RM 250 2007 140 lb rider - what springs to get?

I'm having a hard time dialing in my suspension with the stock springs. They are heavy for me I think. I'm looking at lighter springs now but I'm not sure what rates to buy. With 105mm rider sag at the rear the static is about 45mm so there is hardly any preload on the spring meaning it's heavy for my 140lbs. Stock rates are 0.43 front and 5.2 rear (kg/mm)

Should I go down to 0.40 front and 4.8 rear?

An other thing confusing me is N/mm rates. I know the conversion but if I look at a 4.0 N/mm front spring, that is roughly 0.407 which seems to be a little difference to the 0.43 stock. 3.8 converted to 0.387, now thats on the lighter side. I just don't know what to buy. One thing I know for sure is that I've always felt my suspension is hard. All my bikes.

I've ridden a few steel framed Hondas ('96 '97) and I liked that kinda soft suspension those bikes had. I felt so comfortable on them.

I'm 21 I doubt I'll be gaining any weight soon.

Edited by TommyZ

What class are you? A class, B class, etc. The suspension aficionados will have to know that before they can suggest the perfect setup.

Well I don't race but let's say I'm a B class rider. I ride MX. I don't do 100ft+ jumps so I'd like the suspension to work well on the rough stuff. To trust the bike that it is not going to kick me over when going even on a straight line that is bumpy.

I would go 0.41 and 4.8

That would be 4.0 and 47.5 in N/mm. Thanks.

Im 135 and 4.6 was reading heavy in gear. My bro is 175 and numbers were perfecto. Id go 4.4 just me...

Im 135 and 4.6 was reading heavy in gear. My bro is 175 and numbers were perfecto. Id go 4.4 just me...

I ran a 4.7 on a rm250 with trail gear and it gave me 100/35 at 140lbs.

4.0 and 47.5 N/mm springs are on their way already. Roughly 0.41 and 4.8 kg/mm FYI.The spring chart said these are the right ones for the RM 250 from 55 to 65 kg. Being 60kg I think they'll be alright. If everything goes as planned I can test them at the weekend.

Installed the springs yesterday. The rear turned out to be 48 N/mm but thats not much of a difference. With the recommended 4mm preload the race sag is right at 105 but the static is still a bit off at 40. S-Tech springs anyways. According to their spring chart these springs should be perfect for me and riders being 55-65 kg. I'm 60.

Test ride: Stock clicker settings.

Overall the suspension feels softer and better but sharp bumps still hit me hard in the rear. I think I should go softer on compression. Noticed a bit of headshake as well so I will drop the forks a few mm's.

Edited by TommyZ

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