Disc Brake Rotor Guide
Confirm the BCD first, because it has to match your hub. Then choose the diameter and thickness your brake and bike can take.
Four Numbers on Every Rotor
A rotor comes down to four things. Three are numbers you can read straight off the spec, and the fourth is how it is built.
- Diameter: the size across the rotor, such as 180mm or 223mm.
- Thickness: 1.8mm up to 3.0mm in our range.
- BCD: the mounting hole pattern, 44mm or 54mm in our range.
- Build: one-piece, or floating with an aluminum center.
Diameters We Carry
Road rotors run smaller and gravity rotors run larger. As general guidance, a larger rotor suits longer descents and heavier bikes, and you may need an adapter to step up.
| Rotor | Diameters | Use |
|---|---|---|
| TORQLITE | 140, 160, 180mm | Road |
| HD | 180mm to 223mm | MTB, e-dirtbike |
| X-Power 2.3mm | 200, 203, 220mm | MTB |
| HD-E | 180mm to 223mm | MTB, e-moto front |
Thickness and What It Pairs With
Thickness has to suit your caliper and your pads. EP6-II and EB 20-21 brakes are specified for 2.3mm to 3.0mm rotors, and EP6 pads come in two sizes for exactly this reason.
44mm and 54mm BCD
BCD is the diameter of the circle through the mounting bolts, and a rotor has to match the hub. Most of our rotors use 44mm, including mountain bike, road and e-moto front rotors.
54mm is the e-moto rear pattern in our range. The heavy duty rear rotor and the X-Power rear rotor both use it for the Sur-Ron Light Bee.
Floating X-Power Rotors
A floating rotor separates the stainless steel braking surface from the center. On our X-Power, the outer is CNC 420 stainless steel and the center is aluminum, which acts as a heat sink and helps prevent deformation at high temperatures.
Choose 2.0mm or 2.3mm for mountain bikes. Both come in 200, 203 and 220mm with 44mm BCD.
Road Rotors
Our TORQLITE is the thinnest rotor we carry at 1.8mm, with 44mm BCD for road hubs. It is 420 stainless steel with an ultra lightweight design: 83g at 140mm, 98g at 160mm and 133g at 180mm.
Before You Change Rotor Size
Moving up in size changes more than the rotor. Run through these before you order.
- Your frame or fork needs the right adapter for the new diameter.
- Your pads need to suit the rotor thickness, as the pad guide shows.
- Your brake may already include an adapter. The LHP+ S6 has +20 built in and the EP6-II has PM-PM+20 built in.
- Your frame or fork maker sets the largest rotor it allows. Check that limit first.
Ask Us Before You Order
Email us your hub, your current rotor and the size you want. We will check it against our specs.
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