Group dynamics

When you upgrade to a more expensive groupset, what exactly are you getting for your cash? Cyclist examines the differences between the component hierarchies

There’s always one knowit-all in every bike club, the self-proclaimed fount of all cycling knowledge, and you can be sure of their opinion when it comes to the most expensive groupsets: ‘DuraAce? Super Record? They’re just for sponsored pros and mugs with too much money. Buy a groupset a level or two down – you get all the function for half the cost.’ Annoying as these people are, you have to ask: do they have a point?

With all the major manufacturers’ groupsets now featuring crosscompatibility, 11 speeds and a splash of carbon even at the lower end in some cases, is the top-end gear worth the extra cash? Do manufacturers simply use lighter materials as you go up the pecking order or is there more to these seemingly similar components than meets the eye?

While there are three major manufacturers when it comes to groupsets (for now – see p164), the choice as to which brand to opt for is pretty much down to personal preference, and this article will not be making comparisons between brands. Rather, we’ll be breaking down the differences between components of each brand as we move up the hierarchies.

What does a Campagnolo Super Record rear mech have that isn’t on Campagnolo Athena? Do Shimano Dura-ace shifters have different internals to Shimano 105? Are the carbon arms on Sram’s Force and Red cranks the same, just with different stickers? Cyclist has quizzed the manufacturers and we now have the definitive breakdown as to just how much bang you get for your buck.

For reference, the groupsets we will be comparing are the mechanical variants of Campagnolo’s Athena, Chorus, Record and Super Record; Sram’s Rival, Force and Red; and Shimano’s 105, Ultegra and Dura-ace. We’ll leave electronic for another day.

You pays your money…

There’s a plethora of options and sizes for components such as cranks, cassettes, bottom brackets and other variables, so to give our comparisons a bit of focus we have a theoretical bike to spec. It has a BSA threaded bottom bracket, so all the cranks are 24mm spindle varieties (or equivalent), and we’ll be running a 52/36 chainset with 170mm cranks, and an 11 or 12-25 cassette. A standard short cage rear mech and braze on front mech complete the shifting duties, and 108 chain links complete the drive. With this kit in mind, we’ve gathered weights, prices and the technical data to be able to offer a usable comparison. Some BB30 cranksets may be slightly lighter, and some larger cassettes with bigger sprockets would add some mass, but we can’t account for every tiny variable.

Shift levers

One of the most visible and expensive parts of the groupset are the brake and shift levers: Ergopowers for Campagistas; STIS to Shimanophiles; and simply Shifters to the Srammies. These complex units not only take care of a large part of braking and shifting duties, but also influence the feel of the bike. Their rubber hoods are in your hands for the majority of every ride so it’s worth making sure you like the shape, feel and shift.

Internally, the differences become pronounced at the top end and it’s

While there are three big manufacturers to choose from, choice is pretty much down to personal preference

here that the largest functional upgrades occur. Shimano’s DuraAce shift levers rotate on up to four bearings, rather than the single bushing in an Ultegra STI. The shifting action on Dura-ace requires reduced effort as a result, and the longevity of that light, slick feel is likely to be increased to boot.

Drop down another tier and the primary difference between 105 and Ultegra is the lever material itself – a cheaper alloy alternative is used for 105 in place of the Ultegra’s carbon.

As you rise up the Campagnolo tree, the brake and gear lever material changes from resin through alloy to carbon, and there’s an even lighter carbon used on the flagship Super Record, but the internals of the top three tiers (Chorus, Record and Super Record) share the same bearingbased shift mechanism.

This Ultra Shift mechanism allows for multiple upshifts and a five-gear downshift dump. At the lower end of the scale, Athena’s Power Shift not only loses the bearings, it also loses

‘Shimano has never been able to make a crank as durable or as stiff from carbon as it has from alloy’

the sprint friendly ‘cassette dump’ with just single downshifts available.

Sram’s internals remain fairly consistent across the range, which makes its lower-end Rival groupset a great bet on paper. Just an upgrade to the Red cables will get you the same internal friction levels as the top tier. As you go up to the next tier – Force – you do gain carbon brake levers, and once you hit the Red level, both the shift and brake levers are made from lightweight carbon.

A glance at the weight table (p162) will reveal how Sram’s fewer moving parts and bearing-free internals have a weight benefit. Even its Rival levers are lighter than Dura-ace or Super Record, and Sram’s Red levers are 85g lighter than Dura-ace.

Chainsets

Another substantial chunk of a groupset’s price is the chainset. The crank arms and chainrings are what directly transfer your legs’ power to the chain and onto the rear wheel. Stiffness is the primary objective.

Shimano – unlike Sram and Campagnolo – has steered clear of using carbon in its cranks. A few years ago, it bowed briefly to market pressure and made the 7801 Dura-ace carbon crank, but it was shortlived and not fondly regarded by the engineers in Osaka.

Shimano product manager Pete Griffiths says, ‘There’s no performance value to using carbon for a crank. Shimano has never been able to make a crank as durable or as stiff from carbon as it has from alloy. And the alloy crank is far better value as it’s cheaper to produce.’

So, with all Shimano cranks forged from humble aluminium, what’s the benefit of moving up the ladder? 5800 series 105 shares the same four-arm bolt pattern and shifting guides as its more expensive brethren, but all is not as it seems.

