Strange shock behaviour

[Bassmatt]

I replaced my shock a couple of years ago and had the new one sprung correctly for my (then) weight.
I lost some weight on purpose and then got quite crook and lost a whole lot more.
I'm currently about 18-20 kg under the weight that the shock is sprung for.
So as I expect when I hit big bumps I nearly get thrown off the bike.
But the strange thing is now my number plate which is on a home made tail tidy is being hit by the back wheel at some point when riding and is getting folded up under the bike
How does this happen? I'm lighter so the shock shouldn't be able to compress as much - surely? This never happened when i was fatter.
Theres no fluid leaks or anything, the shock seems fine otherwise.
Whats going on?

[Big Dog]

Perhaps your home made tail tidy has folded down a little from the bouncier ride?


Stupid phone / Tapatalk, apologies in advance.

[Big Dog]

Also the bounce rate should be being restricted by your shock. Is it?


Stupid phone / Tapatalk, apologies in advance.

[T.W.R]

Maybe it's nothing to do with the shock.... chain stretch/adjustment, wheel is now further back in the swing-arm and what was once adequate clearance is now gone :msn-wink:

[pritch]

Maybe the shock being outside its normal operating range is causng the linkage to behave strangely? Speak to whoever you got the shock off?
Let's know what the answer is when you find out.

[Shaun Harris]

GAS pressure in shock is gone, causing it to blow through its stroke MOST LIKELY. What brand of shock and was it new or used when you fitted it?

[AllanB]

Maybe because you are not so fat you are going faster .....

[Bassmatt]

GAS pressure in shock is gone, causing it to blow through its stroke MOST LIKELY. What brand of shock and was it new or used when you fitted it?

Yss. New on bike 3 yrs ago .Serviced about a year ago. How would I check the gas pressure?

[Bassmatt]

Also the bounce rate should be being restricted by your shock. Is it?


Stupid phone / Tapatalk, apologies in advance.

Dunno, tell me more about this

[Shaun Harris]

Yss. New on bike 3 yrs ago .Serviced about a year ago. How would I check the gas pressure?



It needs to be taken to some one up there that has the correct tools to check it over. Norm Cobb in elersley possibly. Yss are an ok commutor shock, but not to good in the build quality dept though, so from what you have said, I am Confident it has lost it's gas pressure.

[Shaun Harris]

Also the bounce rate should be being restricted by your shock. Is it?


Stupid phone / Tapatalk, apologies in advance.



what do you mean by that mate?

[nodrog]

how far does it go down when you sit on it?

I think Shaun is correct (fuck that hurt).

[Bassmatt]

. Yss are an ok commutor shock, but not to good in the build quality dept though, so from what you have said, I am Confident it has lost it's gas pressure.

Build quality is shit alright, it started leaking oil pretty much right after I bought it and it was "serviced" last year because it shat itself and dumped all its oil. Theres a yss authorized dude near me who serviced it last time he said they used crap seals and reckons he put better ones in for me , I guess ill have a chat to him.
Please tell me regassing it is cheap.

[Big Dog]

what do you mean by that mate?

That the shock absorber does the shock absorbing.
The spring does the springing.
That it sounds to me like the shock is not taking the shock out of the stroke, causing the pogoing he refers to.

The why of it is difficult to diagnose for a an amateur like me without seeing oil running out somewhere or the like.
Your gas idea sounds like a better track than that the spring was sprung for someone heavier by only 20 kgs.



Stupid phone / Tapatalk, apologies in advance.

[buggerit]

I replaced my shock a couple of years ago and had the new one sprung correctly for my (then) weight.
I lost some weight on purpose and then got quite crook and lost a whole lot more.
I'm currently about 18-20 kg under the weight that the shock is sprung for.
So as I expect when I hit big bumps I nearly get thrown off the bike.
But the strange thing is now my number plate which is on a home made tail tidy is being hit by the back wheel at some point when riding and is getting folded up under the bike
How does this happen? I'm lighter so the shock shouldn't be able to compress as much - surely? This never happened when i was fatter.
Theres no fluid leaks or anything, the shock seems fine otherwise.
Whats going on?

