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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: ronbuell on October 26, 2014, 08:31:31 PM
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I'm still learning about this bike...'88 K75...
It appears to have a rear shock that is not stock... rather stiff.
It has a threaded lower part with 2 lock rings that you jam together to keep adjustment. There is an air fitting on the bottom as well. And there appears to be a compression adjustment at the top numbered 1-5 and you fit an allen wrench in to turn it. It was set to 3, and I turned it back to 1 to try to soften it some... which it did.
The adjuster wrench (spanner) in the tool kit does not fit the jam nuts, and besides, they are located down at the bottom where the side bags go. So I would have to remove the bracket to adjust it... bad location.... I think stock adjuster is on top.
There are no manufacturer markings on it......... Any ideas?
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greetings ronbuell...
gonna needs some photos...
j o
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OK Johnny
Do I have to post it to photobucket and put the link here?
Or Will the Insert Image actually post from me to here?
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you can post an off site photobucket image link in the body of a post... or you can post an attachment from your device to the bottom of a post...
j o
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OK, trying this again, with pics this time.
Top shows adjusters lock rings with inlet for gas, and bottom show either compression or rebound... not sure.
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what brand is that shock... looks upside down to me...
im thinking the bottom rings would set ride height aka sag... and there is no other adjustment... butts hard to say without more info... caints see whats you gotts circled at the top... and the bottom nubbin is either a charge port or port for remote reservoir... butts caints see much of it either...
j o
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That looks very similar to my Progressive 465, like maybe an older version. Mine has an orange bumper, not purple. I think yours is upside down too.
If it is a Progressive 465, you'll probably want to adjust those threaded rings to about the middle of their range.
(http://www.progressivesuspension.com/assets/images/products/465-series_8.jpg)
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"Most" shox are designed with different rates of dampening - compression vs extension, and as such have a harder compression rate [ obviously ] than extension. UNLESS the valving has been designed otherwise, fitting a shock "upside down" from it's designed orientation is asking for trouble.
I would say in this instance the SPRING is upside down, but the shock is in it's correct orientation.
Here's an over simplification - let's say the shock has 70 / 30 dampening [ just a figure plucked out of the ether ]. That is to say 70% of the dampening effort is on the compression stroke. Now fit it upside down - you have 30% of the dampening effort on the compression stroke.
The control at the bottom looks like dampening adjustment, but it's not clear if there is two way dampening adjustment.
Not foolproof, but let's assume the control is for dampening - set it to it's lowest setting [ usually anti / counter clockwise ], remove the spring and see if their is a significant difference in effort to open / close the shock manually.
While you're at it, you could gradually adjust the control to see what / how much difference it makes.
BTW all the above given I have NO idea of the shock manufacturer, but I DO have 35 year's experience with shox and their application [ race and road ] and having been involved in the design / development of the RAMSHOX for the past 9 years !!
TT - what orientation is your Progressive shock on the bike ?
BTW - the threaded rings adjust the sag / or pre-load and there is a specific proceedure to do that it is dependant on the loaded and unloaded static weight of the bike / bike + rider - the shock manufacturer will have that info. on how to set it up.
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Here's an over simplification - let's say the shock has 70 / 30 dampening [ just a figure plucked out of the ether ]. That is to say 70% of the dampening effort is on the compression stroke. Now fit it upside down - you have 30% of the dampening effort on the compression stroke.
Please explain, my little head don't quite get this.............
When the shockie being compressed, I thought that the oil was forced through the same valves and openings
whatever position it is mounted in.
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I just called Kyle at Progressive Suspension and he said the 465 was designed to be mounted on a K75 with the nitrogen port on the bottom facing the rear.
He said it was designed that way to offer the best clearance options, and that the shock's functionality would not change whether it was mounted right-side up or upside down.
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I'm with you guys.. . looks like it's upside down to me too.
Almost all of my shock experience is with off-road bikes... the later model WR250F and YZ250F is what I have the most experience with. So I'm familiar with compression and rebound, free sag, laden sag, preload etc. I have a rebuilder I work with here and we actually re-stacked and changed the shims to change the damping for my bikes. With 12 inches of travel available, I like to use most of it and still have a soft ride.... getting older, not younger.
