Rake and Trail
 

Ok, I would like this to be a crayon written lesson to start, then as I understand more, we can move up to pencil or pen. (At some point, I plan on get the Trevitt book that everyone is talking about)

Some of you may have read that I'm putting a 2004 GSX-R600 front suspension on the bike.

These are the numbers that I have found for the two bikes:

2000 Honda Superhawk
Rake - 24.9 degrees
Trail - 97 MM (3.7 inches)


2004 Suzuki GSXR600
Rake - 23.25 degrees
Trail - 93 MM (3.66 inches)

From my limited knowledge, this only looks a minor change. Slightly more vertical on the forks, producing a slightly quicker turn in.

Doesn't appear to detrimental to the handling of the bike.

Looks like an improvement?

Sound right?

Thanks guys.


Erik

The shallower rake angle of the Super Hawk will increase the trail, given the same triple clamp offset, so it looks like it will put you in the right ballpark. As long as the setup gives you the same head height.

The Super Hawk likes a steeper head angle. You can drop the nose a bit, but ground clearance becomes an issue. A better solution is to increase the shock length and raise the rear. More swingarm angle helps with anti-squat, too. A shim at the top shock mount is an easy solution.

whoah horsey. That's not written in crayon so that this suspension kindergartener can understand it.

I get the shallow rake angle.

I have a JD shock, but asked for stock length, since I'm still not sure of the overall length of the Suzuki forks, and how it will affect head height. I have a shim in now, and can install it again.

He's saying that you can effectively change the rake angle (decrease it) of the Super Hawk by either raising rear ride height, lowering front ride height or using a combination of both. Steepening the rake (decreasing the angle-making the forks closer to perpendicular to the ground) also decreases the trail, making steering lighter and quicker at the expense of self centering effect (stability). Make any sense?

Yes, makes sense. I didn't know about the self-centering aspect being affected by the rake. That too makes sense though.

Thanks to both of you.

Self centering is a function of trail, but (all other things being equal) steepening the rake also changes (shortens) the trail.

how much shorter are those gsxr forks?
same length wont change rake,couple inches shorter can.
my superhawk is pretty much standing on its nose with the mods ive made.

Not sure. I've got a measurement for the GSX-R forks, just have to go out to the SH to measure those, unless someone already has it.

Taking 1.7 degrees off the rake should help turn in but I would'nt worry about stability. My Buell has 21 degrees rake angle and it's as stable as you like...no worries.

Assuming the forks are the same length then the rake will be the same. The offset of the triples will decide your trail. There is a rake/trail/offset calculator on the web. Do a search for it. It'll help you a lot.