<div class="FTQUOTE"><begin quote>Originally posted by: ptl

It is interesting to see how the weight on the machine is affecting it as well!</end quote></div>

Weight is a huge factor...look at the snowmobile community. All you ever hear about (other than improved power) is how much weight the new year models have shaved off over last year or how much lighter they are than their competition. If fact, a lot of their improved power comes from dropping weight off the frame of the sled or quad in our case. Take the post just above your last post. He says he weighs 130lbs. I weigh 230lbs. Assuming our quads were set up exactly the same. My quad still has to carry 100lbs more than his. One would assume his quad is faster than mine...not so. His quad is the same speed as mine. I just have to carry more weight. If he and I swapped quads. He would beat me with my own quad because I transfered the extra weight to his quad when we switched. It is really simple but a lot of people don't take the weight issue into account when they claim top speeds and a lot of readers don't take this issue into account when asking how fast these bikes go. I would have to heavily modify my bike to see 68mph when the last poster says his bike will go that fast stock.

 

Weight does make a big difference. I'm about the same size as AKMuddy, but notice I said top speeds were obtained going downhill. Weight and tire size dont tend to be the limiting factor as much when going downhill, and that is why I mentioned the rev limiter coming in at 68 mph. 68 mph (or perhaps 69 mph on a steep downhill) is a best case scenario, where the limiter is what is limiting top speed. More weight, bigger tires, lower tire air pressures, etc, all will decrease from that maximum speed. Only re-machining the sheave or replacing the CDI will increase top speed beyond 68 mph.

Level ground on softer terrain, or uphill speeds can be considerbly less, especially with more weight. I remember two years ago I had a Kawasaki V-force with a lot of mods, and my son had a YFZ 450, and we spent a lot of time hillshooting in the sand dunes back then. No matter how I modified the clutch, engine, carb, exhaust, etc. on the V-Force I could not beat my son on his YFZ 450 when racing up the face of Sand Mountain, in UT, which is a 700 foot tall sand dune. The YFZ weighed a hundred and fifty pounds less than the V-Force, and my then 15 year old son weighed a hundred pounds less than me. One time we switched ATVs though, and I must say I was happy to see the V-Force that I had spent so much time trying to make faster run away from me going up the mountain with my lighter son riding it. As soon as you put the hundred pound heavier rider on the YFZ it got beat.

DV

 

I way a tad over 230 and on a straight sandy trail, I could not get the 700 over 60, but it was flat to a slight up hill and I think the 26" Terra Cross were slipping more than digging. I did not have a chance on a different trail material to test the max speed. I personally do not want to go 70 on a 650 pound FIS machine, but to each there own.

Good info anyways.