im looking for some help on making my suspension more plush feeling and not so harsh. the bike is a 06 IH kumicho R with a boxxer race fork(stock internals... medium springs i think) and swinger 4 way with 400lb spring and 170psi. any ideas? maybe fork and shock upgrade? i had the bike quickly tweaked for my weight (205) but its a rough ride.
suspension help
- Thread starter mtbxdrew
- Start date
Probably no need to upgrade anything. The reason your suspension is feeling harsh is because it was likely tweaked for your weight by compensating for a soft spring weight with over-doing the compression dampening. This effectively will lock-out a portion of your travel (unless your REALLY hit hard) and causing the rest of it to feel stiff. Really what you need to do is get the right spring for your fork and shock...then redo the hydraulic dampening (& chamber pressure) on your suspension.
For a plush DH feel a 400lbs spring should be good for you, but since it apparently felt soft, try stepping up to a 450lbs. As for your fork spring, the Boxxer comes stock with a Yellow (Medium) spring. You really need a Red (Firm) spring.
Hope that helps.
For a plush DH feel a 400lbs spring should be good for you, but since it apparently felt soft, try stepping up to a 450lbs. As for your fork spring, the Boxxer comes stock with a Yellow (Medium) spring. You really need a Red (Firm) spring.
Hope that helps.
I have an '06 Kumicho as well. I can't help with your fork since I have the Super T and no experience with the Boxxer, but we have the same rear shock.
It seems as though your rear shock SPV pressure is too high. Manitou recommends about 50-70% of body weight; I have been running around 50% which for me is about 80-90 psi and it works great with about 1/8" preload on the spring. Since increasing SPV pressure also increases compression damping this could be causing the harshness you are feeling. Try less pressure (maybe 110-120 psi for your weight) and a little more spring preload. You could also turn the bottom out adjust up some as well if you find that too bottom too much. However if that doesn't work or you need too much spring preload you may need to step up to the 450 lb spring as the previous poster suggested
It seems as though your rear shock SPV pressure is too high. Manitou recommends about 50-70% of body weight; I have been running around 50% which for me is about 80-90 psi and it works great with about 1/8" preload on the spring. Since increasing SPV pressure also increases compression damping this could be causing the harshness you are feeling. Try less pressure (maybe 110-120 psi for your weight) and a little more spring preload. You could also turn the bottom out adjust up some as well if you find that too bottom too much. However if that doesn't work or you need too much spring preload you may need to step up to the 450 lb spring as the previous poster suggested