Spring Rate Preload and valving!

[Jeremy Wilkey]

Hey all these polls seem to be really cool. I want to conduct another poll and get a veiw for what most people feel is the best way to attain ideal function based on exsperience.

Ok.. Since you can't vote twice, vote in the category that best suits your riding and the results should reveal a pattern. Please state your reasons. As always I will post my veiws as it it unfolds..


Regards,
Jer

 

[KawieKX125]

I picked light springs heavy valving for MX because from what I understand, the KX I ride has light valving and I have to overspring it to get any sort of bottoming resistance. The problem I get from the heavy springs is harshness and headshake. From my limited knowledge and what I can try to deduct from the above info, the light springs would keep the suspenders plush with the heavy valving providing plenty of bottoming resistance and making the suspension controlled on sharp bumps.
Am I even remotely correct?:( :think

Oh ya, if it matters I ride on VERY rough tracks(hardpack with rocks) with big jumps and some pretty tight supercross style rythm sections.

 

[motojunkie]

I picked ideal spring/midrange valving because it seems like that would be the most versatile setup. Light springs/heavy valving is how my 520SX came set up, and I can't get an optimum MX setup out of it. Heavy springs/ light valving, it seems like you wouldn't be able to get proper preload for your weight. Also, I'm not sure here, but wouldn't that cause it to blow through the stroke easily. Oh well, I'm interested in seeing what the "correct" answer is.

 

[KawieKX125]

I don't think their is a correct answer. I do have trouble with preload and sag, but I am super-comfortable with ALOT of sag. Kindof Charmichael-esque in a way? But, heavy springs with light valving is definetly not the way to go as evidenced by the fact that my bike bottoms on some jump takeoffs. Granted they are steep, but it still does not work.

 

[motojunkie]

I realize that riding style, and rider preference will dictate the setup, and that there won't be a correct answer - that's why I put it in quotes. What I meant by that is that I'm interested in what the experts believe is correct. I'm sure Mx-Tech, Race Tech, Pro-Action, Factory Connection, etc. tuners will have a little different philosophy on this, and I'm curious as to why. Thanks Jeremy, I really like these discussions, because as a suspension rookie, I learn a lot about suspension tuning.

 

[Hogwylde]

Elephino!!! That's why I look to people like YOU to tell ME how to set up my suspension for the kind of riding I'll be doing. Planning on sending ya my forks and shock this winter for some reworking. Hope ya can get me dialed in!!

 

[Jeremy Wilkey]

I think I gave away too much... My purpose in doing this is A.) get more people involved and two hopefully generate good strings... I think the important thing to consider is that obvously I have my opion but really as long as your thought process is good we like as forum readers like hearing other ideas.. Since i've had to travel so much this year I have not been around as much, so I've tried to evolve the way I moderate, do more with generaating good ideas more than answering every question... You guys have done a great job at that.. :)

Anyway what do you all think might be some intresting alternatives to the options listed above?

 

[KiwiBird]

HS - light valving, heavy springs, fairly light preload. I like to spring for my weight with maybe 5mm preload and then adjust valving to suit.

 

[00kawa125]

I voted for the ideal spring and the mid-range valving. I have only six months experience with motorcycles, but here's my opinion anyway.

From what I understand, from this forum, is that the valving is speed sesitive and the spring is position sensitive. The spring it seems would keep the suspension higher or lower in the stroke than the valving would. By using a soft spring it would allow the suspension to ride lower in the stoke reducing the amount of travel. A heavy spring would ride higher thus increasing travel. With less travel (soft spring) the valving would have to be stiffer to reduce bottoming, with more travel (heavy spring) the valving could be tamer, for the same level rider.

I would think, for a novice, the soft spring would be good because they would not be using all the travel anyway. Even the valving could be softened. But for a seasoned rider the soft spring would be very harsh because they would use the travel causing the valving to be harsh to keep from bottoming.

01 YZ125

 

[MACE]

Well poop....

If the enduro choices both have light springs, there's not much opportunity to argue:D . My experience with heavy (commonly considered "optimal") springs is that they are too jarring for rootnrocksnruts. Physically painfull after a day or two in the saddle. With "excessive" amounts of preload or low oil levels I can get the same static wheel rate as the heavier springs but the reaction at the bars is less when I roll over that two inch rock.

Light damping works in some conditions like rocks but is limited in it's versatility. There will eventually be a section of nasty whoops and that light valving ain't going to cut the cheese :p in the whoops. Wanna know the damping curve I want? I'll design an inertial valve that reduces damping to near zero under high acceleration. What this would do is let the wheel move freely when it gets a sudden jolt and then smoothly apply damping as the acceleration spike subsides - arresting further wheel motion but avoiding the spike. All this needs to be is a spring and a mass driving a spool valve or perhaps a needle. Put that in your pipe and take a good drag......

It's interesting to see how many hits these polls get compared to the number of posts. Come on guys. Tell us what you think and more importantly, WHY you think what you do.

 

[KawieKX125]

Is someone willing to comment on my bass akwards theroy of why light springs and heavy valving would work best for me? I am dying to know if I am correct, remotely?

 

[marcusgunby]

Arron i adree with you because works KTMs have that arrangement and they are the best suspension IMO.I like the softish spring heavy damping.Light damping even with stiff spring will not work in mx as the damping contols the spring-you can have a silly stiff spring but without sufficient damping it wont be any stiffer than a light one when landing off jumps etc.

 

[KawieKX125]

OK, I am not far off in my reasoning! I was always told the .41's I am using with a 4.8 is WAY to stiff for me yet I bottom consistently over most jumps and takeoffs!:eek: Guess when I get the new bike I will revalve. The only problem I can think of with this set up is a "dead" feelig in the top part of the stroke and packing problems as the spring will not have much stoored energy.

