Living with Multiple Wheels

The road wheels arrived!


Weight Check

Cx (OEM) Road Road, naked
Front 1530 g 1190 g 770 g
Rear 1935 g 1625 g 880 g

These measurements are “ready-to-ride” with wheels, cassette, discs, tires, stems, sealant, and air installed. Naked weight is the manufacture’s claim. Each road wheel is about 300 grams lighter than the Cx wheel.


Torque Wrenches

The calipers rub. I installed the new wheels, gave them a spin, and they ground to a halt. Boo. That means every wheel swap will require a caliper adjustment. It’s quick (see video), but requires a torque wrench. Here’s a quick overview of the types available and how I chose.

How much torque? The spec for Sram Rival Hydro post-mount calipers is 5 - 7 Nm. (Wikipedia spells it “metre”. Cute.) Other small fasteners also range from 5 to 7 Nm, then jump to 34 Nm for pedals, 40 Nm for Cassette, and 54 Nm for crankset. (Updated previous “Torx” post with these values.)

Torque tools fall into a couple types (wikipedia mechanism comparo). Beam-type wrenches bend or twist to indicate the current torque and rely on you to stop when the desired value is reached. They’re simple but can be inaccurate. Click-type wrenches allow you to set the desired torque, then twist the fastener until the wrench clicks to let you know the desired toque has been reached. These are more idiot proof. Here are a couple different click-type tools:

Park ATD-1-2_001.jpg

Park ADT-1.2 ($65)

Adjustable: 4, 4.5, 5, 5.5, or 6 Nm

Drive: Hex, 1/4 inch

Gotcha: The previous version “ADT-1” requires a hex wrench to adjust the setting. The ADT-1.2 can be adjusted by hand.

Park TW-5.2 ($110)

Adjustable: 2 - 14 Nm, 0.4 Nm increments

Drive: Square, 3/8 inch

Park TW-6.2_001.jpg

Park TW-6.2 ($125)

Adjustable: 10 - 60, 0.25 Nm increments

Drive: Square, 3/8 inch

I bought the ADT-1.2. It works for the caliper mount fasteners and other small fasteners. IMHO, pedals don’t really need a torque wrench. If I’m doing crankset or cassette work, I’ll buy to a bigger wrench at that time.

Update: After trying the ADT-1.2, I’m disappointed that it’s not ratcheting. This is only an issue for one caliper bolt which is right next to the seat stay.

Update 2: Cassette alignment is the same between wheelsets. Thank goodness.


Bedding Discs

When pads or rotors are new, “bedding-in” is required. From Sram:

The idea behind bedding in a brake is to evenly distribute pad material across the rotor to improve the coefficient of friction between the two components.

It’s important that during this process you never come to a complete stop or lock up the wheels at any point. Coming to a complete stop causes a build up of pad material in one spot that can lead to pulsing and noisy brakes.

1.) Accelerate to a moderate speed, then firmly applying the brakes until you are at walking speed. Repeat 20 times.

2.) Then accelerate the bike to a faster speed and apply the brakes until you are at walking speed. Repeat 10 times.

The Cx wheels probably didn't get this treatment at the factory or shop before delivery, so I’ll perform the bedding-in procedure for both sets.