11-13-2017, 09:17 AM
(11-11-2017, 08:59 AM)activedirt_imp Wrote: I do hope that this has yet to be discussed on this forum. I did search for it a couple of times but came up empty.
Presently I either own or have owned three (3) different bikes in the past 2+ years. All three bikes pull to the right when I let go of the handlebar as I'm slowing to eventually stop. The Africa Twin does it the most, and by far the most. The CB1100 and the Yamaha FZ07 are basically the same in this regard with perhaps the CB1100 exhibiting this quality the least. I've used Google to find the answer but am left with no firm answer. Please allow me to now turn to this fine and informative forum for a solution. My guess is that this is caused by:
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1) The Gyroscopic effect of "Engine Brake". This would account for the Africa Twin exhibiting this tendency the most and the CB1100 the least.
2) A misaligned rear wheel.
3) The crown in middle of the road (I don't think this is the answer as this pull-to-the-right is very consistent).
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In the Gyroscopic effect, a turning wheel moves as though the force was actually applied 90 degrees down stream from the real point of pressure. The term down stream means in the direction of the spin.
Now herein is a marvelous thing....
Today I take the Yamaha FZ-07 for a ride down some Virginia back roads to Rocky Mount Va. Route 116 then right onto Route 122 into Rocky Mount. The trip home is Route 635 then left onto Route 116.
This trip gives me several opportunities to test the tendency of this bike to pull to the right as I am slowing. This only happens when as I am slowing to stop and I let go of the handlebars, which also means, of course, I have let go of the throttle. I run several tests at roughly 31-35mph and the bike in third gear. It consistently has a slight pull to the right, which also means the front wheel is slightly turning to the left! I repeat the same test but this time I put the bike into neutral. When in neutral there is no pull to the right, none!
This bike, the Yamaha FZ-07, has a reasonable amount of engine brake. Not as much as an Africa Twin but more that the smooth CB1100. At this point I am of the opinion that this trait can be attributed to the Gyroscopic steering effects of the engine brake