2 post - Symmetric or Asymmetic?

[rattle_snake]

Yes, yet another 2 post lift thread (YA2PLT). After doing a fair amount of research my confidence in choosing a product has diminished. This is especially concerning as my engineering mind should not function in this manner, so I blame those responsible for marketing these contraptions.

Main question is to go symmetrical or asymmetrical (or psdeosymmetric/verysymmetirc/sortasymmetic...) Some can be installed either way but I still need to decide. Looks like I could go either way and be OK, but one must be better (for my application) than the other. I would install in a 'wide' configuration.

Lift will be for occasional use, looking to stay below $3k. I have 12' ceiling, although the bottom cord is at 147" @ lift location. Note the bendpak is 12'1"

Lowered mustang, 57/43 weight distribution. Pinch weld is 5" from ground. Forward subframe is 4" (preferred jack point).


8500# crew cab long bed diesel. ~60/40 weight distribution. Planning on 10k lift over 9k as this truck (with someone in it) is close to 9k. Some lifts spec individual axle weight and front is over 5k.



Something like(?):
-Bendpak XPR-10S
-Atlas PV-10P
-Challenger E10
-<some other lift>

I called bendpak regarding their low profile arms. They have same min height as the regular arms. The tubes are more rectangular giving an extra inch at the rocker, but are not as versatile as the standard 2/3stage setup.

So if you have similar vehicles and pondered this very question (or how gravity really works) what did you buy and why? What would you do next time?
Thanks.

 

[zkdiesel]

Rotary spo12ta
Best of everything
True symmetric lift you can use like a asy, with equal length 3 stage arms front and rear

 

[pattenp]

There are 2 post lifts that can be loaded both symmetric or asymmetric. Challenger Lifts makes one called Versymmetric.
http://www.challengerlifts.com/versymmetrictech.shtml

 

[rattle_snake]

There are 2 post lifts that can be loaded both symmetric or asymmetric. Challenger Lifts makes one called Versymmetric.
http://www.challengerlifts.com/versymmetrictech.shtml

Thanks for the feedback. I looked at those. One could say the same for all lifts. Their literature provides no real technical description of what verysymmetic really is. Yes the front arm is 'bent' but that has no change on the statics of the system.
My understanding is that an asymmetrical lift just puts COG behind the post-2-post centerline. That's defined as poor balancing on a symmetric lift. Rotating the columns (asymmetric) just lowers side loading of the carriage/post interface. This still leaves the 'system' unbalanced, with an upward force on the forward concrete anchors. But obviously I'm no expert hence this thread to help educated myself.

I am trying to fully understand the physics & forces involved, and why one method would be chosen over another given an application such as mine. My engineering mind must fully understand before a financial transaction takes place. Call it a curse.

 

[walrus]

Rotary spo12ta
Best of everything
True symmetric lift you can use like a asy, with equal length 3 stage arms front and rear

He isn't buying that for less than 3 grand. I have an Rotary spo10, I think it would lift your car, 4 inches would be tight though. I doubt you are buying that for less than 3 grand also.

 

[WhiffySpark]

Thanks for the feedback. I looked at those. One could say the same for all lifts. Their literature provides no real technical description of what verysymmetic really is. Yes the front arm is 'bent' but that has no change on the statics of the system.
My understanding is that an asymmetrical lift just puts COG behind the post-2-post centerline. That's defined as poor balancing on a symmetric lift. Rotating the columns (asymmetric) just lowers side loading of the carriage/post interface. This still leaves the 'system' unbalanced, with an upward force on the forward concrete anchors. But obviously I'm no expert hence this thread to help educated myself.

I am trying to fully understand the physics & forces involved, and why one method would be chosen over another given an application such as mine. My engineering mind must fully understand before a financial transaction takes place. Call it a curse.

You center the car (for the most part) on a symmetrical lift. Asymmetrical your posts are around your a pillar for a car steering wheel for a truck/rwd.

