Nitron Shock- Hoop Suspension

[Flip]

Can I ask if anyone here is using a Nitron Shock on an early Monster with the hoop type rear suspension please as I have a couple of questions for you.

[pompone]

I think Diego is but I haven't seen him around in a while..

[Rascall]

My 2001 900ie has a Nitron and a hoop

Russell

[Mr Gazza]

Utopia is your man.

[utopia]

Yes, I have one on my M750.

[Flip]

Perfect!! Thank you for replying chaps, now onto a favour if I may?

I fitted my Nitron to my 1997 M900 around 2005 and due to various reasons the bike only got sporadic use for a time during that period and only covered about 12000 miles.

Over the last couple of years I have had more time for road riding and so have decided t treat the old girl to a bit of a refresh and give it a good going over along with some upgrades etc. and as such I have just removed my shock for return to Nitron for a full service.

However, when I got it out I noticed some wear to the body around the top mounting point which look to have been made by the top linkage arm. I am a little confused as to when this has been happening as there has been no indication of it rubbing while sat on the bike, no odd noises at any point. So my conclusion is either it has only come in contact momentarily while riding as the damage isn't 12000 miles bad, OR it has only started to wear quite recently (but the lack of noises don't really back that up).

Now I have checked over the original shock that had done a similar mileage when it was changed back in 2005 and there is no sign of wear on it.

I have spoken to and sent Nitron photos and they are looking into it to see if they have seen anything like it on other Monster shocks returned for service- it is not a massively expensive part to replace (about £25) but I need to know if I need to modify the linkage a little to alleviate it happening when I refit the shock if it is unique to my bike or get them to admit there is a problem and get them to fix for free if there is wear on any other shocks.

So my favour please gents is would you mind having a look around the top of your shocks and the linkage to see if there is any signs of them rubbing even in the slightest. I appreciate this isn't the easiest to do with the tank etc. in place but worth a look if you don't mind.

Many thanks and I look forward to hearing something back!!

http://i1372.photobucket.com/albums/ag329/fluke900/Wear%202_zps9h1qbuej.jpg (http://s1372.photobucket.com/user/fluke900/media/Wear%202_zps9h1qbuej.jpg.html)

http://i1372.photobucket.com/albums/ag329/fluke900/Fulcrum_zpsco7ep7r9.jpg (http://s1372.photobucket.com/user/fluke900/media/Fulcrum_zpsco7ep7r9.jpg.html)

[utopia]

There's no marks on mine, Flip.
There is still a layer of fine dust, with no sign of it being disturbed on either side.

My shock has run with both the std hoop, and one fitted with homemade extenders which add about 20mm.

Couldn't see a part number on the rocker on my bike, but if you know where it is I'll have a closer look and check that mine is the same.
And/or I'm happy to measure stuff if it helps.

The rubbing on your shock looks to be equal on both sides, and also looks like is evenly spread front to rear, so I'm tempted to assume that this is not something that's only happening at full bump or full extension since that would make the marks uneven front to rear.
And I'm assuming that you will have already confirmed that there is no serious wear at the upper pivot.
Bit baffling, mate. But I'm sure we'll get there eventually.

[utopia]

Then, following closer inspection.....

Any chance of a side pic of your shock ?
I think the upper mount may be different on yours.
Not a lot, and not in an obviously relevant way, but different nevertheless.

btw, did you ever get that brake cable adjuster sorted on the little single ?

[Flip]

Yes I agree that the wear looks fairly even but I am certain it is not rubbing when bouncing on the bike at standstill and there are definitely no odd noises coming from it either and again I can't believe it has been rubbing badly for 12000 miles or I would have thought there would be more substantial damage.

I have checked all the pivot points and all are moving smoothly and without any free play and there were no loose bolts etc. when I dismantled the assembly.

I have sent the shock off now so these are the best photos I have from a side view but they may help you to tell if it's different. I had wondered if they had changed the design over the years (bearing in mind mine is about ten years old now) and had noticed a difference on the ones shown on their website but put it down to them perhaps being for different models.

