2 Wheels vs 4

[MX793]

Motorbike vs car.  We've seen this before, and the consensus ultimately ends up that cars are ultimately faster than bikes around a track when you compare the best of their respective breeds (F1 car vs GP bikes).  But that was on asphalt.  Off pavement, it's a whole new game.

http://www.youtube.com/watch?v=ZPlwfED4tdo

Yes, it's a relatively inexperienced off-road driver against a profession racer on the bike.  However, if you don't catch it, the guy on the bike broke the track record that had been set by Marcus Gronholm in a full-blown WRC car by 2 full seconds.

[giant_mtb]

A decent dirtbike with a decent rider can/will outrun just about anything on 4 wheels on dirt or trail.  The ability to lean and to pinpoint your line (instead of having two lines to point) makes a big difference. It's crazy.

Saw that video like a week ago. I want one of those Nomads.

[MX793]

A decent dirtbike with a decent rider can/will outrun just about anything on 4 wheels on dirt or trail.  The ability to lean and to pinpoint your line (instead of having two lines to point) makes a big difference. It's crazy.

Saw that video like a week ago. I want one of those Nomads.

Yes, the thing that works to a car's advantage on asphalt (wide stance and stability) is its Achilles heel in rough terrain.  Uneven chop will upset a vehicle with side-by-side wheels whereas a bike can slice through it with ease.  Launching off of jumps is much easier on 2 wheels as well, since you only have to worry about vehicle pitch and yaw when in the air whereas something with side-by-side wheels needs to be concerned with roll at take-off.  A bike will only experience roll if the rider wants it to (via body english).  If a the jump face is uneven at all, a car/quad/trike will get tossed with some roll for which the driver has no means of correcting.  Bikes also have a greater degree of pitch control when in the air.  If you're a bit nose-low, punch the throttle and accelerate the rear tire to pitch the bike back.  If a bit nose high, tap the rear brake to bring the nose down.  A car could, in theory, do this, but the weight of the wheels are so much less than the vehicle as a whole when compared to a bike that the effect is greatly diminished.

[Eye of the Tiger]

Eh, I can't dirtbike so well. I would be faster in a 2WD car than a dirtbike.

[CaminoRacer]

I'd love to do a Baja 1000 race on a dirt bike. Seems like it would be much less of an investment ($$) vs a lot of the 4 wheel vehicles. As long as you don't die.

[GoCougs]

Gronholm is old right, so that record is old too, right? Plus the last 3 of the last 5 runnings of the Baja 1000 have been won by Trophy Trucks and a bit of Googling shows bikes have never won Pikes Peak, even before it was paved. Bikes will have an advantage on trails that 4-wheeled vehicles can't fit or something specifically tailored for bikes (i.e., Super Cross track), but in general, I'd take the bet that 4-wheeled vehicles will on average be as fast or faster. as 4-wheeled vehicles have more relative grip and down force, and have a much higher degree of tunability for a particular craft; i.e., look at the differences of a Trophy Truck vs. WRC car.

Bikes' advantage is it's relatively cheap and easy to go fast - a high end sport or dirt bike is a way closer to its race counterparts than a WRX or Raptor.

[Rupert]

The argument that the bike has an easier time picking a line doesn't apply on a smooth wide open gravel road like that. I'm not sure I agree that the bike is faster on such a road, all else being equal.

[Soup DeVille]

Plus,
The unlimited class at Pikes Peak has some seriously ridiculous vehicles that use serious aero grip; another thing that bikes can't really take advantage of.

[MX793]

Gronholm is old right, so that record is old too, right? Plus the last 3 of the last 5 runnings of the Baja 1000 have been won by Trophy Trucks and a bit of Googling shows bikes have never won Pikes Peak, even before it was paved. Bikes will have an advantage on trails that 4-wheeled vehicles can't fit or something specifically tailored for bikes (i.e., Super Cross track), but in general, I'd take the bet that 4-wheeled vehicles will on average be as fast or faster. as 4-wheeled vehicles have more relative grip and down force, and have a much higher degree of tunability for a particular craft; i.e., look at the differences of a Trophy Truck vs. WRC car.

Bikes' advantage is it's relatively cheap and easy to go fast - a high end sport or dirt bike is a way closer to its race counterparts than a WRX or Raptor.

Since 1975, bikes have won the Baja 35 times and have won 6 of the past 10.

Altitude at Pikes Peak works to the favor of forced induction.  Fitting a big turbo on a bike is much harder than a car from a packaging standpoint, not to mention that explosive power deliveries due to turbo lag are harder to manage on a bike due to the tendency for bikes to want to wheelie.

[GoCougs]

Thing is car design has come much further since 1975 than bike design, ergo, the majority of wins the last while. The trend will continue IMO, as there is simply much more that can be done to tailor a 4 wheel vehicle to a specific purpose.

[MX793]

Thing is car design has come much further since 1975 than bike design, ergo, the majority of wins the last while. The trend will continue IMO, as there is simply much more that can be done to tailor a 4 wheel vehicle to a specific purpose.

The recent improvement in win ratio could also be due to luck.  There haven't been game-changing advances in Trophy Truck designs over the past 5 years that would explain their recent success.

Bikes have come a long, long way since 1975.  Hell, even since the late 80s when I started riding as a kid.  Those bikes that were winning in the late 70s were air-cooled, steel-framed, points ignition, bi-post rear suspension (with maybe 5-6" of travel), and drum brakes.  Bikes today are fuel injected, digital ignition, variable-rate multilink mono-shock rear suspensions (with over 12" of travel), variable speed shocks, aluminum frame, disk brakes, and liquid-cooled motors.  When the going truly gets rough and uneven (jumps, rollers, significant off-cambers and side slopes), 2 wheels still have a huge advantage over 4.

