What thickness do you use your disc rotors to?

RedClip

I've just replaced my Ultegra Ice Tech Freeza Centre Lock rotors, they were measuring 1.35mm (3770 miles travelled on them).
The minimum recommended thickness is 1.5mm.

Could I have got away with a few more hundred miles on them, or was I pushing my luck by not replacing them at around 1.5mm thickness?

I'm using the bike for leisure cycling, but I live in an area with lots of hills.

Thank you.

ballysmate

My rotors have done about 13,000 miles.
Not entered my head to check their thickness, never mind replace them.
Would expect to get many more miles out of them.

RedClip

ballysmate said:

My rotors have done about 13,000 miles.
Not entered my head to check their thickness, never mind replace them.
Would expect to get many more miles out of them.

Thanks for the reply.
The mileage difference, might be down to, if you live in a flatter area than me. What types of brake pads you've been using. Or the most probable answer, you've just got balls of steel and just don't need to brake as much 😁

First.Aspect

I've been using discs to commute since 2009. Never replaced discs. Not saying I've had a single set by any means but I reckon my commuter has done north of 10k on the same set and I'm with Ballysmate in replacement not even being on my radar.

I don't own a micrometer.

Dorset_Boy

Over 21,000 kms (with 245,000 m climbed) on my Canyon Ultimate. Never occured to me to change the discs yet.

RedClip

Thanks for the replies
Can you please measure your thickness, no not that, your rotor thickness and post it, if possible. Without that measurement, the distance travelled might not be important number.

I'm not being critical, but everyone is saying they haven't considered their rotors, their means of stopping the bike.
From a safety or maintenance POV. Isn't that the equivalent of a motorist saying they don't check the tyre tread depth?
So they go for a drive in the rain, they apply the brakes, they can't stop, crash into a car that's got a seized engine, because that driver didn't check if there was any oil in it?

veronese68

To measure them accurately I'd need a micrometer as a vernier caliper would only measure the edge which should be thicker. I can't be bothered to mess about with spacers and subtraction.
To be honest I would expect them to get quite heavily scored before they become so worn that they need replacing. The scoring is likely to be the thing that would make me replace them.
Mileage is going to vary due to different riding styles, terrain and pad materials. Harder metallic pads will wear discs faster.

whyamihere

Mileage is irrelevant, it depends on how you use the bike, conditions etc. I would definitely replace those rotors. They're already 10% below the recommended minimum. They probably won't fail, I'm sure Shimano's recommended minimum is very conservative, but £100 for replacement rotors is a lot better than having no brakes heading down a steep hill.

First.Aspect

Nope. The analogy would be between checking tread depth on a car and checking your bike's tyres. On account of them both being to do with tyres.

I have two questions for you:

1. How often do you check the discs of your car?
2. How often did you used to check the material thickness of the brake tracks of your bike wheels, before you got discs?

RedClip

veronese68 said:

To measure them accurately I'd need a micrometer as a vernier caliper would only measure the edge which should be thicker. I can't be bothered to mess about with spacers and subtraction.
To be honest I would expect them to get quite heavily scored before they become so worn that they need replacing. The scoring is likely to be the thing that would make me replace them.
Mileage is going to vary due to different riding styles, terrain and pad materials. Harder metallic pads will wear discs faster.

Understood.

RedClip

whyamihere said:

Mileage is irrelevant, it depends on how you use the bike, conditions etc. I would definitely replace those rotors. They're already 10% below the recommended minimum. They probably won't fail, I'm sure Shimano's recommended minimum is very conservative, but £100 for replacement rotors is a lot better than having no brakes heading down a steep hill.

Thank you very much.
Agreed.

RedClip

First.Aspect said:

Nope. The analogy would be between checking tread depth on a car and checking your bike's tyres. On account of them both being to do with tyres.

I have two questions for you:

1. How often do you check the discs of your car?
2. How often did you used to check the material thickness of the brake tracks of your bike wheels, before you got discs?

The analogy could be about anything. Checking your rotors and a fishmonger selling bad fish.
Without a check of the rotor or fish, you don't know if it's "off". The important thing is to check.

1. I don't own a car, but I'd assume the annual MOT test would check the discs. Giving an indication that the discs are in good condition, and would last until at least the next annual check.
2. I only had rim brakes when I was a child

First.Aspect

RedClip said:

First.Aspect said:

Nope. The analogy would be between checking tread depth on a car and checking your bike's tyres. On account of them both being to do with tyres.

I have two questions for you:

1. How often do you check the discs of your car?
2. How often did you used to check the material thickness of the brake tracks of your bike wheels, before you got discs?

The analogy could be about anything. Checking your rotors and a fishmonger selling bad fish.
Without a check of the rotor or fish, you don't know if it's "off". The important thing is to check.

1. I don't own a car, but I'd assume the annual MOT test would check the discs. Giving an indication that the discs are in good condition, and would last until at least the next annual check.
2. I only had rim brakes when I was a child

Oh well in that case this is a bit like getting a hair cut,.or peeling a banana then isn't it?

RedClip

First.Aspect said:

RedClip said:

First.Aspect said:

Nope. The analogy would be between checking tread depth on a car and checking your bike's tyres. On account of them both being to do with tyres.

I have two questions for you:

1. How often do you check the discs of your car?
2. How often did you used to check the material thickness of the brake tracks of your bike wheels, before you got discs?

The analogy could be about anything. Checking your rotors and a fishmonger selling bad fish.
Without a check of the rotor or fish, you don't know if it's "off". The important thing is to check.

1. I don't own a car, but I'd assume the annual MOT test would check the discs. Giving an indication that the discs are in good condition, and would last until at least the next annual check.
2. I only had rim brakes when I was a child

Oh well in that case this is a bit like getting a hair cut,.or peeling a banana then isn't it?

It's life or death to this fella.