I have a question regarding rider weight and tire traction. Since frictional forces increase with weight, what effects do you see on braking and cornering traction for very light riders? And if low rider weight can have detrimental effects on traction, what kinds of modifications to the bike or changes in technique do you recommend to maximize traction? (for example when emergency braking). I have a friend who has locked the front tire twice (they only weigh about a 100 lbs) during emergency braking practice. Of course they are applying too much brake lever pressure too quickly, but is there anything else that could be done to improve front wheel traction in their unique situation? Thanks!
-
There has been a recent cluster of spammers accessing BARFer accounts and posting spam. To safeguard your account, please consider changing your password. It would be even better to take the additional step of enabling 2 Factor Authentication (2FA) on your BARF account. Read more here.
Questions for Keith Code - Round Two
- Thread starter budman
- Start date
Keith Code
New member
Those are good questions. I've seen over 200 lb guys ride very, very quickly at tracks with no problems at all in cornering speed and grip. Then again, I see our very young students, 70 lb guys, on 125 GP bikes go remarkably fast through corners with no grip problems, even on shagged tires.
Locking up the front wheel may be more than just brake application technique, although if they are snapping it on the chances of locking the front does go up sharply. The other thing is too soft a spring in the front where the forks bottom out, that will cause lock up in a heartbeat.
Contrary to that would be springs too stiff that don't allow the weight to transfer and that can lock up the front wheel very easily as well. Best thing to do in the too soft/too hard scenarios is get the spring sag set for the rider then work on the braking technique.
Keith
Burning1
I'm scareoused!
Kieth, in your personal experience, how much of a factor does weight actually play in riding performance, and at what level of competition does it become important? (Assuming of course that the bike is correctly set-up for the rider.)
For instance, if a rider weighed 300lbs, would he be better off attending trackdays, or paying for a gym membership? Is it better to have a low body weight, or to build muscle?
For instance, if a rider weighed 300lbs, would he be better off attending trackdays, or paying for a gym membership? Is it better to have a low body weight, or to build muscle?
Keith Code
New member
Every pro works out---a lot---so your 300 lb guy isn't going to make it in pro racing. Aside from the wind resistance and the acceleration reduction there would be ergonomic problems like hanging off that would be daunting...forget it, go on a diet, lose 100 lb and start there.
Traditionally, riders have been compact people. In GP, that came from the classes run, 125, 250. It used to be 50, 125, 250, 350 and 500 so weight was a consideration and fat guys just didn't do it.
Keith
Not that I'm going to be a pro racer or anything close, but a more subtle question about optimal genetics, mother nature, and racing. I'm sure someone will come along and break the "rules", but how much is borderline too heavy to be competitive at a top level?
Nicky Hayden is 150
Valentino Rossi 130
Dani Pedrosa 102
Are other organizations friendlier to larger people than Motogp? Assuming we're talking about people who are in shape.
If you're 200 lbs., is it safe to say you're gonna have a tough time getting to the top levels in this sport? What about 180? 170? 160?
I guess the reason I ask is if you have kids, and want to get them into a sport they can succeed in. . . wouldn't make practical sense to put a kid who's genetically going to be 5'3" tops into intensive basketball training with realistic expectations of say NCAA div. 1 aspirations, nor would it be reasonable to expect a kid who's going to be a minimum of 6'5" 180 lbs. to be a jockey. I'm wondering where the lines and gray areas are for moto racing.
For most folks like me, it's probably not going to matter much. Being in reasonable shape and enjoying the ride whether it's track days or maybe some club competition will suit me just fine.
Nicky Hayden is 150
Valentino Rossi 130
Dani Pedrosa 102
Are other organizations friendlier to larger people than Motogp? Assuming we're talking about people who are in shape.
If you're 200 lbs., is it safe to say you're gonna have a tough time getting to the top levels in this sport? What about 180? 170? 160?
I guess the reason I ask is if you have kids, and want to get them into a sport they can succeed in. . . wouldn't make practical sense to put a kid who's genetically going to be 5'3" tops into intensive basketball training with realistic expectations of say NCAA div. 1 aspirations, nor would it be reasonable to expect a kid who's going to be a minimum of 6'5" 180 lbs. to be a jockey. I'm wondering where the lines and gray areas are for moto racing.
For most folks like me, it's probably not going to matter much. Being in reasonable shape and enjoying the ride whether it's track days or maybe some club competition will suit me just fine.
