Shimano

Its been three years since Shimano released their first electronic gear shifting system. Di2 was launched as an option on their flagship Dura – Ace group and has seen a good deal of success in recent years —both with victories in the pro – peloton, as well as positive feedback from everyday riders.
Ultegra Di2
Now Shimano has taken the next step and made Di2 more affordable. Where the electronic Dura – Асе came at a hefty premium over their top mechanical group, the newly released Ultegra Di2 will be a good deal cheaper than mechanical Dura – Асе. Youll be seeing Ultegra Di2 on bikes in the $4,000-$5,500 price bracket, far more attainable than the $8,000-$15,000 machines that youd be looking at to get electronic Dura – Ace.
While Ultegra Di2 is a good deal cheaper, it shares all the same features and functions with its more upmarket counterpart. The push – button shifting requires next to no effort and the front derailleur trims automatically to prevent chain rub as you shift across the rear cassette. Like Dura – Асе you should get around 1,000km of riding from a full charge and recharging takes 90 minutes from flat. Theres also a simple inline control unit that lets you tune the shifting if required and a LED light that warns of low battery power.
Obviously there are differences with the lower cost group, and most relate to the weight, as Ultegra Di2 has less carbon and fewer exotic materials used in its construction. Theres approximately 140g of extra weight within the electronic gear shifting components when compared with Dura – Асе Di2. Combine this with the other components and Ultegra Di2 suffers a 300g total weight penalty compared with its upmarket cousin, but its not a massive difference when you take the price into account. Compared to mechanical Ultegra, the electronic group is only 91g heavier, 71g of which comes from the battery.
Beyond the differences in weight, Ultegra Di2 uses different motors to reduce the manufacturing costs. The wiring is also different, with a thinner two core design where Dura – Асе uses a four core loom. In theory the Dura – Ace units should shift with more authority but the difference is so slight that most will never notice a difference. As a side – benefit, the finer wiring on the newer Ultegra system is more discreet requiring smaller holes where internally routed. The connectors are also watertight, so theres no need to use heat – shrink as with Dura – Ace.
So the precedent has been set by the Dura – Асе Di2 group and we know that electronic shifting is a reliable and viable option. Other manufacturers are busily working on their own electronic shifting and Shimano is bringing theirs down in price —we could even see 105 Di2 for 2013, it certainly seems to be heading in that direction. Even though it offers some clear improvements in the ease of shifting, some people remain sceptical about electronic shifting. For some theres something philosophically wrong about needing to plug in and charge your bike for the gears to work, even if its only for 90 – minutes every 1,000km. While theres no denying that it works great, its not for everyone and the mechanical versions of Ultegra and Dura – Асе continue as the most popular options on most bikes. Is electronic shifting the way of the future? Only time will tell.
New Tiagra
A popular choice on entry level road bikes, the Tiagra group has been revamped for 2012. Tiagra previously ran a nine – speed drivechain and now moves to 10 – speed, just like the 105, Ultegra and Dura – Асе groups. Aesthetically it gets a makeover too, with curves and lines that look a little more upmarket. Functionally it gets a few tweaks including fully reach adjustable STI levers for those with smaller hands, and a directional chain design that is shared with the more expensive groups. As with the previous versions, the gear cabling is still routed externally. While this may not be overly attractive, it does provide a nice evenly radiused curve for the cables, which lowers friction and improves the shift quality. Theres also a neat barrel adjuster up on the lever which makes on – the – fly cable adjustment a possibility. Tiagra also drops around 50g in weight thanks to the new lighter cranks and derailleurs. Versatility remains a key feature of the Tiagra group, as it is offered with triple chainring, compact double or standard double chainring options. Expect to see Tiagra on bikes in the $1,000-$2,000 price area.
Off – Road Overhaul
Some years are relatively quiet with only minor cosmetic alterations while others see major across the board change. The latter is the case for Shimanos 2012 off – road line – up. The flagship XTR group was completely overhauled in 2011 with a number of new design concepts and a whole new look. Just one season later and the same ideas have trickled down through the range, with every group from XT down to Deore getting a new look and new features.
Brakes
With new one – finger brake levers and Tee – Tech heat management systems on the upper – end models, Shimanos brakes are a real highlight of their 2012 groupsets. The second – tier XT level gets all the bells and whistles. Ice Tech rotors have an alloy core that is sandwiched within the stainless steel outer shell. This is mounted to an alloy inner spider and the assembly is said to dissipate heat better than a traditional rotor. Like XTR Trail, the XT pads have fins that extend beyond the calliper and offer more surface area for effective cooling. The combined result is said to be lower operating temperatures, more consistent power and longer pad life.
Drop to SLX level and you still get the finned Ice – Tech pads but the standard rotors lack the sandwiched alloy design. However, all of the new model brakes – XT, SLX and Deore – share the same Servo – Wave mechanism in the brake lever. Servo – Wave provides more pad clearance initially to minimise disc rub and ease set – up, while ramping up the power midway through the lever stroke to increase the stopping power. Additionally, all of the new brake levers use a split clamp on the lever to make handlebar swaps and other general maintenance easier.
Drivechain
Both XT and SLX moved to 10 – speed in 2011, but the 2012 line sees further refinement to the shifters and more crank options. Meanwhile, the Deore group makes the leap from a nine – speed cassette up to 10 in 2012.
Just like XTR, the XT group is now offered with either triple chainring or double ring options. Both use closely spaced gear ratios for faster shifting and less interruption to your pedalling cadence when changing gears. The triple uses a 24/32/42 set – up whilst the double comes in 28/40 or 26/38. Shimano sees the double as a good option for those strong enough to push the big ring all day, while the triple offers greater all – round versatility and a very user friendly spread of gears in the 32 – tooth middle chainring. Deore and SLX remain 3X10 only, as they are more for all – round recreational trail use and less for big – ring racers.
XT also gets new Rapid Fire triggers with Dual Release that lets you up – change two gears in one push of the release trigger —this feature was previously restricted to XTR triggers. Another XTR level feature is the optional i – Spec mount, which allows the lever to mount directly to the brake lever for a tidier looking finish. With Ice – Tech rotors, Dual Release triggers, i – Spec mounts and all – new styling, XT really loses nothing to XTR in terms of function; its just a bit heavier and far more affordable.
Pedals & Extras
Beyond the main component groups, Shimano has expanded their options in both wheels and pedals. For 2011 they spit their XTR parts into Race and Trail variants, now this same theme continues with various other parts.
Shimano XT wheels will come in a Race version that uses a 19mm inner width rim, or a sturdier Trail version that features a 21mm inner width to better support wider tyres, as well as 12x142mm rear axle options. Youll also find Trail pedals at the XT and Deore level. I hey have a larger body that makes them easier to locate when riding technical trails, while the wider contact patch also provides extra support for more flexible trail – oriented shoes. Again, a bit of extra weight is the only real penalty with these designs.
Acera Updates
Changes to the entry level Acera group may not be as radical, but it gains an extra cog on the rear cassette to make it nine – speed, replaceable chainrings on the cranks and a new look overall.
XTR
XTR for 2012 gets one new addition; a new Trail version of the rear derailleur. It incorporates a friction damper within the main chain tension spring. This works to reduce chain slap and bounce whilst riding rough and technical terrain. The Trail derailleur is easily identified by the gold switch that engages the friction damper, switching the damper off to make wheel removal and mounting easier. When you consider that the bulk of the changes seen throughout the 2012 Shimano line originated from the top – level XTR group, its a pretty safe bet that a more affordable version of the Trail derailleur will be released in the not – too – distant future.