fork oil leaking

Question
QUESTION: Hello

I have an 11 years old KHS comp full suspensions RockShox Duke XC, 4".   I always park it up side down, on its handlebar and seat when not riding. Never leaked in 11 years.   Recently started leaking oil  from the front suspensions. I  Called and made an appointment with shop mechanic.  However, he is telling me ( on the phone)  that if I keep park the bike like this, it will continue leaking and it is not good idea...

What is the best way to park it ( hanging it from the ceiling is not an option for me)  ?  

Any way to avoid it in the future ( oil leaking)  -  extra sealing?   if I keep park it on its seat and handlebar which I think is better...

And, could I do this basic maintenance on my own? is there any good guide on the internet? And, how often should I do it if the bike is parked in the garage and I do only light trails, maybe several hours a week?  

Thank you?   Gabe?

ANSWER: Gabe,

I am going have to agree with the mechanic and this is not the best way to store a bike with an air/oil shock. What I think has happened is that the top seal of your shock has started to "go" and is now leaking. However, I do not think that storing your bike upside down caused the leak, rather time and wear did and it was going to happen sooner or later no matter which way you stored your bike.

The reason I don't think that storing a bike upside down with your shock is good is that you are forcing the air to what would be the bottom of the shock and the oil to the top - directly opposite of what it should be. In shocks there are a series of valves that control rate of oil passage - this is the shock absorption. The air in your shock acts as the rebound and forces the oil back through the valves. Storing this system upside down I don't think would be good for it. (However 11 years seem to beg to differ - I still wouldn't do it.)

You will need to get you shock rebuilt with new seals put in. This should stop the leaking, which would have started to show up after your rides. (Caveat! If your sliders/stanchions have developed tiny grooves in them then new seals are not going to prevent the leaking, slow it down maybe...) There really is no such thing as "extra sealing" as things a pretty specific to the design of the shock. A boot, and I can't recall if the Duke still had boots over the stanchions, would only hide the leaking.

Rebuilding shocks is not for the back yard mechanic. However, it is not that hard if you have a few specialized tools (snap ring pliers comes to mind along with a shock vise) but it is tedious work that one has to take their time on.

Have you considered a bike rack that holds the wheel, or a wall mounted bike rack such as a Racor system (I have no affiliation with Racor)? A bike resting on its seat and handlebars might be stable, but, again, I don't think it is best for your shock.

Oh, how often to have your shock rebuild? I think manufactures suggest something like every 100 hours of riding. On my personal bikes I have rebuilt exactly one rear and one front shock... and that is only after they started to leak. Not factory specs but real world reality!

One last thing if you do decide to store your bike upside down I would wait about a half an hour at least before you ride just so the oil settles back to where it is suppose to be.

Best of luck!

Tad

---------- FOLLOW-UP ----------

QUESTION: Hello again

I understand.  So, is it perfectly ok to park it on its wheels?  Sometimes I will ride for a few days or even  few weeks or more...  Is it ok for the tires, shocks etc?  

I will see reg. the stand that you suggested.  Just need something inexpensive I guess...  

Thanks again,     gabe

Answer
Gabe,

I think you could find debate no matter how you store your bike depending on who you talk to. I have heard some people argue that you should never hang a bike by its wheels because they will deform (I have never seen it happen, even in bikes that have hung for years). I can see some arguing that you should not hang a bike by its frame if you have suspension since it is putting a negative weight on the shock(s). And I can imagine the argument for not storing it on its tires; but I have never seen that to be a problem.

The only problem that I thought could be a problem is storing a suspension bike upside down and if you did it for eleven years with not a problem, until now, that argument may also be moot.

Just for fun I took a look at the owner's manual for the Duke. According to the manual you should change the oil every 100 hours - not rebuild as I stated before. There is nothing in the manual warning about storing the shock upside down. I would think if this would be a problem it would be there in big bold letters.

I also gave a call to an old friend who used to be a tech rep for another major shock company. He agreed with me about reversing how the fluid is positioned if the shock is upside down but he recommended a 15 minute waiting period before riding. He didn't see a problem storing a bike upside down "if the seals are in good shape." He did say that he wouldn't store it that way for a long time but they used to transport demo bikes in a trailer hanging by the wheels and never had a problem. He did say that they would always check for fluid seepage and check the air pressure before the bikes were released for riding. Company liability I guess. (He also said I still owe him a beer on a bet we made years ago, but I remember it the other way around!)

So, Gabe, I think it comes down to what you feel comfortable doing. I can find no evidence that how you are storing the bike is wrong. I still wouldn't do it because I wouldn't want to scuff my saddle or handlebar grips, but that is just me. I think that the way that you do store your bike did highlight the fact that your seals are going bad; something you may not have noticed for a long time if you stored it upright.

If you really want to put an end to the argument give Rockshox a call, or better send them an email. Then if we are both correct that there is nothing wrong storing a bike upside down you can take a copy of the email into the mechanic and set him/her straight.

If you do get in touch with Rockshox let me know what they say... I would be very interested myself.

Best,

Tad