The missus has put on 40 kg?:shutup:

[nzspokes]

That the shock absorber does the shock absorbing.
The spring does the springing.
That it sounds to me like the shock is not taking the shock out of the stroke, causing the pogoing he refers to.

The why of it is difficult to diagnose for a an amateur like me without seeing oil running out somewhere or the like.
Your gas idea sounds like a better track than that the spring was sprung for someone heavier by only 20 kgs.



Stupid phone / Tapatalk, apologies in advance.

I agree with Shaun. If the gas has gone the shock no longer has any compression damping which backs up the spring.

[Shaun Harris]

Build quality is shit alright, it started leaking oil pretty much right after I bought it and it was "serviced" last year because it shat itself and dumped all its oil. Theres a yss authorized dude near me who serviced it last time he said they used crap seals and reckons he put better ones in for me , I guess ill have a chat to him.
Please tell me regassing it is cheap.



Haha you said SHIT not me. They really are CRAPO shocks that some one is making a fortune of selling, with no regard for the crap that they are. What bike is on mate. The FACT that it has done what is done already, tells me the service should be free of charge! Or next step is contact the importer directly and ellaborate on the crap product. I personally believe in PENSKE shocks streight out of the box as they come. The internal build quality of a Penske shock is = or above any other over priced brand name on the world wide market place. I have seen a race lap record broken at Pukekohe a few years back with the shock exactually as per manufactured with correct spring rate and my final settings and sags done for the rider. And that shock was 100% as DELIVERED and fitted from the manufacture, NO need to fuk around and pull it in out and courier to some one to up speck according to what there computor data tells them to do. I am an ex rider racer, so have the feel that no one else in this country has apart from Ray Clee and his white power shocks, and have an awsome reference from one supplier in this country re my set up skills and understanding of how suspension really works.

[Shaun Harris]

Cheers for the support on my honest opinions team. Now certain shit has finally been put to bed after years and years on here, I AM BACK, and WILL be here to help people again as per when I first started in 2004 on here. I will also be doing an up spec suspension training course for penske and Traction dynamics front suspension in the USA in the next 3 months to get me back up to speed and in the modern world, and to bring home more quality spec suspension tools equipment if required for service work.

[Bassmatt]

thanks Shaun and others. I'll look into having it regassed on Monday.

[Shaun Harris]

thanks Shaun and others. I'll look into having it regassed on Monday.


welcome mate. What bike is it on

[Bassmatt]

welcome mate. What bike is it on

kawasaki ex650

[Shaun Harris]

kawasaki ex650 Hope the guys sought it out for you mate

[Bassmatt]

I've been told its an emulsion shock and if there is no sign of oil leaking ( there isn't ) then the gas can't have leaked out.
I was told to make sure the sag was 10 - 15 mm.
?

[Shaun Harris]

I've been told its an emulsion shock and if there is no sign of oil leaking ( there isn't ) then the gas can't have leaked out.
I was told to make sure the sag was 10 - 15 mm.
?


Sounds like you need to take a ride to me in New Plymouth man. I can show/ guide/advise you face to face how to set it all up properlly. For NO CHARGE as I am currently not working and on ACC due to my old injuries acting up again.

[Katman]

Sounds like you need to take a ride to me in New Plymouth man. I can show/ guide/advise you face to face how to set it all up properlly. For NO CHARGE as I am currently not working and on ACC due to my old injuries acting up again.

You sound really desperate Shaun.

[pritch]

You sound really desperate Shaun.

More like bored rather than desperate?

[Maha]

More like bored rather than desperate?

Helpful and willing to offer (free of charge) his knowledge of suspension set up.

