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Rotor REX 1.1 Cranks


Item # RTR000G

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  • Black, 172mm ($425.00)
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Item # RTR000G


Get cranking.

Rotor has devoted itself to a new line of mountain bike cranks it's calling "REX," and they are based on the same successful Trinity Drilling System as all Rotor cranks. The REX 1.1 is for a 1x drivetrain.

The Trinity Drilling System (TDS) is a method of hollowing out the cranks, which reduces weight and maximizes stiffness. Unlike traditional hollow crankset design, the Trinity Drilling System drills three channels from the pedal to the spindle. While these holes remove excess material, they also leave behind two thin walls, making them stiffer than the design of a single hollow chamber. The TDS creates a maximum strength-to-weight ratio, and the arms were constructed using a new 7055 alloy, which is both lighter and more durable than the more often used 7075.

UBB30 & UBB24 axles ensure maximum frame compatibility. Without the bottom bracket they weigh in at 489grams. The Q-factor is 163.

The Rotor REX 1.1 Cranks are available in sizes 170mm, 172mm, and 175mm. Please note the REX 1.1 does not include a chainring.

Tech Specs

Arm Material:
7055 Alloy
Arm Length:
170 mm, 172 mm, 175 mm
Bolt Circle Diameter:
BB Type:
BSA , BB89 , BB92 , PF30 , BBRight
30mm, 24mm
Q Factor:
Compatible Components:
Rotor QX1/No-QX1
Recommended Use:
mountain biking
Manufacturer Warranty:
1 year



Actual Weight

Actual weights are measured in-house by the Competitive Cyclist team.

Have questions? Chat with a Gearhead



Black, 172mm

Claimed Weight

Claimed weights are provided by the vendor.

Have questions? Chat with a Gearhead

489 g

Reviews & Community


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Unanswered Question

I have a Rotor inPower left side only power meter. I was using it on my road bike with 3d+ drive side crank arm. Could I use it to attach to the drive side of this mountain crank if I wanted to use it on a 1x mountain build?

Unanswered Question
Avg. ride time: 13h 1m per week
  • Average ride time is based on Strava activity over the last 3 months. Give your reviews credibility by connecting your account.

Would I be able to use these cranks on my Trek Boone?

Unanswered Question

I have a pf 92 gxp bb how can I choose a 24mm spindle when ordering a rx1 crank.?

there is no option to choose between a 24mm spindle or a 30mm spindle.

how do I know for sure that the rx1.1 crank that i'm ordering comes with a 24mm spindle and not with a 30mm spindle?

this crank is compatible with BSA (68 & 73), BB86, BBB89, BB92, BB30, and BBRight bikes. if you want to email me at I can help you out on compatibility with your frameset.

Is this compatible with other PF30 Bottom brackets such as Chris King, Enduro, or Wheels Manufacturing?

Yes the King or any other PF30/BB30 BB will work with those.

Unanswered Question

What's the BCD? Spider looks *maybe* close...

What's the BCD? Spider looks *maybe* close to XX1? What about ring availability or cross compatibility if it is a 76 BCD like XX1?