What would happen if you put a 14.5 bottom and 8.5 top in a stage 11? My guess is that it would make it more unstable and turn sharper. I am quite confused, people use the word truck geometry all the time but just mean wheel base, what is the true nature of what happens when you change the ratios?
Running a taller bottom bushing definitely makes for more turn, more than anything. The top bushing has its own uses, but for me the bottom bushing height controls how the truck will feel.
I usually run a lower top bushing mainly to get the kingpin down lower on a conventional truck and angle grind the top of the kingpin off, to allow for more clearance, but some people say that having a lower top bushing also means the truck is more limited in the amount of turn, eg it will turn up to a certain point and then stop. This is a fair assessment, as I do often see the washer marks on the top side of the hanger yoke, but not always.
In messing around with some other trucks, I had cut off part of the top bushing and added it to the bottom bushing, which then creates exactly what you asked about and yeah those trucks turned a lot very quickly, even Ventures, but more so older stage Indy were very good with that done to them. That is the basis of the Ace turn, but to be fair, certain trucks have a better geometry for turning than others. That is the angle and relationship between the kingpin, the pivot point and the hanger. There are some charts and diagrams depicting all this, but I am not one to really go very deep with calculating angles. I am more into the "Lets try this and see how it works" type of experiment.
As for the relationship with trucks and wheelbase, any truck will turn more if there is a shorter wheelbase, or turn less if there is a longer wheelbase. Try it on a 15" wheelbase board and then drill the truck in to 14 or 13 and see how much more it turns. Some trucks will turn a lot more than others if you put them all on the same board, usually Ace, Indy, Thunder then Venture in that order, with others in there usually around the middle, but changing the bushings can definitely affect how any truck will turn.
I think that is about it for basic info, but the easiest way is add a flat washer or two under the bottom bushing, if possible, to see how much of a difference it makes. Even one on top instead of a normal washer allows for way more turn from most bushings, as it gives less resistance to the bushing being pushed this way or that.
Then cutting them, sanding them down or changing different heights of bushings, along with different duros can also have a very profound effect.
At least using the washers to try means you don't really have to do a whole lot and not cutting bushings means it is easier to change back to what you had before too.
Topic: Gear madness support thread (Read 372375 times)