[ST] Fork Oil Changes

[Rich Hartwick <hartwick@xxxxxxx> (by way of Message_Redirector@xxxxxxxxxxxxxx)]

I agree it is not necessary to pull the forks to change the oil, but at
least periodically, it is good to do, and the job is much easier than it
appears.  If there is any seal leakage, they will have to get pulled and
rebuilt.  For normal oil changes (for which there is no schedule)
though,  I have found the following procedure works well.

Support the front of the bike solidly, as with a small hydraulic bottle
jack under the front of the engine while on the centerstand.  Remove the
fork caps and springs.  There is some pre-compression pressure on the
springs, but not that much.  It is not like they are going to jump
across the room once removed.  Just use a large deep well socket, and
hold it firmly with both hands while unscrewing the caps.

Compress the forks fully by putting small boards under the front tire
until the forks are at the end of their travel.  Suck out the fork oil
with a fork oil syringe, the same one you will be using to set the oil
level.  You might want to measure the existing existing oil levels and
write them in your bike logbook.  For a while, many Triumphs were coming
through with low, and different oil levels in the forks.  At least you
will have a benchmark measurement when you refill with fresh oil.

I always waste some fork oil, and add some into both forks, then let
them extend and compress them again, and suck out the rinse oil.  Repeat
if needed.  Everyone has their own oil brand, but I've found the Yamaha
stuff to be readily available at local dealers, and of very good
quality. They use it in their factory race bikes, so it can't be that
bad.  Oil weight is a whole different issue that has been discussed here
in the past.

Once ready, pour in more oil than needed, and work the forks up and down
seveal times to get the air out.  They move quite easily, and you will
find you can kneel by the front tire and work the wheel up, or just keep
adding wooden blocks to raise it.  If the bike is solidly secured, you
won't have to worry about it dropping off the jack and stand onto the
floor.   As every manual will warn you, be very careful of cleanliness,
because any dirt finding its way into the forks will be in there until
the next oil change, scratching the seals and rods.

Now, just set the fork oil level by pulling out the excess oil with a
fork syringe, setting it near the factory level.  This is always done
with the forks fully compressed.  Also, forget the recommended volumes,
which are only approximate, and use the oil height.   Although the forks
are not vertical, if you measure the oil height at the center, the rake
angle will have no effect on the measurement.  Also, this is not rocket
science, so a few mm off from true won't do anything.  I haven't
experimented with the ST much, but the Trophy recommended oil levels
were all over the map, as each year I think Triumph tried to tweek the
ride by adjusting the oil height.  There is a mimum level (from the top
of the tubes), below which they will hydro-lock and blow the seals, but
other than that, there is some flexibility as to where you set the
height.

Once done, don't forget to put the springs back in before screwing the
caps back on (naw, I never did That) - as they seem to be critical for
the proper ride height.  The trick to putting the caps on is to use a
deep well socket, and using both hands while sitting on the seat, push
straight down and turn gently with the ratchet, as they will cross
thread in a second if you are not careful.  Obviously, you want some
nice thick moving pads spread across the tank when you are doing all
this.  It is easy to drop a socket, or scratch something with your belt
buckle, while distracted.

This procedure has worked well for me, and with the Motion Pro fork oil
syringe, by removing the oil-level collar, I can reach all the way to
the bottom of the forks and suck out most of the oil.  By using several
oil rinses, you can get out as much of the gunky old oil as your
patience will permit.  This is a bit easier, I think, than removing the
wheel and the bottom allen bolt, which holds in the damper rod.

Forks are one of those jobs that seem worse than they are.  Once you do
it once, you will be amazed how simple they are.

BTW, not to start a flame war, but I did the Race Tech Gold Valve
emulator thing on my Trophy, and thought it was a waste of time and
money.  The only thing they accomplish is some control over compression
damping, via adjustment of the little valve (and the RaceTech
recommended settings are always way too stiff).  They do nothing
whatever for rebound, which still uses the factory damper rods.
However, rebound, IMHO, if the more important of the two.  They do
indirectly help, I suppose, by allowing you to run thicker oil to adjust
rebound, without making the ride harsh on compression, since you can
loosen the compression valve.  Overall though, I found that just going
to 15W oil on the stock setup achieves probably 95% of the Gold Valves,
without the major headache of cutting new spacers and getting the sag
set up properly.  Just my opinion, but I wouldn't put Gold Valves in
another bike, unless I suppose I were racing or something.

Good luck,

Rick Hartwick
00 ST


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