[GoCougs]

Sure bikes have come a long way but 4 wheel vehicles have come a longer way, again, evidenced by the extreme focus for the task - WRC, Trophy Truck, sand rails, etc., etc. That range of variation doesn't exist for bikes.

[MX793]

Sure bikes have come a long way but 4 wheel vehicles have come a longer way, again, evidenced by the extreme focus for the task - WRC, Trophy Truck, sand rails, etc., etc. That range of variation doesn't exist for bikes.

Plenty of specialization on two wheels.

Motocross


Enduro


Hill Climb


Drag Racing


Rally


Motard/Supermoto


Supersport


Touring


Trials

[shp4man]

WTF, no cruiser pic? 
Here's one: 

[MX793]

WTF, no cruiser pic? 
Here's one: 

Cruisers aren't really specialized to any particular function, same as a standard/UJM (which I also didn't show a picture of).  They do the same thing a standard does, just with a different aesthetic and seating position.

[giant_mtb]

Sure bikes have come a long way but 4 wheel vehicles have come a longer way, again, evidenced by the extreme focus for the task - WRC, Trophy Truck, sand rails, etc., etc. That range of variation doesn't exist for bikes.

[GoCougs]

Guys, pick a motor sport that both compete in - drag racing, road racing, salt flat time trials, desert racing, etc. - and in pretty much all cases 4 wheeled vehicles are the better performers. Why? Because they can be tailored to a far greater extent to the task at hand vs. bikes. The best and most poignant example is F1 vs. MotoGP.  The tech and performance (and cost ) in/of an F1 car is light years beyond a MotoGP bike simply because engineers have far more vehicle characteristics to play with, esp. grip, suspension and aero.

[giant_mtb]

Right, sure, but the variety is still there.  Bikes can do any terrain, race track, whatever that four wheels can do, and come in variations specifically for those different terrains, just like cars do.

[Rupert]

But cars are better at it with few exceptions (and it doesn't make much sense that a gravel road would be one of them).

[MX793]

But cars are better at it with few exceptions (and it doesn't make much sense that a gravel road would be one of them).

This particular gravel course had some jumps.  Have to use much more care when launching a car off a jump, especially if the course isn't straight right after the jump (since you can't turn once in the air).  Because a bike is so narrow, they have more room to jump through a bend, which allows the bike to carry more speed in a section like that.  Also, bikes don't have to worry about uneven jump faces (which would make a 4 wheeled vehicle want to barrel roll).  At the 3 minute mark, you can see the Nomad launching of a jump and the left side is tossed higher than the right because the jump face is uneven.  When the car lands, the chassis is upset a bit and it takes a moment, and a bit of left-right corrections of the wheel, to settle back down and get pointed back in the direction it should so the driver can put the power down.  That won't happen on a bike.

Also, because a bike is so narrow, it can effectively make some slightly curved or zig-zaggy parts of the track straight, whereas a wider car would need to turn a bit to keep all four wheels on course.  Kind of like an offset slalom that a wide vehicle like a car would need to zig-zag to clear all the gates, but a person on a bicycle or motorcycle (or walking) could travel in a straight line and go through all of the gates.

And being able to pinpoint a line matters even on gravel.  The main "lines" where vehicle tires primarily go will have most of the looser soil and gravel cleaned away and be down to more solid ground, not to mention being a bit harder packed (maybe even blue-grooved) from vehicles constantly rolling over those tracks.  Meanwhile, all of the really loose stuff is in the "off line" areas, meaning you will have less grip if you shift very far off line.  The guy on the bike also has the option of railing the burms/embankments on the edges of the track in the corners to keep the bike on course, which you can see at the 1:20 mark, the 6:15 mark, and when the bike overtakes the Nomad at around the 7:30 mark.

[Rupert]

Of course, in that video, the bike won, so it's hard to say if those factors would really matter against the right car with a driver who had similar levels of skill to the bike rider.

[MX793]

Of course, in that video, the bike won, so it's hard to say if those factors would really matter against the right car with a driver who had similar levels of skill to the bike rider.

That facility is still used for WRC and UK professional rally racing.  The guy on the bike beat the standing course record, which happened to be held by a WRC car/driver.

Also, the guy on the bike isn't the fastest rider out there.  He's a local UK talent, not quite a world MXGP or US National frontrunner (note: winning a US National title is considered as prestigious or more so than a world MXGP title).

[Eye of the Tiger]

Win.

[Raza]

What BMW bike is that in the Supersport picture?

[MX793]

What BMW bike is that in the Supersport picture?

S1000RR

[CaminoRacer]

Win.

If your idea of winning is flipping over and dying, sure.

[Raza]

S1000RR

It looks cool.

[Rupert]

That facility is still used for WRC and UK professional rally racing.  The guy on the bike beat the standing course record, which happened to be held by a WRC car/driver.

Also, the guy on the bike isn't the fastest rider out there.  He's a local UK talent, not quite a world MXGP or US National frontrunner (note: winning a US National title is considered as prestigious or more so than a world MXGP title).

WRC cars have limitations placed on them, do they not?

[MX793]

WRC cars have limitations placed on them, do they not?

Sure, there's a minimum weight and maximum displacement limit.  MX bikes have similar limitations (both weight and displacement).

[Rupert]

Well, if they both have limitations, it's hardly a true test of either.