build diary

January 23, 2006: I spent some cold time in the motorcycle graveyard yesterday and came back with a whole pile of dimensions.
Turns out these linkages are right at the bottom of the bike so they're a little awkward to measure. The good news is that the owner offered them to me for $20/pair. Now, if only they have more than one of each bike! I think there are a pair of Kawasakis, I might pick those up just so I have something to play with as I ponder this. One thing that just popped to mind is that I need to be able to bolt it to my shocks, which means a clevis on the linkage - hopefully I'm using the proper terminology there! The problem is that the motorcycle units like that don't tend to have a central bearing which makes life a little more complex. Otherwise I could just make my own out of two plates of aluminum. That's how Yamaha does it on the R1. What I need is something just like the one used on Fraser cars. They never answered my question about where that rocker came from. It may be a custom piece. Alternatively I could mount the bearing to the frame. Or go custom myself. Ducati has a part that's suitable and so beautiful it hurts.

I've decided that I'm just confusing myself with suspension geometry. My insistence on camber curves that matched roll doesn't make sense and is over-simplified. So maybe I'll just concentrate on cutting down the roll for now. That means bringing up the roll stiffness either through sways, stiffer springs or my pushrod setup. Heikki has already gone this way and stiffened his springs. I've become fixated with solving a good pushrod setup so I think I'll continue along that way for a while. The real trick is figuring out what the ratio between the spring and the wheel should be. I have 3" of shock travel. That's not a lot of wheel travel but it's about what I have in the rear. I've also done some thinking about how to keep the suspension from developing a falling rate. That's important!

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