Tire Question for SD

[H-man]

Oy Super Dave,

A mutual friend (the one on whose behalf I asked that t-shirt question ;)) suggested I run the following statement by you for your comments:

"If you don't stick with one brand of tire, odds are you'll never get good enough to notice the differences.  Brand isn't as important as consistancy of using that brand."

This grew from an earlier thread I started where I was looking for input about Bridgestone tires.

My take on the quoted statement is that I disagree with it.  Well, at the novice/amateur level anyway.  Particularly the infrequent racer.  That is, someone who only attends 4 or 6 race events per season.  For experienced experts and pros I would agree with the statement.

   H-man

[Sunny]

My 2 cents.............

If the rider is fast enough, then he/she should feel noticeable difference among different tires.  However, without enough time/knowledge, the judgement could be wrong due to improper suspension setting (each tire has its own optimum suspension setting).

[H-man]

Thanks for your input Sunny.  However, your answer is a bit too broad to be useful to me.

How fast is fast enough?  To use a track we're both familiar, is a rider who does 1:37 at Grattan "fast enough?  What about 1:45?  Or would the rider have to turn sub-30s in order to "feel noticeable difference(s) among the tires"?

Also, I want to leave suspension out of the equation now.  I will grant you your point about suspension.  But I want to try get at a  more basic principle.

There are too many inputs to suspension that are particular to weather conditions (hot or cold, wet or dry), different tracks, weight of the rider - even on the same bike.

[Super Dave]

Yeah, broad question...

Ok, in April of 1993 I raced at Laguna Seca with three brands of tires.  Capped off the year by riding fourth brand of tires.

You cannot really leave suspension out of the issue.

The Michelin combination was my regular tire.  Raced on Dunlops a few times.  A good amount with Avon.

Now, lets just talk about turn in...initiating the corner.

The Michelin combination was my regular set up, so, we could call that the constant.

Now, a rider will probably do the same thing over and over.  Really, we're pretty good at making the same mistakes over and over.  We're human.  So, when we come to a certain spot, we turn the bike a particular way, and, because of the geometry of the bike at that moment on the track, it turns and follows a certain radius....

Now, we change the tire...

Lets say that the tire combination makes the front geometry tighter...tighter steering head angle...

We come to our same spot and we place our regular input into the bike.  Because the steering head angle is tighter, it reacts more immediately.  Tossing the bike over very quicky.  Might even cause the rider to turn inside the line that they would traditionally follow.  

Add to the fact that the trail was reduced...you, of course, as one of my students, recognize that trail has a lot to do with that thing we call "feel"...our feel of the bike mid corner is lost from what we had before.

Now, we go to tire number three.

Compared to the constant, it's the same height, but the actual contour, the shape of the tire is different.  Tires can be kind of round, triangular, and this one, number three was flat with a quick rounding.

So, while the initiation of turn in was similar to the constant, as the bike leaned, it ran wide....

This make any sense?

Really a rider should work almost immediatly on the idea of feel.  Change tires, and it might make the bike "feel" better or "not feel" better.  The reality of the fact is that a tire change can provide better geometry to the bike for greater feedback and comfort for the rider...

Lots of people flounder around with all the dampening settings while never exploring ride height options and different preload options...or even different springs.  

Ok, H...so, to complicate matters, some tracks will favor certain geometries or they will load the chassis in a way that causes it to be a certain way.  

H...give me two or three tracks.  Which one is the one that "feels" the best, which feels the worst.  Tell me about your favorite and least favorite corners on those tracks.  

Let's talk...

[H-man]

Yeah, that was a rather overly broad statement I asked you to comment on.  What can I say?  That was Monte's statement and we both know Monte  ;)

I'll go into answering some of your questions in furthering the discussion, but let me restate/define where I'm coming from.

I'm a recreational racer/rider.  I'm out there for the challenge and fun.  If I ever win wood, I'm gonna be looking around for Alan Font and Candid Camera.  Between WERA, Fasttrax and CCS I'll probably do 4 or 5 race events.  And toss in some track days for fun and practice.  The way I ride I don't burn up tires much.  So I'll probably use 2 sets of tires for the season.