Some shocks are position sensitive. My off-road bikes have a bladder in the pressure chamber and its connected to the shock by hose to the fitting on the valve body. Usual mode of failure is the baldder gets a hole in it and the gas mixes with the fuid and doesn't work properly any longer. They will also develop a leak around the seal at the shaft, which makes the failure visible.
I didn't see any manufacturer marking or stickers on it, but will look again. I can try flipping it and see if that changes anything too.
Geting back to this one... with only 5+ inches of travel, right now, it is too stiff for sure. Does make for very controled ride when the surface is smooth, but really have to slow down when the surface is ruff.... not good at all.
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Here's an over simplification - let's say the shock has 70 / 30 dampening [ just a figure plucked out of the ether ]. That is to say 70% of the dampening effort is on the compression stroke. Now fit it upside down - you have 30% of the dampening effort on the compression stroke.
Please explain, my little head don't quite get this.............
When the shockie being compressed, I thought that the oil was forced through the same valves and openings
whatever position it is mounted in.
Hope this is simpler. However here's an analogy, IF you are familiar with Drag Race cars - you will note that in the good old days the front end would lift violently. The shox typically fitted would be "90/10"s - That is to say 10% of the resistance was on extension - to allow the shock / wheel to fall rapidly and the 90% of the resistance was in compression allowing the front to come back to earth safely [ 'ish ! ].
The same [ less extreme ] is true of roadgoing shox - they manufacturers want to ensure that your wheel is in contact with the road for as much of the time as possible. Standard valving is designed with such ratios [ not 90/10 ! ] - that's why some of the more complex shox have an adjustement for both compression and extension.
TT - did your tame Progressive guru mention the orientation of the spring in the pic ?
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He's not "my guru". I just called Progressive's support number. I did not show him the photo.
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He's not "my guru". I just called Progressive's support number. I did not show him the photo.
My money's on spring USD :2thumbup:
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The spring is at its loosest position and since you dialed the damping down to #1, the shock should be in its least stiff operational condition.
I'd send it off to Progressive for a rebuild, or just replace it.
FYI - The instructions for the 465 specify that the damping adjustment should never been turned from 1 to 5, or 5 to 1. Only 1-2-3-4-5-4-3-2-1.
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Here's an over simplification - let's say the shock has 70 / 30 dampening [ just a figure plucked out of the ether ]. That is to say 70% of the dampening effort is on the compression stroke. Now fit it upside down - you have 30% of the dampening effort on the compression stroke.
Please explain, my little head don't quite get this.............
When the shockie being compressed, I thought that the oil was forced through the same valves and openings
whatever position it is mounted in.
Hope this is simpler. However here's an analogy, IF you are familiar with Drag Race cars - you will note that in the good old days the front end would lift violently. The shox typically fitted would be "90/10"s - That is to say 10% of the resistance was on extension - to allow the shock / wheel to fall rapidly and the 90% of the resistance was in compression allowing the front to come back to earth safely [ 'ish ! ].
The same [ less extreme ] is true of roadgoing shox - they manufacturers want to ensure that your wheel is in contact with the road for as much of the time as possible. Standard valving is designed with such ratios [ not 90/10 ! ] - that's why some of the more complex shox have an adjustement for both compression and extension.
That didn't answer my question..........
I wonder how the damping resistance can change from 70% to 30% by just turning it upside down.........
normally the oil is forced through the same valves and openings whatever position it is mounted in.
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"I wonder how the damping resistance can change from 70% to 30% by just turning it upside down......... "
My guess would be NOT if it works like a dual chamber shock.
I may have found it... or what looks close:
Ikon Suspension 7614
http://ikonsuspension.com/content/product_ranges/7614_series_shocks.shtml (http://ikonsuspension.com/content/product_ranges/7614_series_shocks.shtml)
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Here's an over simplification - let's say the shock has 70 / 30 dampening [ just a figure plucked out of the ether ]. That is to say 70% of the dampening effort is on the compression stroke. Now fit it upside down - you have 30% of the dampening effort on the compression stroke.
Please explain, my little head don't quite get this.............
