RFY Shock Model 0 – Analysis

with 14 Comments
All of the RFY Shock Model 0 parts shown.
All of the Model 0 parts shown.

Over a full year since its start this little experiment with RFY Shocks continues to grow. Recently, I got the chance to do an analysis on one of the less sought after RFY shocks. That of course being the model without the external reservoir. Hardly breaking the bank, this shock can be had for around $100 shipped to your door. As usual, it is tough to get details on these shocks. Sellers, located primarily on eBay, know nothing of motorcycle suspension and instead list the scant details provided by the manufacturer. This is leaves a vacuum of knowledge around the product and understandably is a huge deterrent to purchasing the product.

As always, I designate each model with a name that I hope is easy to understand and communicate and this model is no different. My initial impressions were that this shock was the Model 1 but without the reservoir. After seeing the reservoir-less shock in person I now know that this is not the truth. As a result I have named this shock the Model 0 (zero). It is most simple of the shocks sold by RFY, thusly it only seems reasonable to make it the lowest model designation.

Upon opening the box it did not take long to spot the differences between the Model 1 and this Model 0. The two models use the same spring, lower perch, and clevis or eyelet, but that is where the similarities end. The Model 0 has a significantly larger shock body and a CNC made cap and upper eyelet. The the quality of manufacture on the shock body, top cap and eyelets, as well as the spring preload collars are a step above the Model 1. The preload collars are especially nice with better thread mating characteristics than other models. The machine work is also slightly better, showing more attention to detail.

After dismounting the spring the seal head nut was removed to reveal the shock head seal. The seal is similar to the other models, though it is larger to accommodate the larger shock body. Unfortunately my disassembly fixtures did not work well on this larger shock body. I had to build a second set of fixtures to disassemble the shock completely. The process however was much the same. Pulling the head seal revealed the internal bushing, top out spring, and piston.

Piston from the RFY Shock Model 0 damper.
The piston has a large surface area, large holes oval holes that act in compression and smaller holes that act in rebound.

The piston itself appears to be of reasonable construction. It is very similar to the construction of the Model 1, with a shim stack and some spring washers that are oriented in a way as to open and close holes as the piston travels. Overall surface area is large on the Model 0 piston. The damper design is of an emulsion type with a Schrader valve at the top of the body for adjusting gas pressure.

Before disassembly I ran the damper through its stroke several times by hand. Being an emulsion type damper it was important to keep the damper upright. Unlike other models this damper must be mounted with the shock body at the top. My initial impression was that the Model 0 had little to no damping properties. I then checked for gas pressure, both shocks appears to be pressurized but I did not check if the pressures were the same. I drained the dampers of oil and as is usual with RFY shocks they seemed to have the incorrect amount of fluid. The oil was the same the same yellowish, foamy, mystery oil found in all RFY models that I see. Emulsion type shocks require a very specific amount of fluid to to work properly and immediately it was obvious this is an issue on the Model 0. Filling the damper properly with oil will aid this dampers performance significantly.

RFY Shock Model 0 Damper Bushing
RFY Shock Model 0 Damper Bushing

The caveats with the Model 0 after inspection are two fold for me. The biggest is that the damper bushing is rather sloppy on the shock rod. As of now it I am not sure as to whether this will hinder the performance of the shock or not. My gut tells that the extra slop could lead to premature seal wear at the piston as well as the seal head. This however remains to be seen in the real world. The second caveat is that emulsion type shocks are old technology. There are better designs on the market, though this may only be important to you if you are performance oriented.

To summarize, the Model 0 is a nicely made, fully rebuildable, emulsion type shock, that can be had at an extremely reasonable price. It remains to be seen whether the shock will operate as reliably as the Model 1. The sloppy bushing fit is worrying, and considering that both of the Model 0 dampers that inspected were identical I do not believe this to be a quality control problem but rather a deliberate design issue. In the coming months I will be riding these shocks around some to see how they ride and how they last. Once this has been established under more certain terms I will update this analysis of the the RFY Shock Model 0.

14 Responses

  1. Avatar
    Leigh
    | Reply

    I too have seen these shocks and was considering purchasing them. Have you put some miles on them now and how are they working out? If you service these as you do the others, would you be upgrading the damper bushing?

  2. Avatar
    Jeff
    | Reply

    Leigh has the right question woul d remachine that part. and how would that affect cost, I would like to run a more classic looking shock.

    • Chris
      Chris
      | Reply

      Hi Jeff,

      In the Model 0 rebuild that price includes the machining and installation of the linear bushing.

      – Chris

  3. Avatar
    teigan
    | Reply

    what is maximum pressure for this model? the piggyback reservoir ones specify .5 Mpa=72.5psi

    what you call the model0 has less volume than the model1, correct?
    theoretically, the more volume you have, the lower pressure required for same performance.

    • Chris
      Chris
      | Reply

      Hi,

      The volume for gas depends on the amount of oil used when filling them. So with less oil you can run greater PSI.

      Generally, I run 120 psi in them.

      Regards,
      Chris

  4. Avatar
    teigan A
    | Reply

    thanks for the guideline. i have not done a rebuild so don’t know the amount of oil. guess i will go with about 75psi to be safe. would check against other side, but measurement would let out too much gas. wish i had a way to permanently plumb in a leakless fill valve at the 7mm fitting hole.

  5. Avatar
    Walt
    | Reply

    ” In the coming months I will be riding these shocks around some to see how they ride and how they last.”

    Any chance this ride report will be coming soon?
    I’m also really interested in a set if you can turn them into something worthwhile.

    • Chris
      Chris
      | Reply

      Sorry, Walt. Plans changed. I think I put maybe 30 miles on them and then they went to a different person for testing. We ended up making some small adjustments to the pistons but they work fine. I sell so few of them that it’s kind of off the radar.

  6. Avatar
    Walt
    | Reply

    Is the email address on your policies page OK to use?
    I’d like to discuss getting a pair of shocks built.
    Thanks,
    Walt

  7. Avatar
    teigan
    | Reply

    i am riding this shock at present. will keep you updated. so far about 3000 miles logged. pressured to under 120psi. would like more, but unsure if seals can handle it. no documentaion found anywhere regarding this model, or the olin it was copied from.

  8. Avatar
    Walt
    | Reply

    Hi Teigan, thanks for that.

    I assume you’re using the 8mm spring that came with the shocks? What is your weight and what is the weight of the bike? Have you checked how much sag you’re getting? Does it agree with the spring calculator?

    How would you characterize the ride? Hard, soft, medium, well connected?
    Is your overall impression favorable?

    Thanks again,
    Walt

  9. Avatar
    teigan
    | Reply

    my motorcycle is well over 500lbs dry weight. the shocks handle the weight with no sag using the stock springs. i would call the ride characteristic “soft”. the shock was designed to fit a wide range of vehicles, so unless you are lucky, some of the travel length is wasted by longer brackets. that’s how they price them so reasonably i’d think.

    • Avatar
      Walt
      | Reply

      That’s discouraging if you’re getting zero sag on a 500 lb. bike. Mine is only 375 lb.
      I’ve never understood how you can have zero sag and still have a soft ride.

  10. Avatar
    teigan
    | Reply

    don’t be discouraged. depending on your make and model, they send these out with different stock springs. the bike should not sag until you sit on it, and then only slightly. “soft” ride is subjective which is why i always quote it.

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