Removal and refitting of shock

[steve_sordy]

Time for the shock to have a service. Deflated it and then loosened the upper and lower mounting bolts, so far so good. But then the bolts were held in by residual pressure in the shock (all the air was deffo out, I even fully compressed the shock whilst pressing the valve pin with an Allen key). I used a tyre lever to move the bolt heads out a bit further and then the same tyre lever and a hammer to knock the bolts out. I even tried putting some weight on the saddle to try to find a position where the bolts were not in shear, without success. Anyway, I got the bolts out without any damage to anything.

But I'm not looking forward to getting them back in again. Any tips? I feel that there must be a knack to it!

 

[Jackware]

Was the bike on the ground or in a stand?

 

[steve_sordy]

On the ground.
I have a workstand

 

[Voluptua]

Could you hold the shock in compression with some cable ties?

 

[steve_sordy]

Could you hold the shock in compression with some cable ties?

I see where you are coming from. Good idea! Each end of the shock where the ties would go is slightly domed, so they may slip off during the process. But the extension is controlled by the Rebound so I'm not going to get a shock ricocheting around the garage!

 

[Gspot]

Try tying the tubes?

 

[KenX]

Just unweight the rear wheel, the bolts will slide out easy then.........

 

[Mikerb]

I was thinking the same. Surely you need the rear triangle hanging free .....but with protection to stop the linkage hitting the frame when the shock is removed.

 

[Mikerb]

I was thinking the same. Surely you need the rear triangle hanging free .....but with protection to stop the linkage hitting the frame when the shock is removed.

...and I see no need to remove the air.

 

[steve_sordy]

Just unweight the rear wheel, the bolts will slide out easy then.........

Unless I have misunderstood you, it is nothing to do with unweighting the rear wheel. The shock still had some air in it despite fully compressing the shock and pressing the valve nipple. Because the shock still had some air pressure it was pushing on the bolts. I tried pressing on the saddle to compress the shock while I was pulling on a bolt, in the assumption that at some point between pressing and releasing, the shock mounting bolt would be loose. It never was.
The LBS said to remove the valve core and that would let the remaining few psi out.

 

[steve_sordy]

Try tying the tubes?

I do not understand that advice.

 

[steve_sordy]

...and I see no need to remove the air.

Err, that comment caught me by surprise! I would love to hear more.

 

[Mikerb]

Err, that comment caught me by surprise! I would love to hear more.

I was just thinking that whilst the shock is pressurised it is at max extension and if the rear triangle is left to hang the shock is at the frame eye to eye measurement so there should be no pressure on the bolts. Maybe you had the opposite issue with your shock in that when you let the air out the shock was sucking back.

 

[steve_sordy]

I was just thinking that whilst the shock is pressurised it is at max extension and if the rear triangle is left to hang the shock is at the frame eye to eye measurement so there should be no pressure on the bolts. Maybe you had the opposite issue with your shock in that when you let the air out the shock was sucking back.

I can follow that logic, I will experiment with that when I get the shock back.
I didn't have the opposite issue as the shock was definitely extending back to full extension when left to itself. It moved quite slowly because the low pressure was only just able to overcome the rebound damping.

 

[Mikerb]

I think on some of the how to videos they let the air out because they then go on to doing a service and they leave the top bolt in to help start loosening the can. Anyway....you have reminded me my shock is probably due a service!!

 

[KenX]

The shock at full extension holds the rear triangle in position, remove the shock with full air, or a coil with the spring in and if the bike is in a work stand, the weight of the rear wheel and triangle will pull the bottom attachment point away from the shock, so you need to just take the weight of the rear end on a box or something and the bolts will slide out, no need to let air out or unwind the spring..........

 

[steve_sordy]

That makes sense. Do it in the workstand, not on the floor!