Suspension Setup Tips

My Saturday that feels like Sunday has been pretty lazy. So while I'm watching Gone in Sixty Seconds for the 237th time, I decided to at least pull up my archives and refresh my suspension knowledge. My borrowed suspension knowledge...



I started thinking about how I need to adjust my sag. After riding on new springs and valving for about 800 miles I realized adding luggage and gear has my ride squatting.

So to start this thread, I thought I would share some of the most profound know-how stuff ever posted (personal opinion). Pay attention to the suspension setups and technical section, a properly setup suspension is a wonderful thing.

When I get a response to my request to re-post from the owner's content, I'll substitute my own pics for the graphics depicted on the web site.

Regards

griz http://www.tootechracing.com/Home%202nd.htm

Man, my archives are over ten years old! Where has the time gone? Here is some similar stuff from '98

http://dirtbike.off-road.com/dirtbike/article/articleDetail.jsp?id=264361 (part I)

http://dirtbike.off-road.com/dirtbike/article/articleDetail.jsp?id=264353 (part II)

So is this griz dude a poser? Only time will tell...

Good stuff here. Thanks for the links! Suspension tuning is something I have never done. I just might try it sometime though!

Relaytech wrote:

Good stuff here. Thanks for the links! Suspension tuning is something I have never done. I just might try it sometime though!

When I first brought home my new to me XR650R I was so excited all I wanted to do is ride. It was my first motorcycle in almost twenty years (don't ask) and I hit the fire roads first day I had it home. Imagine my horror when my hands went numb after 10-15 minutes of riding, so bad I would have to stop and shake them out.

Normal pot-holed, cobble-stoned, gravel and dirt roads felt like every small knife edge, hole or small rock sent a crisp shock straight into my hands and butt. After a couple rides, it was so bad I started thinking I had made a terrible error in choosing the right bike.

One day I rode the bike to work. It scared the snot out of me I had not set sag and my 250 lbs. on a bike spring for 180 lbs. had it sagging in the rear like a chopper. The bike didn't want to turn, the front end was hopping all over the place. It really freaked me out -

So I started going through all the setup guides and almost immediately decided something mechanical had to be wrong with my bike. I cranked down the stock shock spring so the pre-load was at the maximum safe spring compression, I reset the shock and fork adjustments to stock settings.

My clickers were all messed up and cranking down the shock spring to set sag was my Hail Mary or get rid of it. My first ride out the bike was like a totally different machine. Even with the stock boingers, old oil, maxed out spring, the ride was like night and day! After talking to a couple suspension experts, I found out I had two strikes against me.

1. I was literally overloading the motorcycles suspension - by being a big guy, my weight had the bike riding in the middle of the suspension stroke instead of the first few inches. Setting sag helped but my shock spring was maxed out.

2. Heavier springs were necessary to get back into the suspensions sweet spot. Springs, revalving and clicker suggestions from an expert made the bike more than I had ever expected.

Since then, I sent my stuff out to Rob Barnum for springs and revalving. Its been gravy ever since. Riding the same dirt roads that almost killed my dream the bike can go all day and floats over everything.

I even think the new suspension probably saved my butt a couple times over the past two years.

Just my two cents - but even a stock suspension, set up properly should really enhance the riding experience.

Rick Johnson gave me permission to re-post his setup routine in exchange for posting his website - Thanks Rick!

www.tootechracing.com

I will summarize for the sake of turning this forum content into hilljack country

Rear Suspension Race Sage is definitely the most important
single adjustment affecting your bikes handling traits.
Check this crucial adjustment monthly to insure it remains at
your
favorite setting. Race Sag is a
measurement of how much the rear suspension sags under the riders weight
compared to no weight on the bike.

But in hilljack country, this means carefully tilt your 300 lb. dual sport up onto its kickstand until the rear wheel suspension is fully extended to the stops. With one hand holding the motorcycle, carefully lock your tape measure and try to catch something down low like a hub lip or something. Once you have a good spot, measure from your low spot to a high spot like a side panel pin or a tail rack. The measurement should be taken vertically.

Record this number in inches, my first measurement was 27 inches.