I've picked up a long bed duramax a few times a week on a asymmetrical 9k lift with no issues. The issue with going up to 12k if the arms may not clear your rockers. But it being in wide mode may help that

 

[04chase]

i have similar vehicle , lowered cadillac CTS-V with little clearance (carbon rocker panel aero mods) and a 07 lifted 2500 hd duramax crew cab short bed ( doesent weigh 9k , and neither does your 250 , maybe 8k on a cheat day)

I went with a bendpak xpr-10a-lp . The arms do have the same clearance but with two stage it can get further under the car without the 2nd stage (higher than 4" ) come into play and that is where it counts. Ive had 3500 dually's on the 2 post quite a few times and have done more than a few suspension lifts using it. The 4 post is for parking and quickies. The two post was my first buy and its been one of the best tools ive got.

 

[gnxtc2]

Your truck is going to be a PITA to lift. You need the spread of 12k lift arms to grab the front radius arm and to reach the front rear leaf bracket. The 12k arms might be too high and too long to work on the Mustang. The issue on the truck is grabbing the frame on the driver side by the fuel tank, especially if you have the off road package (skid plates) hence the reason you need to grab the leaf mount.

Going with a 12k lift, you need more height than 12'. My shop is 12'.

I have a Bendpak XPR-10. I made longer truck adapters to clear the traction bars and running boards on the Ford trucks. The Ford trucks frame are higher that the body. It worked great on my lowered GN, my 1997 Ford OBS truck and my buddy's 2002 Ford Crew Cab, 8' bed. I bought a 2016 Ford Crew Cab, 8' bed with the off road package. With the Bendpak, I had to drop the fuel tank and transfer case skid plates to grab the frame. I have since installed a Titan Tank and traction bars and can't lift the 2016 anymore. With the Titan Tank, the tank sticks out past the outer edge of the frame. You can see in the pics where I had to place the arms on my 2016 truck.

I called up Bendpak and explained the situation that I have. The guy told me that I can put the longer arms from their asymetrical 10k lift onto mine. The arms cost around $350 each.

Before buying a lift, call up the manufacturer and find out about longer arms.

Pic you need more pics, let me know.

2016 truck

Billy T.
[email protected]

 

[rattle_snake]

Thanks everyone for the feedback.

gnxtc2, thanks for the specific info on lifting a 2011+ ford. Very helpful. I do not have the skid plates. I have cussed the fuel tank/frame situation several times installing stuff. My Ford has AMP retractable steps. If I don't disable them I will need long pad extension to clear, and they come down lower than fixed steps.

 

[diviney]

Thanks for the feedback. I looked at those. One could say the same for all lifts. Their literature provides no real technical description of what verysymmetic really is. Yes the front arm is 'bent' but that has no change on the statics of the system.
My understanding is that an asymmetrical lift just puts COG behind the post-2-post centerline. That's defined as poor balancing on a symmetric lift. Rotating the columns (asymmetric) just lowers side loading of the carriage/post interface. This still leaves the 'system' unbalanced, with an upward force on the forward concrete anchors. But obviously I'm no expert hence this thread to help educated myself.

I am trying to fully understand the physics & forces involved, and why one method would be chosen over another given an application such as mine. My engineering mind must fully understand before a financial transaction takes place. Call it a curse.

Justin:

I am also trying to fully understand the sym/asym pros and cons. I would like to take exception to something you stated above. The classic symmetrical configuration is straight-forward. The CG of the load is positioned directly between the posts, and as long as there is symmetry between the forward and rear lift arms, it is balanced. The load on the posts pulls them together in one plane, but there is no tendency to tip forward or back (imbalance).

Contrary to your statement above, the Asymmetric configuration is NOT like a poorly balanced symmetric configuration. In the Asymmetric case, the CG is approximately 36" behind the posts. The "V" shape formed by the front and rear arm is canted back (~30 degrees) such that there is still a symmetry (equal weight on the forward and rear arms). Again, the posts are simply pulled together (along this new 30 degree plane) and they do not want to tip in the other direction. This is also perfectly balanced.

Rotating the posts does not affect balance however, as you point out, it orients the carriage / post interface to it's optimal design point. Of course, if you want the best of both worlds, then using a non-rotated post to perform an asymmetric lift (as with the "verysymmetic" concept) is less than ideal for the carriage bearing surfaces. (and vice-versa).