When the shockie being compressed, I thought that the oil was forced through the same valves and openings
whatever position it is mounted in.
Hope this is simpler. However here's an analogy, IF you are familiar with Drag Race cars - you will note that in the good old days the front end would lift violently. The shox typically fitted would be "90/10"s - That is to say 10% of the resistance was on extension - to allow the shock / wheel to fall rapidly and the 90% of the resistance was in compression allowing the front to come back to earth safely [ 'ish ! ].
The same [ less extreme ] is true of roadgoing shox - they manufacturers want to ensure that your wheel is in contact with the road for as much of the time as possible. Standard valving is designed with such ratios [ not 90/10 ! ] - that's why some of the more complex shox have an adjustement for both compression and extension.
That didn't answer my question..........
I wonder how the damping resistance can change from 70% to 30% by just turning it upside down.........
normally the oil is forced through the same valves and openings whatever position it is mounted in.
Inge ...........................I am talking fluent cobblers of course.
The point I was trying to make referred to an experimental shock that was being developed for a Trike we were building - and NOT of course to mainstream shox as you rightly pointed out.
My apologies to all those who were scratching their heads like you - good job I don't design the shox, just develop them.
Sitting in the corner on the naughty step with my dunce's hat on.
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It would be my understanding that with a shock that was meant to be run in a certain orientation; if it were run upside down, wouldn't the valve pack be upside down? Meaning whatever the ratio that BC is talking about, would be reversed between rebound and compression.
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It would be my understanding that with a shock that was meant to be run in a certain orientation; if it were run upside down, wouldn't the valve pack be upside down? Meaning whatever the ratio that BC is talking about, would be reversed between rebound and compression.
It really does depend on the internal design, and there's so many options this debate could go on forever !
Meanwhile - I still think the SPRING is upside down !!!!!!!!!!!! :dunno2:
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Inge ...........................I am talking fluent cobblers of course.
Thanks, got the answer I wanted.
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I think that's a Progressive 420 shock.
It's not upside down, check this thread: http://www.motobrick.com/index.php?topic=4501.0 (http://www.motobrick.com/index.php?topic=4501.0)
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And the winner is:
Progressive 420 :clap: Congratulations to all those who voted Progressive. Your prize is waiting at the door!
They don't make this one any longer, discontinued. I did find some bad press on it. They came out with another low end, and the 465 which is impressive. The one they designed for the GS models is quite good.
So now its time to loosen the preload a little so it will have some usable travel.
Seriously, thanks for point me in the right direction. :2thumbup:
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That looks very similar to my Progressive 465, like maybe an older version.
What door? Where's my prize??? :yes
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Start putting some change in your piggybank daily -- 420 isn't rebuildable and when it fails you're riding a hardtail. I know...ask my coccyx.
http://www.motobrick.com/index.php?topic=5284.msg32939#msg32939 (http://www.motobrick.com/index.php?topic=5284.msg32939#msg32939)
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Probably go w/Works Performance when this one goes bad. :riding:
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I have a Works on my K75, made a different bike out of it.
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We've [ RAM ] supplied almost 200 shox for all versions of Kays - and every feedback has been the same as your experience - transformed the bike !
I then went on to develop a progressive front spring - as the "good" rear shock showed up the already deficient front end.
The OEM shock is marginal in it's performance and prone to severe deterioration after about 30K miles. A long term owner would "adjust" their riding style to compensate without really pointing the finger at a poor shocker.
BTW - OEM shox ARE rebuildable, but that would cost as much / more as a good quality aftermarket unit with full adjustment ! I think that all ftermarket shox [ with the exception of Ohlins ] will also be cheaper than an OEM replacement. :2thumbup:
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I have a shock marked Progressive with a remote reservoir, and the hose fitting is at the base of the shock body but the number and serial number are almost illegible to my eyes. Anyone have this same model, it is on my '85 100rs.
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I'm going to assist in the thread necro here - I missed it first time round and to be frank I'm shocked.... (what I did there, did you saw it?)
Starting with the 'turning the shock over swaps compression and rebound damping rates' (yes, I called it rebound damping, because y'know, that's what it's actually called...) Are you actually being serious beachcomber? I mean, really?
