Setting fork sag for a dummy...

slowmick

"I am over 1000 kg"
ok, i'm stuffed. i don't understand how to set the sag on my forks.

i tried the suggested air pressure of 90 psi for my weight to start with and got almost no sag. i got down to 50 psi before i was getting the sag required. now i notice that i depends on how i get on the bike to cheekc the sag changes the answer dramatically. i if get on the bike with my body forward of the cranks the forks sink down and then recover when i am in a riding position. if i get on the bike with my weight around the cranks or behind them there is almost no compression in the forks. the sag in the rear shock is pretty much the same no matter how i get on the bike.

Any suggestions as to how I should be doing this properly? I thought this would be the easy bit before I got to grips with compression and rebound damping.
 

Ivan

Eats Squid
[video=youtube;nVVmcrbozVY]http://www.youtube.com/watch?v=nVVmcrbozVY[/video]

The video says 25% sag. I use 20% on forks.

Also, its worth lubing your seals with silicon spray or Juice lube before setting the sag. Don't get it on your discs. :thumb:
 

Jeffgre_6163

Likes Dirt
ok, i'm stuffed. i don't understand how to set the sag on my forks.
i tried the suggested air pressure of 90 psi for my weight to start with and got almost no sag. i got down to 50 psi before i was getting the sag required. now i notice that i depends on how i get on the bike to cheekc the sag changes the answer dramatically. i if get on the bike with my body forward of the cranks the forks sink down and then recover when i am in a riding position. if i get on the bike with my weight around the cranks or behind them there is almost no compression in the forks. the sag in the rear shock is pretty much the same no matter how i get on the bike.
Any suggestions as to how I should be doing this properly? I thought this would be the easy bit before I got to grips with compression and rebound damping.
Setting the static sag is a guide only to final pressures. It can be difficult to get it spot on as the stiction in the forks as well as body positioning can all affect the result.
First up for best results this is a 2 person job
Best way I have found is to set the initial pressure to that recommended by the fork manufacturer.
Put on all your riding gear including a full camel back if you ride with one.
Have a friend hold the bike upright with a leg either side of the rear wheel
You now need to get on and adopt your most preferred riding position, standing in attack mode I have always found gives best results.
The trick is to get on the bike without "bouncing" the suspension, just let it settle in to position, personally I use a couple of milk crates either side of the bike.
Get on and off several times noting how much sag you use.
Average the results and adjust pressure accordingly to where you want your sag [typically 25 - 30% of total fork travel].

Note that this pressure will be just a guide. Once your forks have had a chance to bed in or loosen up with a few kms under them sag may increase. You may also find that the fork is way to hard and you are no getting anywhere near full travel on your normal trails or be too soft.
Best way to final adjustment is to carry your shock pump on your first few rides and adjust up or down until the fork feels right.

As for initial rebound setting in the fork.
Count the full range of clicks in the rebound dial from full fast to full slow, say it is 16, wind it back till it sits in the middle, in this case 8 clicks out from full slow.
Go for a ride and adjust according to feel.
A good base line for the rear I have found is to ride slowly off a normal 150mm gutter while sitting down with your full weight on the saddle.
Adjust the rebound damping so that the rear suspension bounces just once and stops.
If it does not bounce at all it could be set too slow, if it bounces twice its too fast.
adjust accordingly

Hope this helps
Remember, don't be afraid to fiddle, as long as you now where your base settings were you can always start again.
Adjust only one thing at a time don't go altering front pressure, rear pressure rebounds etc all at once on the trail. Once you set your base lines in the garage adjust only one thing at a time on the trail or you will not know what each adjustment is doing to the ride quality.
 

driftking

Wheel size expert
[video=youtube;nVVmcrbozVY]http://www.youtube.com/watch?v=nVVmcrbozVY[/video]

The video says 25% sag. I use 20% on forks.

