Once you invest in a road bike, the next natural course of action is to equip it with proper gear. The right gear can change the very feel and function of your bike. The Shimano Tiagra and the Shimano 105 continue to be among the top contenders for investment-worthy road bike gear. But which is the better groupset? Before we get down to the nitty-gritty of the Shimano Tiagra vs. 105 debate, let’s take a quick detour and cover the basics.
Shimano has six different groupsets; Tiagra and 105 fall under them. A groupset encompasses a manufacturer’s collection (Shimano, in this case) of a bike’s mechanical parts. Each groupset includes brakes, shifters, bottom brackets, chainsets, derailleurs, cassettes, and chains for bikes.
You can opt to use parts of the same groupset, or you can mix and match parts from different groupsets. But that is not what we are here for, so let’s get down to the topic at hand. Which is the superior groupset? Is it the Shimano Tiagra or the Shimano 105?
Shimano Tiagra Vs 105 Comparison
An Overview of the Shimano Tiagra Groupset
This groupset promises improved ergonomics and functionality. It has undergone updates and changes over the years, vowing to be better each time around. In terms of hierarchy, Shimano Tiagra makes up the fourth-tier groupset.
This groupset offers double chainsets too, but it is more famously known for its high-grade triple chainsets.
An Overview of the Shimano 105 Groupset
The 105 takes a comfortable third spot on Shimano’s hierarchy of road groupsets. Often, when riders think about getting gear from this groupset, they consider it an upgrade. And this is justifiable given that the Shimano 105 groupset boasts good looks and offers a good value for money. However, the 105 groupset only offers double chainsets.
The 105 groupset is also lighter than the Tiagra groupset; if that’s a detail you’re particular about.
Their Mechanical Details
The dual control levers in Tiagra are at a 10-speed system, while they are at an 11-speed system in the 105. The bracket in both groupsets is made from glass fiber reinforced plastic (GFRP). Their main levers are aluminum.
The 105 groupset’s gear shifting feels light while the Tiagra is a bit heavier. The former perfectly captures the snappy lever action of the Dura-Ace and Ultegra groupsets, which is great.
The cables in the Tiagra groupset are placed under the handlebar’s tape, much like gear in the brand’s high-end groupsets. This way, you get a taste of high-end gear on a relatively budget-friendly groupset.
Their Braking Performance
The 105 groupset uses the SLR-EV dual-pivot braking system. This design helps equalize braking forces on each arm, so you have better power and control. When riding, you can slow down your bike with minimum pressure to the lever.
Brakes in the updated Tiagra groupset offer more stopping ability as compared to before, but the 105 groupset still takes the cake in this area. Tiagra groupset brakes perform well when you make a hurried stop, but they come a little short in terms of feedback and feel through the levers.
If you have a compatible fork and frame, you can enjoy the direct mount option that the 105 groupset offers. The Tiagra groupset does not extend this option.
Both Tiagra and 105 have the ability to handle tires that are up to 28 mm wide. The most recent version of brakes from the 105 groupset display more drop by a slight margin. This means that you can run 30 mm tires with them as long as you use the right frame.
The 105 groupset features 11-speed disc brakes while the Tiagra groupset has 10-speed disc brakes. The recent 105 R7000 STI units appear to be more streamlined than their predecessors, or even the Tiagra ones for that matter.
The hydraulic discs in Tiagra continue to deliver consistently good performance across different versions. Tiagra brakes fitted to the Genesis Datum 10 significantly improved its performance on downhill terrains.
Tiagra chainsets weight about 910 g while 105 chainsets weigh up to 716 g. The crank arms in chainsets of both groupsets are made of aluminum, with their axle being made of steel. The use of the four-arm spider design and uneven spacing between the arms ensures that there is stiffness and strength where they are needed.
Both these groupsets offer crank lengths of 165 mm, 170 mm, 172.5 mm, and 175 mm. You can also opt for a 160 mm crankset from the 105 groupsets.
When it comes to chainring options, the 105 groupset lets you choose from 50-34, 53-39, and 52-36 tooth setup options. The Tiagra groupset may not offer the traditional 53-39 tooth setup option, which is needed for racing bikes. But it boasts a 50-39-30 (triple chainset) configuration. For this, you will require an additional front derailleur and a left-hand shifter, which is compatible with such configurations.
