Bike Forums

Bike Forums (https://www.bikeforums.net/forum.php)
-   Bicycle Mechanics (https://www.bikeforums.net/bicycle-mechanics/)
-   -   Disc rotor alignment (https://www.bikeforums.net/bicycle-mechanics/1173976-disc-rotor-alignment.html)

rbrides 05-26-19 08:00 AM

Disc rotor alignment
 
I have a "gravel" bike with disc brakes. I bought a second wheel set/tires and brake discs to have one set up for road and another for gravel. Here is my concern. The new discs sit approximate 1/16 of an inch (maybe 1/32) more inboard than the original discs such that it slightly contacts the inboard pad, regardless of which wheel I put it on. It is as if the disc needs a washer/spacer/shim between it and the wheel To keep it off the pad. As if the housing of the new discs are that little bit more narrow than the original.




Is this a big deal? Little deal? No deal at all? How much "gap" is appropriate between discs and pads?




The Wheel spins freely enough (a subjective evaluation) so maybe the friction (if any) is not an issue. I don't know. Should I just try to adjust the pads in caliper and push the pad away from the disc? If so, how?




Both sets of discs are Shimano 160s. Wheels are thru-axles. I torque to bike's specs.




Thanks for reading.

fietsbob 05-26-19 08:22 AM

Option , ( Post mount /ISO style) reset caliper ..loosen bolts hold brake on , while you re tighten those bolts ..

only takes a moment to do..

Andrew R Stewart 05-26-19 08:38 AM

Ah, the cost of improvement.

This is some of the reality of disk brakes with their minimal pad/rotor clearances and varying tolerances of the various parts that make up the system. First- As long as there's no pad/rotor rub all is good. Second- Shims that fit between the rotor and hub are available for fine tuning where the rotor sits WRT the axle end. Third- Whatever you do do will evolve and likely need to be revisited as things wear. Andy

jlaw 05-26-19 08:51 AM


Originally Posted by rbrides (Post 20947994)
I have a "gravel" bike with disc brakes. I bought a second wheel set/tires and brake discs to have one set up for road and another for gravel. Here is my concern. The new discs sit approximate 1/16 of an inch (maybe 1/32) more inboard than the original discs such that it slightly contacts the inboard pad, regardless of which wheel I put it on. It is as if the disc needs a washer/spacer/shim between it and the wheel To keep it off the pad. As if the housing of the new discs are that little bit more narrow than the original.




Is this a big deal? Little deal? No deal at all? How much "gap" is appropriate between discs and pads?




The Wheel spins freely enough (a subjective evaluation) so maybe the friction (if any) is not an issue. I don't know. Should I just try to adjust the pads in caliper and push the pad away from the disc? If so, how?




Both sets of discs are Shimano 160s. Wheels are thru-axles. I torque to bike's specs.




Thanks for reading.

What make/model of brakes? Can you post a picture?

I have TRP Spyre mechanical disc brakes on one of my bikes. When I switch wheels all I have to do is adjust each pad in or out using a set screw - 3 mm allen. I adjust the pads inward until they rub and then back off about 1/8 turn. Simple - takes about 1 minute per wheel.

What tyoe of brake pad adjustment mechanism do your calipers have?

u235 05-26-19 10:16 AM


Originally Posted by fietsbob (Post 20948018)
Option , ( Post mount /ISO style) reset caliper ..loosen bolts hold brake on , while you re tighten those bolts ..

only takes a moment to do..

That's what I do, adds about 1 minute with a 5mm wrench to the wheel swap process and works every time. I also have a bigger ring on one of my wheels sets so I end up tweaking my B screw a little too. Neither a big deal.

HerrKaLeun 05-26-19 11:43 AM


Originally Posted by Andrew R Stewart (Post 20948035)
Ah, the cost of improvement.

If OP has different rim widths, which could be the case since one set is for gravel and one for road, he also would have to adjust rim brakes between wheels. And you have to adjust rim brakes frequently even with the same wheel and rim trueness becomes more important.

rbrides 05-27-19 05:11 AM

I'll try that. Thanks for the input.

rbrides 05-27-19 05:12 AM

I'll look for shims that fit. I like this approach as shims will help me adjust for wear over time.

rbrides 05-27-19 05:14 AM

Shimano BR RS505 hydraulic that came with the Specialized bike.


All times are GMT -6. The time now is 11:24 PM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.