The second measurement is taken with the bike on the ground and the rider standing straight up on the foot pegs supporting himself against a wall or tree. Again, measure the distance between the same two points used above. (Standing on the pegs increases the repeatability of this measurement - per Rick's procedure)


But in hilljack country, we have to adapt, improvise and overcome the lack of a little helper who does not want to be crushed by the almost 600 lbs of precariously balanced ballast.

But I digress... You see I want to be able to carry about 25-35 pounds of gear if I need to. So you can see my dilemma, I already have heavier springs so now all I need to do is simulate all that weight up on top of my bike. This is where hilljack creativity comes in handy:




Now keep in mind, we need to set our suspension preload based on how much weight we are going to be riding with. In reality, I can testify my "dirt bike" made into a dual sport handles night and day different with or without 50 lbs of junk in my trunk.

If I consider my own hefty self at ready to ride weight of 255 (conservatively ) and add 25 lbs of gear to my beast of burden, well I am easily at 280 lbs of motorcycle cargo - good thing I installed heavier springs!

BAG OF SALT = 40 LBS
BAG OF CAT LITTER = 20 LBS
HILLJACK METHODOLOGY = PRICELESS!!

Well I admit, I also see my chain is a wee bit tighter than I would like. The chain also can play a roll in a balanced suspension, but that's advanced stuff I have no intelligent response for.

All I know is my chain is too tight and I'll need to adjust it before loading this thing down and hitting the road again.

So for my next bag of tricks - a little pony and you guessed it! A ball peen hammer...



notice custom made punch from an old 1/2" hole bit - hilljack baby, hilljack...

well you've put up with me this far, you should just keep reading...

Here's where I get a little specific to my XR and say you may not want to bang on your motorcycle with a ball peen hammer. I have pounded on my shock adjust ring and lock ring maybe five times since I've had my bike. It will get dinged up a little bit doing it this way.

Call me lazy, but I got tired of taking my entire subframe apart just to check my sag according to the Honda manual. If you keep your shock fairly clean, the lock ring and adjust ring (and the spring) should move freely once the unlock ring is loosened up.

I was going to get the spanner wrenches, but I figure once I set this thing up I shouldn't have to mess with it again for a long time.

On with the show:

So when I did my first measurement I simulated a loaded bike with rider and got 22 or so inches. Remember you want to subract your second loaded number from the first unloaded number.

At five inches of race sag, I knew I needed to increase the preload on my shock spring. In my book 4 inches in optimum for my style of riding and how I like my XR to handle on the asphalt and forest service roads.

Even 1/2" change can drastically change handling characteristics (read my opening experiences with the chopper effect).

To change the sag, use a long punch and a large (ball peen, he he) hammer to loosen the spring locking nut on the shock. Then turn the preload nut to adjust rear spring preload. Note: Increasing the spring preload will decrease race sag and vice versa.



See the punch going in the side panel and then touching the lock ring? Tap the lock ring counter-clockwise to loosen up, it should spin freely once loose.

Secondly, (and this is just my little tip because I can be a dipshit and forget things) I would suggest marking a start/stop spot on your adjust ring.

I use a sharpy marker. Here's my logic: My sag was fine with just me on the bike but when I added 40 lbs my race sag was about 5 inches or one inch too low for my liking. According to my operators manual, each full turn of the adjusting ring on a stock shock spring is the same as adding 31 lbs of capacity to the preload (it says it right in the operator's manual).

So I figure my stronger spring rate will yield a little more or less to one turn = 35'ish lbs. (I wouldn't even begin to know how to do the math, but I'd bet a buck somebody can calculate the compression rate times the change in length to come up with how many turns to make - or some such nonsense)

In hilljack country, we just mark it and pound away until we're one full turn around (see the mark after I took it all the way around??) It's ok if the spring spins around a little by the way.

What now?

We measure our adjusted sag, again, loaded. This is to verify we have enough preload to bring the bike back up to my XR's 4 inches of race sag



So I did pretty good taking the adjusting ring around one full turn because it raised the loaded bike back up almost an inch.

Remember our first measurement of 27 inches? Subtract the adjusted 23 inches and we're golden at 4 inches

So I'm getting a bit tired and you guys are probably sick of my rant anyway - so I'll hold off on finishing up this thread until Friday evening.

Have a great day folks!

griz

Great...Now I gotta go buy a shitload of salt!

Griz,
Where's that boy of yours when you need him?

Get him one that tape.