Big bike hunting at Texas World Speedway

[zvonler]

Footage from last Friday, the day before the last CMRA round, at Texas World Speedway. The track org that runs most of the practice days has a policy that no 250s are allowed in anything above the beginner group, so here's what it looks like when a decently-ridden 250 has to avoid the big bikes. I'm not super proud of all of this, I don't really think it's appropriate to blow off beginners this way, but that org also doesn't have any passing rules.

Link to original page on YouTube.

[csmith12]

Originally Posted by zvonler

The track org that runs most of the practice days has a policy that no 250s are allowed in anything above the beginner group

Nice riding, dumb rule.

[Panda]

Originally Posted by zvonler

I'm not super proud of all of this, I don't really think it's appropriate to blow off beginners this way, but that org also doesn't have any ...

Then why post it?

For my money I'd rather watch @rojoracing53 pass a bunch of A group riders than watch somebody who is "not super proud" hunt down beginners.

[Motofool]

Originally Posted by zvonler

...........so here's what it looks like when a decently-ridden 250 has to avoid the big bikes.............

Good riding !!!

What is the reason for the big bikes to go slower than the 250 before and during the turns ???

[zvonler]

Thanks csmith12 and motofool.

Originally Posted by Panda

Then why post it?

I figured some people might still like the footage of a 250 running down bikes with quite a bit more power. My point was that I'm not claiming that these passes prove anything about my riding.

Originally Posted by Motofool

What is the reason for the big bikes to go slower than the 250 before and during the turns ???

There's not really a good reason - most of these riders simply don't have a lot of experience on tracks. Well-ridden 600s run 10-15 seconds faster per lap than I'm doing here.

[csmith12]

Originally Posted by zvonler

I figured some people might still like the footage of a 250 running down bikes with quite a bit more power. My point was that I'm not claiming that these passes prove anything about my riding.

Don't sweat it brah. There is much to learn from that video if one would take the time to think about it for a bit.

Closing speed gaps
Sure, most people see it as. A liter bike down the back stretch is gunna blow away a 250. It's a safety issue right??? Well the same thing is shown here, on some of those corners entries, your closing/passing created the same comparable safety concern from the perspective of the beginner group. Couple that with no passing rules. Seems like the two conflict. But anyway.... One can see in the video, larger gaps in speed can be mitigated.

Lines
It shows you can take alternate lines (passing) and still be good. There are a lot of track riders that would snub their noses at riding in such traffic. They would come back to the paddock and complain about it the entire day. When life gives you lemons, make lemonade as you did.

Attitude
Also, the riders in the beginner group can get spooked pretty easy being passed mid-corner. I think you did a fine job keeping your passes clean, it's good for them as well as good for you. And yes, I seen you held back a few passes.

And so on... and so on... and so on...

[rojoracing53]

No 250s in the A group or even the B group sometimes is pretty common for trackdays. If your truly a fast and predicable rider then you can normally get up one class above their normal policy. Or you can just do what I do a walk into the place like your Valentino Rossi and sign up for A group like you own the place

Honestly even at my pace the straitaway speeds are a little to different and it only takes that one guy to pull around me at the last second and leave the guy drafting him only 12" of his tire no time to react and slam into me. I made it a point during the riders meeting my the trackdays I did do on my 250 to explain they senerio to the group and asked them to give me pleanty of space to the rider behind them could see me. I also warned them if they didn't play nice on the straits I could guarantee I would play nice in the corners.

It was fun playing around in the A group on the 250 but it's also fun to hop on a buddies 600 for a session and suddenly be going 15 seconds faster

[Motofool]

Originally Posted by zvonler

...........There's not really a good reason - most of these riders simply don't have a lot of experience on tracks. Well-ridden 600s run 10-15 seconds faster per lap than I'm doing here.

Thanks, Zach

I asked because I have seen that supposed advantage of the 250 discussed many times, but I don't know of any Physics reason that could make a difference.

As I don't have racing experience, this contradiction has been an unsolved mystery for me.

[csmith12]

Originally Posted by rojoracing53

No 250s in the A group or even the B group sometimes is pretty common for trackdays. If your truly a fast and predicable rider then you can normally get up one class above their normal policy. Or you can just do what I do a walk into the place like your Valentino Rossi and sign up for A group like you own the place

Agreed! Sometimes it's best to not ask for permission, but instead ask for forgiveness. If it were to be a problem, they would ask you to bump down and everyone moves on with their day. No fuss, no muss.

[zvonler]

Originally Posted by Motofool

I asked because I have seen that supposed advantage of the 250 discussed many times, but I don't know of any Physics reason that could make a difference.

