Disc/rotor thicknes...
 

[Closed] Disc/rotor thickness

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I've got mt7s but the rotors have a little warp, enough to drag, which I felt I felt in the lakes at the weekend.

I'm thinking of putting hope floating rotors on (I likes the noises) but have read there is a thickness difference but can't find the info.

Magura seem to be 2.0mm with a 1.8mm wear limit. Anyone know thickness of hopes? My Google ability is poor.


 
Posted : 24/04/2018 7:56 am
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1.8mm +/- .05


 
Posted : 24/04/2018 8:36 am
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Can't you just bend them straight?


 
Posted : 24/04/2018 9:15 am
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Pair of long nose pliers and bend it straight again? Only takes a few minutes...

Even brand new rotors often need a tweak.


 
Posted : 24/04/2018 9:24 am
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Rotor straightening is the only sensible use for an adjustable spanner.


 
Posted : 24/04/2018 9:33 am
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Erm yeah but shiny.


 
Posted : 24/04/2018 10:57 am
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Rotors get slightly bent all the time, checking them is as frequent a job as checking tyre pressures, nearly.


 
Posted : 24/04/2018 11:12 am
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Please please please use the proper tool, they're not expensive (circa £15) and you'll use it a lot.
As mentioned above sometimes even new ones need tweaking - transportation of fresh ones takes its toll.


 
Posted : 24/04/2018 12:03 pm
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Please please please use the proper tool

why? I don't think this is an application where you need the proper too just because someone made one.


 
Posted : 24/04/2018 12:38 pm
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Long nose pliers here, since 1999...  No issues...


 
Posted : 24/04/2018 12:47 pm
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Considering the price, you think they'd make ones that were at least straight when they came from the factory


 
Posted : 24/04/2018 1:02 pm
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Well I never there really is a "proper tool"

God bless park, they know how to separate people from their money don't they...


 
Posted : 24/04/2018 11:06 pm
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Ok so the wear limit on magura discs is 1.8mm and hope start at 1.8mm. Does this mean that hope discs are too thin? Will the pistons push out on a worn pad?


 
Posted : 25/04/2018 7:05 am
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The wear limit is in relation to the rotor thickness, not the permissable excursion of the pistons. I thought that Maguras could be run right down to the backplate with no piston issues, like pretty much any disc brake. I would think that they have to be designed like this from a safety point of view anyway.

I doubt that 0.1mm per piston is going to change anything.


 
Posted : 25/04/2018 8:12 am
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I've always used my thumbs to straighten rotors.


 
Posted : 25/04/2018 8:50 am
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Well I never there really is a “proper tool

Unfortunately, there are lots of them - and a significant proportion seem to have driving licences 🙁


 
Posted : 25/04/2018 10:11 am
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Rotors get slightly bent all the time, checking them is as frequent a job as checking tyre pressures, nearly.

Really? What are you doing? I think I have only had to true a disc once in my life?


 
Posted : 25/04/2018 10:43 am
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Rotors get slightly bent all the time, checking them is as frequent a job as checking tyre pressures, nearly.

as above.  I've replaced one bent rotor in nearly 20 years of disc brake use.  Slightly out isn't worth worrying about and trying to correct normally causes more problems than it solves IME.


 
Posted : 25/04/2018 10:59 am
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Never even thought about rotor thickness or checked mine - how often do you typically replace?


 
Posted : 25/04/2018 1:28 pm
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Minimum disk thickness is more to do with the structural integrity of the disk and its ability to dissipate heat that any caliper/pad issues.


 
Posted : 25/04/2018 1:45 pm