Front shocks removal

dduelin said:

I can't speak for your dealership but Honda sells several other types of suspension fluid and they might have to order SS-7 for you or you could order it online from someone else. Fluid turns dark and gunky in use so if the old fluid will look nothing like new fluid. SS-7 is almost clear.

A PVC sink tailpiece is exactly the OD needed and every plumbing store carries them. The wall thickness of a tailpiece is shockingly thin but they are plenty strong in the ST1300 forks. The ones I made have been in use over 100,000 miles.

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Good info...thanks

dduelin said:

A PVC sink tailpiece is exactly the OD needed and every plumbing store carries them. The wall thickness of a tailpiece is shockingly thin but they are plenty strong in the ST1300 forks. The ones I made have been in use over 100,000 miles.

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Dduelin....did you use the plastic or brass sink tail piece?I saw both today...

Kevcules said:

plastic

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Only.

Kevcules said:

Dduelin....did you use the plastic or brass sink tail piece?I saw both today...

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PVC plastic.

Home Depot sells the correct stuff, but it is not in the PVC area like you would think
It was a few rows over near the gardening stuff.
Its about 12 feet long and marked as follows: JM EAGLE 1" S40 Rigid PVC conduit.
Its gray, and fits perfectly inside the fork tubes and the cap sits directly on it.
Igofar

Igofar said:

It was a few rows over near the gardening stuff.
Its about 12 feet long and marked as follows: JM EAGLE 1" S40 Rigid PVC conduit.
Its gray, and fits perfectly inside the fork tubes and the cap sits directly on it.
Igofar

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Electrical conduit is in the gardening area? Strange. things are afoot at your Home Depot.

Igofar said:

Home Depot sells the correct stuff, but it is not in the PVC area like you would think
It was a few rows over near the gardening stuff.
Its about 12 feet long and marked as follows: JM EAGLE 1" S40 Rigid PVC conduit.
Its gray, and fits perfectly inside the fork tubes and the cap sits directly on it.
Igofar

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yeah I did see some PVC conduit, but not the size I needed. This stuff was near the electrical area at Home Depot.... I should finally have some pipe and the drain bolts by the weekend.

Igofar said:

Home Depot sells the correct stuff, but it is not in the PVC area like you would think
It was a few rows over near the gardening stuff.
Its about 12 feet long and marked as follows: JM EAGLE 1" S40 Rigid PVC conduit.
Its gray, and fits perfectly inside the fork tubes and the cap sits directly on it.
Igofar

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I'm sure the SH 40 conduit works but a 1.5" tailpiece is 38 mm OD which is a perfect slip fit in the 38 mm ID fork tubes - 38 mm OD is same as the OEM spacers. 1" conduit is +/- 33 mm OD.... that's probably why your springs rattle in the forks on bumpy roads. The spring/washer/spacer stack gets out of column and hits the inside of the forks.

OK....getting closer. I couldn't find any PVC the right size and length to save my life ,but I did find some aluminum tubing. It had an OD of about 42mm and I had a co-worker turn it down on a lathe to 39mm. (39 fits in the tube) I wanted to maximize the wall thickness ,which is still good.
I made the spacers 215mm long. I want to fill the fluid to within 65mm from the top as suggested. So I added 638mm of fluid as per the manual and if I extend the tube up all the way, with the center rod all the way down. I'm about 4" from the top? (Edit-i need to have the rod and the tube down all the way and no spring inside when checking right?)

Do I continue to add fluid to get my 65mm from the top? Should I check the level with the spring inside or out?

I did go up and down a few times with the damper rod and the fluid did drop a little.

The manual says to install the spring with the tapered end up? I read here saying the tapered closer together part of the spring is down. They were down when I removed them.

To set the fork oil level:

Pump the damper rod up and down through it's full stroke until all the air is pushed out; the resistance will be smooth and even across the whole stroke when that is done.

Pump the fork tube up and down as well, to drive out any hidden air.

