Inside the Reiger Shock

Discussion in 'Trials' started by motobene, Sep 3, 2013.

  1. Jonny042

    Jonny042 Been here awhile

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    I do tend to be very aware, and careful, of the possibility of damaging the adjuster, when adjusting it. Perhaps I came upon a sticky spot on the adjuster, and thought it was "cranked" when really it wasn't - that would explain it - I may have gotten lost in the range of clicks. It's the only reasonable explanation.

    Went riding yesterday (barely above freezing!) and all seems to be well with the shock. It occurred to me that maybe I should flip it back upside down, to keep it warm!!!
    #41
  2. motobene

    motobene Motoing for 44 years

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    It was a guess for me. The stroke also depends on the hit... the amount the end-of-travel bumper compresses.

    Yeah I'll get around to it - eventually. The ranch projects have been flat worn out all the time. My only respites are my few morning hours where I do paper work and play a little here.
    #42
  3. motobene

    motobene Motoing for 44 years

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    A warm and cold-weather shock position... I like it! Too bad the eye spacer aren't the same width to make it easier to flip over. I think most of the time heat is not an issue, as many shocks do OK at just under boiling temp of water. And how many of us motocross these things around the loop on a hot day and when the header pipe then muffler has a flame wave inside and doing a smoky burnout?
    #43
  4. Sting32

    Sting32 Trials Evangelist

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    You do have to adjust dampening for riding temps, I was told.. The guy telling me this is VERY good rider, says he hits a certain rock 2 times, then adjusts how it felt, then he's ready for the day :huh...

    luckily I ride at a significantly lower skill level, than the person that told me this, as I don't change the shock once I set it up at end of august, when the bike was un-crated, lol.
    #44
  5. motobene

    motobene Motoing for 44 years

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    A friend recently told me the Mitani japan web site in an advert for servicing the Reiger shock with this photo of the guts:

    [​IMG]

    Nothing bizarre inside. The design is common to most modern motorcycle shocks.

    Reiger differentiates itself with no use of castings or powder-metal parts. All the aluminum parts are machined on sophisticated machining centers, which is ideal for lower-volume production and manufacturing flexibility. Minimization of steel parts and parts sizes translates to one of the lightest shocks available.

    The gas port is a tiny rubber, needle-fill-style thing in the larger diameter black anodized part. It can be a pain to work with. There is little or no room to fit a much simpler Schrader valve, but I will try when I do mine.

    The seal head is held in with a wire clip (not threaded in) and gas pressure, which is more common these days. The thread-in shock body shuts off against the upper eye assembly having the compression adjuster. Oil being displaced by the rod during shock compression is forced to go through the compression adjuster on its way to the rubber bladder reservoir/accumulator chamber.

    The accumulator is in the enlarged thread-over-shock-body cavity. The shock body seals the bladder to the enlarged cavity by compression of the rubber. This is the same accumulator design used by Showa on the 4RT. A photo, also from the Mitani Japan site, of the Showa accumulator body/cavity and rubber bladder:

    [​IMG]

    Nitrogen gas resides in the aluminum cavity on the outside of the bladder, and the oil is on the inside of the bladder. The volume displaced by the rod during shock compression will bulge the bladder out a little against gas pressure. It is the nitrogen pressure acting on the area of the rod that provides the extension force on the rod of a properly charged shock.

    The piston is machined aluminum. Higher volume production shocks often use a ferrous sintered powder metal piston, which allows for square-angular ports.

    The valve stack (also known as the shim stack) is straightforward. They've got the shock shaft laying the wrong way, so I don't know how much I trust their assembly order, but I think the top row of shims is the compression stack and the bottom row is the rebound stack. Given there are fewer compression shims, I'd guess the compression shims are thicker than the rebound shims.

    I'll be getting into my shock some time soon when I get a break from cows and construction, but this photo answers many questions. Thanks, Steve for sending it to me!
    #45
  6. laser17

    laser17 Been here awhile

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    Thanks for sharing your knowledge in this matter MB. I for one have never rebuilt my own shocks, so its really nice to have someone take me through it. :clap
    #46
  7. motobene

    motobene Motoing for 44 years

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    Nertz! I could use the business :cry
    #47
  8. laser17

    laser17 Been here awhile

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    I'll have you do mine when you figure out the re gassing part using the OEM seal! (when it needs it) Dont go the schrader valve rout if at all possible to keep the factory look. (Its a $1200 shock - i'd pay extra for the OEM seal/look) Im sure this would appeal to others as well. Assuming you would have to make a custom tool, would give you a barrier of entry from the avg garage mechanic with a drill press. (not to mention the shimming secrets)
    #48
  9. wilkinsonk

    wilkinsonk soup de grimace

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    motobene,<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><o:p></o:p>
    <o:p></o:p>
    I'm generally a lurker in the trials forum. I wanted to thank you for taking the time to put together the extremely informative posts you’ve been doing. Between this one and the Gas Gas vibration thread, I’m amazed at the level of detail you go into documenting the subject. Additionally, your thread on fabricating a different brake pedal and the subsequent rebuild of the bike certainly illustrates your skills. If I had to guess, I’d say you run a small job shop? Anyway, thanks for writing up such great posts.

    - Ken<o:p></o:p>
    #49
  10. motobene

    motobene Motoing for 44 years

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    motobene,<?xml:namespace prefix = "o" ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><o:p></o:p>
    <o:p></o:p>
    I'm generally a lurker in the trials forum. I wanted to thank you for taking the time to put together the extremely informative posts you’ve been doing. Between this one and the Gas Gas vibration thread, I’m amazed at the level of detail you go into documenting the subject. Additionally, your thread on fabricating a different brake pedal and the subsequent rebuild of the bike certainly illustrates your skills. If I had to guess, I’d say you run a small job shop? Anyway, thanks for writing up such great posts.