Here's a simplfication that's actually correct. A damper is essentially a washer on a stick in a tube - on compression the stick is pushed into the tube and on rebound it's pulled out of the tube. How is the washer expected to know in which orientation it is sitting? In actuallity, the 'washer' has valves and shims, but they are fixed in relation to the travelling direction of the stick, regardless of orientation of the assembly.
You said you were referring to an 'experimental' shock "for a trike". Until I see some drawings or photographs of how the shock determines which way up it is I'm calling bullshit.
Now, as for the spring being fitted upside down (which going from the order of the thread is what you assumed was the reason for the hardness), again, really? Are you also working on experimental unidirectional springs that only bounce one way?
I know from previous experience that I'm flogging a dead horse by asking this, but what do you actually know about suspension design, other than "it feels better"?
To be quite blunt, saying it feels better means 2 parts of fuck all, a blancmange would probably feel better than a properly fubar OEM shock. And who replaces a good shock? Nobody normal, they replace them because of problems, real or perceived.
From a personal perspective, there is no way I would ever consider buying a shock that someone who said what has previously been said in this thread, had any sort of hand in "developing". It's even been known for me to change my mind about buying something because the person selling it didn't know what they were talking about.
BTW - OEM shox ARE rebuildable
SOME OEM shocks are "rebuildable". The K75 OEM unit is crimped so can't be stripped for rebuild by normal means. They are designed as a disposable unit.
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FWIW - I called the Tech line at Progressive Suspension a while back inquiring whether my Progressive 465 might be upside down.
The tech told me that the shock functions the same regardless of which end is up.
Progressive recommends their shocks be installed one way or the other only so that the fit does not interfere with other parts of the bike, like ABS pumps, etc.
I should add, however, that my original OEM shock was mounted piston-up and when my rear brake master cylinder failed, the brake fluid sprayed onto the piston and seeped into the shock, causing the shock to fail within a day. That shock sucked anyway.
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I got a YSS and it transformed the bike too...probably because the one it replaced was f**cked. In that sense, any new shock will transform a bike which previously either had a shock which was f**cked or of poorer quality than the replacement.
Having said that...pdg, you sure you don't just have a woody for beach after the last head butting extravaganza last year? Works makes quality stuff... I don't think anyone would deny that. Maybe you could frame your valued perspective in perhaps a slightly less confrontational dialectic?
Which translated into simplified Yankspeak means more or less -- 'Dude, lighten up...'
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Having said that...pdg, you sure you don't just have a woody for beach after the last head butting extravaganza last year? Works makes quality stuff... I don't think anyone would deny that. Maybe you could frame your valued perspective in perhaps a slightly less confrontational dialectic?
Works suspension does indeed look like quality equipment with a good reputation for custom built units. However, I am not aware of any connection between Works and Realm engineering. As I have previously stated, I have no experience with Realm engineering products over and above the 'marketing' carried out on a few forums, so I can't honestly say whether they are good, bad or indifferent. The only information I can possibly work from is what is presented on said forum discussions.
Confrontational? I can see how that could be inferred - although perhaps 'blunt' might be a more apt term most of the time. I'm not going to go all 'fluffy' because I might offend someone - remember, offence is taken not given. Personally, I would much rather people just come out and say what they think instead of beating around the bush in a vain attempt at politeness.
When it comes to technical (in)accuracies, I probably do sway more toward confrontational. It very much irks me when people spout utter nonsense while hiding behind 'the voice of experience'. Using a sentence along the lines of "but I DO have 35 year's experience with shox and their application [ race and road ] and having been involved in the design / development of the RAMSHOX for the past 9 years" implies the author would be a good source of knowledge. Sadly, this was shown in great big flashing red neons that in this instance it was so far from the case it couldn't even see the case any more.
It's certainly not a vendetta against any indivdual or company - had a 'spokesperson' for let's say ohlins or WP made the same comments, I would have made the same reply.
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Just read the entire thread and commend pdg on his honesty. The idea that a shock or spring could detect its orientation relative to the earth was something I JUST had to read .... inquiring minds just need to know !