Front end chatter on heavy braking - wtf?

Originally Posted by stuartyboy

Suspension bottoming out - 99% certain. Did the rear end come up like a mini stoppie? Dubious about it being dust on the brakes...would be more of a vibtration under hard braking.

Have you set up your preload properly?

Didn't think they were compressing that much. I was using the back brake too so I don't think I lifted the back. I will check the preload. The fork oil is probably a bit old now (2 years?). Was quite a rymthmic clatter, rather than something sporadic. Pulsing - if you see what I mean?


Now that you mention it, the "clack" noise did sound like when the forks used to bottom out over large bumps before I replaced the stock oil for thicker stuff. I didn't upgrade the springs though so it's probably that they are bottoming out under progressive braking.

[northwind]

You'd probably feel bottoming out rather than hearing it though... Cabletie time! Other possibilites, too much rebound damping from the heavier oil coupled with standard springs? That increases the time taken to recover from bumps or shocks, even tiny ones.

Not really enough info to do more than guess though.

Originally Posted by lawson17

I have experienced the same thing, didn't feel like forks though, sounded more like it was coming from gearbox or something?

I'm not saying it was but thats where it seemed to be coming from.

That was under heavy braking when a pheasant popped out the hedge!

This was probably the back wheel skipping about and making the chain clatter about.

Originally Posted by andyaikido

This was probably the back wheel skipping about and making the chain clatter about.

Yep, I've had this so many times. It's the chain rattling about when the back is skipping. It sounded like it was coming from the front as well.

[northwind]

That rattling/drivetrain noise from the gearbox/chain can also happen when you're braking against the engine- wheel is trying to speed up, brakes are trying to slow it down, leads to Badness. Just like trying to pick up speed in too high a gear. CLUNKCLUNKLUNK

Originally Posted by andyaikido

This was probably the back wheel skipping about and making the chain clatter about.

Ahh, thanks, that makes sense! Good job all you guys are here.

I woudl still check your wheel bearing as this is exactly the symptons I had from a knackered bearing. Better safe than sorry.