If Shimano made machine guns...

In true Hot Shots style, last weeks Product Focus on Drivetrains is back for that difficult sequel.  Although I can’t promise explosions, Charlie Sheen and quality montage action, I can promise we’ll take a look at the big names in the drivetrain world, proprietary technologies and shiny stuff.  Nearly as exciting…


Well they don’t get much bigger than the big S.  From road racing to touring, cyclocross to kids bikes, they have it covered with a great range of products to suit most budgets.  This makes it a little difficult to look at everything, so we’ll just focus on the road range.

The Ultegra chainset with hollow forged arms, and a hollow outer chainring which is trickledown from Dura-Ace.

The main Shimano road groupsets are headed up by the flagship Dura-Ace gruppo.  Hollow forged cranks (a feature which has trickled right down through to 105), hollow chain rings reinforced with a carbon fibre band (now available in Ultegra), titanium cassette sprockets and a further sprinkling of carbon fibre come together to produce a light, strong, smooth shifting and efficient drivetrain which is used by pros and enthusiasts alike.  If Dura-Ace is a bit out of your price range or a bit too bling, the great thing about Shimano is that the groupsets down the line, Ultegra and 105, offer fantastic shifting at an even better price.  You sacrifice some weight, but having spent a season riding 105 I can testify that they work very well indeed and are hard to fault for the money.

The Di2 crank with the battery just visible on the downtube.

A key product (although you may not think so yet) in Shimano’s range is Di2, the electronic Dura-Ace groupset.  Shifting is taken care of by small motors in the mechs and auto-trimming ensures that your chain always shifts perfectly and effortlessly.  The electronic shifting groupset, in theory, should appeal more to the enthusiast than the pro rider (where you’ll mostly see it) who has a mechanic to tune their gears and set up the bike, but it is expensive.  If Shimano (and other manufacturers for that matter) can bring the cost down, electronic shifting might well be the next big thing thanks to its maintenance free perfect shift.  There have been rumours about an Ultegra electronic groupset and although this has been denied by Shimano, there’s no smoke without fire though….

The Ultegra brake/gear levers, both the secondary lever and the main brake lever are used to change gear. The Ultegra levers are carbon and have reach adjust like their Dura-Ace counterparts.

The other main difference between Shimano and other manufacturers is the shift itself.  Shimano road groupsets use a brake lever and a smaller secondary gear lever which are both used to change gear.  Shimano use their STI pull ratio; the pull ratio dictates how much cable movement is required to change gear.  The STI system uses a near 2:1 ratio, meaning the shifter pulls a smaller relative amount of cable for each gear change.  This leaves the system more susceptible to worn gear cables; because they move a smaller amount, any stiction from wear or corrosion will have a bigger impact.  As long as you keep your cables in good condition, or use some of my favourite Gore cables, they will be fine.


The SRAM Red special edition Yellow groupset, celebrating the Tour de France wins of Armstrong and Contador who used SRAM Red.

Look around the peloton and apart from Dura-Ace and a smattering of Campag, the groupsets you’ll see are SRAM Red.  SRAM were relatively late to the road scene, but they’ve made up for that with plenty of success, reflected in their celebratory (and rather lovely we think) SRAM Red Yellow Special Edition Groupset commemorating their Tour de France podium dominance by likes of Schleck, Sastre, Contador and Armstrong (who switched from Dura-Ace to Red).  The entire SRAM range offers great value, with many of the features found on the Red gruppo, the  Force and Rival groupsets will do the job at a very reasonable price point as well.

Coming from the mountain bike world they brought several innovations with them which have proved significant.  The main one of these is Exact Actuation – this is the road version of SRAM’s famous 1:1 actuation ratio found on their off-road systems.  This means, unlike Shimano, that the cable moves the same amount as the derailleur.  The real world implications of this are that SRAM groupsets are less susceptible to dodgy cables (very useful in the off-road world) and Shimano/SRAM components are not interchangeable (except you can use a Shimano front mech on some SRAM systems, this is more popular in off-road groupsets).