The chap at Nitron said he is going to look into it for me but it may be relevant for me to mention the difference in design anyway and see where that gets me.

http://i1372.photobucket.com/albums/ag329/fluke900/Pre-Load_zpstudjqshr.jpg (http://s1372.photobucket.com/user/fluke900/media/Pre-Load_zpstudjqshr.jpg.html)


http://i1372.photobucket.com/albums/ag329/fluke900/Wear%201_zpsx8v54cwh.jpg (http://s1372.photobucket.com/user/fluke900/media/Wear%201_zpsx8v54cwh.jpg.html)
Onto the little single- no I haven't sorted the cable adjuster yet (so much going on with home, work and the Monster so not got round to doing much with the racer) so if the offer still stands that would be great please?

[utopia]

Ah..... as you were.
That now looks just like mine.
It was a trick of the light.

It seems to me that the rubbing can't be happening at full extension because the damage from the rocker would be one-sided rather than even.
I reckon it must be fouling at full bump. (well actually on reflection perhaps not "must", but "might")
If that is the case, I wonder whether it would still happen if hoop extenders weren't fitted ? Its hard to know without plotting the geometry of the linkage.
But as I said, mine has hoop extenders anyway, and has no such problem.
So how is your preload ?
According to my records, when I received my shock the fitted length of the spring was 145.5mm, to which I added a further 7 turns on the adjuster ring (I have no record of the pitch of the adjuster thread on the Nitron, but the original Ducati one was 1.5mm).
This is solo settings, but I have the hydraulic preload adjuster. This is set on minimum for solo, and maximum for pillion, but I didn't measure the total stroke of the adjuster as sag measurements suggested I needed all that it could offer anyway.
But getting back to relevant stuff, my minimum preload settings are as given above, and I'm a lanky, 12stone on a heavy day, with a 450 lb/in spring (turquoise) on the shock.
I mention all this because it seems like your shock may possibly have bottomed out, or nearly so, at some stage.
Have you perchance carried a pillion without increasing the preload ?
Shouldn't really happen anyway I guess, but somethings clearly going on, so I'm just trying to chuck as much as I can think of into the mixer.

Tank happens to be empty at the mo, so I can easily lift it and have a closer look if you need.

And re the adjuster.
Did I have specific details ?
I can't remember now, sorry, but was thinking I hadn't.
I'm busy for a few weeks really, but could do it after that, or maybe reschedule if you're in a hurry.

[utopia]

And ....I've just noticed, I do have the stroke of the hydraulic preload adjuster.
It was a measured 9mm from min to max.
This much extra keeps the sag figures similar for both solo and pillion.
Though naturally its only a compromise where a different spring rate is what's really needed.
But I think I can say that mine is unlikely to have bottomed out under any circumstances.

Hopefully that's not minor info overload and maybe there's something in that lot which sparks a train of thought ???

[Flip]

Well it's back with Nitron to see what they have to say and hopefully replace the damaged bit just so it looks nice again but obviously I need to find out why it was rubbing still.

I don't understand how even if the preload was backed right off (it wasn't) that anything should stop it from having the full range of movement- that would be worse than the old Suzuki TLS where the rotary damper worked against itself to allow a correctly adjusted drive chain to tighten enough to stop further suspension movement which resulted in the famous tank slappers and hedge visits.

I can say there is no play in any of the pivot points and everything looks to be in good working order so I am at a loss really so I welcome any thoughts at all on what to check or look for next so this doesn't happen again please.

[chris.p]

I Might be barking up the wrong tree, but is there supposed to be two top hat type washers/spacers that fit into each end of the shock eye????

[Flip]

I Might be barking up the wrong tree, but is there supposed to be two top hat type washers/spacers that fit into each end of the shock eye????

Indeed there is- they were already bagged and tagged when I took the photos but thanks anyway Chris.