    - Ken<o:p></o:p>

    Ken:

    Thanks. I do appreciate your comments! The level of detail you see comes pretty fast for me (experience). And I love to write. One professor in College said I should make a career of technical writing because I love to paint clear pictures with words.

    I do this mostly for fun though I should be treating it more like a business, such as with the suspension work.

    Daniel Pink in a new management book says the idea of finding your passion is BS. He says to simply look at what you already do, can't stop doing, or want to do more of. That is your passion. My passions are many, but at the center is machines and optimization of machines.

    I'm a semi-retired mechanical engineer (mostly durable medical and industrial tools) with 40+ years of hands-on experience from construction to machining to welding to mechanics, etc. I've accumulated some really nice machine, welding, and other tools over the decades.

    My shop is not a job shop first. It's a support shop to the ranch that happens also to be great for all sorts of other things, including moto maintenance and optimization. My 'job' is owning and managing a recreation and cattle ranch. The Buffalo Dream Ranch happens also to be a stellar trials riding area :clap
    #50
  11. motobene

    motobene Motoing for 44 years

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    When I re valved the 4RT Showa shock I was very happy to find a nice big Schrader valve sticking out of it! I have yet to machine one, but I'm scheming something. The alternative is to buy the needle tool. That I probably should do because a number of shocks do not use Schrader ports.

    The actual guts of a Schrader are very compact. The bulky part become the fillers. The Reiger's port lies parallel to the shock body and very close!

    [​IMG]

    [​IMG]

    But gosh, there are many options from Schrader for valve cores other than the typical ones used on cars, motos, and bicycles. The following pdf shows the many:

    http://www.schraderinternational.co...America/Valves Cores_Collateral_12-01-12.ashx
    #51
  12. liviob

    liviob Been here awhile

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    The disassembled damper in the tray shows a very simple design similar to the Paioli damper. Did you need special tools to disassemble the damper? Personally i would use the gummy valve. Not because its better than a Schrader valve. Only because there probably is not enough room for the larger Shrader valve.
    #52
  13. motobene

    motobene Motoing for 44 years

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    These type shocks (dampers) do not require special tools to disassemble. Dumping the nitrogen pressure will relax the pressure on the seal head, which can be pushed in to get access to the wire clip. Once the wire clip has been carefully removed, the shock shaft with seal head can be pulled out.

    Whatever special tool there are just make the job easier.

    You are right about the gummy valve. It is very simple and takes up little space. It does require special tools, however, to re charge the damper with nitrogen.

    Other special tools can make to job better. For example, a vacuum chamber to remove gasses in solution from the oil before you reassemble the shock. I've never done that and it doesn't seem necessary. But like those people who swear by using nitrogen in their tires, even though air is 78% nitrogen, perhaps it is a little better.
    #53
  14. liviob

    liviob Been here awhile

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    I asked because the Reiger people said i would need to return the shock to them for service because servicing required special tools. They wouldn't say what the special tools were though. It looks like i have all of the special tools necessary for this damper. I wouldn't worry about a vacuum bleed on this damper. Just do a careful hand bleed and you should be fine. What is the factory setting for the nitrogen pressure?
    #54
  15. motobene

    motobene Motoing for 44 years

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    I came home late last night with a message on the answering machine from a suspension guy who said to call him. He said I was wrong to say in this post that no special tools were required and to call him.

    He disassembled his Reiger a few months ago. I'll find out if the special tool is a preference or a necessity. I can't see any major difference between the Showa I just did and the Reiger, but let's see what he has to say.
    #55
  16. jonnyc21

    jonnyc21 Trials Ninja

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    Inquiering minds want to know... :ear
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  17. motobene

    motobene Motoing for 44 years

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    The latest info from the person I talked to:

    The cap over the seal head is not pressed in like on many other shocks. It is, rather, right-hand threaded to the seal head. You need some kind of spanner wrench (or make one) to thread it off. Removal should be done before de gassing the shock or the seal head might turn in the body, making getting the cap off very tough.

    Reiger has made this shock difficult to service. I can understand why they'd want to maintain control, but I believe servicing in Netherlands only, aside from the high purchase price, limits the non-OEM purchases of this excellent shock. Many riders don't like not having a domestic service option.

    The special tool described to me was speculated about during the call, and had to do with re gassing the shock. The person had not directly seen the tool or the process, but knew of something similar used on - I think he said - a White Power shock. This person was the only person I know of -so far - to disassemble and reassemble a Reiger shock in North America. He said a needle-type filler doesn't work that close up against the shock body, and that Reiger uses some kind of fixture that clamps over the shock body to re gas the bladder accumulator and reinsert the two screws somehow through the fixture. Seems a lot of extra work to fill a shock with gas, but if true, it is definitely a barrier to servicing.

    When I can get some dedicated time I'm going to find a slick solution around this obvious barrier. I don't like being told I can't do something! I'd strongly suggest not diving into this shock unless you have a spare shock as a backup and are high level in these matters, in knowledge, experience, and tools.

    Reiger does not publish gas pressure or oil specs. I'm going to wait until I get deeper in before speculating.
    #57
  18. liviob

    liviob Been here awhile

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    Thanks for the update. It is unfortunate that Reiger made this damper difficult to service. While i'm certain the Reiger shock works better than the stock Sachs shock. I will for now continue using it until i cannot service it again as it works well enough for my riding ability.
    #58