Also, its worth lubing your seals with silicon spray or Juice lube before setting the sag. Don't get it on your discs. :thumb:
I will also add when you stop bouncing to overcome the striction don't use the brakes to stop, braking will effect the sag measurement.
 

slowmick

"I am over 1000 kg"
thank you very much for the help guys. i had a go at setting the sag. after jumping up and down and measuring the sag and changing the pressures i gave up on getting a repeatable result and and went for a ride.

I did some loops around the Yarra Trails and the bike felt good. mostly rough cross country trails (no real drops/jumps) and i managed to use all of the travel on the forks but don't remember feeling them bottom out.

Tomorrow i am planning to head out to the You Yangs for some laps on Cressy. At the moment I have all the damping set in the middle of their ranges.

As Cressy has some jumps and drops on it i probably need a bit of travel in reserve from today. To stiffen up the fork for jumps and drops should i add air or high speed compression damping? Do i just do lots of laps and try both options?
 

Jeffgre_6163

Likes Dirt
thank you very much for the help guys. i had a go at setting the sag. after jumping up and down and measuring the sag and changing the pressures i gave up on getting a repeatable result and and went for a ride.

I did some loops around the Yarra Trails and the bike felt good. mostly rough cross country trails (no real drops/jumps) and i managed to use all of the travel on the forks but don't remember feeling them bottom out.

Tomorrow i am planning to head out to the You Yangs for some laps on Cressy. At the moment I have all the damping set in the middle of their ranges.

As Cressy has some jumps and drops on it i probably need a bit of travel in reserve from today. To stiffen up the fork for jumps and drops should i add air or high speed compression damping? Do i just do lots of laps and try both options?
What bike and fork do you have before we attempt to answer that
 

slowmick

"I am over 1000 kg"
I have a 2013 Enduro with the cane creek rear shock and fox 36 RC2 Talas. it may as well be the space shuttle, far more nobs than i know what to do with...
 

Jeffgre_6163

Likes Dirt
I have a 2013 Enduro with the cane creek rear shock and fox 36 RC2 Talas. it may as well be the space shuttle, far more nobs than i know what to do with...
Very nice - Alloy or S-works? not that it is relevant to your questions, just curious.

If you are bottoming out too much add air pressure 5 PSI at a time until you reach a point where you use 80% of your travel 90% of the time [approximately] saving that last 10% for the really big hits, landings or G outs that only come along a couple of times a ride.
As for rebound and compression damping.
If your fork is "packing down", i.e. not returning to the sag position after successive hits, or where successive fast hits progressively reduce the travel available because the fork does not spring back fast enough then you can try speeding up the rebound damping. That is, have less rebound damping. Less is towards '-' on the adjuster. Just move it one or two clicks to start with and go from there, on the other hand if the front wheel is deflecting off trail obstacles like big rock gardens or the front end bounces off line rather than going where you intended when landing a jump it could be that the rebound is too fast, wind on a bit more damping a click at a time and session the obstacle to find the sweet spot

Don't worry too much about the high speed compression damping for now, rebound is the one to get right.
However compression damping will help to hold the fork up in its travel. Low and high speed refer to the vertical wheel speed. In other words the speed the damper is being asked to move.
Low speed comp helps with brake dive, and increasing HSC will keep the fork up when climbing out of the saddle, reduce the bob experienced.
Setting HSC is tricky because you'll not find out the results until you're hitting things quickly.
On all but the top end forks HSC is not adjustable, it is pre set in the factory.

My previous Reign X0 had a 160mm 36 Talas, for the record I set HSC in the middle and never ever touched it again
 

slowmick

"I am over 1000 kg"
s-works carbon Jeff - it was a warranty replacement frame for my 07 enduro pro carbon (very lucky boy).

thank you very much for your assistance. normally i just ride and don't worry about the suspension but have been commuting on a hardtail and thought that the enduro could probably pedal a little better while still eating up the rough stuff.

reading the instructions taught me just enough to get more confused. will work with the air pressure and the rebound and see if i can find a sweet spot. enjoy the rest of your weekend sir.
 

swaz

Likes Bikes and Dirt
Thanks for asking this. I too need to know more about all the levers and dials on my bike
 
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