[utopia]

I don't really see how its likely to be due to insufficient preload either, tbh.
Its just that it was the best idea I could come up with.
If there was any logical thought behind it at all, it was along the lines of.....
When they machine the rocker arm, the critical dimensions are the relationship between the three pivot bores.
Maybe there is some scope for the outer surface of the forging (?) to be less accurately positioned, and you've got one on the extreme of the tolerance ?
Couple that with the possibility that the top of the Nitron shock is a slightly different shape to the original.
Add in the hoop extender factor.
And maybe there's enough accumulation of small issues to cause the problem.
I agree though, that all does sound a little contrived, but .........??????

Those marks must surely be caused by the end of the rocker when the suspension compresses though, mustn't they ???
It can't be anything else, can it ???

Other bizarre notions.....
Has your spring gone weak ?
Has the lower spring mount failed somehow ?
Has the compression damping disappeared ?

I'm not convinced by any of those either really though.

But....
if the upper bearing on the shock is fine, then it virtually HAS to be something along the above lines, doesn't it ?
Are there any witness marks on the end of the rocker ? Can't really tell from the pic.

[chris.p]

Indeed there is- they were already bagged and tagged when I took the photos but thanks anyway Chris.



Just checkng, as my thoughts was without them, that is what could have caused the contact between the rocker and the shock top.

As that is not the case, check with Nitron, that it is the correct shock parts for the bike.

[DrD]

http://i1372.photobucket.com/albums/ag329/fluke900/Fulcrum_zpsco7ep7r9.jpg (http://s1372.photobucket.com/user/fluke900/media/Fulcrum_zpsco7ep7r9.jpg.html)
The greasy arc at the inner leading edge looks like a wear mark to me.
What is it like once clean?

[Rascall]

Checked mine tonight, no sign of contact with the rocker

Russell

[chris.p]

I could be barking up the wrong tree yet again, but here we go.

Take a look at the picture you provided of you shock , now take a look at the shock pic from the Nitron web site.

http://www.nitron.co.uk/pwpcontrol.php?pwpID=17761

As you can see, the pic from the website shows a different length from the top of the shoulder to the bottom of the mounting eye compared to picture of yours.

Like I said , I could be barking up the wrong tree, but they are both different.

[Flip]

The greasy arc at the inner leading edge looks like a wear mark to me.
What is it like once clean?

That is where it has touched but the rocker isn't massively deformed from the contact so I can't believe it has been like it for 12000 miles.

I could be barking up the wrong tree yet again, but here we go.

Take a look at the picture you provided of you shock , now take a look at the shock pic from the Nitron web site.

http://www.nitron.co.uk/pwpcontrol.php?pwpID=17761

As you can see, the pic from the website shows a different length from the top of the shoulder to the bottom of the mounting eye compared to picture of yours.

Like I said , I could be barking up the wrong tree, but they are both different.

Yes I saw that on the website too and did wonder but also thought it might just be a generic photo or perhaps not for a Monster if they do vary the top mount model to model?

Perhaps I need Kato or someone to go through the workings of the suspension mechanism as to how raising the rear by turning the rod ends out has an effect and whether or not anything 'should' come into contact at any normal working angles?

[Flip]

Right then here we go....

To confirm there is nothing wrong with any suspension linkages etc. on my Monster I had an email today from the chap dealing with this matter at Nitron who has told me that they have indeed updated the design of the shock mounts since my shock was made and it is their conclusion that that is the reason behind the clearance issues I have experienced. In addition to that there have also been some other changes to the specifications and they have offered to replace the damaged part and carry out all the upgrades to the latest specification completely free of charge- I am only paying for their full service and a Turquoise spring which I had originally ordered.

So let me just reiterate, they OFFERED (I didn't have to ask or threaten or anything) to carry out the work to correct and update my shock as part of the service which I think is pretty bloody good on what is a ten year old, 12000 mile shock!!

Anybody thinking of replacing their rear shock????

Simply go here:
http://www.nitron.co.uk/pwpcontrol.php?pwpID=17756

[Dirty]

Sign of a quality company

[Wildfire]

Agreed, great show from Nitron. Just wish my insurance co's customer service was as good. I'll be going to Nitron for my MV if it ever gets back on the road and my TVR when I get around to it.