Fork too hard after seals

STmark1300

STmark1300

Ron
Joined
Apr 2, 2012
Messages
174
Location
Council Bluffs IA
Bike
ST1300
This past fall I replaced the front seals. I am thinking they are harder than I like. Is there an easy way to adjust it? Can I pull the wheel and drain out of the bottom screw? Or with a turkey baster pull out the top? What's the easiest way to soften it?
 
You'll have to access the fork oil from the top of the fork. The ST1300 doesn't have a drain screw. The bolt in the bottom is holding the cartridge in place. If you're confident you put the correct amount in during the fluid change then I think your best option is to use a lower viscosity fork oil. Others can comment on the effect of lowering the fork oil level as I don't know all the things that might affect. What type of fork oil did you use?

I switched from Honda 10w to Bel-Ray 10w based on the numbers posted on Peter Verdone's wiki and local availability. With Honda 10w oil I felt the forks weren't compliant enough and transmitted too much impact up to the front end. With the slightly lighter Bel-Ray fork oil the feeling is quite a bit smoother, even with the heavier RaceTech springs I installed at the same time I made the switch.
 
The proper amount of oil needs to be in the forks, taking oil out will not soften the ride unless it is over filled. What oil weight did you use and how much is in each fork.. Right and left take different amounts depending on model:think1:
 
I think the only way to change the oil will be to pull the forks. When doing an R & R, you pour out the oil then pump the fork to get any residual oil out of the cartridge (while the open end is over your waste oil container). It will be very difficult to get most of the oil out with the forks still on the bike. You might pull the caps and use a hose to suck out as much oil as you can. If done carefully, and measured, you will know how much oil you can add and thus calculate the approximate oil weight of the resulting mix. For example, if you used 10 wt oil the first time, then remove half of it and replace that with 5 wt oil, your mix will be approx. 7.5wt. This is going to be a bit messy and might not give you the results you want, especially since pulling the forks is not really a big deal.

Short cuts often are not so short....
 
And if you are going to pull the forks to fix your oil problem I'd highly suggest you get some RaceTech (or other) fork springs to put in your forks.
Huge difference.
 
I felt the forks were a bit harsh in stock form so I settled on a mix of 2 parts Honda's SS-7 (nominally 5wt) and 1 part Honda SS-8 (nominally 10 wt) to a stock height of 62 mm. Weight is not a very good indicator of how oils will act in a fork but are useful when using comparing oils of the same brand.

The springs are too soft for anyone over 165 lbs or so so you might want to look into using longer spacers if you are light enough or stiffer aftermarket springs if you are more than 165 lbs. The springs aren't the problem with harshness though, it's the valving in the cartridges. An alternative for lighter riders is to use a slightly lighter oil to ease the compression damping and get the sag right so the forks won't bottom out. For heavier riders stiffer springs and softer valving will get the bike working in the middle part of the suspension travel and soften the ride.

The forks really need to come out to properly drain the oil. The cartridges retain a lot of oil and a turkey baster or a tube snaked down from the top can't get the oil out of the cartridges.
 
I used the Honda Manuel. Oil was 62mm from the top. The oil I used Pro Honda SS-8 10w. There was an extra 1" spacer added not in the Manuel so I took it out. What is your thought about this fluid?
 
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The 1" spacer was probably there to get the ride height correct for a previous owner. Spacers don't stiffen the ride but rather increase the ride height.
 
That is weird. As I posted in the other forum I had dealer change mine with the same Honda 10W fork oil and my bike rode the same. I'd put that spacer back on there. That's why I don't like buying used bikes cause you never know what the previous owners have done to it.
 
Just found my repair order. ss8 is 10weight. I think that the standard weight.....damn also see where they charged me $137.00 back in 2009.
 
You can slide the forks up in the clamps to get back some of the ride height the spacer increases. My inseam is 29".

Rider weight is great importance to choice of spring. Two of the spring sellers have spring calculators based on rider weight and cargo. The bike weight is a given.

This chart helps choose oils based on centistokes at 40 degrees C and the two VI columns. Find that of Honda Showa Suspension Fluid SS-8, look at how it rates, and pick one with a lower number in the Centistoke column that has the two VI numbers relatively close to each other. Or blend Honda SS oils to get the characteristics you want. It takes the better part of three pints to do both legs so it was easy for me to blend 2 of SS-7 with one of SS-8 to get a blend about 6.7 wt.

http://www.peterverdone.com/wiki/index.php?title=Suspension_Fluid
 
When you say the fork feels too hard, what are your symptoms? Maybe with the spacer removed, you are now bottoming out where previously you weren't. Put a cable tie around the fork tube and take a good ride, then see where the cable tie ends up. From that, plus the stated travel from the manual you can work out how much of the available travel you are using.

The oil height can be used to increase/reduce bottoming resistance by making the compressible air gap over the oil bigger or smaller.

Fresh fork seals can feel a little stiffer than old ones as they will have a little more stiction until they bed in.
 
Is it common knowledge that the ST Manuel is wrong on fork fluid? I am not light, and not average in weight 240 now, so I would think I would be in range with Manuel recommendations.
 
STmark1300 said:
Is it common knowledge that the ST Manuel is wrong on fork fluid?
Click to expand...
I just changed my fork fluid and seals for the first time last year (due to leaking) and went strictly off the service manual for oil type. Afterwards I felt the bike rode much better and straighter with less drift to the right, and of coarse without any seal leaks.;)
 
ST-Traveler said:
I just changed my fork fluid and seals for the first time last year (due to leaking) and went strictly off the service manual for oil type. Afterwards I felt the bike rode much better and straighter with less drift to the right, and of coarse without any seal leaks.;)
Click to expand...
So If you used Honda oil specs I did something wrong. --Unless previous owner set up springs for 2 up or much more weight.
 
If you measured oil quantity by volume, did you make sure to pump the cartridges fully? It takes a lot of pumping. If you measured by height did you make sure the fork was fully collapsed when measuring?


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