zeta xray
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posted March 13, 2004 12:37 PM
Suspension question for the "pros"
I am a track day rider with virtually no motorcycle road racing experience. I know when you make the steering stem more vertical the bike steers more quickly but the trade off is that the bike is less stabile. What I don't know is, which actually has the most grip, less steering stem angle or more steering stem angle? Or does it actually change mechanical grip?
Inquiring minds want to know. Rob Muzzy, Kerry Bryant or anyone have any idea?
  
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K BRYANT
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posted March 13, 2004 12:58 PM
Way to many varibles that you're leaving out that affect that general question. A simple answer is; yes, up to a point. Think of a cruiser. Will it have less grip than a Sportbike becasue it's rake is not as steep? Yes, but the rake angle is only part of it... Ok, let's try to make it easier and help you out. Below is only the beginning of making you more comfortable and faster (assuming thatz what you're looking for, if not ignore my dribble).
You're a track day rider. What level do you go out in and how decent are you in that group? If you can tell me the track & your lap times, it would give me a better idea.
What bike are you riding?
What tires & air pressure?
What are your current suspension settings, include sag.
Where is the fork sitting in the triple clamp; level?, above? below?
What is your wheelbase currently (measure axle to axle)?
Tell me what it's doing or not doing that:
a) makes you want to be more comfortable?
b) makes you want to be faster?
As you think about it, remember the most important factor is comfort. Do you feel comfortable with the bike, with the pace, in the corners, on the brakes, etc. Think about it before you answer. Otherwise you'll adjust and/or click yourself into a mistake. Let's make you more comfortable & confident, then let's make you faster because of it!
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1bad7
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posted March 13, 2004 06:44 PM
KB, you've just helped me somewhat but now it is more difficult. I run a 1.58 at Pergusa here in Sicily, the track is almost 5km long and fast. The really fast guys are doing low 1.50's. When I finally get my ZX10 I was wondering if you'll lend me your advice for setting the suspension up for this track.
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swft
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posted March 13, 2004 07:17 PM
 Edited By: swft on 13 Mar 2004 19:17
Didn't Sport Rider do a really good suspension setup article?
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swft
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posted March 13, 2004 07:18 PM
http://www.sportrider.com/tech/146_0006_susp/
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Andy
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posted March 13, 2004 08:11 PM
You're asking and answering your own questions, thats some serious post whoring. 
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zeta xray
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posted March 13, 2004 08:48 PM
KB, all of my track days have been at Texas World Speedway. The last trip to the track, we had very heavy rain the night before and the track never did dry out. I was riding in the "agressive street rider, licensed racer" group. During one session, I was riding with a licensed novice racer on a GSXR1000. He said his better lap times were 2:07's. He was a little faster than I was. Overall, I would estimate that I was about mid group in speed.
What bike are you riding? 1998 R1
What tires & air pressure? Pirelli Dragon SuperCorsa. SC1 ft, SC2 rr. 30 psi f & r.
What are your current suspension settings, include sag. Forks are stock w/10w Bel Ray synthetic fork oil. Compression and rebound dampning are within a couple of clicks of full stiff. I don't remember the exact ft & rr sag but it is set according to a Ohlins setup guide that came with my shock. Rear shock is an Ohlins set for my weight (170 Lbs). Compression and rebound dampning is near mid settings. I have dialed in more rebound than how the shock came out of the box.
Where is the fork sitting in the triple clamp; level?, above? below? Level
What is your wheelbase currently (measure axle to axle)? Stock? Nearly new chain and std. sprockets.
Tell me what it's doing or not doing that:
a) makes you want to be more comfortable? The bike feels confident and stabile in the straights at TWS with no head shake. I do not have a steering damper installed. But I lack confidence in the front end during corner entry. I think I am a little slow mid corner as well. I know that I do not get back into the throttle as soon as I should or as aggresively as I could. However, when I finally do get on the gas, I feel very comfortable and I am fairly aggressive on corner exits. I have had the R1 spin up exiting turns without any drama. The Gixxer rider was impressed with how hard I was firing off of the turns. My sense is that the front end doesn't have quite enough mechanical grip. I am starting to feel that I might be at the limit of the stock front forks. I recently did some vigerous canyon riding where you are on the gas and on the brakes constantly and it seemed like it was a lot of work to turn the R1 and that the forks seemed to pogo a lot. I found it is easier to be smoother on the race track.
b) makes you want to be faster? I have had the opportunity to spend a fair amount of time on a Ducati 998S Bostrom Replica. That bike gives me more confidence in the front end sticking. The overriding impression is that the Duc almost creates it's own artificial gravity. It sticks where the R1 would be slipping around, so I feel that there is room for improvement.