At the absolute limit of performance, a lighter bike can corner at a higher speed than a heavier bike. That's where the physics comes into play.

That said, I don't think any of my corner speeds are higher than a good rider on a bigger bike could achieve. In my case, the 50-100 pound weight advantage of the 250 merely makes it easier to brake later and turn harder than I would be able to on a heavier bike.

[rojoracing53]

Originally Posted by Motofool

Thanks, Zach

I asked because I have seen that supposed advantage of the 250 discussed many times, but I don't know of any Physics reason that could make a difference.

As I don't have racing experience, this contradiction has been an unsolved mystery for me.

I have yet to find any advantage to the 250 in any aspect of the track in the hands of an accomplished racer. A real supersport is pretty much better in every way that matters on track.

[zvonler]

Originally Posted by csmith12

Agreed! Sometimes it's best to not ask for permission, but instead ask for forgiveness. If it were to be a problem, they would ask you to bump down and everyone moves on with their day. No fuss, no muss.

Yeah, I did that last time: registered for the intermediate group and rode with them for the early sessions. I wasn't even close to the slowest bike out there, and chased down several 600s. Even so, at lunchtime that day the decree came out that all 250s had to drop to the beginner group. I tried convincing the head honcho that it was safer for me to run with the other racers, but he wasn't having any of it.

[rojoracing53]

Originally Posted by zvonler

Yeah, I did that last time: registered for the intermediate group and rode with them for the early sessions. I wasn't even close to the slowest bike out there, and chased down several 600s. Even so, at lunchtime that day the decree came out that all 250s had to drop to the beginner group. I tried convincing the head honcho that it was safer for me to run with the other racers, but he wasn't having any of it.

You can't simply be not the slowest bike while on the 250 and remain in a group. You need to be the fastest rider in that group to the point that the 600's are complaining about you passing them all the time

[rojoracing53]

Originally Posted by zvonler

At the absolute limit of performance, a lighter bike can corner at a higher speed than a heavier bike. That's where the physics comes into play.

That said, I don't think any of my corner speeds are higher than a good rider on a bigger bike could achieve. In my case, the 50-100 pound weight advantage of the 250 merely makes it easier to brake later and turn harder than I would be able to on a heavier bike.

A lighter bike with equally good suspension can corner a wee but faster. You can only brake later because your going so slow down the straits but if a 600 were going the same speed they would be overbraking if they used your same braking markers.

Not criticizing you just trying to keep the "the ninja 250 is the ultimate cornering weapon" misinformation to a minimum.

[Motofool]

Originally Posted by zvonler

At the absolute limit of performance, a lighter bike can corner at a higher speed than a heavier bike. That's where the physics comes into play......

See, that is the statement against which all I know about Physics rebels.

In my theoretical book both machines must perform alike (having everything else equal but the weight).

I have been waiting for some experienced racer to explain how they are different in real life.

Previous posts from CC Cowboy coincide with these posts from Rojo.

[zvonler]

Originally Posted by Motofool

See, that is the statement against which all I know about Physics rebels.

In my theoretical book both machines must perform alike (having everything else equal but the weight).

Two identical machines except for weight are when cornering each undergoing a lateral acceleration. The heavier machine at the same speed will have more acceleration, so it will reach the limit of the tires' grip earlier as speeds are increased. The amount of tire grip increases with downward load, but not linearly, and only up to a point.

[zvonler]

Originally Posted by rojoracing53

You can't simply be not the slowest bike while on the 250 and remain in a group. You need to be the fastest rider in that group to the point that the 600's are complaining about you passing them all the time

Hey, I'm working on it. My frustration in the beginner group comes because I don't get to run any clean laps where I can really string all the corners together.

Originally Posted by rojoracing53

A lighter bike with equally good suspension can corner a wee but faster. You can only brake later because your going so slow down the straits but if a 600 were going the same speed they would be overbraking if they used your same braking markers.

Not criticizing you just trying to keep the "the ninja 250 is the ultimate cornering weapon" misinformation to a minimum.

Not sure if you think I'm spreading "misinformation" - I don't claim 250s are any kind of ultimate machine. I do claim that in the hands of someone that can't reach the absolute limits of grip, they will have an easier time at a given corner speed on a lighter machine.

And on braking markers, I really don't know what you mean. Higher speeds and heavier machines require earlier braking points.

[Motofool]

Originally Posted by zvonler

..........The amount of tire grip increases with downward load, but not linearly, and only up to a point.

We disagree at this point, Zach.
There is nothing in the books or in nature that limits traction, the more weight pushing down, the more resistance to slide (helped by a slightly bigger contact patch).

