What marks the move to a 12-speed double road bike drivetrain? Campagnolo was talking up the perfection of the number twelve (in a playful and amusing way) but it ultimately came down to delivering tightly spaced gearing options, while not giving up overall gearing range. Spin smoothly across the flat and through rolling hills at your ideal cadence, and still have plenty of low gear range for the long steep climbs.
The new 12-speed Record & Super Record groups essentially boil down to a pair of new 12 cogged cassettes and a new, more narrow R12 chain.
12-speed Record level, all steel cassette
The heart of Campagnolo’s move to 12 speeds are the two new Record-level cassettes (11-29 & 11-32) that keep gear ratios close, while providing a broader gear range. Both cassettes share single tooth jumps for the first seven gears (11, 12, 13, 14, 15, 16, 17) to maintain the smoothest possible steps in gearing. Then the last five gears get two to four tooth steps to again maintain smooth steps for a lesser impact of rider cadence.
Adding in the extra cog has pretty substantial effect on smoothing the gear ratio spread, so Campy says that makes just two different cassette sizes necessary. They did however concede, that much like the small but real demand for 11-23 & 11-25 cassettes, they may potentially work on a third pro-specific cluster with even tighter spacing (11-25 or 11-27) for especially flat racing. But so far, Campagnolo’s pro teams have been pleased with the small gearing jumps of the 11-29, which also weighs just a claimed 266g.
The new 12-speed cassettes are only available now in a Record level (not branded as part of a series) and are entirely made up of steel cogs. Lighter versions possibly with ti cogs are in development. So far Campy hasn’t seen performance improvements over these steel clusters, but will continue to work on lighter options.
Both version of the cassette share the same loose steel lower 6 cogs with their 1-tooth jumps. They also get machined aluminum spacers between each cog, which Campagnolo says guarantees more precise cog spacing for perfect shifts.
At the upper end, the largest six gears of the cluster are machined from two 3 cog clusters – with unique gearing combinations for each cassette option (17-19-21 + 23-26-29 or 17-19-22 + 25-28-32). Each triplet cog grouping is machined from a single chunk of steel, making for a light, stiff & durable gearing solution.
A key point of the new 12-speed cassettes is fitting them with the same 11-speed cassette spacing. That means the new 12-speed drivetrains will be compatible with all existing 11-speed compatible bikes. And there will be no need to upgrade or replace any 11-speed Campagnolo compatible wheels.
Of course to fit an additional cog in the same spacing, without increasing overall freehub width, both cog spacing must be thinner, and the sprockets themselves are thinner. That’s a big reason why both Record & Super Record are getting the same all-steel cassettes. The tough steel sprockets can be made to achieve the same durability as 11-speed cogs, also helped by a new chemical surface treatment to the steel sprockets that increases their lifespan.
12-speed Record R12 narrow chain
Making 12 speeds work in the same width as 11 isn’t just the realm of the narrowly spaced cogs on the cassette. As those cogs got closer together, the chain must get narrower to stay in place on the cogs, so that it shifts up the cluster only when desired.
Thankfully adding another cog didn’t require drastic reshaping or redesign on the chain. In fact Campagnolo says that moving from the 5.5mm R11 chain to this new 5.08mm R12 chain they didn’t have to make the plates any thinner.
That means that the new chain gets the same construction as before with <10% narrower pins, actually making for a chain that is both a bit lighter (at 220g) and a little stronger. The end result is the more narrow R12 chain maintains the same lifespan & durability of its 11-speed predecessor.
Record & Super Record 12-speed mechanical road groupsets
Of course, the switch to 12 speeds is a bit more complicated than just a new cassette and chain. The rear derailleur certainly needs a full overhaul to shift across that larger cluster. And of course that means you need a new set of Ergopower lever to actuate the shifts. Plus, Campagnolo also took the opportunity to tweak the design of their cranksets, front derailleur geometry, and it comes in both updated rim and disc brake versions. We’ll update with full tech details on the entire new groupsets this morning.
Bron : https://www.bikerumor.com/2018/04/09/campagnolo-first-to-12-speed-on-the-road-with-new-record-super-record-groupsets/