Like the Ultegra R8100 and Dura-Ace R9200, Shimano’s 105 Di2 road bike system is semi-wireless and 12-speed. However, unlike these two groups, the 105 Di2 is only available with disc brakes. The new groupset weighs 2,992 g and is in direct competition with the SRAM Rival eTAP AXS. Here, we take a deep dive into everything you need to know about the new groupet. We also have a comparison between the SRAM Rival eTap AXS and the Shimano 105 Di2, along with a summary of all the new bikes available with the new groupet. In addition, you can read the thoughts of BikeRadar senior technical writer Simon von Bromley on what it means for Shimano to release a third-class electronic band for the future of road teams. Here are the top five things you need to know about Shimano’s new 105 Di2 groupet:

Like the Dura-Ace and Ultegra, the 105 Di2 is semi-wireless and 12-speed A complete set weighs approximately 2,992 g, depending on the specification A complete groupet Shimano 105 Di2 will be sold for about 1,730 £ / 1,890 $ / 1,869 € For the first time, Shimano will offer a nominal set of 105-level carbon wheels The 105 Di2 will be offered only with disc brakes – RIP rim brakes!

Semi-wireless

Like Ultegra and Dura-Ace, groupset is semi-wireless. Shimano

Like the 12-speed Dura-Ace and Ultegra, the Shimano 105 Di2 is semi-wireless. This sees both derailleurs connected to a central battery, with the gearboxes connected wirelessly to the system. By comparison, SRAM eTap groups are completely wireless, and both derailleurs are controlled by individual batteries. The rear derailleur houses the system brains and is also the charging point of the group set.

12 speeds for everyone

As expected, the Shimano went 12 speeds with 105. Fairlight

As expected, Shimano groupet 105 Di2 R7150 is 12 speeds. The previous two generations of the 105 were 11-speed. Here, we look at each of the components that make up the Shimano 105 Di2 R7150 drivetrain.

Rear derailleur Shimano 105 RD-R7150

A single cage (SGS in Shimano nomenclature) rear derailer is available. Shimano

In the 105 Di2 family, only a rear derailleur with a long cage is available. The Shimano 105 RD-R7150 Di2 rear derailer is compatible with cartridges up to 36t. It is aesthetically similar to both Ultegra and Dura-Ace, but has less complex joint, rectangular and cage formation. The look is also more matte than the glossy finish of the higher tier teams. The charging port for the Di2 system is located at the rear end of the upper hinge. This eliminates the need for a junction box under the stem or on the steering wheel, as was the case with the previous generation Di2 group.

Front derailer Shimano 105 FD-R7150

The new front derailleur is slightly larger than that seen on the Ultegra or Dura-Ace. Fairlight

The new Shimano 105 FD-R7150 front derailer is slightly larger than the corresponding Dura-Ace or Ultegra front derailleurs. The top housing is extended and – unlike the Dura-Ace and Ultegra – does not move out of the cage, increasing the overall derailer footprint. It is not clear why the upper housing is larger, although we would assume that it uses different engines and controllers in the higher-end group sets. We asked for more information from Shimano. The derailer is compatible with chain rings up to 52 t in size. The total capacity of the derailer (the largest difference in teeth between the chain rings) is not specified on the Shimano press package.

Shimano 105 CS-R7100-12 and CS-HG710-12 12 speed cassettes

Only one cassette of 105 brands is available. Shimano

A single 11-34 t (CS-R7100-12) 12-speed cassette will be available at level 105. An additional non-series 11-36t 12-speed cassette (Shimano CS-HG710-12) also comes with the groupset. The first seven gears of both cassettes are individual, with the five largest being mounted on an alloy spider. All gears are made of steel. The cassettes are installed using the new special 12-speed freehub standard, but this is backwards compatible with the 11-speed HG freehub. A second 11-36t cassette is also available. Shimano The new cartridges do not have Hyperglide + technology. Hyperglide +, originally introduced to Shimano mountain bike groups, sees the gears in the cassette being shaped to help guide the chain down (ie, to a harder gear) in the cassette. Hyperglide + then hit the road last year with Dura-Ace and Ultegra. We have found that Hyperglide + is very effective in smoothing out changes and reducing noise in tests. Dura-Ace and Ultegra 11-34t level cartridges are officially compatible with groupset. However, both the 11-30 and 11-28t options are not officially compatible. The groupet shares the M7100 chain, as used in the brand’s groupet mountain bike SLX. Shimano Unofficially, we expect the use of one of these cartridges with the RD-R7150 rear derailer to work, albeit with potentially reduced gear changes. The groupet shares the existing CN-M7100 12-speed chain with the brand’s SLX mountain bike set.

