Technical I'm resisting temptation

Those plastic ramps or "tire cradles" are all engineered to support way more weight than they are rated to support. It's like everything that supports a load, lifts a load, winches a load etc. It will always have a higher load rating than printed on the equipment. If it is made in China maybe not so, though!! Fifty years ago, I worked for a major USA store fixture manufacturer. One of my last jobs in that company was in an area called "the Model Shop". In that shop we would hand fabricate shelving with new modifications. The Engineering Department would come over and load test multiple shelves to failure, while measuring the deflection in the shelf at the same time. No way you would want a fully loaded shelving unit loaded with cans coming down on customers! The same applies to these plastic ramps/cradles. 60 Special

 

It’s not the engineers that concern me it’s the accountants and quality control

 

If you're worried about that, the plastic ramps are still your better bet over the steel ones.

 

Good. You can always die horribly later.

 

Oh I’m not pointing at plastics in particular, I’m well aware of the generally deplorable nature of products produced for the “hobby” market, not many want to pay top dollar for something they use infrequently. We drive this problem from at least 2 directions, first by buying the cheapest item we can find and congratulating ourselves on finding a bargoon, and secondly through investment, who wants to invest in a company that looses or breaks even. We drive the race to the bottom.

 

Oh definitely. All I was saying was that the cost savings and cutting qc corners typically has a more significant effect on metal products in my experience.

 

I have a set of plastic ramps I have been using for about 15 years. Does the plastic deteriorate over time? Or are they still safe today?

 

Generally plastic can deteriorate in oxygen, but usually sees more significant degradation due to UV exposure or exposure to chemicals like chlorine, etc.

As with anything, you can visually inspect them for signs you shouldn't use them such as:

• Whitening (indicates the material has been stressed/deformed and may be compromised).
• Crazing (fine cracking) or cracking.
• Discolouration, changes in finish (not glossy where it was), changes in texture.
• Signs of melting.
• Signs of deformation.

If you see any of the above, avoid using them. If they don't show any of the above items, I'd be confident using them.

 

I won’t go under without 2 different things to protect me. At minimum 6” solid wood under each tire with stops screw in. If higher needed then jack stands but the tires never leave the wood. @ 79 and using only a floor Jack the Eastwood look pretty good since you can remove the ramps.