XTR BR-M9000 Race with 160/140 rotors?

Discuss light weight issues concerning mountain bikes & parts.

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barrysvt
Posts: 96
Joined: Mon Oct 25, 2004 3:51 am
Location: Detroit and Traverse City, Michigan USA

by barrysvt

I am building up a new 29er with XTR BR-M9000 Race disc brakes.
I would like to use 160 front and 140 rear rotors. Fork and frame are both post mounts.
Will this just be a plug and play setup?
Do I need any adapters or tips and tricks?
1956 Rudge Sport
1994 Carbonframes Tetra Pro
(re-branded to Calfee 2006)
2010 Trek Top Fuel
2015 Velovie Vetta
2020 OPEN WI.DE.

Arfer01
Posts: 145
Joined: Wed Sep 16, 2015 9:34 am
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by Arfer01

It depends what size rotor your frame and fork is designed to take. It will most likely be 160mm on the front and rear, adapters are then needed to go up to 180mm plus ect. if you go 160/160 you wont need any adapters on the rear and not on the front. Its all post mount so will go straight on.

by Weenie


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tonytourist
Posts: 1426
Joined: Sat Oct 10, 2009 7:13 am
Location: 90039

by tonytourist

It all depends on the frame and whether it can accommodate a 140 rear, I've been seeing a lot of bikes that can't run smaller than a 160 rotor.
On my MTBs I run 160/140 Freeza rotors with XTR 9000 brakes and have no issues. Which frame will you be using?

barrysvt
Posts: 96
Joined: Mon Oct 25, 2004 3:51 am
Location: Detroit and Traverse City, Michigan USA

by barrysvt

I'm building up a VeloVie Vetta 29er. (wheels due to arrive this week)
1956 Rudge Sport
1994 Carbonframes Tetra Pro
(re-branded to Calfee 2006)
2010 Trek Top Fuel
2015 Velovie Vetta
2020 OPEN WI.DE.

Jmdesignz2
Posts: 272
Joined: Tue Jan 13, 2015 2:27 am

by Jmdesignz2

you need an adapter for the 140 mm rotor

Another guy posted using smaller rotors with XTR brakes and got cracked pistons

Probably due to uneven pressure on the smaller rotor / incomplete surface contact

Jmdesignz2
Posts: 272
Joined: Tue Jan 13, 2015 2:27 am

by Jmdesignz2

Shimano SM-MA90-R140 Post/Standard Rear Disc Brake Mount Adapter

Briscoelab
Posts: 1513
Joined: Thu Jan 26, 2006 6:01 pm

by Briscoelab

IF the frame is post mount, the above adapter won't work. That's for running a 140mm rear on an IS mount frame.

Most frames that are post mount are currently designed around a 160mm rear rotor as the smallest size, especially 29ers.

scant
Posts: 270
Joined: Fri Apr 30, 2004 2:05 pm
Location: S.Wales UK

by scant

I'm using 160/140mm rotors on a 29er with M9000 brakes & so far no issues. on longer descents the brake levers can pump up a little (the brake lever bite point moves further away from the handlebar), but I havent had any fade issues. that said I run the xtr trail brakes with larger rotors on another bike & as you might expect they're noticeable more powerful.

barrysvt
Posts: 96
Joined: Mon Oct 25, 2004 3:51 am
Location: Detroit and Traverse City, Michigan USA

by barrysvt

I have set the bike up with 160/160.
(only about a 10g difference between my 140 and 160 KCNC Kasditor rotors.)
1956 Rudge Sport
1994 Carbonframes Tetra Pro
(re-branded to Calfee 2006)
2010 Trek Top Fuel
2015 Velovie Vetta
2020 OPEN WI.DE.

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



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