Compress the fork tube fully; there will be a bit of extra resistance in the last 10mm or so, which is what the oil lock pieces at the bottom do, basically a hydraulic bump stop so the forks don't bottom out with a clang and break something.

The damper rod should also be fully down.

Now set the oil height, standard is 62mm measured from the top of the fork leg.

After that drop the springs in, and you are correct the manual states tapered end up, which is opposite of all the other forks that I've looked at. No idea if Honda made a mistake or its meant to be that way for a special reason in the ST13. My logic has always been that tighter coils should go to the bottom as they get compressed first for suppleness, and the larger coils only come into play after the tight coils are coil-bound, so you get the smallest mass moving with the wheel. I can't see that it will cause any issue either way, as the spring is being compressed from both ends in a relative sense.

TerryS said:

After that drop the springs in, and you are correct the manual states tapered end up, which is opposite of all the other forks that I've looked at. No idea if Honda made a mistake or its meant to be that way for a special reason in the ST13. My logic has always been that tighter coils should go to the bottom as they get compressed first for suppleness, and the larger coils only come into play after the tight coils are coil-bound, so you get the smallest mass moving with the wheel. I can't see that it will cause any issue either way, as the spring is being compressed from both ends in a relative sense.

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As you say the spring compresses from both ends so it doesn't matter which end the tight coils are at from a spring compression perspective. What's different though is how much fork oil gets displaced by the spring coils. The tighter wound end will displace more oil and raise the oil level more compared to putting the spring in the other way around.

dwalby said:

As you say the spring compresses from both ends so it doesn't matter which end the tight coils are at from a spring compression perspective. What's different though is how much fork oil gets displaced by the spring coils. The tighter wound end will displace more oil and raise the oil level more compared to putting the spring in the other way around.

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Good point Sir. More new knowledge gained! I took a look through a few more Honda service manuals and it seems a bit random which way up the springs go. If the springs are referred to as having a "tapered" end that goes up, if the springs have a "tightly wound" end that goes down. Inscrutable Japanese devils!

thanks guys.....I put the spring back in the way it came out, tapered down. I figured out that compressing the forks fully when measuring the level too made sense. There is that resistance right at the end of the compress stroke also like you mentioned Terry.
I managed to get one shock back together fairly easily. Now for the other side tomorrow....

My 2003-2006 ST1300 Honda Service Manual states to install the springs tapered side down which I've always done in my 2005.

I use a plastic syringe with a piece of appropriate length vinyl tubing slipped over the tip to set the oil level. The tubing is cut to length to make the distance from the top of the fork tube to the oil level whatever you want it to be. Overfill the fork slightly and vacuum out oil to drop the level to the precise level you chose.

Back together and I raised the forks about 5mm above level with the top pinch bolts. I measured quickly and in the dark, without rider weight and get about 30mm of sag. I'll have to measure again when I have a chance during the day.
Would the colder weather affect my sag?

Sag is simply the distance that the suspension compresses to take up the weight of bike and rider; are you wearing heavier clothing for the cold weather? Otherwise I'd have said temperature makes no difference. If was super-pedantic, the air over the oil will be cooler and therefore at a lower pressure when cold, so you would have slightly more sag in cold weather, but I doubt it would be measurable given things like seal friction.

ok...thanks terry

I was hoping for less sag when colder. I measured about 30 mm quickly last night but I will measure again. I did raise the tubes up 5mm so I'll have to re-check the measurement without weight,then with me on it again.

Sag won't change with position of tubes in the forks because it's the difference between fully extended and compressed under weight of bike and rider.

dduelin said:

Sag won't change with position of tubes in the forks because it's the difference between fully extended and compressed under weight of bike and rider.

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You're right....but I was using my last measurement for "no weight" and i can't because i raised the fork tubes.The distance from the fork tree to the shock wind protectors is now different.
If my sag truly measures about 32mm, will I notice any real negatives while driving versus having it at 36mm? Not really interested in pulling those shocks apart again too soon.

thanks

At 172 lbs in street clothes, stock springs, and 215mm spacers I'd bet a dollar to a doughnut the rider sag will be 35mm or more.