Answered Does anyone know what this horrible sound is?

[EnjOy!]

So, sometimes when I'm about to go up on a jump, my (I think) front suspension makes this horrible sound. (Cube Stereo hybrid 140 race with Fox 34 Rhythm fork)
Does anyone know why this happens and how to fix it?
My friend was able to record it, here's the vid.

 

[Gary]

almost certainly sounds like your tyre buzzing something on compression.
mudguard/saddle or hose/cable would be my first port of call. or if it's the front add fork arch/crown to that list

show us a side on pic of your bike with the saddle fully dropped on your dropper

 

[EnjOy!]

almost certainly sounds like your tyre buzzing something on compression.
mudguard/saddle or hose/cable would be my first port of call. or if it's the front add fork arch/crown to that list

show us a side on pic of your bike with the saddle fully dropped on your dropper

This is the best side pic i have with saddle fully dropped, i could take a new one tomorrow if it's not good enough. To me the sound seems to come from the front, it happens right in the curve of the jump when my front suspension is compressed. I have no mudguard installed

 

[Gary]

remove all air from the shock and fork and fully bottom out both ends to see if anything is contacting the tyres when it bottoms out.

(take a note of your pref air pressures first if you don't already know them)

you didn't have a saddle bag fitted by any chance?

 

[EnjOy!]

remove all air from the shock and fork and fully bottom out both ends to see if anything is contacting the tyres when it bottoms out.

(take a note of your pref air pressures first if you don't already know them)

you didn't have a saddle bag fitted by any chance?

Thank you, I will do this tomorrow and let you know the results
No saddle bag either no

 

[Rusty]

Check your cables. Had a brand new big do that on g-outs and found one of the cables needed to be adjusted to stop it touching the tire under full compression. LBS said that could not happen so I dumped the air out of the shock and proved it right in front of them - and asked for the cables to be checked and replaced under warranty if any damage noted.

 

[EnjOy!]

So, I just removed all the air from my suspension and even though i don't have a mudguard installed, I do have a piece of plastic installed where I can put a mudguard on. And when I compress my fork all the way this touches the tire, so I hope this was the problem because that's an easy fix. I still think it's a weird sound for plastic touching rubber tho

 

[Gary]

it's not really the sound of rubber touching plastic. More the sound of your rubber tyre knobs scraping past plastic and deforming and EXACTLY the sound I used to hear at DH races in the 90s and 00s when many bikes bottomed out on harsh landings and the rear tyre buzzed the underneath of the bikes saddles.

You're lucky that plastic bung didn't stop your tyre resulting in you being thrown over the jump without your bike. Running a taller tyre it could.

 

[EnjOy!]

You're lucky that plastic bung didn't stop your tyre resulting in you being thrown over the jump without your bike. Running a taller tyre it could.

I was thinking the same thing, could have been painfull. I just took it off, it's a crap mudguard anyways, keeps slipping off when i'm riding over small bumps.

Thanks a lot!

 

[Mikerb]

well spotted Gary