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Edited Date/Time
1/27/2012 7:54pm
I was just reading this interview http://www.racerxonline.com/2011/07/13/insight-ron-lechien-weighs-in with Ron the "machine" Lechien and he mentioned that Bagget might have an advantage over Wilson due to his being so small and light. He say's 10lbs rider weight = 1 hp. I think there is something to it, fer sure.
Thought's?...........Discuss......
Thought's?...........Discuss......
The flip side of that is the kid is tiny. At what point does your small weight hinder your ability to dig the bike into the dirt for better traction? Is that why he doesn't get good starts or simply because his reaction time is bad? You see this is why I love motocross, none of it matters. The dude who goes the fastest wins, period. On any given day it can be someone different on a different kind of bike. It can be BB smoking the field, or it can be Durham riding out of the back of a box van.
An example would be Malcolm Stewart and also when Troy Adams was racing the 250f class. I think clearly they are at a disadvantage on the track.
I would like to know how much of an advantage he really has (via somebody who knows how to do the proper math formula - whatever that is). I talked to a buddy of mine with a masters in physics and he said he would have a huge advantage. Not only does he have the greatest power to weight ratio of anybody, which is equivalent to extra horse power, but lighter weight means quicker acceleration and deceleration. It's safe to say he definitely has an "edge" over the competition, but he wouldn't be quick as he is without his dedication, fitness, raw speed, skill, etc. Blake is a great rider, and not just anybody would be running up front on a PC bike weighing 125lbs.
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Running the numbers and speculating on them is great mental exercise, but personal desire and motivation far outweigh the physics. Hell, if RC chose to stay on a two stroke, the 4-strokes wouldn't have won the big bore titles until he retired. Not turning this into a 2-stroke thread, but only pointing out that it's the rider's drive/skill/toughness that is what gets it done.
Ok, for the numbers (you plug the actual ones in, 'cause I don't have the exact numbers): hp/weight = (bike's horsepower)/(weight of rider + weight of bike). So, assuming the bike's are equivalent at 40 hp, equivalent at 215 lbs., then throw the rider weight in with that ten pound difference:
40hp/(215 + 130) = 0.116hp/lb, or 8.6 lbs/hp
40hp/(215 + 140) = 0.113hp/lb, or 8.9 lbs/hp
So, a difference of 0.003hp/lb. Or, you could say that the bike with the rider that weighs 140 lbs needs to make 41.14 hp to have an equivalent hp/weight rating. So, yeah, by the very simple numbers, Lechien's correct that 10 lbs, in this case, is about a 1 hp difference.
Is it that important? Dunno. With all of the variables in MX, I'd say probably not as much as you might think. Heck, I'd rather give up that 1.14 hp and have RC's drive, conditioning, skills, and confidence, or at least parts of them.
f=ma force equals mass by acceleration. now remember acceleration is 3 dimensional not just when the rider gasses it. gravity is a form of acceleration and braking is accelerating with a negative magnitude too. in other words acceleration is a term for a rate in change of speed wheter you are going faster or slowing down.
w=fd work equals force by distance so if you have higher forces because the same acceleration is applied to a heavier mass over the course of a lap or moto or any fixed distance that all the riders must complete the heavier rider plus machine does more work.
as i said before this is only theory as there arent two equal riders of different weights to account for this.
It's the same reason a 350 can sometimes out jump a 450. It's not so much necessarily always about HP - as it is how well you can put what you've got to the ground.
I would guess, and it just a guess, but my instincts say that off the line a lack of weight and traction would probably work against Baggett but once the race gets going, his lack of weight must surely be an advantage. Obviously the exact conditions of a standing still start are never repeated again throughout the rest of the race. From that point onwards he'll always be carrying momentum.
