laying frame with 20's

[72GREENC10]

is it possible for me to lay frame with 20's if i have a 4 inch notch? when i get the 20's, there will be extremely low profile tires on it to help it lay. is this possible?

[SCOTI]

Originally Posted by 72GREENC10

is it possible for me to lay frame with 20's if i have a 4 inch notch? when i get the 20's, there will be extremely low profile tires on it to help it lay. is this possible?

Devils advocate here..... I wouldn't suggest super low profile tires as part of the plan to 'lay-out'. These trucks just don't look right when the tires are too short & don't fill the wheel-wells.

Wheel diameter doesn't impact the end result. OD of the tire is what you need to know & plan for.

[N2TRUX]

The 4" notch will get you pretty close in the rear, but it depends on what you do up front. I totally agree with Scot here. The lower the profile, the rougher the ride. Even with an air spring, it will be stiff.

[72GREENC10]

i was guessing that would be an issue, the rough ride. but i dont want to cut out the bed and i want to lay, all i will cut is for the rear pumpkin. but i think ill sacrafice a soft ride to lay frame

[SCOTI]

Originally Posted by 72GREENC10

i was guessing that would be an issue, the rough ride. but i dont want to cut out the bed and i want to lay, all i will cut is for the rear pumpkin. but i think ill sacrafice a soft ride to lay frame

Why the focus on 'laying frame' (which is only done @ limited times) @ the sacrifice of ride quality & visual impact (the rest of the time)?

[N2TRUX]

Besides Scots concerns being very valid, you overlooking something it seems. Your not goin to "lay frame" with stock crossmember. You can lay the control arms, but that frame is still a few inches off the ground.

[72GREENC10]

yeah, i have been overlooking that, checked it out last night. but i would like it to lay level with the front member, is that possible with a larger tire on the 20's?

[panhandler62]

Figure out what the OD of the tire you want to run is. Half of that is the axle center. So, just starting out pretty extream and figureing a tire with 4" sidewalls in 20s your axle centerline will be about 15" off the ground.

To set the frame on the ground you will need neough relief to get the bottom of the frame 15" below the axle centerline. That puts the top of the frame about 10" or so below the axle centerline.

This is all very rough, but I think you would need an absolute minimum of about 13" of frame relief (measured from the bottom of the stock frame and assuming about 4" tube diameter on the axle housing) to get where you want to go. I think you would need a much larger mod in hte bed than just a small relief for the pumpkin.

[gringoloco]

Originally Posted by panhandler62

Figure out what the OD of the tire you want to run is. Half of that is the axle center. So, just starting out pretty extream and figureing a tire with 4" sidewalls in 20s your axle centerline will be about 15" off the ground.

To set the frame on the ground you will need neough relief to get the bottom of the frame 15" below the axle centerline. That puts the top of the frame about 10" or so below the axle centerline.

This is all very rough, but I think you would need an absolute minimum of about 13" of frame relief (measured from the bottom of the stock frame and assuming about 4" tube diameter on the axle housing) to get where you want to go. I think you would need a much larger mod in hte bed than just a small relief for the pumpkin.

Good info here. Just want to add that the rear frame rails kick up ~4" higher than under the cab, and laying control arms up front keeps the rails another ~4" off the ground. So, the 13" notch minus ~8" leaves you with a 5" notch. Fairly small, but will still put the punkin through the floor...

You're lookin' at either an extremely small sidewall, or some 13" spokes...

[panhandler62]

Good point ... I neglected to consider that the frame is not flat. You can't put the frame on the ground in back without putting the body underground.

So... if we figure on laying the frame under the cab right on the ground (assuming the front can manage that) then we need to get the rear axle centerline 9" higher than the bottom of the stock frame. Now, if by a 4" notch we are measureing relief above the top of the stock frame then I think the 4" notch will do it (assuming a 29" OD on the tires, which is rubber-band territory on 20s) but this would absolutely require raising the bed or removing a large section of the bed floor since the notch itself woul be 9" above the stock level of the bed floor.

I have a much smaller drop and I am going to have to modify the bed.