Break-over and departure angles—I'm an odd duck
- Thread starter Irun
- Start date
Guess everything he designed for savvy doesn’t work in TN.
Pretty sure every Jeep he has built will perform great anywhere. He has standards that he doesn’t compromise on. I asked him what his guidelines are for building, I don’t care where he lives.
How would I know?
They are guidelines that I use for this area. They are based on 1000's of hours on the trails watching rigs work and figuring out why they did and didn't do well. This isn't privileged info, just regional. If you don't plan on spending a lot of time in JV, not sure it would do you any good.
Not one of us will spend enough time on trails or make the many observations you have to come up with any kind of guidelines no matter where we live. From a building perspective, I’m also interested in your expert opinion.
35's- roughly a 19-21" belly height, 100ish wheelbase.
37's- roughly a 20-22" belly height, 104" minimum wheelbase.
40's- roughly 22-23" belly height, 108" minimum wheelbase.
Axle widths-
35's- 60-61 front
37's- 63-64 front
40's- 66- 67-68 front
All with around 4" of back spaced rims to 4.5" of BS.
To put that in clear perspective, I have two rigs here right now, one is the standard TJ 4" Currie on 35's. The other is 114" stretch TJ Unlimited on 40's. The Unlimited is 3" taller than the TJ. 2.5" of that height difference is just the tires.
I'm so relieved.
I was afraid that I would have to surrender my jeep keys and hang my head in shame for owning such a totally inadequate jeep, but with my 103.4" wheelbase, 34.6" tires, 17.7" belly height, 61.5" wide axles and 4" backspaced wheels I'm not as inadequate as the Internet told me I was so I might be okay if only I could learn how to drive it.
Can you go in detail how the TJ with 100” wb performs differently than the 93” wheel base? I would say the majority of us are factory wheel base with 35s. From what I’ve read on the forum a 35” tire is the largest we’d want on 93” wb. From your guidelines i would think that at 93” wb we shouldn’t go over a 33” tire. What are we loosing to run a 35” tire?
Your response is precisely why I was reluctant to put up my list which I am now fully regretting because this is exactly how I knew it would go.I'm so relieved.
I was afraid that I would have to surrender my jeep keys and hang my head in shame for owning such a totally inadequate jeep, but with my 103.4" wheelbase, 34.6" tires, 17.7" belly height, 61.5" wide axles and 4" backspaced wheels I'm not as inadequate as the Internet told me I was so I might be okay if only I could learn how to drive it.
Blaine's list has been out there for a long time. And I've spent quite a bit of time comparing it to my experiences and observations. My conclusion is that for what we do out here, the variances in wheelbase, belly height, tire size isn't as crucial as it would be in a more challenging area. To compare, in Colorado I don't believe the differences between short, mid, long arm make the difference between making through an obstacle or not. What does matter the most is lockers followed by tire size and belly height.
OP
OP
What you post up is always useful information. For these items specifically, I get that as tire size goes up, the wheelbase needs to increase accordingly. As does the belly height. These are crystal clear. What I'm struggling to understand is what drives the need for increased axle widths? I dug around, but can't seem to find an answer.
I think it has to do with tire clearance when turning and articulating.
As a tire gets taller, even if tire width stays the same, it is going to get closer to the frame at full lock.This make sense. Even more so if a wider tire is run.
Brianj5600
TJ Expert
The part I don't understand is why there is relation between tire diameter and wheelbase. More than one experienced builder has given basically the same info so I don't doubt the guidelines. Any thoughts on how tire size and wheelbase work together?
As the tire increases in diameter, the corners move further during articulation and turning. It does no good to put taller tires on and wind up with effectively less steering or less articulation because you can't keep the tire off of a shock or the frame and or front swaybar arms.