Heavier springs or just more oil?

[oabike]

I need a little extra bottom out resistance. I had started to bottom too many times per lap. I'll be coming back from a broken finger and surgery to pin it back together in a few weeks. I need some extra protection from big hits. I have a YZ250F. Anyone know the differance in feel going from a .44kg/mm spring to a .45kg/mm against just raising the oil level 10mm at a time? I'm 160 ibs in riding gear.

 

[robmann]

oabike,
stock spring should be fine for your weight, you won't notice much between .44 and .45 this is only about a 1/2 lb difference in spring rate.
for MX set oil level at 95mm, wood set it at 100mm
if you use one of these heights make sure you expel all oil trapped between inner and outer tube.

 

[Saratoga]

To answer your question, going to a stiffer spring will affect the entire travel vs. more oil will only effect the last part of the travel. The feel will be firmer from the very beginning of the travel. Because you will be using the initial travel more, it sometimes feels plusher than using softer springs and sinking into the mid travel.

Stiffer springs will have a more dramatic effect on rebound vs. just adding oil. Also, the tolerance for springs is not that high. That is a .44 spring might not be exactly .44. If you move from a .44 to a .45 the difference could be very small when you allow for tolerance.

With that said, I recommend going to stiffer springs and playing with the oil level. You may find stiffer springs with less oil to be plusher with more bottoming resistance.

My 01 YZ250 has .46/125mm and stock valving. I out weigh you at 195lbs. I have really high bottoming resistance and works good on a MX track. For trail riding I would probably revalve the initial travel some and maybe slow down the rebound. I dont trail ride though, I race MX.

Good luck.