At 3:32 your drawing is wrong about how you measure trail. While we get the concept from the description, your illustration should be using the diagonal steering axis and not the offset fork axis, just as you do for explaining the rake. On some bikes, these two axis are not even parallel, so it is important to use the steering axis angle.
I agree. If you are moving at speed and turn the handlebars slightly to the left, the center of the contact patch moves slightly to the right. A force is generated that wants to move the center of the contact patch back in line behind where the axis of the steering head bearing hits the ground. This is why motorcycles want to go straight and trail is so important. The point where the steering head axis hits the ground, and the center of the contact patch are in balance when they are in line with the forward motion. You don't want to have knackered steering head bearings (from wheelies), tires that have been used while improperly inflated or 10-year-old tires.
When I jack up my son's '96 Road King, the handlebar will always return to center if I turn it left or right. My '01 Heritage Softail will not return to center, it stays where it is turned. I've always wondered why, and this episode explains it. Good information!
I have a 18 Road King, it has traling forks, the fork tubes are behind the steering head, your Heritage has leading forks, the tubes are forward of the steering head
Good video but the reason the Harley is so good at slow maneuvers is that it has a negative offset triple trees. The fork tubes are behind the steering stem. It’s the only motorcycle built that way. It doesn’t push the front wheel it pulls it.
Picked up a rather lovely Triumph Thunderbird Storm. With my other bikes I just counter steer and let the bike fall into the turn. On the Storm the bars behave completely different in a turn. Still getting used to it.
Some thing about your definition of trail and rake doesn’t make sense. The angle off the vertical is the exact same for both. If you take the pivot point of the baseline of the trail distance to the baseline pivot point of the rake, I believe that is the trail vertical to vertical.
Extremely long trail, many are about half the width of the wheel! This was an excellent description of how trail affects steering, but I'd want to maybe look at one or two shopping carts before claiming the contact point is under the pivot, they could never sell one with front wheels like that, it would be impossible to use physical force steering in a manor that works on all carts.
Great, informative and helpful video. Ergos also critical for comfort and control. My hamstrings are tight and I’ve long inseam; besides stretch exercise I’ve learned that feet forward riding position gets wearing as it rotates pelvis backwards causing poor lower back posture (slouch) and hence backache, sadly for me contradicting the assertion that cruisers are designed for comfort….(sigh)!
Excellent and accurate information! I would recommend that everyone starting out riding watch this video. This is one of the factors that make motorcycle selection so difficult and tricky. Particularly if you are a sport tourer rider. I ride a BMW RS 1250 and the increased the wheelbase of this bike over the years from about 58 to 60.1. I understand why but liked the shorter wheelbase and rake.
It appears that putting on a bigger front wheel would change(increase) the trail. If this correct then for a constant rake the stability would increase with the larger diameter front wheel. Am am I seeing this right? Good video.
What do they call the distance the front axle is in front of the centerline of the front forks. On one of my motorcycles it seems to me that the front axle is slightly in front of the centerline of the forks. What is this called and what is the effect on handling? Keep the good stuff coming Kevin.
