jpgmtech
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This may be completely useless information to anyone who doesn't really care about the old sleds... but it's a good brain exercise for me to understand chassis dynamics.
We've been trying to define some of the more subtle effects of the dramatic change in rider position, in the context of mountain riding. I'm sure we are not the first to talk about it, but we find it interesting as I am still running an old-school ZX. (not hardly stock though...)
1) Steep hillclimb seems to pull more on the arms/shoulders when riding a XP, rider is standing with feet farther forward and more erect, causing more of his/her weight to be supported by the arms. On a ZX, feet tend to be farther back, and a 6' rider tends to be crouched, knees bent, more of the mass carried by the feet.
2) When the XP rolls right/left, the handlebars travel through a longer arc for the same degree of rotation as the ZX. That's simply because the bars are higher. On a hillclimb, the result is that my whole body swings back and forth a bit, maybe because I am supporting more of my weight with my arms, and certainly because the bars are themselves travelling a longer roll arc. On the ZX, it seems like I can let the sled roll under me and keep my body position more nuetral, allowing me to input correction with both my feet and arms instead of swinging and twisting my whole body or stepping from one running board to the other.
3) Another factor in all of this is that this particular ZX has been put on an extreme diet - it weighs 500 lbs fully fuelled, which means it's tank-empty weight is around 435 lbs. Less mass to wrestle means it's easier for my body mass (230lbs geared up) to pull it back in line.
A little video here of a comparable hillclimb, one of many that I have watched. Note my Dad riding the XP at 0:20 he gets a little wiggle and uses his whole body to correct for it. At 0:53 I get a major wiggle/bump from bouncing through a big stuck hole and the whole sled dances underneath me but my body hardly moves. I let the sled dance and bring it in with minor inputs from my legs/arms.
Busting Cornice, Mt. Milton, Alan Creek - YouTube
I've been trying to figure out why the old ZX seems so stable to ride compared to an XP. Now I think the ZX is actually less stable on the hillclimb, I'm just able to correct it more easily.
We've been trying to define some of the more subtle effects of the dramatic change in rider position, in the context of mountain riding. I'm sure we are not the first to talk about it, but we find it interesting as I am still running an old-school ZX. (not hardly stock though...)
1) Steep hillclimb seems to pull more on the arms/shoulders when riding a XP, rider is standing with feet farther forward and more erect, causing more of his/her weight to be supported by the arms. On a ZX, feet tend to be farther back, and a 6' rider tends to be crouched, knees bent, more of the mass carried by the feet.
2) When the XP rolls right/left, the handlebars travel through a longer arc for the same degree of rotation as the ZX. That's simply because the bars are higher. On a hillclimb, the result is that my whole body swings back and forth a bit, maybe because I am supporting more of my weight with my arms, and certainly because the bars are themselves travelling a longer roll arc. On the ZX, it seems like I can let the sled roll under me and keep my body position more nuetral, allowing me to input correction with both my feet and arms instead of swinging and twisting my whole body or stepping from one running board to the other.
3) Another factor in all of this is that this particular ZX has been put on an extreme diet - it weighs 500 lbs fully fuelled, which means it's tank-empty weight is around 435 lbs. Less mass to wrestle means it's easier for my body mass (230lbs geared up) to pull it back in line.
A little video here of a comparable hillclimb, one of many that I have watched. Note my Dad riding the XP at 0:20 he gets a little wiggle and uses his whole body to correct for it. At 0:53 I get a major wiggle/bump from bouncing through a big stuck hole and the whole sled dances underneath me but my body hardly moves. I let the sled dance and bring it in with minor inputs from my legs/arms.
Busting Cornice, Mt. Milton, Alan Creek - YouTube
I've been trying to figure out why the old ZX seems so stable to ride compared to an XP. Now I think the ZX is actually less stable on the hillclimb, I'm just able to correct it more easily.