Sharp edges on the one side of Shimano RT76 rotors
#1
Sharp edges on the one side of Shimano RT76 rotors
This might be oddly specific question but according to information written about car disc brake rotors with low quality sharp slots accelerates pad wear.
Shimano RT66 rotor was with the same level of sharpness on both sides but for some reason RT76 is sharp on one side and rounded on the other. This might create premature pad wear on one side?
Shimano RT66 rotor was with the same level of sharpness on both sides but for some reason RT76 is sharp on one side and rounded on the other. This might create premature pad wear on one side?
Last edited by sysrq; 09-06-23 at 04:33 PM.
#2
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Is this on the outer edge of on the braking surface itself?
Rotor outer edges can get razor sharp as they wear. One of the many reasons to not touch them. The pads act like sharpening stones/razor strap. I would imagine any holes or slots would as well. But the sharp edge should point opposite the direction of rotation thus not be an issue
BTW my fix for squeaky rotors it to clean them up with a power sander. An option if you are worried about the edge.
Rotor outer edges can get razor sharp as they wear. One of the many reasons to not touch them. The pads act like sharpening stones/razor strap. I would imagine any holes or slots would as well. But the sharp edge should point opposite the direction of rotation thus not be an issue
BTW my fix for squeaky rotors it to clean them up with a power sander. An option if you are worried about the edge.
#3
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So what do you want to do about it? Sand them down and remove the sharp edge? That'd be even more wear.
I suppose you could replace it with something else. But then while you won't have any wear, you also won't have any useful life out of it and your new stuff will be wearing out sooner than it would if you waited for the stuff you replace to wear out.
I suppose you could replace it with something else. But then while you won't have any wear, you also won't have any useful life out of it and your new stuff will be wearing out sooner than it would if you waited for the stuff you replace to wear out.
#4
Is this on the outer edge of on the braking surface itself?
Rotor outer edges can get razor sharp as they wear. One of the many reasons to not touch them. The pads act like sharpening stones/razor strap. I would imagine any holes or slots would as well. But the sharp edge should point opposite the direction of rotation thus not be an issue
BTW my fix for squeaky rotors it to clean them up with a power sander. An option if you are worried about the edge.
Rotor outer edges can get razor sharp as they wear. One of the many reasons to not touch them. The pads act like sharpening stones/razor strap. I would imagine any holes or slots would as well. But the sharp edge should point opposite the direction of rotation thus not be an issue
BTW my fix for squeaky rotors it to clean them up with a power sander. An option if you are worried about the edge.
#5
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my best advice to you is to Shut Up and Ride.
if anything.. the stamping radii would hold dirt, act as ramps that would aid that dirt getting between the pad and rotor, creating tiny little trenches that will eventually become bigger trenches......
And you'll have pre-sanded the living crud out of those discs long before those trenches ever become visible.... which creates random wear, btw...
part of maintaining a Race Car Clutch system is to resurface the Faces involved before every event, if the crew is thurough and blessed with time... Top fuel and funny cars get that resurfacing done between Every Run. Their flywheels and pressure plates get re-machined regularly too.
i'd imagine team-sponsored bike racers get new discs EVERY EVENT or two, depending on budgeting.
Go to an MTB event and ASK Them if they bother chamfering each clean out hole on the new discs.
i bet they'll say "No".
BTW..... Pad Wear Equals Fresh Braking Surface.... which is what you do when you sand the discs....
i resurface pads to clean them.. the side of a 10" grinding wheel works great.. if your fingertips are callused enough, and you're skilled with that sort of thing... getting the pressure even is not easy...
Last edited by maddog34; 09-06-23 at 05:35 PM.
#6
#8
In the end settled for TRP TR33 since TRP doesn't have any rotors classified as narrow or wide so they should work with TRP HY/RD calipers using wide type Shimano pads. Most of them being drilled instead of slotted also seems to be more inline with Shimano recommendations for wide type resin pads.
Turns out TRP TR33 is 201 or 202 mm instead of specified 203 mm, so the washers under the caliper might not be needed anymore, except for thermal expansion or radial pad adjustment (there was some clearance issues with Shimano).
TRP TR33 also has 1.84 mm thickness instead of 1.76 mm like Shimano.
The only current drawback is outer edge of the pads being aligned in the middle of drillings which might create stress risers as the rotor wears.
Judging by wear track on old rotor there shouldn't be any stress risers since there aren't any sharp corners caused by wear.
Turns out TRP TR33 is 201 or 202 mm instead of specified 203 mm, so the washers under the caliper might not be needed anymore, except for thermal expansion or radial pad adjustment (there was some clearance issues with Shimano).
TRP TR33 also has 1.84 mm thickness instead of 1.76 mm like Shimano.
The only current drawback is outer edge of the pads being aligned in the middle of drillings which might create stress risers as the rotor wears.
Judging by wear track on old rotor there shouldn't be any stress risers since there aren't any sharp corners caused by wear.
Last edited by sysrq; 09-08-23 at 10:02 AM.