Actually, with enough force pushing down, contact welding between two materials is achieved in industry (no heat is needed).

According to this diagram, both bikes must lean the same, as the mass cancel each other in both directions.



In real life, the bike with the wider tires and lowest CG must lean a little more.
That may be a reason for the 250 to have some advantage.

[zvonler]

Originally Posted by Motofool

We disagree at this point, Zach.
There is nothing in the books or in nature that limits traction, the more weight pushing down, the more resistance to slide (helped by a slightly bigger contact patch).

I get my info from places like this: http://en.wikipedia.org/wiki/Tire_load_sensitivity

"Tire load sensitivity describes the behaviour of tires under load. Conventional pneumatic tires do not behave as classical friction theory would suggest. The load sensitivity of most real tires in their typical operating range is such that the coefficient of friction decreases as the vertical load, Fz, increases. The maximum lateral force that can be developed does increase as the vertical load increases, but at a diminishing rate."

[CC Cowboy]

All I can say is two killed at Daytona caused by slower and faster bikes. Safety is more important ego.

[rojoracing53]

Originally Posted by zvonler

Hey, I'm working on it. My frustration in the beginner group comes because I don't get to run any clean laps where I can really string all the corners together.



Not sure if you think I'm spreading "misinformation" - I don't claim 250s are any kind of ultimate machine. I do claim that in the hands of someone that can't reach the absolute limits of grip, they will have an easier time at a given corner speed on a lighter machine.

And on braking markers, I really don't know what you mean. Higher speeds and heavier machines require earlier braking points.

Imagine a corner has a hard braking zones with for example 5 braking markers from 1 cone first to 5 cones as you get farther into the corner. Now if the big bikes are using the 1st marker at 130mph and your using the 4th marker at 90mph then yes you are braking later on the track. But if someone on a big bike limited their top speed to only 90mph then they could go past the 4th marker and get closer to the 5th marker because the braking power to weight ratio is better on the big bikes.

But here's the one that will get most people because they've never ridden both bike to the limit. So I can corner both my R6 and 250 through said corner at 50 mph within a couple mph. On the 250 I use the 4th braking marker from a top speed of 95mph while on the R6 I use the 2nd braking marker from a top speed of 150mph. On the R6 while on the brakes I pass by the 4th braking marker at 105mph while continuing to slow down to 50 mph. If your still following me then technically the R6 is getting on the brakes early on the track but is braking later then the 250.

It's rare to have this happen perfectly but if a 250 and 600 with comparable riders both reach their respective braking markers at the same time. You'll see the 600 catch the 250 going into the corner but because the 250 was 60' or so ahead the 600 wont be able to pass. Now if you swapped the ninja 250 with a RS125 then everything is different because the weight to braking power swings in favor of the 125.

Most of this honestly doesn't apply to trackdays because unless their happens to be a true pro class racer there just killing time I doubt anyone is able to push any of the bike to their limits so it come down to ride more then bike.

I hope at least some of that makes sense

[rojoracing53]

oh and by the way the amount of traffic your dealing with in your video is basically what I have to deal with during A group while on a R6 and is the main reason I used to hate trackday for track testing. Unfortunately there is no Group faster then A so like you I get stuck dealing with traffic while trying to get in some clean laps and it's just frustrating so say the least.

It wasn't until recently when I tracked the ninja 250 that I had fun at a trackday because I was lapping at the same time as the other riders so we rarely held each other up

[csmith12]

Originally Posted by CC Cowboy

All I can say is two killed at Daytona caused by slower and faster bikes. Safety is more important ego.

Yep, and in this case, bike CC's aren't amounting to a hill of beans. 250 or no, he don't belong in this group. Someone in that org simply don't care. 250 = Novice, no exceptions.

[Snake]

Awesome riding man!

[iZapp]

Originally Posted by Motofool

There is nothing in the books or in nature that limits traction, the more weight pushing down, the more resistance to slide

LOL, then we do we keep falling down???!!!

[rojoracing53]

Originally Posted by iZapp

LOL, then we do we keep falling down???!!!

Ground magnets Duh

You hear about them being placed in different turns during trackdays all the time.

[Motofool]

Originally Posted by iZapp

LOL, then we do we keep falling down???!!!

Only the ones that disrespect the fair but unforgiving laws of Physics

In motorcycling, some master balance and limits and take total control of any situation, some don't.

Riding well beats riding too fast and falling down several times ........... unless you are a trained and skilful athlete desperately reaching for that trophy ........... winning which may beat anything else.