If I were in your shoes (plenty of room, and probably some utility for both lift modes), I would purchase a lift that represents your most frequent usage (maybe asymmetric if you tend to work more on cars than trucks). Then when you want to work on the truck and symmetric is desired, just drive further forward to put the CG between the posts and set the arms accordingly. You will get a symmetric lift and yes, maybe the carriage bearing surfaces will be non-optimal. The lift companies seem to be OK with doing this however... I think you can do this just fine with the BendPak. It may require some jockeying of the vehicle while setting the arms (and they don't have the bent arm or a spiffy name).

In my case, I am considering a BendPak XPR-10 too, but I am severely constrained in floor size and height. I will have to allow the posts to penetrate my ceiling (124" high) and install the crossover in the attic area (dodging the trusses). I also have to commit to a mode because I only have a 19' length. If I bolt the posts to provide an asymmetric mode, I would not have enough room to drive an extra 36" to get the CG into the symmetric position !! I have to make a commitment (UGH).

My saving grace is that I do not have such a disparity between vehicles as you do with your big-**s truck ! Mine range from a Miata to an Accord (with several in between).

BTW - I saw your other thread, and your new setup is very impressive. Now all you need to have is more time to enjoy yourself.

 

[rattle_snake]

Diviney,
Thanks for the info and explanation, I agree with your assessment. As for loading the anchors, I guess either configuration will do so to the outer ones. For a symmetric clear floor type this force could be reduced/eliminated with the top bar (as the forces are opposite and in-line). but I don't believe this is the intent of the design, and in either case the outer anchors are holding the load above your head.
I think either type of several brands would suit my needs fine. Still leaning towards a symmetrical bednpak at this time. My main use of the lift will be the project vehicles I haven't purchased yet.

I'm in the same boat with ceiling height. My ceiling is 12'+ but... I called bendpack and they stated that you need 6" more than the column height to assemble the unit (to get the top plate installed in the columns). Their install instruction spec 1". So I think I will place lift between truss bottom cords and when I get around to dry walling the ceiling, have that area raised.

Good luck with your decision.

 

[Y2KFirehawk]

Old thread but I wanted to say thank you for all the great information! A friend is trying to convince me in to the Atlas PV-10 but I'm concerned of loading my Z06 on it, being so low. For a while I have had my eyes on the Bendpak XPR-10AS and not reading about the low profile benefits detailed here. I feel like the XPR-10AS-LP may be the way to go.

 

[gnxtc2]

Old thread but I wanted to say thank you for all the great information! A friend is trying to convince me in to the Atlas PV-10 but I'm concerned of loading my Z06 on it, being so low. For a while I have had my eyes on the Bendpak XPR-10AS and not reading about the low profile benefits detailed here. I feel like the XPR-10AS-LP may be the way to go.

I have the Bendpak XPR-10 symmetrical set up in the wide stance. My friend brought over his 2018 Gran Sport Convertible. Being a convertible, he bought the pucks so the Vette could be lifted in the proper spot. I was afraid of possibly lifting the car in the wrong spot and cracking the fiberglass.

I couldn't get the car positioned in the proper spot to lift it. Either I could lift the front or the back. The arms were to long. Hopefully that helps.

Billy T.
[email protected]

 

[pbon]

Common problem. You can drive onto planks if the car is too low. You may need to put a rubber or wood puck substitute onto the middle of the arm rather than the end at the rear of the car and use a lifter puck at the front of the car to get the heights even.

 

[CraigStu]

Before I retired the last shop I worked in had Rotary 9k asymmetric lifts. The installers put a double hump plate on the floor to locate the LF tire. Like this except made from steel.
https://www.garageenvy.com/shop/park-smart-parking-mat.html
99% of cars we put the tire between the humps. The huge SUVs we put the tire ahead of the plate. moving the suv forward moved it's center of gravity forward. Over the years the used car team put every kind of vehicle on these lifts no problem including a big American dually pickup.

 

[brownbagg]

that a big truck, might want to increse the lift to maybe 12 or 14

 

[mautotech]

I have an asymmetric Rotary SPOA10SWEH1-TRIO Shockwave lift at home and I've lifted Super cab, 8ft, F350 diesels with no problems at all. Super stable and no problem placing the asymmetric TRIO arms. Mine is the extended height version to accommodate higher trucks so that's a plus, (and necessary for some trucks). I've got the pad adapters and the truck adapters and have been able to lift everything with those two types.