 

[John Curea]

Man, I've been away too long.........

This is a really good thread.......

For woods riding, I would go with light springs and light valving. I recently raced a 4 hour harescramble, I tell you, during the last part of the race, my suspension couldnt have possibly been plush enough. I went into a survival mode, things got a little blury and I picked the wrong tree to go around, major center punch (somebody has to keep the handlebar manufacturers in business)......

Anyways, in a woods enviroment, I think for most riders, need a softer spring and valving than MX. (although I have a friend who likes a full moto set up in the woods, I dont think he has any pain receptors in his brain).
A quick run in the woods is one thing, but when you are in the saddle for a couple hours at one time, an MX set up will beat you up. 90% of trail is usually rocks and roots, a whoop out section or jump section are usually far and few in between. I would rather valve and spring softer for 90% of the ride and deal with moto stuff at a slower pace, I beleive your lap times will be faster.

On the flip side, I believe motocross needs a heavier spring and heavier valving. Again, most motocross races last about 15 minutes at the most (excluding national events) we can valve and spring heavy for the extreme sections of whoops and jumps. An average rider can hang on pretty strong for 15 minutes, and we can valve and spring for max speed through the whoops and also handle the jumps (also handle the mis-timed jumps safely).

Mace, lets kick that inertial valve idea of yours around some more......:cool:

Take Care, John

 

[Yamamoto]

HS: MX springs, lighter valving.

This is because
I am a light guy on an MX bike, but like to be versitile so that I do not have to ajust much to adapt to woods riding or big jumps.

I also fine this set up with MX springs and lighter valving to be good because the stiffer springs help keep the ride height up and therfore making the suspension responsive to the small stuff but also allowing big stuff with out harsh bottoming.

My opinion on bottoming is that its normal, if you do not bottom out you are not useing 100% of your suspension and that means you are wasting it.

 

[MACE]

When KYB Steals thi maybe they will give me a free sticker or something...

Originally posted by KXVET#207
Mace, lets kick that inertial valve idea of yours around some more......:cool:

This has been keeping my brain grinding when I should be sleeping. I find that Edelbrock has something similar on a car shock. I think the Edelbrock shock might have an acceleration sensitive rebound circuit which seems backward to me. Check out Edelbrock's execution:

http://edelbrock.com/automotive/ias_shocks.html

I've got a few different ideas for actual hardware. What I don't have is a good idea of what sort of accelleration should trigger the "dump". I need to know that to size the mass and resisting spring. Does anyone think this is just a totally stupid idea? I think it has a lot of potential.

 

[John Curea]

MACE
I did a quick look at the info.......

I think the acceleration rebound circuit would work, I beleive that fork packing would be greatly reduced. You would be able to run the rebound as slow as you want and still get quick extention of the fork over whoops and potholes without the front end diving sensation.

I applaud your "reinventing the wheel" attitude, I have been kicking around an idea of having a variable displacement piston rod. With the narrowest part of the taper in the center of the rod. This would give you an initial reduction of fluid flowing through the base valve for the first half of fork travel, then increase the flow the further you go into the stroke.

....This has been keeping my brain grinding when I should be sleeping

.......I know that feeling........:cool:

 

[P_Taylor]

Originally posted by KXVET#207


variable displacement piston rod. With the narrowest part of the taper in the center of the rod.


[/B]

any ideas on how to seal the top of the cartridge with this rod?

 

[John Curea]

P_Taylor

That's what keeps me awake...........:cool:

 

[Esp1]

MX: Ideal spring/ midrange valving
-I think heavy valving/light springs will not be sensitive enough in begn of stroke. It will use too much of the stroke if you like to keep the free-sag.

By the way; What is Theoretical Ideal Springs? Why is the theory not the same for MX,HS,Enduro,SX?

 

[Yoken]

When I race a MX track, I tune my suspensions mainly for the turns. In Cyprus, most of our tracks are made of hard clay and rocks with supercross type jumps and tight turns. I definitely go for the following setting:

- relatively hard springs, but with low pre-load,
- moderate low speed compression damping,
- light high speed compression damping.

It seems that the low pre-load (3 to 5mm on the fork springs) keeps the fork plush and more responsive on small bumps. Also, it allows the front end to dive moderately when I set up for a corner (I need that because my KX does not turn if the front end rides too high).

Than the springs get harder as the fork goes deeper into the stroke. This usually gives me sufficient bottoming resistance.

I need moderate low speed compression to keep both wheels on the ground in the turns.

The light high speed damping helps me to reduce "vibrations" in the bar as I ride a high speed section with little bumps and rocks.

For those slippery conditions, I like to run a low air pressure in the tires (around 800gr only). And I install 2 inner tubes to increase the resistance to puncture.

 

[rollingp]

censored

 

[michigan]

Sheeshz. If I didn't live in Michigan this would be easier. I weigh 220 withOUT gear, so heavy springs are in order, just to achieve the proper ride height. I only ride in the woods, so in most places I'd be happy with heavy springs and light valving, but Michigan woods are filled with big ole' whoops.

Actually, I don't care what's inside them. I just want them to work. Before the snow melts, I'm sending them out!

 

[Fred T]

Is that what thos are?

Originally posted by michigan
Sheeshz. I only ride in the woods, so in most places I'd be happy with heavy springs and light valving, but Michigan woods are filled with big ole' whoops.

Is that what those are? I thought we were just riding up and down hills!

 

[James]

Is this a trick question:think

Don't you always want the "Correct" spring which may be heavy or light depending on the weight of you and your bike and then the valving to match the springs and the riding you are doing??

Right now, I need stiiffer springs and stiffer valving in my xr400 because the frame is always dragging the ground.