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Product Information

Internal gear hubs (also known as hub gears) are a popular option for commuters and those who want a robust and relatively maintenance-free drivetrain. However, there’s a limit to how much force your legs can generate (and your knees can take), so there comes a point where it’s preferable to shift gears to reduce the required force input and increase your cadence.

As explained in the full article above, CUES (which stands for Creating Unique Experiences) will see Shimano amalgamate its mid and budget-range city, touring and mountain bike groupsets (everything with flat bars essentially) into one family of interchangeable 9-speed (U4000), 10-speed (U6000) and 11-speed (U6000 and U8000) components. This means that parts can be mixed and matched, which should make sourcing and fitting replacements much simpler. There are no rim brakes in the range, just hydraulic disc brakes, and you can either have a single chainring or a 2x set-up, leaving no room for the almost extinct triple chainset.Those chainsets are paired to just two cassette options, one of which is available now, that being an 11-34T. There will also be an 11-36T option coming at a later date to provide a sub-1:1 gear combination for really steep slopes. This is usually paired with a wide-range cassette at the rear. This arrangement is referred to as a 1x (one by) setup.

The bike may also have a front derailleur, which shifts the chain between chainrings, which are part of the crankset.

INTERNAL GEARS:

The 12-speed version of Dura-Ace was at the same time the most anticipated and most predictable product launch of 2021, yet the most surprising. Anticipated because it was preceded by a year of leaks, patent and FCC filings and race appearances; predictable because both SRAM and Campagnolo had already introduced 12-speed systems and Shimano has been making 12-speed mountain bike components since 2018; surprising because there's no mechanical version of 12-speed Dura-Ace, and also because Shimano introduced a 12-speed version of Ultegra Di2 at the same time. More of that later. The gears at the front provide large jumps, which effectively change the range of your gears, so they are more suited to high-speed, flat-terrain or low-speed climbing. The cassette enables you to select your gear more precisely within that range as you modulate your effort. If you’re riding up a hill or into the wind, your perceived effort will increase, so it makes sense to shift to a lower gear to account for that. One big no-no is that you shouldn’t shift when you’re at a standstill with an external drivetrain. Always ensure you are pedalling to perform smooth shifts and shift gradually across the range of gears to find the right one.

Like the Di2 version, the new Shimano 105 R7100 Mechanical is disc brake-only, and features a redesigned gear range with the ability to accommodate (officially) up to an 11-36T cassette. The wider gearing range is arguably the biggest chance from the 11-speed version, other than the new look and extra cassette cog. SDP/SI is a well-known manufacturer of high precision standard and custom gears for a wide range of applications. Our fine to medium pitch gears are manufactured for some of the most demanding customers in the aerospace, defense, and medical industries of today. The rear derailleur has a longer cage than on the more expensive models to cope with the larger range of cassettes, and just like on those models, this is where the brains of the system are housed. It’s also here that you will find the battery charging point as well as the wireless connection to Shimano’s STI shifters and other third-party devices. Dura-Ace is really aimed at racing bikes, making Ultegra a more versatile groupset. With a range of chainring and cassette options, it can be fitted to all sorts of bikes, from racing cycles to touring and adventure bikes. From an 11-23t cassette and 53/39t chainset for the racers to an 11-34t cassette and 50/34t compact chainset for sportive riders, it covers a lot of uses.

It’s a favourite with amateur racers because the weight penalty is minimal, especially if built onto a decent carbon fibre frame, and the performance is nearly identical. You still get the carbon fibre brake lever as well like you do on Dura-Ace, and the cranks, brakes and derailleurs share the same design as Dura-Ace. Shimano’s fourth-tier groupset last had a major update for 2016, and Shimano last announced some tweaks and extra options in 2019. The changes brought it a similar appearance to the Shimano 105 R7000 above it, with the same four-arm crankset and new shifters, and the gear and brake cables hidden underneath the bar tape. As well as the drop-bar kit, Tiagra is available with flat bar levers and shifters, so expect to see it on commuter and city bikes as well. There is a R8150 version with rim brakes that is slightly more widely available to buy than the latest Dura-Ace with rim brakes, but again it's very rarely seen on full bikes off-the-peg. Like the previous 11-speed option, the new 105 Mechanical 12-speed RD-R7100 rear derailleur uses Shimano’s Shadow RD technology, meaning that it doesn’t extend as far outboard of the bike as a more conventional design. This is intended to reduce the possibility of damage and, Shimano says, means that the derailleur doesn’t hit the chainstay in rough riding conditions.