Last edited:
Keith Code
New member
Here are the numbers that I believe are correct. In order to match acceleration, for each 7 pounds you have to have one more horsepower to be equal. You can do the math on that yourself and see that some are going to fit and some not. For pro racing, where horsepower figures are very close, what do you think would be in the ballpark?
hitman5532
The Anti-Squid
If you have kids, you should let them compete in whatever they have FUN DOING not just because they will win. I was severly undersized for football, played through college and went all american. I would never be looked at seriously because of my size, and that sucks, but I would never take back the experiece, challenge or fun in taking such a challenge. I am severly oversized for being top level moto, but I am still going to try to become the best rider I can be and enjoy the sport for its challege and fun.
JUST GO RIDE!!!
Burning1
I'm scareoused!
I believe that kids should be given lots of opportunities to try different sports in order to find the ones that they enjoy and excel at. But with that said, every parent wants to open doors for his child. If the boy is going to grow up to be 5'8" and loves motorcycles and basketball, which sport would you focus on..?
Last edited:
hitman5532
The Anti-Squid
Desmodromic
Captain Slow
^ Amen, I played all types of sports but I played Bball the most in my younger years and I was around 6ft and about 160 ish. I had a great time and held my own against equal and better players. Now in Moto's I'm 6'1 and 180ish pounds and Hitman5532 would kick my ass on the track/street with a Vespa while ironing his shirt.
And it's still fun!
BTW, Rossi is not 130lb is he?!
And it's still fun!
BTW, Rossi is not 130lb is he?!
Dr. Evil
Mother of God.
Bunch of lightweights in here. 
< --- 6'1" 210 lbs.
And Keith, I was wondering about reference points. I would check my copy of Twist/Wrist rather than bother you, but I have mislaid it.
I know that RPs are supposed to be something rather obvious so you don't take your eyes off the track, but is there a point where you can have too many? I suppose you can, but what mental processes would occur while riding would suggest to me that I can discard some, and as an aside, should I base the number of them on units of distance or perceived time or whichever is comfortable for me?
< --- 6'1" 210 lbs.
And Keith, I was wondering about reference points. I would check my copy of Twist/Wrist rather than bother you, but I have mislaid it.
I know that RPs are supposed to be something rather obvious so you don't take your eyes off the track, but is there a point where you can have too many? I suppose you can, but what mental processes would occur while riding would suggest to me that I can discard some, and as an aside, should I base the number of them on units of distance or perceived time or whichever is comfortable for me?
hitman5532
The Anti-Squid
Bunch of lightweights in here.
< --- 6'1" 210 lbs.
And Keith, I was wondering about reference points. I would check my copy of Twist/Wrist rather than bother you, but I have mislaid it.
I know that RPs are supposed to be something rather obvious so you don't take your eyes off the track, but is there a point where you can have too many? I suppose you can, but what mental processes would occur while riding would suggest to me that I can discard some, and as an aside, should I base the number of them on units of distance or perceived time or whichever is comfortable for me?
<--- 5'10" 205 at leanest, 225lbs nomial, 245 football game weight... just my genetics
Obviously Keith will have a better answer than I, but all say what I noticed. For years I would use a starting point as my braking marker, let's say a seam in the ground. At the end of last year however, I was really trying to work on getting better at my braking and downshifting transitions, and I experimented with trying to rewrite my thought process, and the actions/motions which resulted from it. What I ended up doing was instead of focusing on the point where to BEGIN my braking, I focused on the point where I wanted to have my braking COMPLETED by. It took a little mental rewiring, but came to find I was able to brake harder, later and smoother, because I wasn't locking myself into a particular point, which was making me platou.
Now I am able to focus more on the entrance and also was able to use many more lines and adjustments than before, because I simply am using my idea and senses, of speed and location, to make a judgement of being able to slow down enough by THAT point, instead of simply hitting the brakes at THIS point.
It has opened up some things for me, and may only help so little I end up scraping it down the line, but it has at least given me another tool in my tool box.
Last edited:
Bunch of lightweights in here.
< --- 6'1" 210 lbs.
And Keith, I was wondering about reference points. I would check my copy of Twist/Wrist rather than bother you, but I have mislaid it.
I know that RPs are supposed to be something rather obvious so you don't take your eyes off the track, but is there a point where you can have too many? I suppose you can, but what mental processes would occur while riding would suggest to me that I can discard some, and as an aside, should I base the number of them on units of distance or perceived time or whichever is comfortable for me?
I'm neither a racer or a very fast rider, but I love to ride and have been fortunate enough to attend 3 of Keith's classes. So this is just from memory(so you may correct me Keith if I'm wrong), but as I recall if you close your eyes and run a lap "in your head" timed. If its way too slow you have too many reference points, too fast, not enough.
jen
Jet City
New member
THANKS KEITH!
9 years later I still remember what he taught me.
I still need to take a refresher course when I have the chance.
9 years later I still remember what he taught me.
