Chasing an annoying...
 

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Chasing an annoying rattle…

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My Stumpy has got a really annoying rattle when going fast over repeated rough terrain (rock gardens / stutter bumps mainly). It is definitely from the rear end.

Things I’ve checked:

All bolts are done up correctly (plus it’s the last model Stumpjumper with the flex stay suspension so not that many bolts to check!)

Brakes - they are the infamous rattling shimano slx, BUT the rattle remains even if I pull the back brake. I suppose the only way to fully be sure is to remove the rear pads and give it a ride, but given it only happens when going fast over rough terrain I’m a bit apprehensive of doing so.

The clutch on the mech - thats what I first thought it was but it’s fine and working as it should.

Any other ideas? Thanks!


 
Posted : 30/07/2024 8:26 am
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I'd be checking cables and shock bushings.


 
Posted : 30/07/2024 8:28 am
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Cassette fully tight?


 
Posted : 30/07/2024 8:53 am
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I’ll check the cassette, good point.

Don’t think it’s the cables although I’ve only had a cursory check - it’s internally routed.

I’m pretty certain it’s from right at the back of the bike, but would be willing to check the shock bushings - except I don’t know how?


 
Posted : 30/07/2024 9:00 am
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I chased a rattle for ages and replaced all the bearings in my frame only for it to turn out it was my rear  floating rotor which had developed play...


 
Posted : 30/07/2024 9:03 am
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Internal routed cables can be a pain for rattles - my Marin and sons older Stumpy Fatty are/were pains for rattles this way.


 
Posted : 30/07/2024 9:06 am
yodaveg, dyna-ti, dyna-ti and 1 people reacted
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I’ll definitely try the cheaper simple things first - doubt it’s my bearings given its usage.
I’ll check the rotor too to make sure that’s tight.


 
Posted : 30/07/2024 9:07 am
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Any loose spokes?


 
Posted : 30/07/2024 9:22 am
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Your teeth 😉


 
Posted : 30/07/2024 9:44 am
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Internal routed cables can be a pain for rattles

The gear cable and brake hose on my Hightower have a foam tube around them inside the rear end of the frame to stop rattling, not sure if specialized do similar but if not I wouldn't be surprised if thats where the noise is coming from


 
Posted : 30/07/2024 10:18 am
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@pothead - I’m not sure but I hope not as not sure how I’d sort that!

@matt - haha think you’ve cracked it!


 
Posted : 30/07/2024 10:39 am
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Older Fox float internals can rattle, known issue solved by getting a different shock.


 
Posted : 30/07/2024 11:08 am
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It’s a newish fox dps shock, and I’m fairly confident the rattle is from right at the rear of the bike, so hopefully can rule that out!


 
Posted : 30/07/2024 11:18 am
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Dropper post/Saddle?

My chain still rattles a bit when I'm in the little sprockets at the rear - there's a bit of slack and the the chain starts off close to the chainstay.

valve stem? Less likely with tubeless...


 
Posted : 30/07/2024 6:38 pm
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Guess I’ll just note down all the suggestions on here and work my way through them. Hopefully will be pads or cassette not quite right as easy to check and sort.


 
Posted : 30/07/2024 11:56 pm
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Clatter

Rattle

Metallic

What sort of sound


 
Posted : 01/08/2024 7:50 am
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Cassette fully tight?

This was the culprit on my latest rattle/creak.


 
Posted : 01/08/2024 9:34 am
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Rattle is the best way to describe it. Think it will either be the slx brake pads, the cassette or maybe the internal routing - but apparently this is really uncommon having checked on the Specialized forum on mtbr.

just need time to check through the suggestions above, but haven’t had it yet! Got a hardtail being delivered today so I could always just ride that instead!


 
Posted : 01/08/2024 10:32 am

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