The 105 chainset is lighter than the Tiagra, but you can set up a 105 chainset in a Tiagra-gear bike if you wish to do so.
The front derailleurs in both groupsets are made using the same materials. One of the major differences between the two is that the Tiagra is 10-speed compatible and calls for a large chainring that is between 46 and 52 teeth. The 105 groupset, on the other hand, is meant for 10-speed use and goes with a chainring with 46 to 53 teeth. You’ll have to check out front derailleurs from the Dura Ace groupset if you want chainrings that are 53 teeth and larger.
The appearance of the front derailleurs for the 105 and Tiagra are very different. The 105 ones follow a design idea that the brand calls ‘compact toggle design.’ The Tiagra front derailleurs are known to shift smoothly and with minimal noise even when under pressure.
The updated rear derailleurs of the 105 groupsets incorporate the brand’s shadow design. Shimano originally created this design for their mountain bikes. Under this design, the derailleur is tucked into the bike so as to increase its sprocket. The revamped Tiagra derailleurs offer long-lasting and precise performance.
The derailleurs in both groupsets are available in short and long cage versions to be used with different cassettes. Short-cage Tiagra derailleurs can handle at least a 28-tooth large socket, while the 105 can take on up to a 30-tooth sprocket.
In the long-cage versions, both groupsets can handle a 34-tooth sprocket, with the 105 R7000 groupset being able to shift to a 40-tooth chainring with ease.
The cassettes for both groupsets have nickel-plated steel sprockets. The 105 version goes a step further with its anodized aluminum lockring and spider arm. The 105 version is available in 11-25, 12-25, 11-34, and 11-32 tooth options. The Tiagra offers 12-28, 11-34, 11-25, and 11-32 tooth options.
The 105 groupset’s cassettes are especially beloved for their resistance to wear and tear.
The chain is lighter and narrower in the 105 groupsets than in the Tiagra groupset. One of the chief reasons being that the 105 is 11-speed while the Tiagra is 10-speed. The chains in both Tiagra and 105 feature Sil-Tec (PTFE) coating, which equips them to run quietly.
Weight-wise, the bottom bracket in the Tiagra is 92 g, with the 105 version weighing 77 g – not a significantly major difference.
The Shimano 105 groupset features pedals which boast a lovely low profile. You can lean these pedals up to 31 degrees.
A quick skimming of gears in these groupsets indicates that the 105 is more expensive than the Tiagra. But it would be unfair to say that the Shimano 105 groupset is superior to the Shimano Tiagra because it is pricier. It would also be unfair to say that the Shimano Tiagra is better than the Shimano 105 because it is the more considerate of your wallet’s contents. The gears in these two groupsets come with features that are completely their own. So, you pay for the features and not the products, with these groupsets.
Pros of Shimano Tiagra
- This groupset offers reliability and durability at an affordable cost.
- Its brakes and shifting range are commendable.
- It has a premium look.
Cons of Shimano Tiagra
- It is only a 10 speed.
Pros of Shimano 105
- It is an 11 speed, and that helps with gearing.
- It delivers on efficiency and sturdiness.
Cons of Shimano 105
- The 105 is relatively costlier than the Tiagra.
The Major Differences Between Shimano Tiagra & 105 Groupsets
One of the main differences between these two groupsets is their pricing. The Tiagra is slightly cheaper than the 105, but offers about the same quality. Also, with the Tiagra, you may not be able to modify it to a 105. But with the 105, you can upgrade to Dura Ace or Ultegra groupsets, part by part.
The Final Verdict
The Tiagra groupset equips your bike with everything it needs to be a reliable mid-level road bike. But if your heart is set on an 11-speed, the 105 is the better choice for you. Also, if you have a Tiagra-gear bike, it may be challenging to upgrade to a 105 because that will demand a lot of change in your bike’s components. With 105-gear bikes, you can gradually swap components with the Dura Ace or Ultegra groupsets.
Performance and design, the 105 is undeniably the superior groupset. But the Tiagra offers just as good a performance at a lesser cost.