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MTB - How can a human be able to react so quickly

WildBillTx

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imagine what an engine could do for this fellow.
In one of the world cup downhills a couple of years ago was won by a ride who broke his chain just after starting. In other words hi coasted 99% of the course to win.
 

_RG_

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They do get practice on the course, but mostly its a healthy disregard for personal safety.
I wondered...there are a couple of jumps where he landed in the rut of a turn. Unless he has a rudder or knew where to launch that'd be pretty unlikely. Still though...rascal can flat out ride.
 

craftkr

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Don't forget those bikes they have now, the suspension on them is insane. Very impressive run, I couldn't do that.
 

TNC

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Don't forget those bikes they have now, the suspension on them is insane. Very impressive run, I couldn't do that.
You are so correct about the suspension. I was a dirt motorcycle guy before also doing mountain bikes. The lack of suspension on MTB's kept me away from them. Long about the mid to late 90's, MTB's started getting some decent suspension design. I went whole hog into MTB's, especially the big hit, long travel models...doing Moab, UT for 2 weeks at a time on trips, etc.

Those downhill bikes in the vids have front forks and shocks that some have more bells and whistles than our dirt bikes. My dirt bike has a 43mm fork. Many downhill bikes have 40mm forks. Where MTB suspension has excelled is the design and technology of air suspension...8-10 inches of travel being common.

I currently ride a pedal assist MTB...emtb...that has a dual crown fork with 8" travel and rear travel at 7". It's freakin' awesome. You still have to pedal...you still work...but it allows you to feel like a pro downhill racer...LOL!
 

WildBillTx

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And besides the super suspension is the are the 29" Plus wheel tire combos that are larger in diameter than a 21" 90/90 mc wheel combo.
 
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And besides the super suspension is the are the 29" Plus wheel tire combos that are larger in diameter than a 21" 90/90 mc wheel combo.

One of these 29" plus are maybe 2" larger in diameter than a motorcycle 21" 90/90. Of course depending on the tire. Could be closer.
 
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I was pretty amazed at how this rider took some of those rock gardens at speed. There really is very little tolerance for mistakes.

Yeah, MTB suspension is light years ahead of motorcycles. Especially on DH bikes, the suspension has far more advanced damping, but mostly that's in order to allow pedaling while still being responsive over bumps, and also to prevent rear rebound from pitching the rider OTB or rotating the bike forward to position the weight too far forward on the next obstacle. The big thing about mountain bikes vs. motorcycles is that the rider typically weighs 8-10x as much as the bike on a MTB but the rider typically weighs much less than the bike on a motorcycle. So that means the COG of the motorcycle+rider is below the midline of the motorcycle chassis, while the COG of the mountain bike+rider is very close to the rider's COG. That makes a huge difference in what you can ride.

Until my foot problem that went critical in 2019 I was an avid mountain biker for nearly 30 years. I used to joke that mountain biking takes three main things: fitness, experience (which includes skill), and guts. You can compensate for a lack of one or the other with more of another facet. This particular downhiller seems to have max of all three. Pretty amazing in action. One small error could cause a life-threatening crash. Oddly enough, it was only after I switched to mostly riding motorcycles and quit riding bicycles that I became aware of just how tremendously dangerous mountain biking is, not to mention road cycling.
 

WildBillTx

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One of these 29" plus are maybe 2" larger in diameter than a motorcycle 21" 90/90. Of course depending on the tire. Could be closer.
I was surprised to see a 27.5 plus wheel/tire combo the same size as a 21" 90/90 wheel tire on a DRZ 400.
 
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I was surprised to see a 27.5 plus wheel/tire combo the same size as a 21" 90/90 wheel tire on a DRZ 400.

Yeah it's because MTB tires measurement is roughly outside diameter of the tire (a 29" tire should be 29" diameter, or so) and motorcycles are the rim size. Bicycle tire and wheel sizes don't conform to one standard.
 
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