[nzspokes]

Helpful and willing to offer (free of charge) his knowledge of suspension set up.

Which is a cool thing to do when he has much more knowledge than pretty much anybody that posts on here.

Free advice for a top IOM rider does not come along everyday.

[Shaun Harris]

Which is a cool thing to do when he has much more knowledge than pretty much anybody that posts on here.

Free advice for a top IOM rider does not come along everyday.



Thankyou Nzspokes

[Robert Taylor]

I've been told its an emulsion shock and if there is no sign of oil leaking ( there isn't ) then the gas can't have leaked out.
I was told to make sure the sag was 10 - 15 mm.
?

No that is not neccessarily so. When the shock is lying idle ( the bike not being used ) most of the nitrogen gas will be at the top of the shock, it will demulsify out of the oil. If there is any leakage path out of the top of the shock it can lose gas pressure without passing oil. Also in my experience emulsion shocks can lose gas pressure with no discernible loss of oil The other very real possibility is that there is a loss of compression dampening because the shims may no longer have enough seat pressure or there is a distorted or fractured shim. Really the shock should come completely apart and such components inspected. As to who is liable is up to everyone to haggle among themselves.
But as other people have eluded to in more brutal terms, the said shock cost a certain amount of money and what was recieved was commensurate with that amount of money. In fairness we from time to time have the odd warranty issue and even when its ''grey'' in terms of the circumstances we err in favour of the customer
We could dyno the shock for the rider but of course there has to be a charge because of our considerable investment in striving to provide a totally proffessional suspension service.

[BuzzardNZ]

No that is not neccessarily so. When the shock is lying idle ( the bike not being used ) most of the nitrogen gas will be at the top of the shock, it will demulsify out of the oil. If there is any leakage path out of the top of the shock it can lose gas pressure without passing oil. Also in my experience emulsion shocks can lose gas pressure with no discernible loss of oil The other very real possibility is that there is a loss of compression dampening because the shims may no longer have enough seat pressure or there is a distorted or fractured shim. Really the shock should come completely apart and such components inspected. As to who is liable is up to everyone to haggle among themselves.
But as other people have eluded to in more brutal terms, the said shock cost a certain amount of money and what was recieved was commensurate with that amount of money. In fairness we from time to time have the odd warranty issue and even when its ''grey'' in terms of the circumstances we err in favour of the customer
We could dyno the shock for the rider but of course there has to be a charge because of our considerable investment in striving to provide a totally proffessional suspension service.

Welcome back, but odd that you should show your face after this ( coincidence I wonder )...

http://www.kiwibiker.co.nz/forums/showthread.php/174994-Shaun-Harris-admits-to-cheating

[F5 Dave]

Ahh welcome back Robert, you have been missed here.

[Robert Taylor]

Haha you said SHIT not me. They really are CRAPO shocks that some one is making a fortune of selling, with no regard for the crap that they are. What bike is on mate. The FACT that it has done what is done already, tells me the service should be free of charge! Or next step is contact the importer directly and ellaborate on the crap product. I personally believe in PENSKE shocks streight out of the box as they come. The internal build quality of a Penske shock is = or above any other over priced brand name on the world wide market place. I have seen a race lap record broken at Pukekohe a few years back with the shock exactually as per manufactured with correct spring rate and my final settings and sags done for the rider. And that shock was 100% as DELIVERED and fitted from the manufacture, NO need to fuk around and pull it in out and courier to some one to up speck according to what there computor data tells them to do. I am an ex rider racer, so have the feel that no one else in this country has apart from Ray Clee and his white power shocks, and have an awsome reference from one supplier in this country re my set up skills and understanding of how suspension really works.

NO ONE in this country is making a fortune out of selling suspension, especially given very aggressive competition from offshore resellers working on extremely tiny margins. Of course these resellers dont plough their profits back into our local economy, they dont employ Kiwis and are insulated by distance if there are issues, which too often there are.

