Joined in 2023 
82 
63 About this deal
According to Smith, swapping out a worst-case scenario of the least-efficient chain lubricated with a particularly ineffective lubricant for a best-case scenario saves more than 10 watts (when testing at a 250w load). For absolute maximum Racing performance where every watt counts, re-lube (by dripping) every 600km or sooner in dry conditions and after every wet ride. If you race, apply a day before the race. In contrast, Dura-Ace 7800 requires a 20-degree throw for both upshifts and single downshifts, so if anything, downshift throw on 7900 has gotten longer. Perhaps Shimano were measuring 7900’s throws from a vertical line? Either way, tsk, tsk. In the past, Dura-Ace has been quite narrowly focused on the needs of road racers, with hardcore gearing to match. Each lever is powered by a CR1632 coin cell, claimed to last around 1.5 to 2 years of riding. Riders can choose to run their levers wired if desired, which apparently has the side-effect of increasing battery life by around 50 per cent.
speed full-suspension mountain bikes require slightly longer chains. The difference is just one link. Here is Shimano's recommended sizing method for full-suspension bikes.
If big gears are your jam, the cranks are available in a 54/40t option, as well as standard compact (50/34t) and semi-compact (52/36t) versions. As you can see, some components have lost weight, others have gained a little, and in total the new groupset is claimed to be 35g heavier than its predecessor. The wattage cost for pulley systems - shown here - are among the drivetrain efficiencies Smith tests R9270 is semi-wireless. The levers are wireless and powered by small coin cells, while the two derailleurs are wired directly into the central battery using new, thinner SD-300 wires.
The front upper section above the lever pivot is fully enclosed, an aesthetic departure from previous years.
Dura-Ace R9200 front derailleur
Do you have a GRX ( RD-RX815 (2x), RD-RX817 (1x)) bike, or a 12-speed MTB? Shimano's recommendations for these bikes are slightly different. You’re almost there, but there’s one more thing to keep in mind. Some chains are directional. They’ll either have an arrow ‘ printed’ on them, or something that indicates the inside or outside of the chain. Shimano has provided claimed weights for every component in the disc groupset, along with a comparison to an equivalent R9170 Di2 groupset. s braking performance is definitely superior to 7800 with a snappier and more fluid lever feel plus noticeable improvements in power and modulation. Many readers have lamented the revised cable pull ratio on 7900 – thus sullying the idea of mixing groups – but if that is what was required to get this level of performance, so be it. Despite the concealed housing’s additional bend, cable friction is only slightly increased over 7800’s more direct route. Add in Shimano’s typical Light Action feel and you get a slightly more vague and disconnected feel than before but rear shift performance is still on par with 7800 overall if not quite as crisp. Chain movement across the cassette, though, is impeccably smooth – aided in part by the new asymmetrical chain – and full-power shifts are as reliable as ever in spite of the curiously flexy carbon rear derailleur cage.
The new lever feels more substantial, with a significant increase in girth (roughly 165mm vs 140mm at the base), while the flatter and longer top distributes pressure more evenly for better long-term comfort. The slightly canted and broader carbon fibre lever blades are slightly easier to reach from the hoods, too, and a reach adjust mechanism is hidden within. With the miles I found the shifting imprecise and needing to be readjusted constantly. Also being in mountains I had to regear and found the cassette 22-30 only to exist in shimano. When receiving the shimano cassette, as an engineer I was disappointed with the construction vs sram. However the new gearing was perfect for the hills in my region. Recently I returned to road bike and indulged myself with a cervelo S5 VWD. When selecting the components I went for SRAM RED all the way for the weight and being so impressed on how fast the shifting happened. The shifting from shimano dura-ace seamed slow and the handle less pleasant in comparison.Shimano probably could have made the new calipers lighter but we wouldn’t trade their superb stopping power and fingertip modulation to save a few grams: shimano probably could have made the new calipers lighter but we wouldn’t trade their superb stopping power and fingertip modulation to save a few grams James Huang Braking performance – best yet from Shimano
Have the two chain ends meet at the large chainring, and then add two or three links, depending on the zero point shown in Shimano’s image below: Perhaps the most visually arresting part of the new groupset, the ST-R9270 hydraulic lever bodies are slightly larger than those of R9100, and the lever bodies curve inwards slightly. What is a "non-shadow RD", you ask? Well, all 10-speed Di2 derailleurs and the first generation 11-speed Di2 road derailleurs: With "at home" lubricating methods or ultrasonic application, you can achieve great results, if done correctly. But, this process is simply on another level of performance.There you go! You should now be able to size the chain. If you need some chain tools, these are the ones I use: The reality is that there’s no demand for mechanical from the pros who race on Dura-Ace, and it’s certainly waning on the consumer side too. During our work on the lube development we have learned that initial application of any liquid lubricant has a profound impact on the chain performance and friction. It also depends on how well you strip the chain from the factory anti-rust substance. For this reason, we have developed our special multi-stage vacuum process for the ProTour teams to squeeze extra precious watts on top of the best performing lube. This is what differentiates us from everyone else. We expected it to be at least partly wireless, and it is. We were sure it would be 12-speed, and it is.
Great Deal 
New Comment