Ultegra chainrings are made from a higher-grade alloy that improves stiffness, so the shifting is slicker and the bottom bracket axle is also a higher-grade steel, helping to reduce the weight by nearly 60g. Jumping to Dura-ace gets you a different forging process and materials that increase crank arm stiffness yet further, plus the outer chainrings themselves are hollow (as are the Ultegra rings), improving the rigidity of the structure and most significantly improving front-end shifts. Chainring stiffness has a profound effect on shift quality.

For the Italian fans, Campagnolo Athena has an old school five-arm alloy or carbon option with an impressive (sub-650g) weight, but jumping to Chorus gets you the new four-arm crank. The arms allow you to swap between compact and standard chainrings on the same crank, but they’re also stiffer than their five-arm cousins, offering better shift quality. As you ride up the Campagnolo ranks, the weight drops and bearings improve, up to ceramic level, but the shift quality is likely to remain pretty steady from Chorus level upwards.

It’s a similar story at Sram: alloy cranks for Rival, simple carbon cranks and alloy spider at Force and a full carbon affair at Red level. The improved X-glide chainrings are present across the range and, like Campag, the top-flight Red groupset has ceramic bearings in the bottom bracket. Ceramic bearings are generally harder and smoother than steel, offering less friction and greater longevity – at a cost.

In terms of benefits, the shift quality across the range of groupsets is affected very little by the rear derailleur

Front and rear mechs

At the business end of any shifts you make are the front and rear mechs. These components derail the chain and move it onto an adjacent sprocket without the need to stop pedalling. It’s one of the most complex pieces of engineering in the groupset, and would therefore seem to offer the greatest potential for improvements in performance for extra cash – but strangely that isn’t the case. In terms of tangible benefits, the shift quality across the range of groupsets is affected very little by the rear derailleur. Shifting performance at the rear is influenced more by cables and shifters than the rear mech itself.

So what does your money buy you at the top tier? A bit less weight thanks to carbon cages, titanium bolts and hollow pivots, and the longevity should improve as a result of sealed bearings and (in the case of Campag and Sram) ceramics, but otherwise you’re mainly paying for sexy looks.

It’s a different story up front. The front derailleur may seem like an altogether simpler beast than its rear sibling, but it’s here that extra money buys noticeably improved performance, mainly due to increased cage stiffness. Across the ranges, a higher leverage design is now present for all the brands, reducing the force required at the lever, but the accuracy and speed of the shift is affected far more by the resistance to bending of the mech’s plates.

Shimano improves the quality of the steel (and the longevity of the surface coating) as you rise up the ranks, whereas Sram and Campagnolo change material entirely as you ascend. Sram mixes alloy and tool steel (high-grade steel) for its rangetopping Red front derailleur, whereas Campag chooses carbon for the less stressed outer cage. Drop down a notch and Campag simply loses the titanium doodads, but Sram swaps the lighter alloy outer plate for tool steel.

The front mech may not see as much use as other components on your bike, but it stands to benefit greatly from increased stiffness, and the resulting improvement in shifting means it’s an area where money is well spent.

Brakes

Much like the front mech and the chainsets, braking is one area where components’ inherent stiffness makes a huge difference to the overall feel and performance. The manufacturers all come at this in remarkably similar ways. With the length of the primary lever dictated by modern frame design (a rim’s braking surfaces are between 40 and 50mm from the centre of the mounting point for a standard brake calliper) one key performance improvement that manufacturers can make is with the brake arm stiffness.

A secondary upgrade is often found in the pivot material: Shimano and Campagnolo both use a large bearing, rather than a bush, for their top-end callipers. This also has the benefit of reducing friction in the brake itself, lessening the force needed to retard the rim. This means Campagnolo’s Record and Super Record brakes will make your hands ache less than Chorus or Athena. In the same way

Dura-ace will be easier on the hands than Ultegra and 105.

Brake pad compound improves as you spend more too, but this is temporary as they are a disposable item, but it is worth mentioning that Sram’s Red brake has what is called the Aero Link. The name may hint at saved wattage, but the real benefit is improved modulation and control at the powerful end of the lever stroke. Of all the brands, Sram’s Red callipers probably offer a bigger jump in performance over its lower level brakes than with any other brand.

Cassettes and chains

Finally we get to the chain and cassette. Once again, the more you spend, the more expensive the materials that are used. Campag and Shimano both mount the larger sprockets on their top-end cassettes on alloy or carbon carriers. Dura-ace has three titanium sprockets on a carbon structure; Campag has three or six sprockets mounted on an alloy carrier for Record and Super Record.

Sram’s Red groupset uses a different method. Its Powerdome cassette is machined from a single piece of stainless steel. The hollow structure is both impressively light and very hard-wearing, and this is a rarity with high-end cassettes. Usually the lighter cassettes offer little performance gain and you trade lower weight against decreased lifespan, but with Sram, you get light weight and some of the longest lifespan we’ve come across at any price point.

By way of conclusion, and to offer a response to the club know-it-all, yes there is a whole lot more to the groupset hierarchy than just dropping some grams. While each company may go about solving the issues in different ways, they all have the same aim. As you increase your spend, your money does get you less mass but it also gets you a lot more performance through detailed engineering and higher-spec materials.

Ultimately your budget is likely to be the biggest limiting factor, but at least if you spend the top money you can expect plenty of gains beyond impressing your mates when they see your bike at the café stop.

Neil Webb is a freelance writer who agrees that quality is proportionate to payment