Given this, my aim was to determine whether I could switch to a less costly tire that was still reputible.  I started on the Metzeler M-1s, then switched to and loved the Pirelli Super Corsas.  I know that was a change from a mostly street/some track day tire to a DOT race so the imporvement would be huge.  None-the-less I like the Pirelli.  The price a set of the Bridgestone BT-002 has caught my eye.  Hence all these questions.

For a really silly reason (that I won't embarrass myself by noting here), I've been against using the Michelins.  But that may change with the reports I've been hearing about their fast heating Power Race tyres.

Let's see... tracks....  There's a few I've been on but Grattan and Gingerman are the one's I ride most frequently.  While I know the parts that I feel least confident, I'm not that comfortable looking to the tire or suspension or geometry when I know that my body positioning, line or execution may well be the biggest cause for not being smooth.

At Gingerman [here's a map of Gingerman http://www.gingermanraceway.com/ - click on "track-specs at bottom of page] my biggest headaches are turns 2 and that double left turns 5 & 6.  My favs are turns 7-9. I feel planted, fast and confident going through those series of turns.

At Grattan....[for those of you still following along, here's a map of Grattan - http://www.grattanraceway.com/thetrack.html]  The bus stop is the bus stop.  It's simply a slow and tough turn (for me).  Turn 3 (the infamous downhill, off cambre, decreasing radius left is tricky but it's actually turns 2 and 7 (both right-handers) that give me the greatest pause.

[Super Dave]

First things first...saving money on tires just seldom works.

I think you understand that.

Riding/racing really is about mistakes.  I can play video games all day, and it's no problem.  But there's no concequence if you wreck.  Selling things has to do with the market.  So, the tire companies that are well placed in the market understand their costs, etc.  There's gonna be a window for a "proper" tire...I won't say "premium" because if you're gonna make mistakes, you need "cushion" to help you out.  You'll make more mistakes starting out.

my biggest headaches are turns 2 and that double left turns 5 & 6

Ok, so there's something there that's similar.  What are you doing on the bike at that time?  Don't get too wound up...keep this simple.

My favs are turns 7-9

And here, I bet you're doing the "opposite."  Talk to me...

[H-man]

While I like Gingerman a lot, those da*mned seams do play on my mind.  I know.  I've been told to ignore them.  I've experienced how the rear will only momentarily step out if you cross over it at a shallow angle.  None the less they still bug me and I'm sure have an influence on the line I select at different parts of the track.

One difference between all the turns that give me trouble and the ones I like (or at least am comfortable) is my confidence.  That is, I feel good about my entry speed.  I'm sure it can and will be greater even in my good turns, but for now, I'm fiddling around with too much just prior to turn in.

My problem typically is at the exit of the turns.  Running wide.  I suppose I'm just not on the gas early enough.  No.  For turns 2 and 6, there are actually points when I'm off the gas.  Then I realize, I'd better gas it in order to achieve more lean and tighten this turn.  I thing better body positioning will enable me to hang off and achieve the proper lean angle from the beginning to be able to be on the gas all the way through.

Turns 7-9 are simply a blast because I'm on the gas.  Steadily increasing the amount of throttle.  Flipping the bike over quickly for the left hand turn 9 is the shiznit.

I just enjoy all sweeping turns.  While others rave about the Dragon's Tail (US-129) I didn't really enjoy it.  I much preferred the Cheorrohala (sp?) hwy.

[H-man]

Anyway, aren't we a bit off topic?  While I'm loving your personal advice, I don't want to use up band width for something that may benefit only me.  Maybe I should just e-mail or PM ya.

As for tires, I'll stay with the Pirellis.  Depending on where I am when my current ones go, I may try the Michelin PRs.

Standing by.

