Jump to content
Sign in to follow this  

An FCR question and a Suspension question.

Recommended Posts

First question for you guys is, what exactly does the air fuel screw do? I know it controls the air/fuel mixture. but what does turning the screw in vs. out do? If you turn the screw in, does it restrict the ammount of air entering the jet at idle? Turning the screw out, does that allow more gas into the jet? Please explain.

Suspension question, does lowering the clamps on the forks, give better speed stability or better cornering? Say I want to corner better, would I raise the clamps or drop them?

Share this post


Link to post
Share on other sites

Screwing in=Leaner, out, richer.

The pilot air jet meters the air entering the circuit. Then the fuel screw further fine adjusts that. This air then goes to the pilot jet and emulsifies the fuel which then 'bubbles' out into the carb. So the jet controls how much fuel is involved, the fuel screw and pilot air jet controls the air portion.

Lowering the fiorks increases rake. This speeds up steering, enabling faster transitions straight to cornering. It does decrease stability.

Share this post


Link to post
Share on other sites

For real? I would think lowering the forks would make it more stable. I would believe the TT addict tho..

Share this post


Link to post
Share on other sites

lowering the fork slows turning and improves straight line stability, raising them does the opposite.:thumbsup:

Share this post


Link to post
Share on other sites
lowering the fork slows turning and improves straight line stability, raising them does the opposite.:thumbsup:

Not to be too blunt but.... You are backwards. Lowering the forks makes them longer (moving the tubes Up the triple clamps towards the bars), raising the bike (moving the the tubes down the triples towards towards to being flush with the triples), this in turn makes the rake larger. LOL, unless we are saying the same thing only not communicating clearly, which happens in these little messages!

Dirtbikes - Lots of rake, stabile, slow turning (not an issue as the speeds is also slow)

Sportbikes - minimal rake, not too stabile (But good traction, ie asphalt, solidifies things) Very fast turning.

Ever ride a sport bike on gravel or grass? Pretty shakey/scary!

Share this post


Link to post
Share on other sites

There's a dark side to less and less rake. Steers faster, but it will tuck on you faster too. Go too far it will slap you quick, without warning. More rake, more feel at the limit.

Share this post


Link to post
Share on other sites

Lowering the clamps on the fork tubes quickens steering..Raising them increases high speed stability and rake..A dragbike is the extreme example displaying a set up for high speed stability..lot of rake in degrees. less rake makes for a twitchy ride at speed especially under hard front braking. Like WM said.

Share this post


Link to post
Share on other sites

im a little confused right about now, wouldnt lowering the clamps lower the bike? bottom line.. does lowering you center of gravity not increase stability?

Share this post


Link to post
Share on other sites

I'm confused. I hear both sides of the fence?

Here is what is going on. I now have 2 drz's the Kicker and the S. The S feels as if it wants to fall over in the turns, quicker steering in my opinion. The kicker feels like it is really stiff going into turns, it doesn't want to turn, you have to make it. So the sorks on the K are a bit higher in the clamps than the S. Is that why I feel a differant type of turning?

Share this post


Link to post
Share on other sites

your forks arnt at the centre of your bike ....

Share this post


Link to post
Share on other sites
your forks arnt at the centre of your bike ....

that comment makes no sence

Share this post


Link to post
Share on other sites

does the kicker have softer suspension at the rear cause that will change the way feels

Share this post


Link to post
Share on other sites

Let's define our terms! :thumbsup: Technically, the forks rest on the ground so they can't be raised or lowered!

I believe what William meant by lowering your forks was to lower the clamps on the forks, which would cause the fork tops to protrude more and also lower the bike slightly. This indeed would cause the rake to decrease (i.e., the forks are more vertical) which would promote steering quickness and decrease stability (slightly). If you raise the clamps on the forks it has the opposite effect. If memory serves you want the line on the forks to be 5 mm above the clamp surface (somebody please verify).

Share this post


Link to post
Share on other sites
I'm confused. I hear both sides of the fence?

