Rear rotor failure - ever seen this?

[MTBRIDER1234]

any chance you could post a picture of both sides of the rotor? I am just curious to see if it was worn on both sides, or if the caliper was not aligned.

Nonetheless, this is why I always tell people to check their brake pads and rotors, I have seen how fast metal on metal destroys rotors and I can guarantee that a new set of pads is always cheaper than a new rotor.

Also that rotor rub must have provided some serious drag and resistance (brake rub slows you down way more than you might think)

[Hairy]

2 hours ago, Marcv said:

hey

Is the hub tight? i.e. the wheel can't move from left to right? i'm thinking maybe you braked in a corner and the wheel pushed to one side and that placed some sideways load on the disk which then sheered off.

 

The Hub used to be tight .... oh wait, you mean that hub!

[Hairy]

I am more keen to see pics of the caliper body!

[ChrisF]

26 minutes ago, MTBRIDER1234 said:

any chance you could post a picture of both sides of the rotor? I am just curious to see if it was worn on both sides, or if the caliper was not aligned.

Nonetheless, this is why I always tell people to check their brake pads and rotors, I have seen how fast metal on metal destroys rotors and I can guarantee that a new set of pads is always cheaper than a new rotor.

Also that rotor rub must have provided some serious drag and resistance (brake rub slows you down way more than you might think)

 

People often over estimate brake pad life on MTB.

 

Friend was totally surprised when I pointed out his rear brakes were a fraction of a mm from ripping in the spacer spring.

 

 

Metal on metal .... all bets are off.  

 

The wear marks certainly hints at an allignment issue.

[DieselnDust]

2 hours ago, FrancoisdeVille said:

This looks like it was worn down at the caliper to so thin it sheared off.  Not defending the brand, but it looks like caliper or worn pads. 

those edges are so precise they look like they were cut with diamond coated cutting disc.

I've never seen a disc rotor fail so uniformly, ever in 22years of disc brake use

[Jbr]

10 hours ago, Hairy said:

The Hub used to be tight .... oh wait, you mean that hub!

That hub is tight every day of the week except on fridays 😜

the wear outside the breaking track is definitely the cause of that failure is probably is due to a mis-alignment of some sort.

Even when changing your pads when needed, the rotors do wear quite quickly, I had to change my rotors on the TCR about 10 000kms in, bike probably had 5 to 10k km before me. On a mtb it could be more often not sure, would be interesting to see if the brake track thickness is still in the tolerances, if it isn’t, and if the wear is the same at the top of the track and where the mounts are, I wouldn’t blame the brand for the failure.

Also I guess that’s why we must always have two functioning brakes !  (Although if your front break fails like this on a road bike going down kloofnek it’s going to take a looong time to stop on the rear brake 😜😜)

 

 

Edited September 22, 2022 by Jbr

[Spinnekop]

I am also questioning the caliper alignment/setup.

Twice I have now found in my circle of friends (and it happened to me) that the mechanic has set up the caliper for a 160mm rotor and the bike had a 140mm rotor on.

 

[TheoG]

Just now, Spinnekop said:

I am also questioning the caliper alignment/setup.

Twice I have now found in my circle of friends (and it happened to me) that the mechanic has set up the caliper for a 160mm rotor and the bike had a 140mm rotor on.

 

Too many idiots out there that THINK they know what they doing ....  

[Rudii]

Was the major service also done by the Cyclelab workshop? And how long ago was that? Surely this must have been picked up by them.

[CLC5850]

The person at Cyclelab said he had seen it but it was not done there! Thanks for all the comments. Cheerrs

[droo]

That's just badly installed, nothing to do with the brand of rotor.

I don't think I'd be able to repeat it if I tried, but I uncover new and amazing ways to cock things up on a weekly basis so it's far from surprising.

I can't see what brand of caliper that is, but if it's Avid it's probably got something to do with the spacer washers, which are often creatively arranged.

[Johan A Marais]

13 hours ago, Hairy said:

I am more keen to see pics of the caliper body!

Pictures of Caliper's body - yes please.

 

Oops, sorry wrong forum, my bad...🤪

[dave303e]

the caliper spacer/washers/universal join spacing is incorrect on the bike. The caliper is sitting probably 3-4mm too close to the center of the axle(point of rotation). Your break pads should only contact with the outer circular part of the rotor and not the break rotor "spokes" for lack of a better word. My 2c is that someone removed the caliper at some stage and didn't put washers/spacers back in correctly...

[reteid]

never seen this before.the better question would prob be how many of these are seen by LBS around the country s they see more bikes.

[reteid]

This post just had me running to the garage to go and check rotors and brake pads on the mtb.

[Steady Spin]

I have rotors older than some hub members and I've never seen one wear like this.