OT: Weight limit on lift
01-04-2018, 12:25 PM
#1
Race Car
Thread Starter
OT: Weight limit on lift
All,
Thought I'd ask this here because this seems to be the group with a lot of toys.
For those with experience with car lifts, how much do you trust the published weight limit? Example: If a lift claims to have 8K lbs capacity how much weight would you be comfortable storing on it? 8K? 6K? less/more? Is this like tires that say they will get 60K miles but really get 20K?
Thanks.
Tim
Thought I'd ask this here because this seems to be the group with a lot of toys.
For those with experience with car lifts, how much do you trust the published weight limit? Example: If a lift claims to have 8K lbs capacity how much weight would you be comfortable storing on it? 8K? 6K? less/more? Is this like tires that say they will get 60K miles but really get 20K?
Thanks.
Tim
01-04-2018, 01:10 PM
#4
Often lifts are safety tested at almost double the rated weights. For most of the name brand lifts I would feel comfortable going all the way to the rated weights but in most cases people are only storing 4k lb cars so 10K lb lifts are overkill anyway.
01-04-2018, 01:25 PM
#5
Drifting
From an engineering perspective, their should always be a "safety factor" multiple. Depends on certification issued out or manufacture for the lift of what the safety factor is.
A safety factory of 1.20 means that it can handle 20% more of what's actually rated for. Contact the manufacture and ask them what's their safety factor on the lift. Generally speaking - most here would be shocked to find out how strong metal really is when structured correctly. I wouldn't be surprised if the SF of the lift is about 2. Meaning it can handle twice the weight, that it state's it's rated for.
The biggest unknown and variable for a manufacture of a lift is the concrete the lift is on, and properly secured bolts. That's were my concern would start before start questioning the metal giving away (given that the metal is a high quality steel)
A safety factory of 1.20 means that it can handle 20% more of what's actually rated for. Contact the manufacture and ask them what's their safety factor on the lift. Generally speaking - most here would be shocked to find out how strong metal really is when structured correctly. I wouldn't be surprised if the SF of the lift is about 2. Meaning it can handle twice the weight, that it state's it's rated for.
The biggest unknown and variable for a manufacture of a lift is the concrete the lift is on, and properly secured bolts. That's were my concern would start before start questioning the metal giving away (given that the metal is a high quality steel)
01-04-2018, 05:35 PM
#6
Intermediate
You don’t specify what type of lift you intend to use to store you car. If it is a two post lift I would have some serious concerns.
Likely your question is for a four post lift. A 4” thick non structural slab on grade, the type of slab in most residential garages, most likely would support your car if installed in accordance with mfg’s Instructions. This installation, however, would not likely comply with California Building Code. The reasons for this are beyond the scope of this kind of posting.
if you do purchase a four post lift remember that CA regularly experiences earth quakes which will result in lateral loads applied to the lift structure and attachment to the concrete slab due the lift self weight and the weight of the elevated car.
i would not recommend that a vehicle be stored elevated on a two post lift without engineering the attachment to the slab and the design of concrete slab itself. Not saying this hasn’t been done or that the results would be catastrophic.
Likely your question is for a four post lift. A 4” thick non structural slab on grade, the type of slab in most residential garages, most likely would support your car if installed in accordance with mfg’s Instructions. This installation, however, would not likely comply with California Building Code. The reasons for this are beyond the scope of this kind of posting.
if you do purchase a four post lift remember that CA regularly experiences earth quakes which will result in lateral loads applied to the lift structure and attachment to the concrete slab due the lift self weight and the weight of the elevated car.
i would not recommend that a vehicle be stored elevated on a two post lift without engineering the attachment to the slab and the design of concrete slab itself. Not saying this hasn’t been done or that the results would be catastrophic.
01-04-2018, 06:31 PM
#7
Addict
Rennlist Member
Rennlist Member
I would think the slope of the floor would have a big impact on some designs too - my garage floor is pretty sloped (for drainage purposes, I guess?).
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01-04-2018, 07:24 PM
#8
Burning Brakes
In the case of a 4 post lift you need to be aware of more than just the total weight capacity. This is often overlooked. The info below is from the Bendpak website for a 9000lb rated lift:
For example my Cobra wheelbase is about 90". That would equate to about 42% of the rated capacity of my 9000 lb lift or 3780 lbs. The car is only 2400 lbs so still have a nice margin.
Definitely something to consider though.
- Min. wheelbase @ rated capacity: 135" / 3,429 mm
- Min. wheelbase @ 75% capacity: 115" / 2,921 mm
- Min. wheelbase @ 50% capacity: 95" / 2,413 mm
- Min. wheelbase @ 25% capacity: 80" / 2,032 mm
For example my Cobra wheelbase is about 90". That would equate to about 42% of the rated capacity of my 9000 lb lift or 3780 lbs. The car is only 2400 lbs so still have a nice margin.
Definitely something to consider though.
01-04-2018, 07:43 PM
#9
Race Car
Thread Starter
In the case of a 4 post lift you need to be aware of more than just the total weight capacity. This is often overlooked. The info below is from the Bendpak website for a 9000lb rated lift:
For example my Cobra wheelbase is about 90". That would equate to about 42% of the rated capacity of my 9000 lb lift or 3780 lbs. The car is only 2400 lbs so still have a nice margin.
Definitely something to consider though.
- Min. wheelbase @ rated capacity: 135" / 3,429 mm
- Min. wheelbase @ 75% capacity: 115" / 2,921 mm
- Min. wheelbase @ 50% capacity: 95" / 2,413 mm
- Min. wheelbase @ 25% capacity: 80" / 2,032 mm
For example my Cobra wheelbase is about 90". That would equate to about 42% of the rated capacity of my 9000 lb lift or 3780 lbs. The car is only 2400 lbs so still have a nice margin.
Definitely something to consider though.
01-04-2018, 07:46 PM
#10
Burning Brakes
Please keep in mind that is for a specific lift the Bendpak HD9XW. It is big enough to put my crew cab F150 on it so is longer than standard. I would assume a different ratio would exist for different length lifts. Find the one that is specific to what you are using.
01-04-2018, 07:51 PM
#11
Instructor
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I have a Challenger that is gold labeled. That means the testing company put 1.5X the max weight and it held fine. Mine is a 7500lb so it was tested at 11,250lbs. With that said I would never exceed the max weight, but have had my Cayenne on it which is heavy as $hit and it went up and down like nothing was on it.
01-04-2018, 08:28 PM
#12
Originally Posted by GrantG
I would think the slope of the floor would have a big impact on some designs too - my garage floor is pretty sloped (for drainage purposes, I guess?).