Arctic Cat Forum banner

1 - 6 of 6 Posts

·
Premium Member
Joined
·
106 Posts
Discussion Starter #1
Out of sheer boredom (I'm sick of winter already!) I Googled the "ATV world speed record".
According to the Guinness Book it was broken in 2007 at an airport in Oregon by a guy named Terry Wilmeth.
He rode a "Rocket Raptor" to a top speed of 155.04 MPH or 249.51 KPH.
I wonder how well he would do in the mud? slaphappy
Maybe there is a speed freak on Arcticchat with a Thundercat that might be willing to take a shot at it? :atv2:
 

·
Registered
Joined
·
923 Posts
wont happen with the modifications made today. the raptor is a chain drive bike, and can be re-sprocketed to give it whatever gear ratio it wants. i'm sure the bike had a super top end, but had to be pushed off the line cause the gearing was so tall it would not start itself rolling off the line. the thundercats are ring and pinion geared with a 3.1-1 differential. at 8,000 RPMs the fastest a bike can do right now is 102 with my clutching. however if you raise the rev limiter to 10,000 RPM you could get somewhere in the neighborhood of 118mph but still nowhere close to 150. besides, if you watch on youtube, you can see countless videos of CVT clutches exploding when pushed to 11,000 ROM. people have swapped CVT style clutches to banshees and drag bikes to try and get a taller gear ratio, and for some odd reason, these CVTs like to explode around 11,000 RPM. i suppose from not being balanced good enough. on the arctic cat clutches, the outter movable sheave in the primary is balanced from the factory. BUT i have seen some that even though they were balanced, wobbled from poor casting or poor machining from the factory. i have seen some that made me wonder if my spindle that i chuck the sheaves up on was bent. even though the movable sheave is balanced the inner fixed sheave is not. it is just cast and then surfaced. so if there is some discrepancies in it and it is out of balance, it would cause it to sling apart at high RPMs. the secondary is the same way. the outter movable sheave is balanced, and the inner fixed sheave is not. so again it would cause a heck of a mess when run to super high RPMs and reached its harmonic distortion rate and exploded.

not all clutches are out of round or wobble. i'm just saying i have seen a few that made me wonder how they passed quality control. so dont go thinking your bikes gonna blow up because i said this. the factory rev limiters on these bikes are set alot lower than the usual limits of these clutches.
 

·
Registered
Joined
·
923 Posts
oh yeah sure go try it then!

i was thinking about it last night and decided to do some math this morning. if you could get the gear ratio in the T-cat down to about 1.8-1 you could run 155 with the stock 8,000RPM rev limiter BUT!! that tall of a gear would lug the bike down and it probably would not even be able to make it to 100 with its weight and non aerodynamic characteristics.
 
1 - 6 of 6 Posts
Top