Shimano 105 R7100 Mechanical 12-Speed Groupset

The Shimano 105 R7100 Mechanical 12-speed groupset has improved ergonomics while maintaining the quality shifting and braking found before. But while much of the change is incremental, this is also filling a gaping hole in the market.

Shimano was always going to release a mechanical version of their 105 R7100 12-speed, and not just to quash the shock and disdain of the cycling public at this midrange stalwart arriving with electronically-actuated Di2 shifting only. This mechanical version fills the hole in the line-up for those who want a wide spread of gears.

From a performance point of view, apart from the extra cog very little has changed over the 11-speed predecessor R7000. And that's a good thing. In his review of it, Dave said, 'the best value performance groupset is better than ever' and I'd definitely go along with that – it's what's been on my go-to bike for poor-weather rides throughout the last few months.

Riding this 12-speed version alongside the 11-speed blindfolded, you'd never tell the difference unless you counted the rear changes from one side of the cassette to the other. Though by the time you got to 12, you'd probably have other things on your mind anyway, such as whether the paramedics would take the blindfold off for you without laughing.

The shifting is as clean and crisp as ever, and as the 11-speed version is only marginally slower and less precise than its high-end Ultegra mechanical sibling, that is nothing to be sniffed at. Ultegra has since gone Di2-only, so comparisons with the new groupset aren't possible anymore.

I'm a fan of the feel through the shift levers. The whole action is light enough to be a pleasure even after many hours in the saddle, but there is enough weight there for good feedback, and a positive click as the mechanism locates the next gear.

The whole set up works well regardless of how poorly it has been maintained, too – at least within reason. I'm not a huge fan of cleaning bikes until they have to go back, so this groupset was covered in black sludge from road spray, salt and lube well past its prime. Also, as it was fitted to the Ribble CGR SL gravel bike, it was coated in mud and grit many times over too.

As a result it didn't always run quietly, but gear shifts never felt compromised. This isn't a groupset you need to treat with kid gloves, which makes it ideal for everything from racing to commuting or touring in poor weather. The parts aren't overly pricey either, so replacing them due to wear and tear shouldn't be prohibitive.

105 may have made gears mechanical again, but there is no return to rim brakes, unfortunately. I get it from a commercial point of view – most new bikes still using rim bikes are very much at the 'budget' end of the market, and as such are more likely to wear Tiagra or Sora groupsets than 105.

The hydraulic set up used here is great, though. The rotors aren't quite as flash-looking as some, but provide plenty of power, and of course, excellent modulation. Disc brake bingo completed!

So while there are no leaps or bounds in performance over the previous version, as we all know – if it ain't broke, don't fix it. It was already excellent.

Let's take a look at the components individually.

RD-R7100 Rear Derailleur £59.99 / 248g

From an aesthetics point of view the rear mech has changed quite a bit, with the face plate and body having a more blocky, flat-looking style to it. I like it – it looks much more modern.

It uses the same Shadow design as previously, a low-profile shaping first seen on Shimano's mountain bike groupsets that aims to reduce the risk of crash damage by tucking everything in as hard as possible.

Officially the previous rear mech could handle a largest sprocket of 34T, but this newer version can cope with a 36T. Handy really, as that is the largest on offer in the range.

CS-R7101-12 Cassette £69.99-£84.99 / 361g

In fact, there are just two cassette options available – 11-34T and 11-36T. The latter (CS-HG710-12) costs an extra fifteen quid, at £84.99.

The cassettes use Shimano's Hyperglide design, which involves shaping the teeth (and bits in between) to aid shifting. As I said above the gear changes are quick, crisp and (so long as you don't let it all crust over with filth) quiet.

The good news is that the 12-speed cassettes are compatible with the 11-speed freehubs, so there's no need to change your wheels if you upgrade.

FD-R7100 Front Derailleur £41.99-£44.99 / 95g

There aren't any huge changes here over the previous version. The only thing I can see is a slight styling update to the plastic piece connecting the cage to the mechanism. There are two versions on offer: a band-on clamp and a seat tube mount design.