[Super Dave]

My problem typically is at the exit of the turns.  Running wide.  I suppose I'm just not on the gas early enough.  No.  For turns 2 and 6, there are actually points when I'm off the gas.  Then I realize, I'd better gas it in order to achieve more lean and tighten this turn.  I thing better body positioning will enable me to hang off and achieve the proper lean angle from the beginning to be able to be on the gas all the way through.

Turns 7-9 are simply a blast because I'm on the gas.  Steadily increasing the amount of throttle.  Flipping the bike over quickly for the left hand turn 9 is the shiznit.

I just enjoy all sweeping turns.  While others rave about the Dragon's Tail (US-129) I didn't really enjoy it.  I much preferred the Cheorrohala (sp?) hwy.

Not off topic at all.

You are trying to tell me that some problems are related to you.

I'm telling you that a lot of problems are related to how the bike works.  

Ok, so you like sweeping turns.  You're probably holding the gas steady, etc.  That creates anti squat that picks the bike up.  Sounds like in other places where you're not on the gas, the bike just kind of sucks.  

Ok, yeah, Rossi could ride it faster, but he would rider it faster if the chassis were better...and so would you.

So, how much sag do you have in the back?  In the front?

My bike is really easy to ride, because I work with Jim and the guys at 4&6.  Basically, I want to ride a couch really, really fast.  But, even then, I'm looking for minor changes to help little things here and there.  

Example.  Ok, I can go so fast on the bike.  But I, as a human, will have issues.  So, last year, I would ride my bike and brake at a certain place.  It came to a point where my performance was causing me to slow down too much for the corner.  I really want to brake to the apex with feel from the chassis.  But I was getting it all done too soon.  Tried and tried and tried to make myself to stuff, but I just always ended up too slow before the apex...

What to do...

Change the bike.

I changed the bike so that it's braking performance was different in a way that I wouldn't use the brakes so hard...that got me into the corner just a hair further...

[Sunny]

Thanks for your input Sunny.  However, your answer is a bit too broad to be useful to me.

How fast is fast enough?  To use a track we're both familiar, is a rider who does 1:37 at Grattan "fast enough?  What about 1:45?  Or would the rider have to turn sub-30s in order to "feel noticeable difference(s) among the tires"?

Also, I want to leave suspension out of the equation now.  I will grant you your point about suspension.  But I want to try get at a  more basic principle.

There are too many inputs to suspension that are particular to weather conditions (hot or cold, wet or dry), different tracks, weight of the rider - even on the same bike.

Well, I was just providing a general answer to a generally broad question.   ;)

1:37 at Grattan on a 600 is not fast (even with your older F2).  Average fast 600 racers are in 1:25-1:27 range.  I think fast on a F2 should be close to 1:30.  but one probably doesn't have to go that fast on a F2 to feel the difference.  However, I am not sure a 1:37 F2 rider can feel the difference in traction at Grattan.  However, as Dave said, you can definitely feel the effect of different tire heights/profiles.  As you know, there are many aspects of tire.  It all depends on which ones you want to discuss.  So generally broad question gets generally broad answer.  To me, confidence inspiring is an very important factor, and Pirelli has provided that for me, and hence why I like it (and the fact that it is very good).   ;)

[Sunny]

My problem typically is at the exit of the turns.  Running wide.

Sounds more like a geometry/suspension problems..........  Have you have them checked?  I can do the basic tuning pretty good, but I know you don't like anyone except pros to touch your bike.  Therefore, I suggest you use say, Keith, when you attend STT trackdays.

[H-man]

but I know you don't like anyone except pros to touch your bike.

ROFL!!  Where'd you ever get this kernal of knowledge?  I wrench on that ole '94 myself.  I like the bike but I'm not so sure it's a valuable keeper for me to hold such an attitude.

In philosophy there's a saying "you cannot know what is not so."  What you wrote just isn't true.  So how can you "know" it.

Actually, Keith has done my basic s/u a couple times.  I never got the numbers he set for the bike though.  I'll need some help to do things like measuring sag.  I may just take you up on your offer.  Though since you live so far from me, I'll try look for some guys who are a bit closer.