Ok, I rode today with the 3 250f clutch springs. 3 Thumbs Up! It worked great. The pull got a lot lighter after a few miles of ride time. I did get it to slip, but not very much. In fact, it was a good slip. I would rip it wide effing open coming out of a corner or attacking a loose dirt/rock hill climb, and it would slip just enough to get all the power down to the ground. Very similar to how an Auto Clutch slips. It only slipped when I was WFO or very close to it. I really liked this a lot on the 450. Felt like I could get uber aggressive. I had ZERO issues lifting the front end, in fact, I found it way more controllable to wheelie. Navajo's springs didn't come in in time, but he rode mine and came back with a smile on his face. If you don't ride real aggressive, you probably won't ever get it to slip. I'm talking like A rider hauling ass aggressive. The only negatives I can see for me will be an annual clutch pack replacement. Which is cheap and easy to do. I'll take it. The other negative is how it will do in the mountains on real long climbs where you are in the upper revs for a while. Which for me, will not be very often. However when I do hit the mountains, I will still just replace the clutch pack after if I need to bc the benefit far out weighs the negative. This mod is very cheap, $20, and takes just 5 minutes to do. Ya'll should try it. Install tip, take a marker and number the clutch cover bolts before removing. I pretended it was a clock face and numbered them as they would appear on a clock. They are all different lengths, so good luck if you skip this. Also, just put the 250f springs in a triad pattern, basically every other one. The 250F springs are shorter than the 450f springs, so don't be alarmed. Any questions, fire away.