Black Friday road bike transmission: discounts

What does road transmission of the Black Friday include?

Three pages make up the selection. The road chainrings are the most numerous, with inner, middle, and outer types, followed by cassettes ranging from 8 to 12 speeds and chains, including quick links. Derailleurs and shifters can be found in the all-purpose transmission of the Black Friday.

Number of speeds: the rule that governs everything

Each added speed tightens the gears and narrows the chain: a transmission only works well if the chain, cassette, and shifters share the same number of gears. The cassette is also dependent on the freehub body. For Shimano, a road cassette with 12 gears fits the freehub body designed for 11; Sram road cassettes with a small 10-tooth gear require an XDR body, and Campagnolo has its own standard. Some manufacturers, like Miche, offer the same cassette for Shimano and Campagnolo mounts.

Chainrings: bolt circle diameter, number of arms, and position

A chainring is chosen based on the fixing diameter of your crankset, known as the bolt circle diameter or BCD, which is 110 or 130 mm on many road cranksets, and based on the number of arms, four or five. The next consideration is its position, whether outer, middle, or inner, and its tooth count. Recent four-arm asymmetric cranksets from Shimano require chainrings designed for them: the reference of the crankset, R7100, R8100, or R9200 for example, is included in the name of compatible chainrings.

Chains: length, attachment, and wear

A new chain is often sold too long and needs to be shortened to the correct length at the chain tool. The quick link, specific to the number of speeds, makes it easier to remove for cleaning. Check for elongation with a wear indicator: changing a chain in time saves the cassette and chainrings. Outside of the operation, the full offering can be found in the road transmission; for another bike, check out the MTB or urban transmission from the Black Friday; the clearance gathers the discontinued series throughout the year.

Comparing two discounts on a cassette or a chainring

A crossed-out price on a cassette is only valid for the same number of speeds, gearing, and mounting: the Primato from Miche exists for Shimano or Campagnolo freehubs and in many gear ratios. For a chainring, compare two listings with the same bolt circle diameter, tooth count, and position before looking at the displayed price; for a chain, check if the quick link is included.

The transmission brands in the selection

Shimano offers cassettes ranging from the Tiagra 10-speed to the Dura-Ace CS-R9200 12-speed, as well as replacement chainrings for its 105, Ultegra, and Dura-Ace cranksets.

Miche, based in San Vendemiano near Treviso, manufactures its Primato cassettes in steel, available for Shimano or Campagnolo freehubs in many gear ratios.

Specialties T.A., founded in Clamart by Georges Navet and now located in Aisne, owes its name to the front traction of a crankset that remained a project; its Zéphyr, Alizé, Syrius, or Hegoa chainrings are cut from 7075 aluminium.

Stronglight, based in Saint-Étienne, designs and manufactures road chainrings in 7075 aluminium in France, for both Shimano cranksets and Campagnolo's Ultra Torque.

KMC, a Taiwanese manufacturer from the industrial chains sector, has developed its own quick link, the Missing Link; its E9, E11, and E12 chains are designed for electric bikes.

Frequently asked questions

Does a new chain require a new cassette?

Not if the chain is replaced in time. An overly elongated chain wears out the cassette: a new chain will then skip on the most used gears, and both will need to be replaced.

How do I know which chainring will fit my crankset?

Measure the bolt circle diameter between two chainring screws or look for the value engraved on the current chainring, along with its number of teeth and speeds. The model of the crankset, engraved on the crank arm, helps verify compatibility.

Which cassette gearing should I choose?

A small gap between gears, such as 11-28, is good for flat terrain and group riding. For climbing or moderate fitness levels, a large gear of 30 to 34 teeth helps maintain a comfortable cadence on the slopes.

Can I change only the large chainring?

Yes, as long as you keep the same bolt circle diameter and number of speeds. However, the chainrings of the same crankset are designed as pairs to facilitate switching from one to the other: stay within the same range when possible.

Do I need to wait for the Friday of the Black Friday?

Not necessarily: the operation is named after the Friday after Thanksgiving, but the transmission discounts from Vélo-Store cover the entire month of November. An overly elongated chain should be replaced without delay to avoid damaging the cassette.