Jump to content
Bryan Bosch

Tuning your suspension - Where to start?

Recommended Posts

9 hours ago, Oregon Comrade said:

I really like the laser idea...but how did you mark the wall if you are sitting on your bike?

Handlebar was close to wall. balanc it just long enough to turn around and mark the decrease. Better if you have a helper. Best susp/handling tutorial i've found on the web is over on slavens' website.   

Share this post


Link to post
Share on other sites

2007 yz250f rider weight 160 fully outfitted
Novice rider, set for 100mm sag but think i will increase to 110 to lower seat height from 37" to closer to 36"
15 year old 5 foot 7" figured better control would benefit more than ideal setup.
And setup on rebound and dampening vs stock.

Share this post


Link to post
Share on other sites
54 minutes ago, Dcummins69 said:

Hey guys , quick question...is adding more fork oil going to soften or garden the suspension?

Less air space will result in it having the feel of a higher spring rate, more bottoming resistance.  I guess you could say it gardens it.

Share this post


Link to post
Share on other sites

I just went through this. I have 2019 kx450 spring forks with Honda billet lugs for my 07 CR250. Knowing they would be to heavy/stiff for me I wanted to ride them before changing springs/valving. I decided to start with a low amount of oil after putting them back together after the lug swap. Even though most reviews said the 2019 kx forks felt soft I thought they would be harsh going on a lighter bike with my 155lb ass on it. They actually felt better on the first ride than my older KIT forks did. They were more plush on the smaller bumps/normal riding terrain but still had a slight “jackhammer” feel. Even though I’m my head I was convinced the valving and springs were to heavy from the start, I decided to add more oil to the forks. I ended adding another 30cc and it was a win! The forks feel plush and smooth and flat out great. I don’t see any need to change the valving or springs because they feel so great (but I will anyway).

So.... adding more oil is supposed to increase bottoming control and stiffen the forks. I could be way off here but.... I suppose adding fluid could also help the forks stay in the upper stroke where the forks is more plush. Play around some and find the sweet spot. I started with a low oil volume so even adding 30cc I’m still in a lower range but it worked for me. I’m sure there’s a point that the forks will become harsh with a high oil volume. It’s easy to experiment with although and could pay off.

Share this post


Link to post
Share on other sites
I just went through this. I have 2019 kx450 spring forks with Honda billet lugs for my 07 CR250. Knowing they would be to heavy/stiff for me I wanted to ride them before changing springs/valving. I decided to start with a low amount of oil after putting them back together after the lug swap. Even though most reviews said the 2019 kx forks felt soft I thought they would be harsh going on a lighter bike with my 155lb ass on it. They actually felt better on the first ride than my older KIT forks did. They were more plush on the smaller bumps/normal riding terrain but still had a slight “jackhammer” feel. Even though I’m my head I was convinced the valving and springs were to heavy from the start, I decided to add more oil to the forks. I ended adding another 30cc and it was a win! The forks feel plush and smooth and flat out great. I don’t see any need to change the valving or springs because they feel so great (but I will anyway).

So.... adding more oil is supposed to increase bottoming control and stiffen the forks. I could be way off here but.... I suppose adding fluid could also help the forks stay in the upper stroke where the forks is more plush. Play around some and find the sweet spot. I started with a low oil volume so even adding 30cc I’m still in a lower range but it worked for me. I’m sure there’s a point that the forks will become harsh with a high oil volume. It’s easy to experiment with although and could pay off.

I have found sometimes forks get plusher with more oil

Share this post


Link to post
Share on other sites
I just went through this. I have 2019 kx450 spring forks with Honda billet lugs for my 07 CR250. Knowing they would be to heavy/stiff for me I wanted to ride them before changing springs/valving. I decided to start with a low amount of oil after putting them back together after the lug swap. Even though most reviews said the 2019 kx forks felt soft I thought they would be harsh going on a lighter bike with my 155lb ass on it. They actually felt better on the first ride than my older KIT forks did. They were more plush on the smaller bumps/normal riding terrain but still had a slight “jackhammer” feel. Even though I’m my head I was convinced the valving and springs were to heavy from the start, I decided to add more oil to the forks. I ended adding another 30cc and it was a win! The forks feel plush and smooth and flat out great. I don’t see any need to change the valving or springs because they feel so great (but I will anyway).

So.... adding more oil is supposed to increase bottoming control and stiffen the forks. I could be way off here but.... I suppose adding fluid could also help the forks stay in the upper stroke where the forks is more plush. Play around some and find the sweet spot. I started with a low oil volume so even adding 30cc I’m still in a lower range but it worked for me. I’m sure there’s a point that the forks will become harsh with a high oil volume. It’s easy to experiment with although and could pay off.


Great info, thanks a lot. I actually am in a similar situation… I have a 2005 RM 250 that I purchased and the previous owner had the suspension done by factory connection, he was a much larger rider (190 pounds)as to where I’m only 160 pounds myself.
The suspension is not awful but I do feel like it could be a bit softer. I have the motion pro tool on the way and will begin searching for that sweet spot.

Share this post


Link to post
Share on other sites

Just bought a yz450f 18. Im 210 pounds i will eventually put stiffer springs in it. But i havent touched any of the suspension. But i noticed when i jump it kicks me and i realize my forks are gonna be soft but what could i do to my forks. Basic knowledge of suspension i have

Share this post


Link to post
Share on other sites

What are your sags ? The yzf is setup for a heavier guy as STD

Share this post


Link to post
Share on other sites

I think what is confusing the guy is the table is showing less oil on the hard setting and more oil on the soft setting when compared to the standard settings. The reason for this is the thickness of the coils themselves so the oil level is adjusted to compensate for the oil displacement of the spring in order to keep the oil level at the same height.

Share this post


Link to post
Share on other sites

Hello.

 

Can someone recommend a rear spring for a DR-Z 400 S 2007, suitable for a rider 100 kg naked. On top a this, gear and 30kg of luggage must be considered.

A link to a shop will be appreciated.

Thank you.

  • Like 1

Share this post


Link to post
Share on other sites

6.10 kg/mm is the recommended spring for just your body weight, but the closest spring is 6.0kg/mm. However, considering the extra cargo weight, I'd go with the next next heavier spring of 6.3 kg/mm.

https://thumpertalk.com/shop/Race-Tech-Shock-Spring-DR-Z400-ALL-p2006835316.html

We don't have the 6.3 listed for some reason, but we sell it. It's p/n SRSP 672763. If you order, order the 6.0 and in your order notes, put in p/n SRSP 672763. Same money, so we'll just edit your order and send you an updated invoice. We ship to Romania via USPS Priority Mail International. Pretty quick and no brokerage charges like FedEx or UPS. There's a standard service that's about 7 days (excluding customers) and an express option as well (more money). Shipping calculations can be see before checking out by adding to your cart.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...