beware of avon tires warranty

[zoot .]

Got the shock body apart today to find the inner piston sealing ring was munched, and the inner body of the housing well scored. 30K miles by my rough math. Don't know whether changes of shock oil are a recommended maintenance activity, (since what was in there was certainly colorful), or whether it would have lengthened the life of the shock. Glad I've got the old stocker for now so that riding isn't hindered. Now if only I had a solution for the tachometer. Ah well, don't really need it until I 685 the engine. Ya.... right. t.

[cycletip]

Wasn't aware you could rebuild one DYI style.  You must have a spring compressor tool or something?  Replacing the rear shock seems to be one of the most costly fixes there are for a KLR.     

[T]

Decompressing the spring was just a matter of backing off the preload nuts on this unit. Removing the core was a little more interesting, with the need for some light air pressure to load the shaft retainer so that it would unscrew from the innards. Once apart, the rebuild looks to have been easy, except for the scoring of the barrel caused by the piston oil ring failure allowing metal to metal contact. As to why the oil ring seal failed,... who knows. 30K miles with everything from dirt road on the way to work each day, fully loaded overnighters to the hinterland, and other dual sport excursions in between. Interesting to have the shop mechanic relate that most piston retainers mount by screwing into the barrel, not to the innards, as with this one. Some commentary about made in China, but again, 30K miles, so whether more is to be expected is an open discussion. t. On 10/29/2015 9:38 AM, cycletip@... [DSN_KLR650] wrote:

Wasn't aware you could rebuild one DYI style. You must have a spring compressor tool or something? Replacing the rear shock seems to be one of the most costly fixes there are for a KLR.

[jet_doctor2002]

This is interesting.  I looked at a cut away of this shock on Progressive's website, and it looks like a fairly standard shock.  They show the damping piston without the piston ring, but what it shows if fairly telling.  There is no groove cut for an O ring in the piston under the piston ring.  Most shocks use an O ring to push the piston ring out and center the piston.  Without this "energizing" O ring, the metal (steel?) piston can hit the walls and do damage.  As you see here Gold Valves have this ring, as do most shocks: SMSA Shaft Assemblies SMSA Shaft Assemblies View on racetech.com Preview by Yahoo   When you talk about the piston retainer, are you talking about the seal head?  Most seal heads are held in by a ring, and the nitrogen charging the shock holds it in place.  What usually happens in your situation, is the nitrogen charge leaks out.  Then, the seal head floats around, the piston hits the walls of the shock tube and damages it. One thing to consider when deciding on purchasing a shock like this is that there is a floating piston that separates the nitrogen and oil.  This piston significantly reduces the overall travel of the shock.  Really, there are 2 pistons in this shock--the one on the shock shaft for damping, and a second one to separate the oil and nitrogen.  I have Bilstein monotube shocks on my Jeep, and while they are nice on the road, they limit wheel travel off road.  Separate reservoirs are really worth the money.      I have never been impressed with Progressive's mono-shocks.  Yes, the price is right, but they seem to be harsh, when a shock in this price range should be plush and controlled.  I had one on my Concours, and now I understand what was going on.  The wheel travel was less than using the stock shock.  Progressive also uses really heavy spring rates with no pre-load on their shocks.  Oddly, this is the reverse of the fork springs they sell which work exceptionally well.     There are some great videos on Youtube that Paul Thede of Racetech has done.  It will probably make understanding what happened to your shock easier to understand.  He also imparts a lot of info on how suspension works and how to make suspension work better.  I really like the Gold Valves.  Custom premium suspension that you can do in your garage.Cheers,Doug      

[zoot .]

Piston technology isn't my strong suit, but the progressives look to use a seal ring that lays in a recess on the piston head, as opposed to an o-ring. I suspect that Doug is right in assessment that the nitrogen leaked out allowing the seal ring to be damaged, since the ring itself was floating and contorted when we disassembled the shock. Interesting to see the gold valve option for existing KLR shock bodies. I'll keep that in mind if/when I toast the Progressive that Mark is sending me. Todd On 10/30/2015 10:04 PM, walk9940@... [DSN_KLR650] wrote:

This is interesting. I looked at a cut away of this shock on Progressive's website, and it looks like a fairly standard shock. They show the damping piston without the piston ring, but what it shows if fairly telling. There is no groove cut for an O ring in the piston under the piston ring. Most shocks use an O ring to push the piston ring out and center the piston. Without this "energizing" O ring, the metal (steel?) piston can hit the walls and do damage. As you see here Gold Valves have this ring, as do most shocks: SMSA Shaft Assemblies SMSA Shaft Assemblies View on racetech.com Preview by Yahoo When you talk about the piston retainer, are you talking about the seal head? Most seal heads are held in by a ring, and the nitrogen charging the shock holds it in place. What usually happens in your situation, is the nitrogen charge leaks out. Then, the seal head floats around, the piston hits the walls of the shock tube and damages it. One thing to consider when deciding on purchasing a shock like this is that there is a floating piston that separates the nitrogen and oil. This piston significantly reduces the overall travel of the shock. Really, there are 2 pistons in this shock--the one on the shock shaft for damping, and a second one to separate the oil and nitrogen. I have Bilstein monotube shocks on my Jeep, and while they are nice on the road, they limit wheel travel off road. Separate reservoirs are really worth the money. I have never been impressed with Progressive's mono-shocks. Yes, the price is right, but they seem to be harsh, when a shock in this price range should be plush and controlled. I had one on my Concours, and now I understand what was going on. The wheel travel was less than using the stock shock. Progressive also uses really heavy spring rates with no pre-load on their shocks. Oddly, this is the reverse of the fork springs they sell which work exceptionally well. There are some great videos on Youtube that Paul Thede of Racetech has done. It will probably make understanding what happened to your shock easier to understand. He also imparts a lot of info on how suspension works and how to make suspension work better. I really like the Gold Valves. Custom premium suspension that you can do in your garage. Cheers, Doug

[cycletip]

This is a great thread.  Thanks for all your insight and information.  My KLR has an older 420 series unit (I think?) but not many miles on it.  Use to ride buddy up a lot but not so much any longer.  Maybe that will help longevity some?  Suspension parts do make for great eye candy and big $$$.