Rear cantilevered long(er) travel

[sleepydad]

wondering if anybody has seen or has any experience with rear cantilevered suspension.

it seems like it's starting to show up more and more. getting more rear travel without having to cut holes in the rear fenders/body seems like a much easier way than traditional vertical shock/coil arrangement.

it also seems like rear leafs to locate the rear axle assembly would be much simpler than links because of that dam gas tank.

I have always been very hesitant to go front long travel because getting a matching rear setup meant frame chop/body mods.

just curious if anybody else has considered looking into this setup?

Thank you

 

[phattyduck]

A carefully placed rear shock mount on the outside of the frame (above frame level) can get you like 10" or more of travel (and more articulation) without modifying the link locations. It has to be done carefully (with the right offset wheels too) to make it all work.

How much travel are you looking for?

-Charlie

 

[sleepydad]

A carefully placed rear shock mount on the outside of the frame (above frame level) can get you like 10" or more of travel (and more articulation) without modifying the link locations. It has to be done carefully (with the right offset wheels too) to make it all work.

How much travel are you looking for?

-Charlie

the front setup I'm looking into is about 14" possible

so I would want to get something close to that in the rear.

they claim upto 18" on this one

00-06 Tundra Rear Cantilever Kit - MCM Fab & Design

<iframe width="800" height="600" src="https://www.youtube.com/embed/E8hjqsTnJh8" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

it's just an interesting setup because all the space would be in the back where it's all unused space right now anyways. unless you do the F150 tank deal.

just not sure about the on road ride quality. I would guess with the correct leafs it would be just fine.

If I decide to to long up front I would probably want a diamond for the rear. so I could try and match the track width. I have ridden in a wider front end Chevy and the kind of ride would bother me. it seems to want to wander on the back end.

 

[Black798]

Funny this thread popped up because I am in the process of doing this to my truck using a custom built axle housing of my own design and a 3 link setup. The way its designed right now Ill be netting 13 to 14 inches of travel using a 8 inch coilover with an antirock swaybar. Ride quality will be far better than any of the options for longer travel in the rear on the market right now. As far as gas tank contact with proper link setup it become a non issue

Axle housing...
full float with chromoly axle shafts, 9.5" diff, airlocker, disk breaks and lots of other things.
<a data-flickr-embed="true" href="https://www.flickr.com/photos/147275993@N05/49119125112/in/dateposted-public/" title="Rear Axle Master Assembly Front"><img src="https://live.staticflickr.com/65535/49119125112_c35ec20b6f.jpg" width="500" height="279" alt="Rear Axle Master Assembly Front"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
<a data-flickr-embed="true" href="https://www.flickr.com/photos/147275993@N05/49118932251/in/dateposted-public/" title="Rear Axle Master Assembly Rear"><img src="https://live.staticflickr.com/65535/49118932251_4e356a9611.jpg" width="500" height="279" alt="Rear Axle Master Assembly Rear"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>

Cantilever geometry at ride height
<a data-flickr-embed="true" href="https://www.flickr.com/photos/147275993@N05/49230271303/in/dateposted-public/" title="Screenshot (2)"><img src="https://live.staticflickr.com/65535/49230271303_1ab5fee476.jpg" width="500" height="281" alt="Screenshot (2)"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>

 

[phattyduck]

I know you already know this... but watch those motion ratios. :madgrin:

-Charlie

 

[Black798]

I know you already know this... but watch those motion ratios. :madgrin:

-Charlie

Motion ratio right now is around 1.625:1 with a coilover shaft velocity curve that essentially linear to gradually increase the dampening as it approaches full bump this will compliment the hydro bumps quite well. In reality the attached graphs will be inverted so slope is positive they just worked out negative because of how i took the measurments since I started from full droop cycling to full bump

 

[sleepydad]

Funny this thread popped up because I am in the process of doing this to my truck using a custom built axle housing of my own design and a 3 link setup. The way its designed right now Ill be netting 13 to 14 inches of travel using a 8 inch coilover with an antirock swaybar. Ride quality will be far better than any of the options for longer travel in the rear on the market right now. As far as gas tank contact with proper link setup it become a non issue

so... I would be super interested if you wanted to share any numbers on things because your way farther down the road compared to where I'm sitting.

I pulled some numbers off my spare frame sitting in my driveway. I need to put it on my frame rotisserie so it's easier to mess around with it.

so by 3 link you mean keeping the stock lower arms and then a new track bar?

 

[Black798]

so... I would be super interested if you wanted to share any numbers on things because your way farther down the road compared to where I'm sitting.

I pulled some numbers off my spare frame sitting in my driveway. I need to put it on my frame rotisserie so it's easier to mess around with it.

so by 3 link you mean keeping the stock lower arms and then a new track bar?

Ive already redone the link geometry of both my lower and upper links. The cantilever will necessitate the panhard being moved from behind the axle to above the center line of it. Ill also be redoing the lower links again to make them around 30 inches long and significantly higher clearance than stock. The stock geometry really isnt good for anything over 10 inches of travel or 3 inches of lift. Ill be past both of those. Going to any form of long travel in the rear is a complete waste in my opinion without making the link geometry proper.

The 3 link I do on my truck will be very similar to the one that I setup on this truck. This one had 14 inch shocks that cycled right around 14 inches of travel.
<a data-flickr-embed="true" href="https://www.flickr.com/photos/147275993@N05/48737486482/in/dateposted-public/" title="IMG_20190825_152302"><img src="https://live.staticflickr.com/65535/48737486482_20a02d7814.jpg" width="500" height="375" alt="IMG_20190825_152302"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
<a data-flickr-embed="true" href="https://www.flickr.com/photos/147275993@N05/48736987288/in/dateposted-public/" title="IMG_20190824_215938"><img src="https://live.staticflickr.com/65535/48736987288_ed975d8495.jpg" width="500" height="375" alt="IMG_20190824_215938"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>

Biggest reason Im not just doing this same setup on my truck is I want the adjustability of coilovers in the rear since I plan to go SAS in the front and dont want to be limited by the poor selection of coils we have for these trucks

 

[sleepydad]

Ive already redone the link geometry of both my lower and upper links. The cantilever will necessitate the panhard being moved from behind the axle to above the center line of it. Ill also be redoing the lower links again to make them around 30 inches long and significantly higher clearance than stock. The stock geometry really isnt good for anything over 10 inches of travel or 3 inches of lift. Ill be past both of those. Going to any form of long travel in the rear is a complete waste in my opinion without making the link geometry proper.

The 3 link I do on my truck will be very similar to the one that I setup on this truck. This one had 14 inch shocks that cycled right around 14 inches of travel.

Biggest reason Im not just doing this same setup on my truck is I want the adjustability of coilovers in the rear since I plan to go SAS in the front and dont want to be limited by the poor selection of coils we have for these trucks

agreed 100% the rear coil spring setup is frustrating. it's trial and error. Even though the geometry is more complicated for cantilevered I think the trouble should be worth it. the ability to run coilovers in the rear ++

I have just been looking at crawlpedia and trying to understand their calculators but nothing seems to exist out of the box for cantilevered setups.

initially leafs seem to simplify things but... I will have to do a lot more thinking I guess.

looking forward to seeing what you come up with, thanks.