Hey fellow 150F pilots! You guys know I'm all for racing a cheap 150F in it's stock mod form. I could bolt up a 150R front end, along with a Fox Shock, but I like racing on the cheap. I've tried a few different spring configurations in my stock 150F forks, and here's what I did, and what I've learned. Bear in mind, I weigh 150, and I use the bike for pit bike races that generally take place on big bike MX tracks. The Race Tech chart calls for a 9.0 rear spring for my weight, which lucky for me is the stock rear spring rate. I did send my shock to John Hlebo for a revalve, and it's fine. Dialing the forks has been a bit trickier.
First mod, a set of .44 fork springs, and nothing else. Waaaay too stiff! So I pulled one spring out, and put a stock .32 spring back in. That rate averaged to .38. This was alot better than stock, rideable, but still bottomed well before the rear did.
Next I sent the damping rods to Hlebo, where the valving was changed by welding some holes shut. I went up to a set of .40 straight rate springs in order to prevent bottoming. Well-- the forks were too stiff, and they wouldn't soak up small chop. The reason being IMO, is that the stock fork springs have dual rate springs. They start off at .22, then stiffen up to .32. The straight rate springs are only .02 stiffer than the averaged rate a .44/stock spring combo, but when you do the straight rate, you lose the benefit of the lighter initial rate that soaks up the small, choppy stuff. Also-- the Hlebo revalve adds some stiffness.
Now-- I went back to the same .44/stock spring configuration that I was running last year, and it feels about perfect now with the modded damping rods.
Summary-- There is a huge benefit to a set of dual rate springs with this bike to have a plush front end. Ideally-- I'd run a set of .30 or .32 initial rate springs, and have them stiffen up to .38 or .40. Prolly the .38's. Wonder if Cannon Racecraft could do a set of dual rate springs? I was going to try a set of damping rods modded by Bruce Triplett. I've heard that his work is terrific. I was going to try those in conjunction with the springs I'm running at present to see how that works. If the action is good, and the rods work well with the present spring rates, then I'll see if Cannon can do a set of custom dual rate springs. Many will argue that the soft initial rate will cause the forks to blow through the 9 inches of travel, and slam into the stiffer rate, but I haven't felt that at all. I think the modded damping rods hydraulically control that diving action I had before. It seems to work pretty well, and alot better than the straight rates. It's been a definite learning experience. Hope this will assist you in your fork setup. --L*64
First mod, a set of .44 fork springs, and nothing else. Waaaay too stiff! So I pulled one spring out, and put a stock .32 spring back in. That rate averaged to .38. This was alot better than stock, rideable, but still bottomed well before the rear did.
Next I sent the damping rods to Hlebo, where the valving was changed by welding some holes shut. I went up to a set of .40 straight rate springs in order to prevent bottoming. Well-- the forks were too stiff, and they wouldn't soak up small chop. The reason being IMO, is that the stock fork springs have dual rate springs. They start off at .22, then stiffen up to .32. The straight rate springs are only .02 stiffer than the averaged rate a .44/stock spring combo, but when you do the straight rate, you lose the benefit of the lighter initial rate that soaks up the small, choppy stuff. Also-- the Hlebo revalve adds some stiffness.
Now-- I went back to the same .44/stock spring configuration that I was running last year, and it feels about perfect now with the modded damping rods.
Summary-- There is a huge benefit to a set of dual rate springs with this bike to have a plush front end. Ideally-- I'd run a set of .30 or .32 initial rate springs, and have them stiffen up to .38 or .40. Prolly the .38's. Wonder if Cannon Racecraft could do a set of dual rate springs? I was going to try a set of damping rods modded by Bruce Triplett. I've heard that his work is terrific. I was going to try those in conjunction with the springs I'm running at present to see how that works. If the action is good, and the rods work well with the present spring rates, then I'll see if Cannon can do a set of custom dual rate springs. Many will argue that the soft initial rate will cause the forks to blow through the 9 inches of travel, and slam into the stiffer rate, but I haven't felt that at all. I think the modded damping rods hydraulically control that diving action I had before. It seems to work pretty well, and alot better than the straight rates. It's been a definite learning experience. Hope this will assist you in your fork setup. --L*64