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K BRYANT
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posted March 14, 2004 10:41 AM
Edited By: K BRYANT on 14 Mar 2004 10:45
Hmm.... Try to keep you going in the right direction without too much confusion.
a) Get a steering dampner. I'm impressed that you're going as good as you are without one. But pleeze get one before you do many more track days (very cheap insurance). Doesn't really matter what brand. Scott's makes a good one for the R1, but most any of them are better than none. The R1 is a nervous bike (I had a '01 model). Adding a steering dampner increases a tractable feel in the front (not just for tank slappers).
b) Raise the fork tubes 3-5mm. This will increase the "planted" feel in the front, while quicking the steering somewhat. I only recommend this if you are going to install the steering dampner.
b) Feeling "smoother" on the track is a natural. Testing the limits of an R1 on the street will make for a short career.... If your not feeling the "pogo" affect on the track, then you need to smooth-out your style on the street. The feeling should be roughly the same when it comes to suspension feedback (keeping in mind the obvious speed differences).
c) "I" normally run 1 or 2 psi less in the rear on the track, than the front. I have not been to Texas World in forever. When I was there it was really chewed up and extremely fast. But your air pressure is close.
d) If you're riding hard enough to spin the rear, then your front is sticking fine. You would not be able to accomplish this without good front tracking.
R1's are notorious for not feeling stable in the front end. The steering dampner will help significantly. As far as "mechanical grip". Never really heard it put that way. Normally mechanical relates to a solid type of action. You've got springs & oil (fork), and rubber (tire) involved. So you're going to have to settle for a predictable "comfort zone" of enteria action/rebound, give/take. This comfort zone is what will ultimately make you faster. When actions become predictable, speed follows more easily.
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zeta xray
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posted March 14, 2004 04:02 PM
KB, thanks for the input. I am hoping that my next track day will be on a green ZX10. However, the R1 will still be around. I imagine that my efforts and money will be devoted to the Kawasaki for a while. You confirned what I suspected about the R1 and the direction I need to take with it. I think I am going to have to get some kind of fork kit for the R1, in addition to the steering damper. The forks feel slightly harsh but, at the same time they seem to lack control.
Since you had an R1 I would be interested in your impressions comparing the older R1 to the ZX10.
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k bryant
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posted March 14, 2004 07:00 PM
Honestly, I hesitate to say night & day, but I probably need too... The 10 simply did everything better than the R1 ('01 model). It's got no flaws that stood out. I would not even get a steering dampner for the street. It simply felt planted.
The '04 R1 feels very comfortable at speed. But it still had that nervous feeling that my '01 did. It's fast and flicks very easily, but it needs more attention paid to it in transisions requiring alot of handlebar pressure. Also, undulations in the road mid-corner brought back the old feeling of it clicking the bars and feeling like it wanted to tank slap. It' puts more pressure on the wrists than the 10. The pegs also felt lower, which I don't really like.
I'm buying a 10.
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swft
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posted March 14, 2004 07:02 PM
Any word on when the CA models will be in? Washington state is getting bikes this week.
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k bryant
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posted March 14, 2004 07:06 PM
Nope. Haven't got a clue. Luckily I've had my "fix" and it'll last me a little longer...
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swft
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posted March 14, 2004 07:09 PM
*grins* Yah, I hear ya...Everything's lining up nicely. Only potential downer is if the dealer doesn't get a black one right away. I should know tuesday.
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swft
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posted March 14, 2004 07:16 PM
Also, where in the hell did the tradition of dealers being closed on mondays come from? It it because most dealers want to keep their employees at 39 hours, hence they aren't full time and they don't have to pay benefits for them? Just trying to figure it out... 
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Erich
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posted March 15, 2004 12:28 AM
I just wanted to add that I beleive what you mean by mechanical grip is actual or absolute grip. In other words will changing the rake actually increase the grip at the front end.
The answer (if that was the question) is no, it will not. But change how it reacts/feels and you may or may not like that depending on your preferences and the tire profiles you run.
I have had a 99 and 02 R1, they both suffered from poor front end feel. And that is really what your are encountering. Part of it is in the factory damping, so a revalve will help, but the other part if the higher CG they run combined with the lack of trail. These bikes (98 - 01) really respond well to aftermarket triples that allow you to change the offset to put more trail in the front end (after you fix the damping).
I hate to say it, but even though the bike is good, even worked on they will not give you the front end feedback that some others do. Good luck with it.
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beansbaxter
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posted March 15, 2004 12:28 AM
I cant figure that out either...why all the dealers are closed on Monday. They are open on Saturday, so there weekend is Sunday/Monday.
The Kawi dealer in Clarkston, WA though is the only place I have ever seen that is only closed on Sunday. So if a Monday does roll around, its nice to know they are open.
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