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Rear shock tester

4846 Views 13 Replies 7 Participants Last post by  ARider
i want to design & build one of these as buying one is not an option in the country i live......

But im no sure about some of the dimensions.......

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the main thing im not sure is how much leverage do i have to design in the tool

mainly bikes have a leverage ratio is around 1:3 but thats when you sit on the rig with your whole weigh..........

in this case you have to put pressure on the shock only with one hand.......so it must be more that 1:3

But dont know exactly how much...........

and also im open to any other advise...............giudance or any kind of tip......for building this tool


Thanx a lot...........
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For trunnion shocks, Fox makes a nice tool that you can use with a dyno as well as to work on the shocks;
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Here is a very nice dyno to use for design inspiration;

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There are two that I use;

One has a handle that has maybe 18" of leverage on the shock. It is mostly used for checking the damper alone, not for a shock that is aired up.

The other one has a longer handle, maybe 28-36" of leverage on the shock. This one is mainly used for equalizing the positive/negative air chambers on shocks without a bike. But it could work for testing a fully aired shock.

I think mostly you look at testing the damper alone, and test the fully aired shock on a bike.

The shock mounts can be super simple. You don't need to capture each end, the bottom can just rest on a piece of wood or plastic. The top mount can just be a simple 1/2" bolt that passes through the eyelet (with hardware removed). All shocks have a 12.7mm diameter hole in the eyelet, so a 1/2" bolt is perfect.

For trunnion shocks, Fox makes a nice tool that you can use with a dyno as well as to work on the shocks;
View attachment 1969234



Here is a very nice dyno to use for design inspiration;


Thank you very very much for your support & info

I really dont kow why the heck no link works for me on MTBR..........it just shows 403 forbiden

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But after a search i came to this is it the one you linked ?

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Thank you very very much for your support & info

I really dont kow why the heck no link works for me on MTBR..........it just shows 403 forbiden

View attachment 1969269
you have a tracker
that can be a problem
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For trunnion shocks, Fox makes a nice tool that you can use with a dyno as well as to work on the shocks;
View attachment 1969234
Do you happen to know the name for this part or perhaps even the product code? Thanks.
4x leverage is good to fully stroke a pumped up shock. You want a stronger base than most use.

Here is mine: http://instagr.am/p/CF0wpiYHEmR/ I have changed the upper plate design since to work better with trunnion shocks and still haven't wired in the load-cell. It is an extremely useful workshop tool.
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4x leverage is good to fully stroke a pumped up shock. You want a stronger base than most use.

Here is mine: http://instagr.am/p/CF0wpiYHEmR/ I have changed the upper plate design since to work better with trunnion shocks and still haven't wired in the load-cell. It is an extremely useful workshop tool.
Load cell ?? whats that brother ?
The load cell is the silver & white box under the shock. It is for measuring force.
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Load cell ?? whats that brother ?
It's the mechanical part of a digital force meter. So later I can add a display that tells me how much force is on the shock.
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Do you happen to know the name for this part or perhaps even the product code? Thanks.

The part number seems to change around a bit, but it's called;
Fox 54mm Trunnion Eyelet Torque Fixture Tool
The part number seems to change around a bit, but it's called;
Fox 54mm Trunnion Eyelet Torque Fixture Tool
If you get the Andreani shock tester you can use the trunnion mount part as a trunnion tool, except it does not have a square drive for a torque wrench,
If you get the Andreani shock tester you can use the trunnion mount part as a trunnion tool, except it does not have a square drive for a torque wrench,
The socket drive is great for shaft removal, and if you have an X2 or DPX2 you will probably be using it... 😁
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