For the 2013 WR250F we recommend a 5.8kg spring for a 190 pound rider without gear. Then reset sag per our instructions. Many find the YamaLink with heavier spring alone makes the front of the WR250F handle tremendously better due to less front wheel weight transfer. You won't be blowing through the travel as easily. I'd set the YamaLink + 5.8kg spring + resetting sag per our instructions BEFORE doing anything to the front.
Wednesday, October 1, 2014
The stock 2003 WR250F spring is a 4.8kg. At nearly 14 stone you need a spring of 5.6kg to achieve proper sag BEFORE a YamaLink is installed. WITH a YamaLink at 14 stone a spring rate of 5.9 kg or closest is recommended.
The 2012 YZ125 stock spring is a 4.7kg. At 145 pounds without gear + YamaLink the ideal spring rate is a 4.9kg to achieve 1.5" lowering at 100mm sag. If you do not want to get a heavier spring we recommend setting sag at 94mm stock is 100mm) which would give you 1.25" lowering (100mm - 94mm = 1/4 inch less) and following our instructions for high speed compression and rebound adjustments. For off-road and trail riding this setup would be very good. For pure MX we'd put on that heavier spring with a 1.5" YamaLink at 145 pounds.
Hello. Your YamaLink comes with instructions that give you several options for the fork raising. About 99% of riders start at about 12mm and then adjust up or down a few millimeters based on personal preference. It is 18mm maximum that we recommend raising the forks tubes; any more than that and there is a great possibility of wheel vs fender contact. There is no 1:1 ratio of front vs rear lowering because changes to the front effect the Yamaha geometry at a different rate than changes to the rear.