So did everyone read the tech links?
Does the basics of trail need more examples/explanations?
I could cad some examples.
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So did everyone read the tech links?
Does the basics of trail need more examples/explanations?
I could cad some examples.
Another tech link to much of the same info.
[URL="http://www.motorcycle-superstore.com/4125/mngr/rake-and-trail-explained.aspx"]http://www.motorcycle-superstore.com/4125/mngr/rake-and-trail-explained.aspx[/URL]
Great job guys
Here we go.
In an attempt to simplify in pictures.
This will be an example only, based off of some typical numbers
Here we have a donor bike.
[ATTACH=CONFIG]47615[/ATTACH]
Note the names of the geometery elements.
Also note that in stock motorcycle form it already has more trail than what you want for a trike.
Now we want to cut this off the bike and weld it into the trike frame we are building.
Of course "raked out" is the cool thing to do. So naturally we want to increase its angle.
Guess what happens then.
[ATTACH=CONFIG]47616[/ATTACH]
No part of the bike front end has changed.
Only the angle it is attached.
Note the height will be lower.
And look at that trail.
So now the head was too low to fit in the frame so now lets put 10 inch over fork legs in.
[ATTACH=CONFIG]47617[/ATTACH]
Got the neck up but did nothing to improve the trail. Actually because we most likely did not raise the back the same amout we rotated on the rear and gave it slightly more trail.
So to make the stock hydraulic forks work we have to change the trees/yokes.
Increase the offset.
[ATTACH=CONFIG]47618[/ATTACH]
Or raked trees, yokes.
[ATTACH=CONFIG]47619[/ATTACH]
The same geometry hold true with whatver neck height you want.
Way up 30 over, still the same rules.
[ATTACH=CONFIG]47620[/ATTACH]
So now we have the aftermarket front ends.
The descriptions and dimensions are confusing as all get out. Seems to be no standard to anything. You must do the math and know exactly what you need to be able to find one with the right numbers to fit. Very very few places to buy a custom fit front end.
Same geometery with different forks.
Springer.
[ATTACH=CONFIG]47621[/ATTACH]
Drop pivot springer.
[ATTACH=CONFIG]47622[/ATTACH]
Leading link.
[ATTACH=CONFIG]47623[/ATTACH]
Different styles of front ends is not what fixes the trail.
It is the dimensions/numbers that make it right.
Any style of front end can be made correct.
Springer
Leading link
Hossack
Spirder
Telescopic
Girder
Shocker
Now as we typically are building our own frames to no standard production dimensions the front end will have to be custom to it to be totally correct. Even though it may be possible to get there with carefully researched and fitted bought parts. Especially if you use all aftermarked harley parts as there is a large aftermarket for them.
By a large amount the most common front suspension for a hand built trike is a hand built leading link. It also is one of the easiest to build in a hobby shop in the garage.
[ATTACH=CONFIG]47624[/ATTACH]