After watching every how to video and reading every possible thread on how to do it, I Finally installed 1.7mm of shims and purple spring. The home made sheave holder works perfectly and was very simple to make and use. I also used a large adjustable wrench and the stock rim spring compressor to remove and install new secondary spring. It all went perfectly smooth just like the videos. The starting ratio was 2.44:1 and after the mod the ratio was just over 2.6:1. Wow made a big difference in the terrain I have been riding on. Very slow rock crawling and extremely tight trails. I went on a 10 mile ride to make sure everything was working properly and it was. Much easier takeoffs and better creeping with stock tires. Never got a chance to check top speed. Next day the 26" Bearclaws went on. They did seem to suck up some of that low end torque but really made a huge difference rock crawling. They are huge compared to stock and are much better looking in person than in pics. Can’t wait to send out primary sheave for some machining!!!!!