Evenin' All...
Well you know what they say when finally it seems all is going will
.....this from this morning
Decided to go into town this morning and when I parked the bike noticed oil dripping on the pavement...initially thought it to be brake fluid, but a finger dip put paid to that
Now I am getting some help from my local motorcycle repairer with this bike and although he put this seal in I don't blame him for its failure...it appears the seal may be dry and during the
removals-n-installations of the stanchion since the seal was put in, I have no doubt the stanchion has been rotated and has picked up the seal...can happen...an unintended consequence
Anyway moving on...
(Hope photobucket eventually turns these pics the right way up)...OK, if you wish to add more pre-load packing to the left (rebound), leg with it insitu, it can be done thus. But it is difficult and for the sake of removing 3 more screws you cane work on it thus...
...just be sure the stanchion doesn't slide back into the fork body...it is much easier to work on held in a soft jawed vice.
OK if you feel you have to add packing to this leg, then these 2.25mm x 37mm washers are a good way to go. In this case I added a packing just for demonstration purposes only. The 5mm turned
packing I added to the Right (compression) leg (which also happens to be the leg that popped its seal this morning), was more that adequate in achieving the
static sag of 20-25mm I set out to achieve.
Ok so now for the first of the unintended consequences...
I have loosened the spring pre-load to it's lowest physical limit without having it rattle about, which worked out to be 203mm...another bit of trivia I worked out was 1 complete revelation of the pre-loading nut, shortened (or lengthened), the spring by 1 to 1.5mm.
In a previous thread I stated the above after spending a day fitting the Progressive rear I got off flea-bay...Now if you read this sentence and wonder "
what the hell is he trying to say"...I now have to join you
Because it has
absolutely no relevance whatsoever in setting up the rear shock at all...but it
DID produce an
unintended consequence 
By lengthening the spring to
203mm I effectively
increased the
static sag to such a level I not only
un-loaded the front suspension, but in all likelihood
added camber to the overall rake angle and thus softened sharpness of steering
...now I didn't realise this at the time...I HAD TO BE SHOWN this by the friendly motorcycle repairer
Static sag. Static sag I am reliably told is the distance the bike drops when it supports its
own weight from distance it was, with its wheels off the ground. Simple enough concept to get I thought. So what is that ideal distance then?
Well, I really don't know. However, there is a chain of thought that that distance should be around 1" or 25mm. As I said I really don't know what is optimum for a 300kg ST, but I have to start somewhere, so
20mm became my goal...beginning to sound a familiar distance now?
I did NOT set out to add packing to the front forks, until I got the static sag to 20mm on the rear.
The above pic shows (in part), how I got to get that 20mm static sag on the rear shock. Other items I need was a tape measure, 2 reference points and a willing Wife. The Wife is importance, because she and she along will be responsible for ALL measurements...so no pressure here then
The red tape at the corner of the pannier cover flap was her
top reference or reading point (Oh, I forgot 1300 don't have a nice neat pannier cover, do they
)...the bottom was the end of the tape measure in the
dimple of the axle, RIGHT side. The unweighted measurement is taken with the bike on the centre stand and all other measurements were taken with the bike on its wheels with moi holding it level, while
off the bike. I simple wound up the preload until I go the bike to sag only 20mm, under its own weight.
And before you ask....
- YES, factors like amount of petrol in the tank and whether the bike had just been ridden, did all effect the static sag. I have chosen as my
starting reference to measure a cold bike with a full fuel load.
- YES the ride is quite firm. I am about 75kg, a Senior citizen with a Corbin saddle that has probably seen better days...YES AJ, Baz Bugle player et al , anything that has had to look at my arse for 17 years has had a hard life in itself.
- YES I will in all likelihood continue to play around with
tweeking withe front stanchions, may even try varying oil weights in each stanchion (have done so in the past), but not in conjunction with spring pre-loading
- NO I wont be repairing that popped seal, I will leave it for my motorcycle repairer. He has a lot of suspension experience and I want to learn more.
- ? will I replace the spring on the Progressive. Perhaps.
Just one other point for this post is: When I refer to LOW or HI-SPEED speed damping I am referring to the suspension speed and
NOT the bike speed.
Ok, all for now...will add a bit further in a week or so.
Cheers the can :-)
