighter than the shocks, but I didn't weigh any of the parts. If I had to guess, maybe half the weight. I'm not sure how effective they are in an accident, but the factory was using them for years on ROW cars after introducing the shocks to the US. The shocks were designed to deal with 5 mph impacts, so I'm not sure how much added benefit they would have vs the crush tubes. I picked up my tubes from Aase Sales — Welcome.

I noticed that Rennline also makes some.

I guess that crush tubes only take one accident because they don't retract and spring back. After a hit they would have to be replaced.

[kerthunk]

Yes, if the crush tubes do their job correctly, they are definitely a one time use item. I thought that the factory recommended replacing the shocks after an impact as well. I think that most folks don't replace them unless they start leaking their fluid. New shocks run $550+ each from the host. The crush tubes run around $100 each.

[RSBob]

Aase Sales — Aase Sales Porsche body parts

Crush tubes - thanks a lot Porwolf

[911dean]

Aase Sales — Aase Sales Porsche body parts




Crush tubes - thanks a lot Porwolf

Ditto

[javadog]

The front crush tubes weigh about 25 ounces. The rears are a few ounces more. Neither will survive much of an impact.

JR