Help with Roadwing issue

[matthewd92]

So I did all the research on here regarding the rear shock on the RS being too weak if you are larger (300 lb, 6'4") and decided to go with the Roadwing setup. I found the instructions to be clear and easy to follow and got it all installed over the weekend. Finally got to take it for a ride today and on the way to work it was freaking awesome. Bike rode so much better, could not believe how nice the ride was. On the way home though I lost all of the preload, figured it was a bleeding issue and that I had gotten air into the system or something. But when I jacked up the bike so I could check all the fittings I noticed oil coming from out of the rubber boot that goes over the preload adjuster. I also found that the pump was totally empty as I had tried adding a little more preload on the way home. I refilled the system and energized it and when I did I could hear the oil coming out of the preload adjuster.

I took the shock back off the bike, took the spring off so that I could get the preload adjuster seperate. I then filled the pump back up and applied just a little pressure to get the adjuster to move, I then was able to squeeze the piston back into the adjuster and oil just leaked from all around the piston.

So the question is do I have a bad preload adjuster and there is nothing that I can do without buying a new one or is this repairable. I have tried searching the forum and internet and I cannot find any information regarding this issue. Any advice is greatly appreciated.

[matthewd92]

So I found the issue, does anyone know if the inner seals on the piston can be replaced? You can see here the outer seal is broken, the inner seal is really brittle as well.

[Shores]

Wow never heard of that! Call Honda to see if you can get just the parts you need.

[matthewd92]

Going there tomorrow actually as the local Yamaha/Honda dealer is installing a new rear tire on the bike. Just reinstalled the original shock back into the bike until I am able to figure out a fix for this or find a used one that is in good shape.

[Doc_V]

The shock is made by Showa and yes, they can be rebuilt. Check on line for rebuild kits or check your area to see if you have someone local who rebuilds them.

[matthewd92]

Went to Honda this morning, there is not a Honda kit for rebuilding the preload adjuster cylinder. Will need to source the shaft and cylinder seals somewhere, guess I will need to get out the calipers.

[Brad_G]

That's too bad it can't be that easy. There are many here that run that exact setup. Keep detailed notes on what you find and part numbers. It may be a very vital piece of information for other here at some point. Thank you.

[Smokescreens]

i ran into about 3 off those so far. i had to eat the cost of them as i never was able to find a seal for it. what i ended up doing was selling them cheap as non adjustable shocks. but i could have put a spacer in there cheap and easy to add the preload as well. there are places that will rebuild them im sure but i doubt we can buy just the two seals for that piston.

[davej]

I Don't know where you live but if there is a hydraulic cylinder rebuild shop near you they may be able to help with what you need.

[Doc_V]

Good point, hydraulics is hydraulics.

[matthewd92]

So I was able to finally get some seals for it. Worked with the local Parker Hose shop and we figured out which o-rings would do the job. We wound up with 2 o-rings in both the inner and outer piston grooves as a single o-ring while the right diameter had too much groove. We used a thinner o-ring of the same inner diameter to act as a backing ring. I have part numbers for all of the o-rings we used.

Here’s a couple of pictures of the assembly with the o-rings installed and of the o-rings themselves.






Was able to get all back together this evening. No leaks and it’s a nice tight assembly now. The hardest part of the entire fix was getting the spring off the shock and even that wasn’t too hard. Used the jack and strap method and didn’t take long to get it off and even faster going back together since I now knew what I was doing.

Overall if you have a leaking pre-load adjuster this is not a hard fix at all.

The o-ring seal numbers we used are:

Piston OD, 1 each of 141 and 036
Piston ID, 1 each of 134 and 032
Cylinder ID, 1 of 134

The great thing about going to your local hose shop for these things is they can also make you a new hose assembly if you need. The fittings for the hose are 8mm banjo fittings. I’m going to have them make me up a new hose assembly as I wound up mounting the pump in my left hand saddle bag. There was too much electronics under the right cover to get it all to fit. I’m even thinking of adding a hydraulic quick connect fitting so if I need to drop the saddle bad for any reason I can quickly disconnect the hose and not lose any pressure or fluid.

Took the bike for a quick trip and man what a difference it really makes on the ride. My ride to the office last week was awesome. I could definitely tell how much better the shock was so I was really bummed when the seal failed. I’m all happy again though.

[Aussie John]

[Brad_G]

matthewd92, nice! Thanks for taking the time to explain everything and add the pics. I'm sure it will be helpful to others over time as well.