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I have heard a number of times that the maximum angle of the Left Rear Upper Bar should be no greater than 47-50 degrees. Does that still hold? Based on some recent observations it looks like there are a lot of guys running more than that 47-50 degrees. Based on the physics, I understand not wanting to run more. Just curious as to what theories people are currently operating on.
The "zero" index stuff has helped alot with the negatives of running excessive lru bar angle. Everything revolves around getting the spoiler to the moon these days. Everything ends becomes a nessacary compromise
The 45 degree rule was a very crude way of seeing when the lift/rollsteer curve leaned towards rollsteer. Meaning once the upper bar reached 45 degrees on most LR suspensions, it was adding more rollsteer (loosen car) then lift (tightening car) so when you extended chain more and passed 45 degrees you are likely to loosen the car.
The LR travels in an arc (think an arc going from 3 o'clock to 6 o'clock) once it reaches around 4:30ish its going forward more then down thus loosening the car if you let it go to say 5:30.
Clear as mud, right? The 45 rule was always a pet peeve of mine because it wasn't all that accurate but it did serve a purpose to get the general idea across for typical std LR suspensions on a LM
Both, good information. I guess I neglected to think about the travel path of the upper bar. Ultimately, once you get passed the 45 degree angle you start to hit a acceleration point of where the birdcage indexes into the spring at a faster rate. Thinking about droop load as it is affected by the upper bar: Given that the lower bar stays in the same position and the hike stays the same wouldn't the adding upper bar angle (lets say from 45 degrees to 55 degrees) tighten the car since you are actually inducing more load into the spring? Although, this wouldn't necessarily be affect anything as long as you set your eye to eye droop load to a specific number at that specific upper bar angle. But it would, in fact, bring in load faster right before the rear end hit the chain which would make sense why everyone is moving to the zero index stuff so you don't get into a scenario where you have increased acceleration of the birdcage indexing into the spring. Looks like that gives me some thing else to mess with during the off season. Well, to the spreadsheets I go.