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Discussion Starter · #1 ·
Tried adjusting my suspension this weekend and came across what I perceive to be two issues:

1. Tension Nut is nylon coated instead of aluminum like the locking nut. Shop manual shows the tension nut as aluminum which is odd that it's not that way on my bike.
2. Furthermore, the tension nut seems to have been mounted cockeyed on the shaft of the rear shock so that when you tighten down the locking nut, the front end of that locking nut hits home before the rear portion, leaving a gap between the two.

So which should it be - nylon or aluminum for the tension nut? And for those who have adjusted their suspensions, are both nuts parallel? Need some help before I call the dealer. Sorry guys but this is getting a little old.

Stuart
 

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Re: Suspension Tension Nut Issues

Might help if you mention year and model of bike... stock shock?

Unclear what you're up to...

Are you trying to adjust preload? If so the adjusting ring/nut and lockring/nut should (obviously) be parallel. If they are not, something is amiss. Hard to speculate without more info.
 

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Discussion Starter · #4 ·
Re: Suspension Tension Nut Issues

Sorry - 2007 S4Rs - stock Ohlins rear shock and yes, we were adjusting the preload. I agree that the locking/tension nuts should be parallel but before I call the dealer, would like confirmation from someone else.
 

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Re: Suspension Tension Nut Issues

Yes, yes, more info please, we are intreagued.
 

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Re: Suspension Tension Nut Issues

Locking ring is plastic. But it should be completely parallel and flush. I posted up about the plastic ring when I got my bike because I don't like the fact that the Ohlins spanners chew into the plastic. Want to either replace with aluminum ring or get a rear shock with remote preload (which is better anyway if you regularly ride with a passenger).

Chris
 

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Re: Suspension Tension Nut Issues

1. Tension Nut is nylon coated instead of aluminum like the locking nut.
Locking ring is plastic.
::) cheezy... (Penske) ;)

Well something doesn't add up here unless the OP's shock has the rings on in the wrong order. If the rings are on in reverse order the nylon ring could strip, get cross threaded if being used like an adjusting ring.
 

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Discussion Starter · #9 ·
Re: Suspension Tension Nut Issues

Guaranteed that the tension nut is made of nylon and the locking nut is aluminium. And really, how much more would it cost to have used two aluminum nuts? Sometimes companies cut costs in the total wrong place. BTW, the tension nut is NOT stripped, it's just not mounted correctly - extremely weird & of course, very frustrating.

Stuart
 

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Re: Suspension Tension Nut Issues

Stuart / Chris / Other S4Rs owners..........

The Nylon/Plastic nut on the rear shock was designed that way on purpose. The Nylon nut is not "LOAD BEARING", it is simply a locking nut and does not need to be made from Metal. [laugh] All it is for is to prevent the lower Metal load bearing nut from backing off. [thumbsup]

Metal lock nuts if tightened too much or not adjusted for long periods of time can seize so tightly that it's a real BITCH to get them apart to adjust the rear preload. Scraped knuckles and allot of cussing were the norm if you needed to adjust your rear preload on the road and the Metal to Metal nuts had seized. :p :-X

The Nylon locking nut should be tightened until snug. If you are tightening it enough to cross thread it, or that your wrench is cutting into it, THEN YOU ARE TIGHTENING IT TOO MUCH! :eek: :p

Relax Guys, and enjoy the engineering for what it was designed for. [cheeky]

~Steve ;)
 

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Re: Suspension Tension Nut Issues

I'm not tightening it enough to have the wrench chew into it due to that force... the problem is that the wrenches from Ohlins have a little nub on them so that you can use them in either direction.

The distance between the hook on the wrench and this nub is so ever slightly smaller than the distance between the lugs on the nylon ring. Thus the wrench "clicks" into place and tears a little bit off the nylon ring every time. I have two wrenches and they both chew up the nylon ring.

I know the solution is to take the dremel and remove some of the metal from the wrench, but I haven't done it yet.

I adjust mine frequently enough that a metal ring would be preferable, but I don't care all that much. Idealy a remote preload adjuster would be great... maybe when it's time to rebuild/replace my shock.

I believe Stuart's ring was fubarred when he got it, not from him screwing with it.

