Rear Shock bolt keeps snapping

[Plentipotential]

I'm on a Giant Trance and replace that bolt about every 2 years, also weigh too much.

 

1. Stainless steel fasteners are not as strong as high tensile fasteners unless you buy A4 - 80 stainless steel.

2. Titanium fasteners also come in a variety of materials and for strong you need a Grade 5 heat treated.

3. Standard high tensile fasteners with a head marking of 8.8 have a tensile strength of 800 Mpa. Stainless steel A2 - 50, 500 Mpa, Stainless A2 - 70, 700 Mpa. Titanium Grade 2, 344 Mpa and Grade 5 heat treated, 950 Mpa.

 

Cheap solution? Socket head cap screw Grade 12.9, 1200 Mpa. Make sure you get unplated as hydrogen embrittlement caused by plating will effect tensile strength. 

[DubbelBuys]

Is your shock bottoming out? If it does you may not realize how hard it's bottoming out & that may be the cause.

What I recommend to be on the safe side of bottoming out:

Deflate the shock & press it down until it bottoms out. 

Cut a piece of cable tie about 2 mm shorter than the shaft between the shock's seal & the travel indicator O-ring.

Inflate the shock & set desired sag. hop around on your bike & land as hard as you can. Check the O-ring. It should never go beyond your cable tie's length.

The large volume shocks have a much more linear stroke & may bottom out with less force than a shock with a smaller air can (inflated to the same psi / sag) The smaller air can ramps up much faster & won't bottom out that easy.

If your bike's shock has the larger air can you can always insert spacers to prevent the shock from bottoming out.

 

I can't imagine that a bolt snaps because the shock is inflated too high. 190psi for a shock isn't high at all.

If you think about it: if the shock doesn't bottom out it shouldn't snap the bolt unless there's something else causing it. (or the bolt is made out of cheese)

 

As mentioned before:

Remove the shock, cycle the suspension & feel carefully for any 'binding' in the pivots.

 

Is the frame is carbon or alu?

It may even be misalignment if it's alu & because of a crash. (or manufacturer 'defect')

 

I have rear of similar issues on some of the older Santa Cruz Bronson frames where the rear axle wears much faster than expected due to misalignment.

 

Hope this helps.

 

 

 

90kg isn't anywhere near a Clydesdale, but if a Yeti can't handle a rider of 90kg then I'll recommend another brand         

[Goodbadugly]

I'm on a Giant Trance and replace that bolt about every 2 years, also weigh too much.

 

1. Stainless steel fasteners are not as strong as high tensile fasteners unless you buy A4 - 80 stainless steel.

2. Titanium fasteners also come in a variety of materials and for strong you need a Grade 5 heat treated.

3. Standard high tensile fasteners with a head marking of 8.8 have a tensile strength of 800 Mpa. Stainless steel A2 - 50, 500 Mpa, Stainless A2 - 70, 700 Mpa. Titanium Grade 2, 344 Mpa and Grade 5 heat treated, 950 Mpa.

 

Cheap solution? Socket head cap screw Grade 12.9, 1200 Mpa. Make sure you get unplated as hydrogen embrittlement caused by plating will effect tensile strength. 

This

[porqui]

This

 

Yep !!