ST-R7120 Hydraulic Brake £279.99 / 306g (shifter) 134g (caliper)

There are subtle changes here as well, but you have to look closely to notice them. First up the graphics are a bit bolder, and ironically those kind of hide small changes to the lever body.

The new 'blade' has a curvier shape when seen from the side, bringing it slighter closer to the handlebar. Again it's a difference you have to look for to notice, but it's easy to feel – your fingers can sit in a more natural crook while just covering the brakes than with the straighter levers of the 11-speed.

On longer downhills it feels more relaxing and natural, especially when riding in the drops. When in the hoods though (where I spend probably 90% of the time) things don't feel any different for light braking with my top two fingers. The upper curved section is still the same, allowing your index finger to rest naturally.

The shaping of the hoods remains the same (comfortable), while the rubber is supple and grippy. That's a must for me as I ride without gloves in warm weather, and unpadded gloves in the cold.

Dropping down to smaller cogs is done one at a time, although when going back up, a full sweep and hold of the lever will see the chain skip up three cogs at a time. That's perfect for getting you out of trouble when a climb steepens quicker than you were expecting.

All cables and hoses run under your bar tape, or through your handlebar if you have the holes required.

The price of £279.99 per side includes lever and flat-mount hydraulic caliper, but you can buy just the lever for £179.99.

The calipers are BR-7170, the same as with the Di2 groupset. These offer 10% more rotor clearance to minimise brake rub, especially when banking the bike side to side when accelerating or climbing, than Shimano's earlier versions did.

For 12-speed these levers are the only option, so 105 isn't compatible with cable-operated brakes.

FC-R7100 Crankset £159.99 / 766g

Unless you're a racer, you won't be seeing the traditional 53/39T chainset specced on many bikes these days, so it's no surprise it's not even an option in the 105 line-up.

Ratios are limited to just two options, namely a compact 50/34T and a semi-compact 52/36T. Both offer a good spread of gears either end of the range (especially for those who focus on speed), but if you want something lower then Shimano's GRX groupset is designed primarily for gravel riding and comes with smaller chainrings.

In terms of wear, I've always found 105 chainrings to last well, so mileage isn't going to be an issue.

The crankarms are available in lengths of 160mm, 165mm, 170mm, 172.5mm and 175mm, and have new, more square look that compliments the rear mech.

The rotors (SM-RT70) are £29.99 each, while the CN-M7100 12-speed chain is £34.99. They weigh 143g (each) and 252g respectively. The groupset as a whole, including hoses and cables, is around 3,055g.

Value

The total RRP for 105 mechanical is £986.91-£1004.91, which is a bit of a jump from the £630.92 the old 105 commanded in 2020. We all know how much prices have increased across the board since then, though. According to the Bank of England's calculator, inflation accounts for around £132 of the extra £356.

The key factor for me though is the servicing cost is relatively low. A cassette and chain, the main two items that'll wear, aren't going to break the bank when they need replacing.

There isn't a huge amount of competition either; well, at least not on a like for a like basis. SRAM's road groupsets are now all eTap AXS, or in other words electronic. In fact, the only mechanical groupset SRAM offers in road or gravel ranges is the Apex XPLR. Being gravel-focused, though, it's only available in a 1x setup. It's £1,015, a similar ballpark to the 105.

Campagnolo still offer a range of mechanical groupsets, starting off with Centaur. That's rim-brake only though. Its hydraulic disc brake/mechanical groupset range starts with Chorus, a beautiful 12-speed groupset for both performance and looks, though that's more a match for Shimano's Ultegra, which if you didn't know is one above 105. You get things like carbon fibre crank arms too, but it's reflected in the price: £1,867.

Overall

Shimano has filled a gap in its lineup with this mechanical 105, and while pricier than the previous model, it is still competitive in the wider market. Especially as it's about £685 cheaper than the Di2 version.

The subtle changes have improved it over the 11-speed, especially from an ergonomics point of view, and while there aren't any huge changes in terms of performance, there really didn't need to be. This 105 still delivers very well from a performance/cost point of view, making it the all-rounder choice for everyone from racers to weekend warriors, club run attendees to commuters and tourers.

Verdict

Subtle tweaks and an extra sprocket make this 'all-rounder' groupset an even better performer