Shimano 105: Like clockwork
Reliable technology, flawless shifting behaviour, top ergonomics: With the 105 groupset, Shimano offers an inexpensive alternative to expensive electronics.
A transparent mechanism has impressive advantages. It is independent of rechargeable batteries or batteries and you can see and feel what is happening. If something does get stuck, it is usually easy to recognise what the problem is. So it's no wonder that the purely mechanically operated derailleur on road bikes still has a lot of fans, even in the age of electronically driven rear derailleurs and front derailleurs. They can now breathe a sigh of relief: Shimano is launching the mechanical version of the 105 as a state-of-the-art gearbox that works without batteries, radio signals and other electronic frippery.
State-of-the-art technology means: with twelve sprockets on the rear wheel, it offers a gear range that was previously reserved for significantly higher-priced bikes and is almost universally characterised by electric gears. Our first test clarifies the extent to which the ensemble can be an alternative for modern racing bikes.
The crux of train routing
Strictly speaking, only a few parts of the groupset are new: the shifters, rear derailleur and front derailleur. The drivetrain and brakes correspond to the 105 Di2 presented in 2022which remains in the Shimano portfolio as an electronically actuated twin. Nevertheless, we were particularly excited about the update for several reasons: Firstly, it is a tradition for Shimano to introduce technical improvements in the most expensive groupsets first and then pass them on to the cheaper ones later. However, since the more expensive Ultegra and Dura-Ace drivetrains have only been developed as electronic versions since 2017 at the latest, there is basically no "role model", and it will be an exciting question as to whether Shimano can still elicit improvements from the mechanics at all.
Secondly, the road bike has changed a lot since the last generation of the Shimano 105, which came onto the market in 2018. Today, cables and lines run almost exclusively on or in the cockpit and from there directly into the frame, even on inexpensive road bikes. However, experience has shown that such angled cable routing can severely impair the function of Bowden cables. We therefore paid particular attention to the smooth functioning of the gears when riding our test bikes.
Ergonomics of the Shimano 105
However, we experience an initial positive surprise without having ridden a single metre: In terms of ergonomics, the new levers of the 105 are far superior to the competition. Your hands have plenty of contact surface on the rubber grips; at the same time, the grip bodies are slim enough for even small hands to grip them well. There is plenty of space between the lever and the handlebars at the top end and there is no obstructing edge when pedalling; further down, the brake lever approaches the lower handlebars in a sweeping manner and even short fingers can get a good grip on it. The brake lever is also very easy to reach in the brake lever position and offers a large area for the fingers. The lever also allows grip width adjustment, although this is not really necessary due to its sophisticated shape.
Fast and precise gear changes
We can also report mostly positive results from the test rides. With the levers slightly out to the side, several gears can be changed at the same time without straining your hands. We find the shifting behaviour of the front derailleur particularly remarkable in a positive sense: When changing to the large chainring, you first have to overcome a pleasantly defined resistance - then everything happens incredibly quickly and the chain engages cleanly on the neighbouring chainring in a fraction of a second. It feels like shifting a high-quality shifter - apart from an audible "click", it's almost silent, without grinding or jamming, no matter how much pressure is applied to the pedals.
The chain also drops securely in reverse. The rear gears change slightly less defined, but, as usual with Shimano, smoothly and flawlessly - at least as long as the correct cassette is fitted. For the mechanical version, Shimano had to slightly adapt the 105 cassette compared to the Di2 version, which can be recognised by the designation R7101 (instead of R7100). Apart from that, there is no visual difference, but you should stick to the recommendation. Some test bikes were fitted with the CS-R7100 Di2 cassette, presumably due to delivery problems. It tends to make slightly louder, cracking shifting noises when changing to larger sprockets under a lot of chain tension, but otherwise works smoothly. This should also be the case with cassettes from the other twelve-speed groupsets Dura-Ace and Ultegra.
Shimano 105: Friction
However, the aforementioned cable integration does not appear to be a problem for the mechanical Shimano 105. On our test bikes, there are only marginal differences, if any, in the shifting behaviour. The operating forces are low on all of them and the sensitive rear derailleur also works precisely and without delays across all twelve sprockets. This is remarkable in that just a few years ago we had to advise against the combination of mechanical shifting groupsets and internally routed cables: In many cases, the friction was so high that the rear derailleur only responded with a delay and the shifting could not be adjusted cleanly.
Even low-friction coated inner cables are no longer necessary with the new 105. It works completely faultlessly with the simple, uncoated cables supplied. A modified cable routing on the rear derailleur, where the cable now describes a larger curve, seems to compensate for the losses.
Shimano 105: High performance, high weight
Otherwise, the groupset has all the strengths and weaknesses that also apply to the Di2 version. Powerful and very easy to modulate disc brakes as well as good wear behaviour are on the plus side. The chain is borrowed from the SLX mountain bike groupset and is known to be durable and inexpensive, as is the large 11-36 cassette. It could be criticised for its comparatively high weight, as almost all parts have become a little heavier compared to its predecessor.
Road bikes under 8.5 kilograms are only possible with a lot of effort, most complete bikes are closer to nine kilograms. The limited gear ratio options for the new generation could also bother some prospective customers: With the 11-34 and 11-36 cassettes, Shimano offers plenty of scope for steep climbs and is aimed at less trained recreational athletes.
In addition, these large sprocket sets fit on wheels with an eleven-speed freehub, so that no new wheels need to be purchased for a conversion. However, both cassettes are somewhat coarse. If you are only travelling on flat terrain and are looking for finer leaps, you will have to switch to Ultegra cassettes, which, as described, do not work entirely smoothly and cost more. But critics of electronics on road bikes will swallow these pills.
Wheels with Shimano 105 in the TOUR test
Conclusion on the Shimano 105
The groupset is likely to be a success for Shimano because it is basically unrivalled. There is no cheaper way to build a road bike with this level of functionality than with the mechanical 105. Competitor SRAM concentrates entirely on electronics for road bikes and only offers a mechanical drivetrain with the Rival, which is designed for gravel bikes and cannot compete with Shimano in terms of operating concept. Campagnolo products are in a completely different league in terms of price and are hard to find on complete bikes.
To summarise, we can say that electronic shifting is of course more convenient. But the new mechanical 105 will delight all those who have no problem with mechanical shifting systems and are looking for an inexpensive, durable and carefree alternative to electric shifting. In any case, you can't go wrong with this decision.
Jens Klötzer
Editor
