Need Some Spring & Sag Info, Please....


5 replies to this topic
  • Mr. Neutron

Posted August 15, 2010 - 06:19 PM

#1

Hey, All!!!

I guess maybe I've been riding Orange for so long that maybe I've forgotten how to deal with linkage. And for some weird reason, I'm having trouble finding suspension articles I used to be able to find at www.mx-tech.com, Bruce's Suspension's website, and other suspension places/websites. I can't get the the articles from Too Tech Racing that GrayRacer linked to in another thread to open up. Maybe that's a security setting issue here, or whatever.... I haven't had much luck doing a "SEARCH' in this forum, or the Suspension forum....

I recently bought member steve_97060's '06 YZ450F. I like this bike a lot. The suspension is stock, with oil changes done. But I am having probs with it bottoming on me at the local mx track, especially on the rythym sections. Steve_97060 probably weighs around 170 lbs. or so, and I weigh around 215 (235-240 with gear). I had to buy stiffer springs for my KTM 300 as soon as I bought that bike, & I've pretty much decided I need to do that for this bike. I've been to mx-tech's website, used their spring selector deal, and have pretty much figured out what springs are needed.....

My questions are mostly about setting the sag. First, I can find no mention of what we at the KTM site call "static sag", which is a measurement of the sag with the bike off of the stand, no rider. My manual gives shock spring "ranges" that I assume are basically preload ranges. I guess if you exceed the amount of range/preload for a certain marked spring, you need a spring marked for either the next stiffer or softer range, depending on your needs.... :banana:

Right now, to get 98mm of rider sag, I have to have the static sag at about 1/2"(12-13mm).

Does the old thing I seem to recall about 1"(25mm) of static sag, with the appropriate amount of rider sag (95mm to 105mm), pretty much confirm you have the correct spring????

Do most of y'all just worry about the adjusting the rider sag to get the bike to corner as you like it, if you're reasonably close to the factory targeted rider weight???

Once I get my stiffer springs on, it would probably be fair to say I'd be doing right to firm up the rebound clickers a few clicks, huh?

Also, does a guy pretty much need to remove the subframe & airbox to get to the shock to adjust the spring? I think my Katoom spoiled me in that department....

Sorry for the long post. I guess I rely on lots of info to resolve problems, and hope that what I've written can help y'all solve mine. Thanks for any help you may be able to give!!!!

Jimmie

  • crf450319

Posted August 15, 2010 - 06:33 PM

#2

I'm the same weight as you and I called DSP (http://www.diverse-m.../motocross.html ) and the set me up, cheap too - $169 shipped. I ride MX only and they sent me fork springs that are 0.50 kg/mm and a shock spring that's 5.9 kg/mm.

With that spring my sag is at 100mm and my static sag is around 25mm, I couldn't get there with the stock springs.

I thought the suspension was good stock, with these springs the big hits I used to cringe on are no problem at all. Do yourself a favor and re-spring for your weight, you'll thank yourself later !!!

  • Mr. Neutron

Posted August 15, 2010 - 06:51 PM

#3

I'm the same weight as you and I called DSP (http://www.diverse-m.../motocross.html ) and the set me up, cheap too - $169 shipped. I ride MX only and they sent me fork springs that are 0.50 kg/mm and a shock spring that's 5.9 kg/mm.

With that spring my sag is at 100mm and my static sag is around 25mm, I couldn't get there with the stock springs.

I thought the suspension was good stock, with these springs the big hits I used to cringe on are no problem at all. Do yourself a favor and re-spring for your weight, you'll thank yourself later !!!


Cool, CRF450319!!! ;) Thanks for kinda confirming what I thought!!

I actually have already bought a set of .50kg/mm fork springs from a member here at TT (thanks, cudenver!:banana:). I was going to go with a 5.8 (recommended by mx-tech) for the shock. And Diverse sure seems to be the best deal going for the money, huh?

Two things here:

1: Riding style. I, being of old age, tend to ride sorta "old school" at times. Weight more towards the rear, rather than being "centered on the bike" (I'm working on that....). So I think I kinda "punish" a rear end in whoop/rythym sections harder by floundering through them, probably harder than someone with good technique. You think there'd be much difference between the 5.8 & the 5.9 springs? Your sag numbers certainly seem to be right on..... Would I be better off with the slightly stiffer 5.9, with my "Vet/Amateur" skill level, and sorta lack of technique?

2: Clickers. I know a person will have to mess with these regardless, but generally, did you need to go a little stiffer on the rebound at both ends??

Again, thanks for your help!!! :eek:

Jimmie

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • crf450319

Posted August 15, 2010 - 07:33 PM

#4

Hey Jimmie,

I can't say what the difference between the 5.8 and 5.9 would be as far as "feel" goes, but I can tell you that I am LOVING mine !! When I was ordering mine I ended upi talking to the tech who works in the shop, I guess the sales guys had forwarded their incoming calls to his phone. Anyway, he suggested I run the 5.9, I was a little hesitant at first because I made a pretty significant change but like I said, this set up is awesome !

I'm guessing that a 5.8 would feel almost identical ?

Clickers, here's what I did. I service my own suspension (and all of my buddy's by default) and during the last oil change - which I perform at 20 hour intervals - I put 340ml into the outer chambers in each fork. Recommended amount it 350, but I thought since I had put in springs for my weight I might be able to get away with a little less fork oil and as a result, have a more "plush" feel. Good in theory, but I'm going to add the 10ml as I found I had to tighten up my comp. damping clickers to compensate for the bottoming I was feeling in a couple sections on the track. It wasn't anything terrible, but noticeable. Once I turned my comp. clickers in 2 clicks the bottoming went away, I also tightened up the hi-speed comp. damping on the shock by an 1/8th of a turn. Both of those helped, but I'm sure by adding the 10ml, I can set them back to where they were.

I use MXA's settings as a baseline and go from there, but haven't needed to stray too far from what they suggest to get the bike to feel like I want it to.

Rebound clickers... When I had the stock springs in (front and back) I'm pretty sure I was 2 clicks further out from where I'm at now, just to slow things down a little.

I was telling a buddy tonight at the track that I thought the stock susp. was awesome, putting these springs in took it to another level. I can over jump stuff (a 105' uphill) and not leave a crater behind, where as before I would have been hurting from a hit like that.

You will love the new springs, especially on big hits.

  • grayracer513

Posted August 15, 2010 - 08:24 PM

#5

Yes, the stock springs are too light for your weight, as indicated by the low static sag readings. "Generally", yes, you probably would need to clamp down the rebound a little.

The suspension will be much better once you respring. If you ever find the need to improve on it, it can definitely be improved.

  • Mr. Neutron

Posted September 04, 2010 - 05:45 PM

#6

Well, the new springs are in, & I FINALLY got to put in a ride on a practice day at the local mx track.......

crf450319, and Grayracer, you guys could not have been more right about having the correct springs for a person's weight. :foul: :bonk:

I took way less of a beating today at the local mx track than I did on the bike's "inaugural ride" a few weeks ago. Little things like being able to count on preloading/compression & rebound off of jump faces were MUCH easier & better. Short doubles were cleared much easier. I'm really liking this!

Thanks for your very good advice, you guys!!!! You rock! :D

Could you help me ride faster now? :lol:

Jimmie





Related Content

 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.