The SRAM Red Double Tap shifter, all shifting is taken care of with the smaller gear lever leaving the brake lever completely free for braking.

When it comes to the shift, SRAM  utilise the Double Tap shift where up and down shifts are taken care of by a single gear lever leaving the brake lever solely for braking.  There is no major advantage or disadvantage to this, it just depends what you’re used to and what you like!  Inevitably, systems have their fans, but a bit like a new mobile phone, it’s easy enough to get used to a new system and after a few rides you won’t notice.  Honest!  Zero Loss is another highlight of the SRAM range.  Although it doesn’t sound exciting, Zero Loss removes any cable slack in the shift – so when you press the lever you get an instant change.  This is one of those features which when on the bike, makes a big difference to your ride.

Finally a quick word on SRAM chains. SRAM have built up a pretty devoted following with many running SRAM chains whatever make their groupset.  As long as the chain is the right speed, this should cause no problems, although we do recommend running a Dura-Ace chain on a Dura-Ace groupset as Shimano chains are now directional and chamfered for optimal performance.  SRAM also have a rather useful joining system for their ten speed system called Power Lock.  Similar in look to the SRAM Powerlink system (used on 7-9 speeds) Power Lock is a quick and easy way of joining a chain, it can however only be used once (unlike Power Link which is multi-use) so make sure you have a couple spare in your seat pack.


The 2011 Campag Chorus groupset, not to be sniffed weighing in at around 2100g (Manufacturer claimed) for a complete gruppo.

Finally, in this review of the big three manufacturers we’re going to look at Campagnolo.  Campag components stand out for many thanks to their timeless Italian design and heritage.  One of the main differences between Campag and SRAM/Shimano is that Campag offer 11 speed groupsets.  Available in the Athena, Chorus, Record and range-topping Super Record (which weighs in under 1900g!) groupsets, 11 speed gives you an impressive gear range even when running a double front set-up.  Fears over longevity and shift quality have proven ill-founded, with features like more trimming options for the front mech making set-up and running as smooth as you’d expect.

The Ultra Torque system, bearings sit on either side of the axle and the two sides join in the middle via a splined interface which is secured with a single through bolt.

A key selling point for the Campagnolo range is the Ultra Torque/Power Torque BB/chainset design.  Introduced in 2007, Ultra Torque provides a very stiff, light and compact way of joining both sides of the crank together on high end Campag groupsets.  It also has a much narrower Q factor than existing BB designs, providing more ankle clearance.  Power Torque is a new system introduced for 2011 which provides many of the advantages of Ultra Torque like the narrow Q factor and the stiffness to weight ratio but at a more affordable price point.

Ultra Torque and Power Torque BB systems are available for standard external bottom bracket systems and also now

The cups for running a Campag chainset in a BB30 frame.

for integrated BB30 and BB86 type bottom brackets with these cups.  This means you can run the same Campag drivetrain whatever frame you have (or upgrade too), a useful feature given how long Campag components last!

If you’re after the ultimate bit of bling weight saving, check out the Super-Record Titanium Edition chainset.  Titanium axles and joining bolt make this lighter, stronger and infinitely more lovely.  We had it sat on the desk for a few days just looking at it!

Interestingly Movistar are using an 11 speed electronic Campagnolo groupset this season – it will be interesting to see how it performs and whether it makes it to market for 2012/2013.  Initial rumours suggest it might use a single motor which moves the mechs via cables – it strikes us that this might remove the advantage of an electronic groupset if you reintroduce fragile cables back in to the system?!  Time will tell…

So there we go, a look at the main manufacturers in the drivetrain world.  Don’t forget you can still take a look at part one.

Just in case you are thinking of a new groupset, for a limited time we have 25% or more off ALL groupsets on PBK.  Take advantage, it won’t be for long!

What drivetrain do you swear by?  Are you a through and through Campag fan, or is it the big S all the way?  Let us know what you like, we try and test as much as we can but it is great to have your feedback!

Girl rescued, drivetrain chosen - job done!




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