Willis
NAXJA Forum User
- Location
- Hoquiam, WA
Almost every suspension geometry thread I can find is in reference to the rear. I'd like to talk about the front. With track-bar, without track bar, parabolic uppers, 3 mid-length arms, etc, etc...
The information I am looking for is in reference to the geometry involved in properly building a front suspension. The specific questions I have would be this:
Anti-dive, how is it calculated, and what effect does it have on road, and offroad? Where would the optimal anti-dive be set?
Instant Center. This is commonly talked about when building a rear 4 link suspension. This convergence point between the upper and lower control arms have a lot to do with anti-squat in rear application. However, in many situations in the front suspension, the instant center would be located just inches rear of the front links, usually under the front seats. How does the IC effect a front suspension, or is it only in reference to rears? And, what if the lower arm mounted higher than the upper arm, the arms would cross and the IC would end up somewhere around the front floor boards or even forward of that?
What about front steer (like rear steer, as in fore and aft movement of the axle during articulation). Is this as noticeable in a front application since you can easily correct it with steering input?
The reason I want to get in depth with this is that it seems a lot of people just build a front suspension and don't think about the geometry at hand. There are a lot of long arms fabricated at home, where the only paper used was the paper used to wipe their :moon: .
I have a bunch of designs on paper, from Beez's parabola, to Goat's 3 mid arm, to a 33" 'J' arm that mounts outside, but next to the frame rail. I want to build it right the first time, or at least get it close
Thanks,
Steve
The information I am looking for is in reference to the geometry involved in properly building a front suspension. The specific questions I have would be this:
Anti-dive, how is it calculated, and what effect does it have on road, and offroad? Where would the optimal anti-dive be set?
Instant Center. This is commonly talked about when building a rear 4 link suspension. This convergence point between the upper and lower control arms have a lot to do with anti-squat in rear application. However, in many situations in the front suspension, the instant center would be located just inches rear of the front links, usually under the front seats. How does the IC effect a front suspension, or is it only in reference to rears? And, what if the lower arm mounted higher than the upper arm, the arms would cross and the IC would end up somewhere around the front floor boards or even forward of that?
What about front steer (like rear steer, as in fore and aft movement of the axle during articulation). Is this as noticeable in a front application since you can easily correct it with steering input?
The reason I want to get in depth with this is that it seems a lot of people just build a front suspension and don't think about the geometry at hand. There are a lot of long arms fabricated at home, where the only paper used was the paper used to wipe their :moon: .
I have a bunch of designs on paper, from Beez's parabola, to Goat's 3 mid arm, to a 33" 'J' arm that mounts outside, but next to the frame rail. I want to build it right the first time, or at least get it close
Thanks,
Steve