RFY Shock Updates

with 2 Comments
Spring rate graph for several RFY springs.
Spring rate graph for several RFY springs. Most notably the dual-rate and the 375mm spring has been added.

It’s be a while since I have managed to post, it’s not for a lack of trying though. Over the last few months I have been extremely busy and as a result have not been able to find the time to produce quality content. One thing I have needed to do is give some RFY shock updates. There has been significant progress made in all areas of the project over the last half a year. I have tested new springs and retested old springs, I have worked with new seals, piston adjustments, etc., and all that testing is fairly worthless unless I use that data for something. There has also been a host of other developments, so please read on.

First up, I have developed a CB1100 shock and spring package based on a RFY unit. I worked closely with a couple of CB1100 owners building a longer more “café” style rear shock for these bikes. The spring for this package is a 120lbs/inch spring. This spring is slightly stiffer than a standard CB1100 spring, which I find is better for today’s riders who are generally clad in more gear and require stiffer rear springs than riders from 30 years ago. Moreover, this stiffer spring is better aligned with a sportier ride that is desired in the café scene, while the longer shock reduces rake and trail offering quicker steering characteristics. This package comes in a range of lengths, I can build them as short as 362mm (stock length), and as long as 395mm. Oil choice is the same as usual, with 3w, 7w, and 10w all available. The shock is charged properly and given a total going through to assure that it functions as best as possible. This package may work for Suzuki GS models as well as others, though I do not have the specifics ironed out for those bikes.

On a different topic, over the past few weeks I also got my hands on the elusive RFY dual rate spring. This spring is very similar to those made by Works Shocks and many other brands. I had seen this RFY dual rate spring in various photos, mostly of guys whom had them on their bikes. I had not however ever been offered a set from my supplier. Needless to say I snapped them up immediately. The conclusions are simple. If you in the market for a 340mm shock and have a very light bike (</= 300lbs) and are a fairly light rider (</= 180lbs), these springs are probably the ones for you. They are by all measures the softest of the RFY springs with a initial rate of about 85lbs per inch for the first inch and half of travel but then that rate gets steeper providing about 120lbs per inch once you are into the second spring. This should provide nice supple ride over the small bumps but prevent harsh hits against the bump stops over large bumps and hits. I plan to test these springs on my bike in the near future to compare them to the 7mm conicals I use now. I will write a more comprehensive review then.

The RFY dual rate spring is similar to those offered by other brands.
The RFY dual rate spring is similar to those offered by other brands.

Finally, I am currently in development of seals for all the standard model of RFY shock. These seals are of my specific design and are meant to not only outlast the seals that come with RFY shocks, but should out perform the existing seals in many ways. Mainly, my seal design removes the large backside cavity that requires careful bleeding of the shock during assembly. This will help to reduce the potential for air introduction into the damper system and ultimately provide an improvement in performance. The other goal was to reduce seal on the shaft friction which again will boost performance. The seal system is still in development and probably won’t be available for some time, but should my goals be met there will soon be a reasonably priced set of upgraded seals available for your RFY shocks.

2 Responses

  1. Bryan
    | Reply

    As an owner of a CB1100F I’m stoked.

    • Chris
      | Reply

      Awesome, Bryan! I am stoked as well!

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