Yes Penske shocks are excellent quality and performance with some clever ideas but WP, Ohlins and now Nitron are at least equal in quality and have their fair share of clever ideas. WPs elliptical forks that are dong such a stellar job in Moto 2 being a prime example.

Lets take a recent example of ''straight out of the box'' in NZ. 3 weeks before the final Taupo round of the 15 NZSBK nationals we went testing there with Jaden Hassan. We had a complete set of forks ready to interchange that had the worlds only set of prototype Nitron brand cartridges in it. When installed the bike was instantly 0.5 seconds per lap faster. So going by the methodology of what has been said these were ''straight out of the box''. The reality is we had spent in excess of 90 hours over the previous winter building, perfecting and dyno developing these cartridges before they even went to a track. Of course Penske very much embrace laboratory dyno testing and so do their indycar teams who use their equipment. Each team will have mobile dynos in their rigs and a dedicated suspension engineer who will endlessly be changing internal and external settings. So for anyone at all to infer that everything is always a land of milk and honey ''out of the box'' is just plain wrong, there is ALWAYS scope for further improvement and a dedicated / committed race engineer will always be looking for that.
I remember several years ago Ben Perese ditching his ''out of the box'' Penske at Pukekohe because the settings in it didnt get on with that track. So in the absence of a Penske engineer he ran Ohlins, to better effect. Of course given time the Penske could have been revalved and the Ohlins could have been made better as well. But also of course such service would have been expected for free on the assumption that profits were so huge from just sales that such service could be free...................
Any suspension irrespective of pedigree is only as good as its settings and the tenacity of any suspension engineer to get the very best out of it. In Jaden Hassans case we knew that from that first test we could make it work better again and of course that was emphatically proven at the Taupo round. Also relevant to this he was running settings inside his Ohlins rear shock that havent fundamentally changed for 3 years. That doesnt mean it was perfect as nothing ever is

[Robert Taylor]

Welcome back, but odd that you should show your face after this ( coincidence I wonder )...

http://www.kiwibiker.co.nz/forums/showthread.php/174994-Shaun-Harris-admits-to-cheating

I can assure you this is total coincidence and if some people dont believe that Im not going to lose any sleep re same.

If this has given the owner of the said shock some direction of what it may be ( gas pressure loss as reasonably asserted by Shaun or loss of compression seat pressure ) then its all good.

[BuzzardNZ]

I can assure you this is total coincidence and if some people dont believe that Im not going to lose any sleep re same.

If this has given the owner of the said shock some direction of what it may be ( gas pressure loss as reasonably asserted by Shaun or loss of compression seat pressure ) then its all good.

I don't believe it.

That "I cheated" thread was the best one ever on KB ( i'm sure many will agree ) and it fucking sucks that it's gone and that you're back to be honest!

[nzspokes]

Ahh welcome back Robert, you have been missed here.

+1:woohoo:

[Robert Taylor]

I don't believe it.

That "I cheated" thread was the best one ever on KB ( i'm sure many will agree ) and it fucking sucks that it's gone and that you're back to be honest!

Really I dont care whether you believe it or not. I offered another very real possibility of why the shock had lost its dynamic ride height control. If that gives the owner a very plausible argument to help in seeking redress then thats very positive.
And into the bargain I spent time illustrating that in general ''out of the box'' is such a misleading marketing line
Alas, as is so common on accursed forums this could open pandoras box. Just evidence the 90 or so hours spent on developing some cartridges with no inclination to go near this forum, look how productive that was!!!! Tonight I got curious and spotted some errors. And at no time did I give any indication of being ''back'', whatever that means

[Kickaha]

I don't believe it.

That "I cheated" thread was the best one ever on KB ( i'm sure many will agree ) and it fucking sucks that it's gone and that you're back to be honest!

It's only gone because the fuckhead that created it had it taken down

[BuzzardNZ]

It's only gone because the fuckhead that created it had it taken down

I wonder if he'll chime in explaining why he did that?

