Ceriani 38 mm - settings ??

markQLD

markQLD

Hero member
Location
QLD Australia
what's a 'usable' fork travel to be working out the suspension settings for a '78 1200.  (Clyde)

i'll measure it meself, next time the springs are out, but reckon some knowledgeable forum blokes would know ??
the last run it used about 105 mm,  but reckon there should be a bit more in the travel?  maybe not too much?
these emulator things feel to be working the forks a lot better.
today,  spring rate = 0.90 kg/mm.    oil = 7.5 W
cheers,

, & don't be concerned,,  i ain't gunna start machining anything based on any numbers ya tell me.    8)

 
Mark your using the same spring and oil weight as I am.I am probaly 130kg,maybe a bit more.The std spring from the green book is 1.25,I think the .9 was a bit light for me so probably ok for 100kg or so.The oil height I am using is 130mm forks bottomed and springs out.Don't know how much travel it uses,its got gators fitted.Don't feel any harsh bottoming under brakes.Thats with emulators.No negative comments= no problems for me,its a good test out the back of Wisemans Ferry.Not much road maintenance happens out there ,that is till the road slides into the river.
 
When it was first done I would nearly bust a poofle valve getting the fork cap on,really scary hoping it wouldn't strip the thread.It took quite a bit of preload to get the 1/3 sag number,not so tough these days,I guess the spring has sacked a bit.Anyway I still like the action.
 
mark, i'm about the same riding weight
my 1200, with marzos, runs 2 turns preload on blue emulator springs .85 spring rate and 15w bel-ray fork oil
it is set up for sport touring accounting for rider, fuel, bags etc
which also makes it just about right for track days
at least at my skill level (old and slow)
i think for normal riding without all the extra weight i could use .80 springs

i'm inclined to think .90 springs are too stiff for your weight

i normally set my sag at 1/3 of the total travel as public roads around here are not so smooth
my total travel is around 100mm or so

fully extend the front suspension and measure from the fork seal to the bottom triple clamp
this is L1. put on your regular riding gear and hop on your bike, assuming your normal riding position. have a friend hold the rear of the bike so that you can keep both feet on the pegs. your friend needs to take the same measurement as in step one. once after pushing down on the front end and slowly letting it settle up (L2), and again after gently lifting the front end and letting it settle down (L3). L2 and L3 would be identical in a perfect, frictionless world.

static sag is calculated as: sag= L1-(L3+L2)/2. averaging the two measurements with you sitting on the bike negates any stiction that may be present. aim for approximately 30-35mm of static sag for street riding,  if you have too much sag, tighten up the front preload. too little, loosen.

do the same for the rear

remember the emulator only does the compression damping, rebound is controlled by oil viscosity. not all fork oils have the same viscosity.
sit in your normal riding position as moving rider weight will change the numbers

cheers,
scott

 
jotacorsa said:
i'm inclined to think .90 springs are too stiff for your weight
... aim for approximately 30-35mm of static sag for street riding,  ,,,
Click to expand...
thanks Scott,  reckon i'm close to ya static sag figures.  and i had thought the same about 0.90 springs.  but,,  it got to 105 travel on a cruisey ride on ok sort of roads.
hence, the question about just how much is left in the fork travel.
i'm ok with all the calculations, just can't be bothered to pull the springs out today.  or is today already tomorrow?  maybe i could do it the day after next ??
 
all the travel is still there...~1/3 down and 2/3 up  :D

with a tie wrap on the leg go for a spin then do a quick measure
squeeze the front brakes and lean over the bars
measure again...should get you pretty close to what's left in compression
 
suspension got a good workout today around the Mt Lindesay.
fork travel measures 127 mm.  & da wilbers used all the travel they had, so will up da preload, and 'av a ponder about the damping.
actually, the suspension feels good, real bloody good, and it sure is working.  but this is just da beginning, i reckon.  i spooked meself once or twice!  ;)
gotta pull the clutch out of Clyde tomorrow, so will pull the springs out of the Ceriani's for a measure.
 
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