Crank Shimano FC-R7100

A single transmission option will be available on the go. Shimano

The new Shimano FC-R7100 crank is very similar to the top crankshaft Dura-Ace R9200, with a slightly less glossy finish and the same flat outer surface on the crank arms. Available in crankcase options of 160, 165, 170, 172.5 and 175 mm and, during launch, in a combination of speeds of 50-34 t. An option 52-36t will also be “available at a later date”, according to Shimano. The crankshaft has a Q 148 mm coefficient and shares the same Hollowtech II design as most of Shimano’s high-end cranks. This sees two forged halves of the crankshaft coming together to create a lightweight and rigid crankshaft set. An additional non-serial crank designed for 135 mm rear bicycles is also available. Shimano An additional non-serial compatible 12-speed crank set is also launched with the groupset. The FC-RS520 crankcase has solid cranks and is designed to work with bicycles using a 135 mm rear end. Most modern road bikes with axles have a 142 mm rear end. This affects the bicycle chain line and the crank FC-RS520 will shift to cover this. The crank is available in options of length 160, 165, 170, 172.5 and 175 mm and in a combination of speeds 50-34 t.

Shimano 105 Di2 ST-R7170

The 105 R7170 shifter is almost indistinguishable in shape from the Ultegra and Dura-Ace. Shimano

The new Shimano 105 Di2 ST-R7170 shifters are identical in layout to the 12-speed Ultegra and Dura-Ace. This includes the new covered lever and the revised position of rotation, which is said to improve braking performance when driving on the hood. The gear levers do not have the auxiliary hood button that appears in the two higher tier group sets. They also lose the option of installing satellite switches (or so-called ‘sprint shifters’). Unlike the Dura-Ace and Ultegra, the brakes also do not have a Servo Wave. The Servo Wave makes the relationship between the brake lever and the brake pad non-linear, improving the configuration. Servo Wave also appears on the brand GRX gravel set. Shimano 105 Di2 ST-R7170 inverters are claimed to have a battery life of up to three years. They are powered by a pair of CR1632 coin cells at each shift.

Goodbye to the rim brakes

Unlike the Ultegra R8100 and Dura-Ace R9200, the 105 Di2 R7150 will not be offered with a rim-brake option. Shimano

The new Shimano 105 Di2 groupet is only available with disc brakes. This is the first generation of any Shimano road bike family family to offer without a rim brake option. This is not surprising, as few modern road bikes are equipped with rim brakes and the vast majority of 105 Di2 sales will be to OEM customers. While it may be a bit of a joke, we expect that most riders who want to upgrade to an older rim-brake bike will consider either the Dura-Ace or the Ultegra – both are available with rim-brake gears and brakes respectively. That said, we expect riders who want to use 105 Di2 powertrain components in combination with rim brakes to be able to use either the Dura-Ace or the 12-speed Ultegra, but this has not yet been confirmed by Shimano.

Revised disc brakes

The new disc brake calipers are very similar in shape to the Ultegra and Dura-Ace. Shimano

The new Shimano 105 BR-R7170 disc brake calipers adopt the revised layout introduced with the Ultegra and Dura-Ace. This includes the adoption of a new vent door, which is accessible from the outside of the caliper. This makes venting the brakes much easier, especially when mounted inside the rear triangle. The brakes can now be vented from the side of the caliper. Shimano The gap from the tampon to the rotor is also said to have increased by 10%, reducing the chances of rubbing in dirty conditions. The brakes are only available on a flat basis. Non-serial post-mount calipers will also work with groupet if you are upgrading an older set of frames. The nominal 105-level SM-RT70 and SM-RT64 non-series rotors are ported from the previous generation group set.

Shimano 105 Di2 R7150 groupet weight

The complete group set weighs 2,992 grams. Shimano

The Shimano 105 Di2 R7150 reportedly weighs 2,992 grams for the full group set. The required weights for each item in the new Shimano 105 Di2 R7150 set are as follows: This is about 276 g heavier than an Ultegra R8100 Di2 group, which comes to 2,716 g, according to Shimano. Although it is difficult to compare apples and apples, a set of SRAM Rival eTap AXS groups is said to weigh 3,109 grams to a generally similar specification.

Price group Shimano 105 Di2 R7150

The suggested retail price …