Chris
 

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Re: Suspension Tension Nut Issues

Shadowchaser:
The Nylon nut is not "LOAD BEARING", it is simply a locking nut and does not need to be made from Metal. All it is for is to prevent the lower Metal load bearing nut from backing off.
Stuart:
Guaranteed that the tension nut is made of nylon and the locking nut is aluminium.
Yeah but... Stuart keeps saying his TENSION ring is nylon and you other two are saying the opposite. So either his rings are on in reverse or he is cornfused about which one is the Tension and which is the locknut.
 

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Re: Suspension Tension Nut Issues

Hey Chris.

I hear ya remote preload would be the handiest. [thumbsup]

I just got off the phone with Stuart.............His shock was evidently put together "bas akward". :p On his shock the Nylon nut is on the bottom and touches the washer and the spring directly. His Metal load bearing nut is on top! No wonder it is stripped. He's calling the dealer to get the whole shock replaced under warranty, due to manufacturing defect.

I wonder who's fubar it was Ducati, or Ohlins? [cheeky]
 

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Discussion Starter · #14 ·
Re: Suspension Tension Nut Issues

On Steve's recommendation I'm posting a picture to show everyone what they should NOT have. The tension nut (aluminum) should be on the bottom and the locking nut (black nylon) should be on the top. Of course in the interest of science, I like to be different :-\ so I ordered my special from Ohlins. (the basbackwards version) Also note that the spring perch is also bent and needs replacement. I went to the parts catalog and noticed they do not have either the tension or locking nut listed with a separate part number. I'm guessing they are going to have to replace the entire shock absorber - which would obviously be my choice.
 

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Discussion Starter · #15 ·
Re: Suspension Tension Nut Issues - Photo Added

Now I'm totally confused - called two three different dealers and they all confirmed that the nylon nut is lower then the aluminum nut. Go figure, unless we're all dealing from the same bad batch. (sounds doubtful) Would other S4Rs owners please take a look and report back what they have? Shop manual was no help as it shows two aluminum nuts - no nylon at all.

Stuart
 

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Re: Suspension Tension Nut Issues - Photo Added

I don't know. That just plain, flat out, looks wrong to me. I mean real wrong. That'd be some tough stuff nylon nut to compress that spring and those threads are too fine to support the load. IMO. Send that picture to some Ohlins experts and see what they say.
 

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Discussion Starter · #17 ·
Re: Suspension Tension Nut Issues - Photo Added

Couldn't agree more - doesn't make sense too me either. Yet I called three different dealers and they are all exactly the same - nylon nut applying the tension.

Stuart
 

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Re: Suspension Tension Nut Issues - Photo Added

That's the first application I've seen with a nylon nut. Interesting.

Even though it looks wrong, there is some engineering science involved in putting the nuts in that order. Something I learned working around ships and large boats and naval engineers that knew their stuff...

The nut closest to the spring actually gets "unloaded" quite a bit when the outer locknut is tightened against it, thus transferring most of the clamping load to the outer nut. The inner nut is literally floating on its threads as the force vectors from the object being clamped and the outer nut are pretty much in equilibrium. It is for that reason on marine applications that a propeller is properly installed on a shaft with a thin nut closest ot the prop and the full thickness nut on the outside. Because the outside nut is actually doing all the clamping once it is tightened. You'd be surprised how many people can't or won't understand it, but it is in the naval engineering manuals for good reason.

On a coilover spring you would need the same thing - the softer nylon nut next to the spring and the metal nut on the outside.
 

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Discussion Starter · #19 ·
Re: Suspension Tension Nut Issues - Photo Added

Thanks Mark - I appreciate an intelligent explanation and yours is the first I've heard. Any idea as to why the nylon nut got cockeyed on the shock body? Mechanic told me once most of the load is backed off, you should be able to adjust both nuts by hand and trust me, that wasn't happening on the nylon nut.

Stuart
 

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Re: Suspension Tension Nut Issues - Photo Added

Well I'm no engineer, but it seems to me that Mark's theory is misapplied here. It may be true that the "outer" nut accepts the load when they are locked together, but when adjusting the preload the locknut is loose, not in contact with the nylon nut. So ALL of the load is on the nylon nut during adjustment, and it sure looks to me like it can't take the pressure... either that or it was cross threaded from the get go.

And what about Shadowchaser's bike that apparently has the nuts in the opposite order?

HAs anyone called Ohlins?
 
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