Posted 8/5/2016 6:40 PM (#90229 - in reply to #90227) Subject: Re: Triple Trees
Location: SW Ohio
So, the Ultima trees will do the same job as the Champion trees? Both are 6 degrees. What I am getting at is that I've read once the extended trees are mounted it is inadvisable to ride the bike without the car. The Ultima trees however are advertised for baggers with those clownish 26-28 inch front wheels. Am I missing something?
Posted 8/5/2016 11:54 PM (#90231 - in reply to #90229) Subject: Re: Triple Trees
Location: Hazel Dell Vancouver, WA USA
Most Motorcycles that are made into permanent trikes/ three wheelers usually increase the rake by 3-5 degrees.
There is a basic science of handling characteristics. A friend told me this is how it works, I am copying this from n Email I saved some 12 or so years ago. I hope this is about right.
Rake can be described as an angle at which the headstock of the motorcycle is inclined when compared against a vertical line drawn perpendicular to the ground. The rake angle effects steering ability, the smaller the rake angle then the easier the bike is to corner but will be less stable in a straight line.
The distance on the ground between a straight line drawn through the center of the front wheel spindle and a line drawn through the center of the headstock axis. The greater the trail distance, then the greater the straight line stability but the harder it is to make the bike corner.
The distance between a line drawn through the center of the steering stem/ headstock axis and the center line of the front fork tubes. Typically the offset inversely affects trail, if offset increases then the trail will decrease.
Altering the rake angle will change the stability/agility of your bike. Steepening the rake angle will sharpen your turning but you will lose straight line stability. If you make the rake angle more shallow then the opposite of what I have just described will happen. You’re stability will increase but agility will decrease.
If you increase your rake angle, you effectively increase the amount of trail you have. The trail will determine the amount of “centering” force available [caster effect]. With an increase in trail, the bike will center itself more efficiently but with less trail, it will become less stable again.
Now the trail can be altered whilst maintaining the same amount of trail if you are to offset the forks with the use of a different angled triple clamps.
With trail you have small increments measured in millimetres and rake has small increments of degrees. You can search for some bike specs to see what their standard rake angle and trail are. That will give you an idea of how small a change is but how much it alters the steering geometry you will have to try on a bike for yourself to understand how effective it is.
It was 12 years ago inquiring on a Goldwing trike conversion at a place that assembled them. I rode a just almost finished trike conversion with stock forks and head on a test ride around a closed area, as it started moving about 5mph there was a pretty violent shudder of the handlebars that I was told to "ride thru" that speed, which I did, went to the end of the parking lot then I came back, got on another one that had the 4 degree triple tee installed and it didn't have that.
Be sure to check your states laws. There are more and more states requiring a separate endorsement if you add a sidecar, or make it a three wheeler by adding a two wheel rear axle because of the big difference in handling.
Posted 8/6/2016 6:59 AM (#90232 - in reply to #90120) Subject: Re: Triple Trees
Location: Pittsboro, Indiana 46167
The only difference that I could see is that the fork extenders on the Champion ( which Jiggle has on her Champion Conversion 2001 FLHTCI) are manufactured to fit the standard 16" front wheel and the Ultima is not. I think her Champion were 3 degree... That is going to change the frame height clearance at the front engine mount. JMHO.