Author Topic: dialing in the stock rear shock  (Read 4477 times)

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ShanMan

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dialing in the stock rear shock
« on: March 05, 2003, 02:21:13 PM »
OK guys, please refrain from the flames...I readily admit to my ignorance! That said, I assume the dial on the rear shock is to control dampening in the REBOUND? Further, I am also assuming that in order to stiffen the shock for compression (i.e spring rate), I need to crank down the jam nut on the shock body? PLEASE, I need a crash coarse in suspension fundamentals here! Thanks in advance. :?

Rick

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dialing in the stock rear shock
« Reply #1 on: March 06, 2003, 02:40:36 AM »
The rear shock is  pretty simply to setup, but there are lots of different opinions on the process.  Here is what I do:

1. The first thing you need to do is to set your static sag.  The is the amount of drop you bike has when going from a stand to resting on the tires.  The process is simple.  Place the bike on a stand, and measure from the axle nut straight up to a spot you have marked on the rear fender.  Write this number down.  Take the bike off the stand, and push down on the seat a couple of times.  While a friend holds your bike at the handle bar (with no pressure on the seat), measure the distance from the axle nut to the same spot on the rear fender.  Write this number down, and compare it to your first number.  You should have a difference between 7/8 inch and 1 1/8 inch.  I put the range, as some folks believe it should be spot on one number or another, but unless your an expert level racer, you probably will not feel the differenct. If the difference is more or less than this, tighten or loosen the spring nut to adjust the static sag to the proper setting.
2. Put on your riding gear on.  Mount your bike  :oops: , and stand in your normal riding position.  Have your friend measure the distance from the axle nut to the same spot on the rear fender.  Compare this number to the first number (the one you measured while the bike was on a stand), this is your race sag.  Your race sag is somewhere between 3 3/4 inches, and 4 1/4 inches.  Here again, I list a range, as some folks believe that it should be spot on 4 inches.  However, a range works for most good trail riders.  If the your race sag falls outside this range, you will probably be well served to replace the spring with one that is better suited to your weight.  Some folks will just change the spring nut settings, but this is far from the the best method.  For the $80 you will spend on the correct rear spring, you will enjoy the ride a lot more.
3. Once your spring is setup and properly sized for your weight, you need to adjust the clickers.  You have two adjustments, one at the top of the shock, and one at the botton.  The top adjustment changes compression, while the bottom changes rebound.  Ironically, you can change the rebound "feel" by changing the compression and visa-versa, so it takes a little time to dial in a shock.
4. To start adjusting the clickers, turn each adjustment screw in all the way (do not tighten too much, just screw in until it stops), and then count the number of clicks as you turn the screw full out.  Once you know the total number of clicks, put each screw right in the middle by counting the clicks from all the way in.  
5. Go out to your favorite riding area, something with which you are familiar.  Select a section of trail (maybe 2-3 miles long) that has varying terrain.  This is your test section.  Ride your test section a few times, paying attention to the feel of the rear end.  If you are unhappy (which you most certainly will be), try and define why and where you are unhappy.  For instance, in the big whoops, does the bike have too much rebound, or not enough compression dampening.  With this insight, change one of the clickers only.  For instance, if you don't like the rebound , turn the bottom screw in 3 turns and go for another ride.  If things get worse, return the screw to the middle, and turn it our 3 turns.  Go for another ride.  If things get better, but still not there, try a couple more turns.  If things get worse go back one at a time until you find the best setting.  Now turn you attention to the other screw, and perform the same trial and error.  Don't be afraid to return both screws to the center, and start your testing again, this time starting with compression adjustment.

Suspension tuning is very personal, so no one can do it for you.  It also takes some time to fine tune your ride.  You will have to make some compromises to get the best ride in different terrain, so take your time and get it setup just right.  

Good luck

Rick

KX4Life

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dialing in the stock rear shock
« Reply #2 on: March 06, 2003, 02:43:36 AM »
When you are "dialing in" your suspension you are setting it up for your weight or terrain. Some shocks/forks are fully adjustable. Others only offer one or two or none of these features. A fully adjustable will offer rebound/compression damping and spring preload. I believe you are confusing spring preload with compression damping. Compression damping is actually what controls the rate at which the shock compresses. The rebound damping will change the rate that the shock or fork returns. In most suspensions turning your adjustment in (clockwise) will speed up the shock and out (counter clockwise) will slow things down. The spring preload basically just allows you to change the stiffness of your spring. Clockwise will be a harder rate and counter clockwise would be softer. The best thing to as a starting point is to find out the factory settings and tweak from there. The art of suspension tuning is not as easy as some would make it out to be. Best thing to do is change one thing at a time while keeping detailed notes and then ride and see what effect it has.
Hope this helps.
Ken

Offline Paul

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Re: dialing in the stock rear shock
« Reply #3 on: March 06, 2003, 02:57:36 AM »
You won't find that here, the people here are very knowledgable and don't mind spreading that around.
Quote from: ShanMan

OK guys, please refrain from the flames...I readily admit to my ignorance!