[F5 Dave]

That's a great idea let's start that shitfest again and we're back to this thread section being a shadow of itself and our senior technical advisor being Drew. No real offence to Drew but even he would agree.

[Robert Taylor]

In lieu of anyone at all using overly emotive and over simplistic statements such as suspension products being overpriced ( and a number of examples do abound ) its worth noting that just this last week iconic Italian suspension manufacturer Marzocchi closed its doors, with 120 job losses.
Marzocchi found it increasingly difficult to be profitable and indeed have been making losses. Also with the electronic revolution now a part of the suspension world there was an unwillingness from its backers to place huge amounts of money into r&d to be part of that, with no guarantees ofstrong returns.
Personally I will miss some of their higher end products because in certain aspects of design they had some clever engineering

[nzspokes]

In lieu of anyone at all using overly emotive and over simplistic statements such as suspension products being overpriced ( and a number of examples do abound ) its worth noting that just this last week iconic Italian suspension manufacturer Marzocchi closed its doors, with 120 job losses.
Marzocchi found it increasingly difficult to be profitable and indeed have been making losses. Also with the electronic revolution now a part of the suspension world there was an unwillingness from its backers to place huge amounts of money into r&d to be part of that, with no guarantees ofstrong returns.
Personally I will miss some of their higher end products because in certain aspects of design they had some clever engineering

I believe part of their demise was shifting the bicycle component manufacturing to Asia. It became unreliable after that.

[Bassmatt]

No that is not neccessarily so. When the shock is lying idle ( the bike not being used ) most of the nitrogen gas will be at the top of the shock, it will demulsify out of the oil. If there is any leakage path out of the top of the shock it can lose gas pressure without passing oil. Also in my experience emulsion shocks can lose gas pressure with no discernible loss of oi[.

Well the bike sat for nearly three months when I was sick so that seems a likely explanation to me.
I had the shock off the bike on the weekend and noticed if i shook it i could hear the oil sloshing around - it didn't sound like there was a lot of space in there. Should I be able to hear it?

[Robert Taylor]

Well the bike sat for nearly three months when I was sick so that seems a likely explanation to me.
I had the shock off the bike on the weekend and noticed if i shook it i could hear the oil sloshing around - it didn't sound like there was a lot of space in there. Should I be able to hear it?

Absolutely not!

[Bassmatt]

Two questions before I head into battle.
is it still safe to ride and will I do any damage to it if I did ride? Apart from issues mentioned in the op it feels pretty stable.
thanks everyone.

[nzspokes]

Do not ride the bike untill the shock is fixed or replaced.

[Big Dog]

If it is as you describe it will cope with normal, Just pogo a lot. On the other hand not very stable at a decent lean or when braking or accelerating hard.
Get it fixed without delay but if you have to ride it take extra care.

Sent via tapatalk.

[Robert Taylor]

Two questions before I head into battle.
is it still safe to ride and will I do any damage to it if I did ride? Apart from issues mentioned in the op it feels pretty stable.
thanks everyone.

I really hope some of the respondents in this thread don't work on aircraft............... DONT ride it until it is fixed. Whilst the most likely cause is indeed los of gas pressure what if there is an internal component failing that if gone unchecked may lead to damage to other internal components?

[Shaun Harris]

I really hope some of the respondents in this thread don't work on aircraft............... DONT ride it until it is fixed. Whilst the most likely cause is indeed los of gas pressure what if there is an internal component failing that if gone unchecked may lead to damage to other internal components?



If an assembly mistake was made after a rebuild of a shock and gas pressure set, is it possible for the shock to loose gas pressure after it was activated in the bike? I believe it IS, But you are the expert on this and not me.

[imdying]

But the strange thing is now my number plate which is on a home made tail tidy is being hit by the back wheel at some point when riding and is getting folded up under the bikeStop riding it in reverse and you should be sweet.