Shock service and preload conversion

jrusell

Well-Known Member
Joined
Aug 23, 2017
Messages
460
Location
Dartmouth, Nova Scotia, Canada
I just received my shock back from it's service. Last fall I noticed there was a light mist of oil on the hydraulic preload adjuster body. Never lost full charge, but it was set with 4m of additional preload and was now sitting with only 2mm.

If it leaks one time I figure it will leak again, so I decided to see if I could convert it to a simple threaded adjuster. My shock is a yacugar and is not a very popular up here in Canada. I was quite sure it shares a lot of it's parts with the Hyperpro shocks so my plan was to get it serviced at a suspension shop that sells Hyperpro as they would most likely be able to confirm their adjuster will work and source the parts for me.

While it was there the virus hit and issues sourcing parts became an issue. They were able to come up with an alternate solution of using the inner portion of my current hydraulic adjuster, so we went with that.

I have a longer 170N spring in the garage and wanted to give it a try, so I needed to make a spring seat for the top of the shock. The stock seat was very narrow at 4mm and I didn't feel comfortable with it. Luckily I have some 6mm sheet aluminum and some patience. Spent some time with the jigsaw today making a new seat approx 10mm wide and modified an old spring preload wrench I had kicking around to fit this shock. I also bought a new Torrington bearing for the top seat to make adjusting much easier.

Maybe not the prettiest but it works and it will never leak. I generally get the bike setup for normal riding which is with a top box with a few tools and then a second preload setting for fully loaded for traveling or camping. Having a manual adjuster vs a hydraulic is a non issue for me, maybe a few minutes more to change the setting.

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ballisticexchris

Guest
Jrusell please measure before you ride. Just by looking at that spring, the coils look like they are going to hit before you reach the end of your travel. I have went down this road before. Longer springs with lots of preload create all kinds of strange issues with not only compression/preload damping, but also run the risk of the coils hitting.
 
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ballisticexchris

Guest
I am by no means putting down your work. Looks like you got tunnel vision and just missed the big picture. Please let us know the outcome. You did a lot of well thought out assembly. I sure hope I'm wrong......
 
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ballisticexchris

Guest
Suspension travel is 7.5 at the axle, suspension geometry allows for significantly less travel at the shock.
I get that. That's why I edited my post. Still I think those coils have a chance of hitting.
 

jrusell

Well-Known Member
Joined
Aug 23, 2017
Messages
460
Location
Dartmouth, Nova Scotia, Canada
Hitting what? Coil bind?
Look at the first pic.
Original 160N/mm spring is 184mm free length, New spring 170N/mm 220mm free length with 2 mm less installed preload.
Yes the wire is slightly larger 14.75mm vs the 13.5mm for the black original spring, but when worked out the total gaps is almost exactly the same for both springs.
Linkage ratio is 2.91 for our linkage, so 65-66mm shock travel for 190mm wheel travel. Coil bind is not an issue.
 
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