Rick has listed a basic intro to the rear shock and after a while - ie when your very comfortable on the bike and know what it is doing - you'll begin to easily determine what isn't "just right" and you'll have the knowledge to change those things.

Don't worry about any flames, we're here to spread the knowledge :mrgreen:

husqrider

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shock adjustment
« Reply #4 on: March 06, 2003, 03:14:21 AM »
pretty simple--
the knob at the top of the shock ( just under the seat ) adjusts the compression dampening. this controls the shocks force going down. just as a note, there was a tips article in Dirt Rider magazine a couple months ago by Dick Burleson, where he stated to adjust your compression as hard as you can stand. he is a super fast off road guy, so you may try that theory, i know i will.
the adjuster at the bottom of the shock is the rebound dampening. I am not sure what year  KX 5 you have and if the adjuster is different than mine, but mine is a slotted screw type that is just above the lower shock mount bolt in the alum. clevis end of the shock. This adjuster controls how fast the shock returns from being compressed.
the 2 spanner nuts on the threaded part of the shock body adjust the preload on the spring. This is how you set what is known as "sag" What sag is the difference in measurement between when the bike is up on a stand with the rear tire off the ground and when you are sitting on the bike, wearing your full riding gear ( for proper weight ) and sitting forward on the seat so your weight is centered on the bike. Setting sag plays a big part in how your bike handles and turns.
I hope this helps and have fun!

ShanMan

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dialing in the stock rear shock
« Reply #5 on: March 06, 2003, 03:43:36 AM »
:shock: Awesome replies! Thanks to every one of you (in particular Rick for taking the time to write a how-to article) for the knowledgeable words. I hope one day to be able to pass it on myself. I am a moderator of a vintage Mustang website myself. Maybe one day you guys will have a question about classic car restoration, and I can be of some help. In the mean time, I will get home tonight and get the rear shock set up as best as possible for this weekend. Again, my thanks!  :)

HULKSTER

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dialing in the stock rear shock
« Reply #6 on: September 30, 2003, 12:15:45 AM »
Yep....that's good info....I'm going outside now and starting on the 500 I just got....great thread.

Offline John

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Race sag.
« Reply #7 on: September 30, 2003, 03:46:34 AM »
Hi all,

Is there anyone out there who actually knows how the race sag is calculated on a bike? My guess would be a ratio of some variables probably including the full stroke of the suspension and the spring characteristics. On all the bikes I've had the race sag is more or less the same? Could be that I am only adjusting the race sage on my MX bikes - duh.

I?m just curious.

BTW. I found this information on the net (locking for formulas) with pictures and all, see 4 strokes??. The principle is the same for 2 strokers  :wink:

Another BTW. Don't buy one of these expensive tools to adjust your spring pre-load. Use a blunt screwdriver and a hammer. There is not a lot of space around the spring.

/John

Offline Paul

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dialing in the stock rear shock
« Reply #8 on: September 30, 2003, 03:59:42 AM »
Thanks for that link John, thats good information there

teamgreen500

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dialing in the stock rear shock
« Reply #9 on: September 30, 2003, 01:36:42 PM »
At one time, I must admit...Oh the shame :cry: ...I was at a Showa (Honda) test session and I heard the ratios being discussed. It was 3:1...Travel:Sag-loaded. This is actually the basis for determining correct spring values. This was many moons ago and in a Galaxy far, far way...I'm so ashamed...wait a tick :roll: ...this WAS in the day of David Bailey...Hmmmmppphh...Its cool! :lol:

I might suggest that a person might find it very educating to, one at a time, try testing his bike with FULL light and then FULL hard COMPRESSION and then find where the settings seem to be best.

Then, do the same on REBOUND...HOWEVER, It's REBOUND  :!:  :!:  :!: that can REALLLLY hurt you! SO BE CAREFUL! If you do this and experiment with it, you'll discover why these adjustments exist and you'll also find out why some of us actually adjust our suspension during long/multi-terrain events (shhhhh...that's a secret!).

Best of Luck and Care,

Manny

HULKSTER

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dialing in the stock rear shock
« Reply #10 on: September 30, 2003, 02:29:14 PM »
Quote from: teamgreen500
this WAS in the day of David Bailey...Hmmmmppphh...Its cool! :lol:


David was my favorite racer for a long time. He was the best ever to me. A true champion. I've seen him make some awesome comebacks. He was probably the smoothest racer ever. Sucks how he got messed up. BIGTIME.