Here is what is going on. I now have 2 drz's the Kicker and the S. The S feels as if it wants to fall over in the turns, quicker steering in my opinion. The kicker feels like it is really stiff going into turns, it doesn't want to turn, you have to make it. So the sorks on the K are a bit higher in the clamps than the S. Is that why I feel a differant type of turning?

You may have other issues going on.If you can imagine an OCC chopper an an example of your forks being say flush with the clamps. That adds rake. Riding a "chopper " makes for hard steering..ie...bike wont turn and want to flop..Now if your rear suspension is not set right(too much sag/soft) you will further exaggerate the increase in rake by having your forks stuck way down in the clamps by having your rear down too low. I just had that problem with my S model..A new rear spring was the fix..along with proper set up.

Comparing the two bikes just based on where the forks are in the clamps may not give you accurate feedback as to what is going on..Adjustments, rear sag, spring rates, fork oil weight and volume, overall bike weight, tires, tire pressure, etc all play a part.

Maybe somebody else can chime in and explain better...I'm no expert at this..kind of a learn as I go guy.

Share this post


Link to post
Share on other sites
im a little confused right about now, wouldnt lowering the clamps lower the bike? bottom line.. does lowering you center of gravity not increase stability?

Bottom line: Yes, it lowers the front of the bike. No it does not increase stability since lowering only the front of the bike decreases rake angle. Rake is what makes a bike want to continue in a straight line on it's own. As you decrease rake angle the bike will turn much quicker at the cost of straight line stability.

Share this post


Link to post
Share on other sites

How much do you weigh? Getting the proper rear spring fixed more steering issues then anything I could do to the forks. And I'm only 190 lbs. Switch shocks on yours and see how it feels.

Share this post


Link to post
Share on other sites
Let's define our terms! :thumbsup: Technically, the forks rest on the ground so they can't be raised or lowered!

I believe what William meant by lowering your forks was to lower the clamps on the forks, which would cause the fork tops to protrude more and also lower the bike slightly. This indeed would cause the rake to decrease (i.e., the forks are more vertical) which would promote steering quickness and decrease stability (slightly). If you raise the clamps on the forks it has the opposite effect. If memory serves you want the line on the forks to be 5 mm above the clamp surface (somebody please verify).

Yes, on all counts, but... the forks do not rest on the ground, the tire does, and well, I do too sometimes. :thumbsup:

The 5mm (SM's have a line on the tube) is correct, idea being you have about 5mm +/- to play with according to the factory. But you really have more than that. Currently, I am running my flush.

Share this post


Link to post
Share on other sites
I'm confused. I hear both sides of the fence?

Here is what is going on. I now have 2 drz's the Kicker and the S. The S feels as if it wants to fall over in the turns, quicker steering in my opinion. The kicker feels like it is really stiff going into turns, it doesn't want to turn, you have to make it. So the sorks on the K are a bit higher in the clamps than the S. Is that why I feel a differant type of turning?

my guess is the K needs the steering stem regreased a common DRZ weak spot

try this jack the front end off the ground and try turning the handlebars any stiffness or if it doesnt turn completly smooth lock to lock you need to regrease the stem

Share this post


Link to post
Share on other sites
my guess is the K needs the steering stem regreased a common DRZ weak spot

try this jack the front end off the ground and try turning the handlebars any stiffness or if it doesnt turn completly smooth lock to lock you need to regrease the stem

Did that already. When I got them, I took a day to tear them apart and grease everything. I don't have to work that much, so I have a lot of free time. I had previously bought some SM wheels that have universal carriers. When I knew I was getting the bikes, I bought what I needed to fit the DRZ. So I am able to take either one on SM duty to the store and back. I hav ebeen on SM's before and the DRZ seems a bit heavy, but I like how smooth the power delivery is. It's not like a YZ or KTM. THe just want to jump out from beneath you.

I'll ge tit figured out, but in the meantime, it is hard going from one bike to the next and having two differant feelings. The K revvs so much quicker too. I'd compare the K to a YZ in revability. You snap the throttle and the motor is there working. I think I may actually keep both of them. We'll see.

-Wayne

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×