I still need to take a refresher course when I have the chance.
Last edited:
Keith Code
New member
Bunch of lightweights in here.
< --- 6'1" 210 lbs.
And Keith, I was wondering about reference points. I would check my copy of Twist/Wrist rather than bother you, but I have mislaid it.
I know that RPs are supposed to be something rather obvious so you don't take your eyes off the track, but is there a point where you can have too many? I suppose you can, but what mental processes would occur while riding would suggest to me that I can discard some, and as an aside, should I base the number of them on units of distance or perceived time or whichever is comfortable for me?
Dr, E,
There is an enormous amount of data on vision BUT little of it has been evaluated enough for it to make any sense to you or me. Now, there are two conditions that reduce a rider's ability to smoothly track with the space in front of him or her. Too many or too few RPs. When lost, humans tend to frantically scan for something familiar. In other words, they are lost. When we have too few RPs we tend to target lock. In other words, we are lost--and getting sucked into something.
Consider the fact that in a medium speed corner we are spending just a few seconds. Do this: Close your eyes, spin yourself around and, even a familiar room, you'll find that you can easily burn up one second reorienting yourself.
The number of rider errors that can easily be traced back to visual errors is astounding. That is why I started to develop visual drills at the schools. Take it apart one piece at a time and restructure our internal wiring on what we look at and why we look at it. Not easy for most riders.
One of the big reasons that a good rider doesn't always make a good coach is precisely that. They see the way they see and expect that everyone else sees what they do. Not even close. As it turns out our visual skills are based on quite a complex, and I can't say I fully understand it, group of perceptions.
To make it clear, we all see things a little differently and that is the cut between a really good rider and a really bad rider and all points in between.
Keith
Keith Code
New member
Exactly, that was written in the first "A Twist of the Wrist" book and it was something that I sometimes have my one on one students do. That is a simple exercise that anyone can do, provided they have the times.
Keith
Keith Code
New member
YES, another "A Twist of the Wrist" Vol 1 piece of data. I remember the day I figured it out at the old Ontario track in So Cal. I was blown away by what I gained. Then, I went to Sears Point for the first time and applied it at an AFM race. It made riding so much easier and braking, in particular, a joy. Why? It added time to something that seemed sooooooo hurried and hectic.
keith
twitchmonitor
New member
Keith:
I just cornerworked at your CSS Streets event (4/23-24). It was my first time at that track and I had a really tough time with the 12-13-14 series of corners, in both clockwise and counterclockwise orientations.
I was riding a stock-engined EX500 with Keihin CR flatslide carbs, which means that in order to not bog the engine down, I have to keep it above 4500 RPM at least. More RPM provide smoother power. In first gear, I was going through at about 6000 RPM and the the bike felt faster than I wanted it to be and I was running wide. Less RPM and the rear got destabilized as the engine started to deliver bursts of power instead of smooth power. In one of my low RPM attempts (going the "right way" around the track) I actually lowsided the bike exiting 14. I also had trouble because in the "wrong" orientation I was coming off turn 1 in 3rd, and had to drop down to 1st, resulting in an unstable rear end.
In the middle of my second day I broke my shifter and was stuck in 2nd gear for 3 sessions. This actually helped with those corners, but I had to feather the clutch to keep from bogging the engine.
After 2 days of focusing on those corners (among many other things!) I still didn't feel like I understood them at all.
Do you have any feedback?
(I just signed up for your Sears event in Sept. but figured this was a good place to ask about Streets).
Thanks,
David.
I just cornerworked at your CSS Streets event (4/23-24). It was my first time at that track and I had a really tough time with the 12-13-14 series of corners, in both clockwise and counterclockwise orientations.
I was riding a stock-engined EX500 with Keihin CR flatslide carbs, which means that in order to not bog the engine down, I have to keep it above 4500 RPM at least. More RPM provide smoother power. In first gear, I was going through at about 6000 RPM and the the bike felt faster than I wanted it to be and I was running wide. Less RPM and the rear got destabilized as the engine started to deliver bursts of power instead of smooth power. In one of my low RPM attempts (going the "right way" around the track) I actually lowsided the bike exiting 14. I also had trouble because in the "wrong" orientation I was coming off turn 1 in 3rd, and had to drop down to 1st, resulting in an unstable rear end.
In the middle of my second day I broke my shifter and was stuck in 2nd gear for 3 sessions. This actually helped with those corners, but I had to feather the clutch to keep from bogging the engine.
After 2 days of focusing on those corners (among many other things!) I still didn't feel like I understood them at all.
Do you have any feedback?
(I just signed up for your Sears event in Sept. but figured this was a good place to ask about Streets).
Thanks,
David.