some time this year or early part of 2008 i'm going to have me a chopper a built or customized rather. the only two things i'm still trying to figure out is the rake and stretch. i'm just curious to what that means? for example, a rake can be 42 degrees with a stretch of 5 inches. can anyone help explain this to me so i can tell the company how i want my chopper designed.
2007-03-27 04:31:32 · 7 answers · asked by eyes_of_lonewolf 1 in Cars & Transportation ➔ Motorcycles
stretch comes in two versions.. up and out..
up is accomplished by lengthening the down tubes this moves the neck higher.. out is backbone stretch making the bike longer..rake is the angle of the goose neck 31 is stock..
my bike i just built is 6" up 2" out
it has a 42 degree neck
(with 5 degree trees.to correct the trail)
for a total of 47 degrees of rake..it handles well
2007-03-27 04:42:45 · answer #1 · answered by dumbo 3 · 1⤊ 0⤋
I believe the actual term is rake and trail. As stated above the rake is the degree of angle of the neck. The trail is measured by the inches the front axle is in front or behind the center line of the neck. There is a formula to figure this but us old schoolers run a rod along the neck to the ground at what ever degree angle "rake" the neck is. Then another rod at 90 degrees down from the axle point. then measure the distance between to two point. this gives "trail". a good rule of thumb is no less than 3" and no more than 6" trail.
To little trail makes the bike hard to handle at higher speeds. To much trail and it is heavy in the corners.
http://en.wikipedia.org/wiki/Rake_and_trail
This sight will give you the basic Idea.
2007-03-27 13:49:22 · answer #2 · answered by dreamwever4u2 5 · 1⤊ 0⤋
Ahhhh,,,, "Ken Y" beat me to the answer but he has it absolutely correct.
There is a formula used to engineer correct geometry based on the center of gravity the rake and stretch and the more you deviate from that formula, the worse the bike will handle.
So if they are the experts then I would let them handle that part of the design.
Good luck with your new chopper.
2007-03-27 11:48:31 · answer #3 · answered by The Dest 4 · 1⤊ 0⤋
This site will explain "RAKE":
http://www.jpcycles.com/Tech/Articles/techtalk6.htm
Stretch refers to the amount either the down tubes (that run down in front of the engine) and/or the back bone (that runs under the gas tank) has been extended. I. E., 2 up and 3 out means 2" stretch in the down tubes, 3" stretch in the back bone.
2007-03-28 09:24:30 · answer #4 · answered by strech 7 · 1⤊ 0⤋
When you "chop" a bike, stretch--in your case--refers to how much longer the new forks are as compared to the stock ones. Since customs come stock with long forks, there really is no such thing as stretch.
A previous poster said something to the effect of stock bikes have 31-degrees of rake. Actualy, it varies from model to model. Rake effects trail and too little trail can cause speed wobbles. Too much trail can cause the front end to feel heavy.
2007-03-27 20:09:38 · answer #5 · answered by Chuck Z 2 · 0⤊ 2⤋
the rake is the angle of the neck
the stretch is how much longer than stock the down tubes are
2007-03-27 14:15:39 · answer #6 · answered by Anonymous · 0⤊ 1⤋
yeah, everybodys pretty close on this.
seens like your this close, you must have a pile of chopper magazines. if not, go spend some time in mag. store til u see somthg u like. 99% of articles contain all this information, w/ pictures........then take that to your builder.
2007-03-27 14:25:40 · answer #7 · answered by DennistheMenace 7 · 0⤊ 0⤋