this is how to properly adjust your sag for front
and rear suspension using a bmw s1000rr as an example
as shown in the other videos i've already swapped out the stock front and rear suspension with a
set of old ones i've left the compression and rebound as it was from kyle racing
but what i'm going to do today for his direction is to properly set the sag for both of them now
sometimes in a manual all it'll tell you to do is check the bike with it resting by itself and the
difference between that height and with yourself on the bike what i'm going to do today is suspend
the bike get the fully extended value and measure that difference from when i'm on it and have it
compress so it's going to be a bigger number but it's what they recommend to get a more accurate
calculation for this work you're either going to need a front stand like this or a way to suspend
the bike because you have to pick the bike up and have it so the front wheel is off the ground
i'm going to use one of these stands but before that pin can get inserted i need to remove this
piece and that break point that bottom panel and the piece for the brake tee are off if
you're worried about scratching it obviously you can take your fender off or whatever you want to
i know i can get in there easy enough so i'm not too worried about it but what you're trying to
do now is you got to get that pin into the stem back here so you can raise the front end i already
have the rear end on the stand so the bike is centered you want to do that before trying to
put this front stand in now you can see the tire is clear and we can get a full length measurement
of the extended distance on that fork i've got this gadget over here that tells me where it is
and it is 4.75 i'm going to pull that front end stand out because i should be done with this
now with the front end resting back on the ground and being supported in the rear yet
you want to measure this distance now and it's going to be less than when
it was fully extended and the difference between fully extended and what it is now
that's going to be your static sag amount you're going to want to write that down too
now i'm all suited up i'm going to get on so i can press it down as low as it can go
in the book it says that one turn of the adjustment screw will cause one millimeter
change in spring load one turn of the screw will cause one millimeter change so since
i'm at 42.29 and i was recommended to set it at 40 by kyle racing i'm gonna set it
two millimeters increased spring load and i have to do those on both sides of course you
can see what i did here is i put a plus sign on the tape right where the plus sign there is
and i did the same thing over here so that i know where my spot is now i just need to move
those inward two full turns each to get my two millimeters of additional spring load i'm gonna do
one turn again we're going inward there's one there's exactly two turns on that one
two full turns two full turn now that i'm getting 1.5 on each side that converts to 38 millimeters
so i guess it went double so one complete turn is actually not a millimeter of sag like i thought
it was so i need to go backwards one turn and that should get me right at 40. backed both of
them off one complete turn so they're basically one turn inward from where they were originally
final position on the preload ended up being one turn further in than it was when i got
him originally so after all that iteration final is one turn in i ended up at 40.39
millimeters so it's just over 40 but the manual says 41 so that should be perfect for the front
now i can put these parts back in place brake tee and that panel are both installed again so
the whole front end is back solid and now we'll move on to the rear now we're gonna do the same
thing with the back we've already got it raised on the rear stand i've got some jack stands that
i put under each peg make sure the pegs don't fold up or anything you can see those are rigid
so i'm going to just slowly back that jack out and drop the pegs into the jack stands
okay and it's going free because we don't see it stopping us against the ground now
we have to measure the fully extended position we've got my gadget that i'm going to use here
there's not a fork to measure like we did on the front so i kind of have to use something like this
so that backed off and just stick it in there start tightening it feels fairly snug now
all right it's now it's 25 inches exactly and we should have room for clearance
all right as it came it's at 27 millimeters
uh for ride height the book says 28 kyle racing told me 30 so we'll kind of aim for that 29 mark
now for this component of the suspension this is the guy that actually adjusts your spring preload
similar to the way that the front forks did so i need to turn it in to go up in spring tension
but since i'm already just a little bit too tight i need to actually loosen it so
i'm going to try loosening at one turn i've marked the stem as well as the outer piece
i'm gonna go one turn and see what that does i couldn't actually even go a full turn i got about
maybe a third okay after backing it off as much as it would go which was only a quarter or third
turn whatever it was it's just in the 27 to 28 millimeters 28 is what the owens book says
kyle's group said 30 so it's in there but just every little bit you mess with geometry on these
things effectively what i guess that means is that it's not compressing more in the back
so it's going to have a little bit less rake than it could if i could loosen it up a little
bit since i adjusted the rear backing off all the preload on the spring and i was only at
27 millimeters which is just a hair under that kind of 28 930 range i went back to the front
and i adjusted it down to 39 just over 39 millimeters and any it says you know
38 to 40 maybe even 41 so this way it keeps the bike pretty close to level
and it does allow for if i do gain a little bit of weight but it's keeping everything right where
it needs to be and it should perform really well this way without messing up any of the geometry
now that the sag rear in front is set right where i want it per the instructions and recommendations
the next thing i wanted to do is just do a gut check on where i was
as far as the geometry goes so i put a straight member across the two tires shimmed it up to make
sure it was level and then just made a plumb bob you can see the string and the bolt hanging there
the rake measured just under 24 degrees and i think it was like 23.5 or 23.9 is the spec
on it so that means my geometry should be really good with the sag really good now and so i'll go
ride it and right now it seems to be real easy to turn in much more than what the aprilia is and so
i've just got to figure out if it's too easy to turn in and if it is
then i can adjust the rear position height because the tubes are the stock position in
the trees so i don't want to mess with them if i need to i will adjust the height of the rear shock
not the spring and sag that's good then what that means is i need to add just a little bit more rake
and if i do that that would be squashing the back end right so you bring down the back pushes your
rake out and makes it just a little less easy to turn so that's what i would do if i decide that i
don't like how it handles right now it'd just be taking this bolt out loosening the blue jam nut
turning the link in to bring the rear down a little bit
which would give you more rake and lessen the sensitivity of the steering a little bit
then re-tighten the jam nut and put the bolt back in now the suspension in the
front and the rear are properly checked for full sag everything's adjusted with where
they sent it should be good i'll take it out in the morning and give it another ride but
didn't make any major changes so fully expect of anything it'll be an improvement i'll leave
the indicator on and i'll just watch that like you would a zip tie and see how far it goes but with a
little bit more preload up front it should keep it from getting anywhere near bottomed out this time
after some riding in the hill country you can see that the compression indicator is still a decent
amount above bottoming out which is what you want but it's using a lot of the travel so it's where
we want it to be the bike now flicks really easily into turns but not to the point of being unstable
i'm using good travel on my suspension it feels good even going around the chattery curves in the
hill country everything is behaving really well for this so i'm very happy with how the suspension
is set up the bike handles and rides awesome just like this motorcycle should subscribe to
my youtube channel if you want to learn more about how to enjoy amazing machines like this