You have to use the torque instead of the hp to really quantify it, so here's my assumptions:
Max Torque = 25 ft/lb
Final Gear Reduction = 27.69 for 1st gear (assuming constant throughout start for max effect)
1 ft distance between application of torque and final point of contact
Blake Bagget + bike = 345 lb
Dean Wilson + bike = 375 lb
I have also assumed that they are able to maintain maximum torque to the ground, 0 mechanical or frictional losses, and perfect traction! This is the best way to see the absolute maximum advantage that Dean Wilson would have.
Over the length of a 50 meter start (I use metric when I do these, so bear with me):
Final Velocity for BB = 44.35 m/s or 99.2 mph!!
Final Velocity for DW = 42.56 m/s or 95.2 mph
The difference in time that it would take them to get to the 50 meter breaking point mark is
Time BB = 2.25 s
Time DW = 2.35 s
Sooooo, what's my point here? BB sure has a huge advantage on paper and should be able to get to the first turn a full second faster than Dean, but we don't see that. We also don't see them doing 95 mph down the start straight because of all the different factors involved with putting the power down to the ground. Once you start estimating for mechanical and frictional losses in power, loss of traction to the dirt, different rider techniques and weight distribution on the bike, etc. that second is quickly eaten up by everything else.
Lose weight, lol.
Or give min. and max. weight for bike & rider combined..
Big football players, like lineman, exert tremendous amounts of energy in the 10 minutes of playing time during a game. Yet they are exhausted. It takes a lot more energy to keep Wilson going than Baggettt. At the 20 minute mark, Baggett just turns it up. Small guys always have this advantage, no matter the sport.
Another aspect is maybe Baggett lets the bike do more work, hence he doesn't tire. Both are just my two cents are just thoughts. In a 4 lap race, it doesn't mean anything, or maybe a big guy has a slight advantage, but in longer motos, smaller guys have an advantage for sure.
But there is probably a 30 or 40 pound difference between Baggett and a guy like Wilson or Tomac. At the pro level, where these guys are all in shape and can ride a 250F WFO almost the whole time, it adds up. Hauling that much extra mass out of every tight corner is not an advantage in most conditions.
It's also why you don't see many 200lb pro riders, even on fire-breathing 450s. It's a cliche saying in MX, that rider ability makes all the difference. This is true, but all else being equal, big guys are at a disadvantage.
Time BB = 2.25 s
Time DW = 2.35 s
Sooooo, what's my point here? BB sure has a huge advantage on paper and should be able to get to the first turn a full second faster than Dean,
You are correct BB would get to a fixed mark more quickly then Dean but fail to account for kinetic energy once that point is reached. kineticEnergy = 1/2mass(velocity squared)......BB's increased top speed would require a greater breaking distance thereby nullifying, to a certain extent BB's advantage.
Pit Row
It looks like most of you are coming up with what we see on the track. That is BB slowly pulling away tenth of a second by tenth of a second until he has a decent gap.
Shoot, I experience it at the local tracks with my friends. I have to ride a bike with more HP just to be competitive with guys who weigh 140-165 lbs. I'm pushing 210 and can feel it when trying to exit corners and making a jump that
is right out of a corner. There is no proof of this, but I know it exists, i can feel it.
K-Dub in the lites class a season or two ago (or more?). Top 3 times in practice (which is saying something since he's normally not one of the quickest in practice). I think he barely made the top 20 in the race? He was about 200lbs at the time.
Now that will be the excuse for Ricky Ryan winning '87 Daytona SX......
I made some assumptions in order to calculate the absolute largest gap and difference it could make. The fact that BB would have to hit the binders first would obviously decrease the advantage, as would all the other factors I mentioned and didn't include in the calculations.
The point wasn't calculating what it is in the real world but showing that it would take completely unreasonable circumstances to make a significant difference.
The key thing here is the traction which is a function of the force applied to the ground, where Dean has an advantage.
At the end of the day I think they are even. Dean has more muscle and a longer body to maneuver the bike around better and BB has to be more precise because he can't muscle the bike back in shape like Dean could. But Blake may last longer. It's pretty even if you ask me.
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