Anybody had issues with broken upper bolt holding shock

Slow Goat

New Member
Aug 4, 2021
19
6
USA
I have seen some reports of upper (front) bolts holding shock snapping on Rise. Anybody had such bad luck? They are made of aluminum. Is there an alternative part made out of steal?
 

IRideBikes

Member
May 9, 2020
12
16
Preston
ive seen one, on a bike with a coil shock and a very heavy spring on but nothing else so far. ..hard to say whats gone on from a few reports though, as you never know what conditions it has failed under, ie repeated heavy bottom outs, putting coils on bikes that were never designed for them will always shorten the fatigue life of a component, particularly those sold in a lightweight guise. i wouldnt worry too much personally
 

steve_sordy

Wedding Crasher
Nov 5, 2018
9,033
9,483
Lincolnshire, UK
I've had a lower shock mounting bolt fail on a Focus Jam2. It came loose and slowly unscrewed itself. When the threaded section came under shear, it sheared! The solution was a new bolt (obvs) but I used Loctite blue and the correct torque. It never came loose again.

My fault, I should have checked the bolt torque when I bought the bike and/or checked on a regular basis for loose bolts. We all know that is good advice, how many times have we seen it written down or been told it? But I still get caught out from time to time. :rolleyes:
 
Last edited:

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,581
5,068
Weymouth
Its a problem not restricted to any brand of bike and the cause is as Steve above has said.....incorrect installation. The shaft of the bolt and the rear face of the bolt head, should be greased, and blue loctite applied to the thread (after ensuring the thread is cleaned with IPA or similar). The bolt should then be torqued to spec and left for 24 hours undistrurbed to allow the loctite to create a seal.

That applies to any bolt where there is no other mechanism to retain torque.....like a spring or serrated washer or where a bolt compresses 2 components and those components effectively act as a spring........ or rotational forces act to try to tighten rather than loosen the bolt.

A male /female thread is designed such that when the correct torque is applied the mating faces of the threads reach maximum friction. The torque is set below the shear point of the bolt used. Engineers have tables that specify the required torque based on materials used, bolt diameter and thread pitch. So it is specific....not just made up!

Using a steel bolt through an ally shock mount is a bad idea since those 2 metals react together causing corrosion.

Neither is copper slip ( which is a grease, so totally counter productive to maintaining torque)/anti seize a good idea. Copper slip is designed for high temperature applications and the copper in it, in contact with ally, only needs a salt added to create an unwanted chemical reaction. That salt can come from road salts etc. Copper slip is used on components in a high temperature environment.............classic application would be the threads of a spark plug ( which has a form of spring washer to maintain torque.)
 

PsyMac

New Member
Jul 16, 2023
5
0
DK
This has just happened to my Orbea Occam. The bolt just snapped on landing a 1m drop. The problem now is getting the remaining (theaded end) out (it does not go all the way through but bolts into the top tube).
Any suggestions on how to do that?
Thanks View attachment 120289
20230713_144050.jpg
 

Plummet

Flash Git
Mar 16, 2023
1,152
1,634
New Zealand
It's a sacrificial bolt. It's designed to bend and or fail so the frame doesnt. Make the bolt stronger and ge transfer the failure point to the next week point on the frame.


If you are snapping or bending shock bolts it means you have a) set your suspension up too soft and are bottoming out too hard too often. And or b) you are riding the bike past its design limits.


The fix for a) is to set the suspension up correctly for your weight so you old bottom softly on your hardest hit.

The fix for b) is to buy a a stronger bike with more travel that can handle the abuse you are throwing at it.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
9,033
9,483
Lincolnshire, UK
............. The problem now is getting the remaining (theaded end) out (it does not go all the way through but bolts into the top tube).
Any suggestions on how to do that?
............
There are extraction tools that look very much like a drill bit that spirals the wrong way. You also need a drill that has a reverse gear.

First thing is to drill a small pilot hole with a conventional drill bit. That will give the extraction tool something to bit on quickly, rather than skittering about on the fractured surface (you might have that problem with your pilot drill, so try a centre punch first to make a start).

I know you said the bolt does not go all the way through, but can you actually see the other end of it? If so, you may be lucky. Just drill through from the other end with a conventional drill bit and the drill set in the normal clock wise direction. If you are lucky, the torque from the drill will unwind the broken bolt.
 

PsyMac

New Member
Jul 16, 2023
5
0
DK
There are extraction tools that look very much like a drill bit that spirals the wrong way. You also need a drill that has a reverse gear.

First thing is to drill a small pilot hole with a conventional drill bit. That will give the extraction tool something to bit on quickly, rather than skittering about on the fractured surface (you might have that problem with your pilot drill, so try a centre punch first to make a start).

I know you said the bolt does not go all the way through, but can you actually see the other end of it? If so, you may be lucky. Just drill through from the other end with a conventional drill bit and the drill set in the normal clock wise direction. If you are lucky, the torque from the drill will unwind the broken bolt.
Thanks. I do have an extraction tool actually.
I can only see as much is shown in the photo, from the one side. I'll give that a go
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,581
5,068
Weymouth
There are extraction tools that look very much like a drill bit that spirals the wrong way. You also need a drill that has a reverse gear.

First thing is to drill a small pilot hole with a conventional drill bit. That will give the extraction tool something to bit on quickly, rather than skittering about on the fractured surface (you might have that problem with your pilot drill, so try a centre punch first to make a start).

I know you said the bolt does not go all the way through, but can you actually see the other end of it? If so, you may be lucky. Just drill through from the other end with a conventional drill bit and the drill set in the normal clock wise direction. If you are lucky, the torque from the drill will unwind the broken bolt.
Agreed but there is something you could try first. Remove the bottom shock fixing so that any pressure on the remains of the bolt is alleviated. As you move the shock now through the available amount of travel does the bolt stub remain still or does it rotate with the shock.
Whilst severe bottom out may shear the bolt it appears to me that more often the reason for breakage is that the bolt has come loose maybe because it is seized on the bushing. When unscrewed slightly the weakest part of the bolt........the beginning of the threaded section.......is then taking the strain.

With the back end of the shock unbolted you may find that the stub is in fact loose/ partially unscrewed. If that is the case you may even be a ble to lever the shock to one side a little and unscrew the remains of the bolt by putting some pressure on it with a punch or similar when moveing the shock clockwise and removing that pressure when moving the shock anticlockwise.....................or by glueing another bolt to the stub with araldite or super glue ( not hugely strong so only worth trying if the stub is in fact loose.
 

PsyMac

New Member
Jul 16, 2023
5
0
DK
Thanks for the suggestion. Good to know possible causes. I just bought the bike used, in good condition, rode it just once before. It is a possibility that the bolt had become loose, but I did bottom out when it snapped, most likely that is the cause. Will need to adjust the travel.
 

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