 

[MSPoirier]

I installed a simetrical Forward lift I-12pro. I have a similar problem because my two vehicles are the f350 dually and a VW TDI Jetta. With 3 stage arms it makes either vehicle easy to fit but this one had the lowest pad hight I could find (4 3/4") for the Jetta but it is still 12k. I would suggest a 12k because on that truck the front loading arms will be high (over 2.2k per front arm) I have been very happy with my lift so far but I don't think it can be had for $3k.

- Sam

New England Region

 

[Coodeville]

Old thread but I wanted to say thank you for all the great information! A friend is trying to convince me in to the Atlas PV-10 but I'm concerned of loading my Z06 on it, being so low. For a while I have had my eyes on the Bendpak XPR-10AS and not reading about the low profile benefits detailed here. I feel like the XPR-10AS-LP may be the way to go.

I just purchased the XPR-10AS-LP. Be aware though that the arms are shorter than the non LP version. Bendpak fails to mention that. Im trying to get them to switch arms for me.

 

[Coodeville]

I have the Bendpak XPR-10 symmetrical set up in the wide stance. My friend brought over his 2018 Gran Sport Convertible. Being a convertible, he bought the pucks so the Vette could be lifted in the proper spot. I was afraid of possibly lifting the car in the wrong spot and cracking the fiberglass.

I couldn't get the car positioned in the proper spot to lift it. Either I could lift the front or the back. The arms were to long. Hopefully that helps.

Billy T.

I wish I had those long arms as Im lifting a '73 Caddy hearse and a '76 Caddy Series 75. I purchased the LP. Bendpak doesnt state on their site that the LP arms are smaller

 

[Y2KFirehawk]

I just purchased the XPR-10AS-LP. Be aware though that the arms are shorter than the non LP version. Bendpak fails to mention that. Im trying to get them to switch arms for me.

I went with the Bendpak XPR-10AS-LP and has been perfect for me. Have to drive the Z06 on 1/4 boards but then plenty of space for the arms. The LP arms also worked fine for my Expedition (non EL). Good point they should call that out in documentation though.

 

[Metallitubby]

I went with the Bendpak XPR-10AS-LP and has been perfect for me.

I think it will be perfect for me too. Thank you for the updates.

 

[infinkc]

I just purchased the XPR-10AS-LP. Be aware though that the arms are shorter than the non LP version. Bendpak fails to mention that. Im trying to get them to switch arms for me.

yea they fail to mention that, but when i bought my lift the vendor told me so i went with the standard arms. They are the identical pad height, just the LP allow you to go under lower rocker panels. I have yet to run into an issue and have some pretty low cars. i lift a full size truck also so they said the LP are only good if you work on lowered cars full time.

 

[skycrane]

Is everyone here feeling comfortable using the 10k lifts on the full size trucks. My F350 scales out at 8600lbs and keep hearing the chinese lifts failing. Anyone have any experiences with the ATLAS 10X tall/wide?

 

[johnehr]

Is everyone here feeling comfortable using the 10k lifts on the full size trucks. My F350 scales out at 8600lbs and keep hearing the chinese lifts failing. Anyone have any experiences with the ATLAS 10X tall/wide?

I have the Atlas 10X tall/wide and it has been rock solid for everything I’ve thrown at it, including my full size crew/long box (6.4’) Ram 1500, though not a 3500.







Sent from my iPad using Tapatalk

 

[Ign]

Is everyone here feeling comfortable using the 10k lifts on the full size trucks. My F350 scales out at 8600lbs and keep hearing the chinese lifts failing. Anyone have any experiences with the ATLAS 10X tall/wide?

I've got the XPR-10XC (extra height, clear floor, symmetrical). Granted it's from '09 and allegedly BP quality might have suffered since then, but 90% of what I lift is full-size 3/4 and 1T trucks, all 4wd. Never had a problem.

Right now an '02 ECLB CTD is on there. Other regulars are an '08 CCSB Duramax and '11 F350 CCLB 6.2

Also this '94 GM 2500 6.5TD, here the cab-over was high even for my 2' extra clearance but I was able to roll under it sitting on a stool to replace ****** lines: