A groupset consists of shifters, brake levers, front and rear brake calipers, front and rear derailleurs, crankset/chainrings, bottom bracket, chain and a cassette, basically the mechanical and/or electric parts that are involved in changing gears, propelling a bike forwards and stopping.
The groupset is the second most important part to look at when buying a bike (the most important is the frameset) and is a key factor in determining whether a bike is good value for money.
There are three major manufacturers of groupsets and bike components: Shimano, SRAM and Campagnolo. There are two relatively new manufacturers of top level full groupsets: Rotor and FSA.
Shimano, SRAM and Campagnolo all offer a range of comparable groupsets at competing price points. As the price of a groupset increases, the efficiency, durability and shifting performance improves and the component materials change, which reduces the overall weight.
Entry-level groupsets are generally made from aluminium and steel, which then move to higher grade alloys and then ultimately to the highest grade alloys, carbon fibre and even titanium for the top-tier groupsets.
View the weights of every road groupset in table form
Select the brand below to view the specifications, reviews and weights of their groupset range.
The groupset hierarchy for each manufacturer is shown in the table below.
Mechanical vs Electronic Groupsets
Each major groupset manufacturer offers mechanical and electronic gear shifting options.
How does it work? A signal is sent from the shifters to the front and rear derailleurs via wires or wireless technology (similar to Bluetooth or ANT+ devices).
What’s available? Shimano has ‘Di2‘ (Digital Integrated Intelligence), SRAM has ‘eTap‘ (Electronic Tap), Campagnolo has ‘EPS‘ (Electronic Power Shift) and FSA has ‘WE‘ (Wireless Electronic)
Shimano Di2 and Campagnolo EPS both use wires that connect the shifters to the front and rear derailleurs. SRAM eTap and FSA WE are wireless.
PROS OF ELECTRONIC SHIFTING
+ Precise shifting, Levers are easier to shift, Decreased cable routing, Less cables needed (for wireless groupsets), Programmable shifting, Downloadable information on shifting habits and efficiency.
CONS OF ELECTRONIC SHIFTING
– Batteries need to be charged, System won’t work if a battery is flat, Electronic groupsets are much more expensive and are heavier than mechanical groupsets
How does it work? When a shift lever is moved, it pulls or releases the cable between the shifter and the derailleurs, which then activates the derailleurs to shift up or down a gear.
PROS OF MECHANICAL SHIFTING
+ Lower weight and price compared to electronic groupsets, No need to charge batteries or worry about a battery going flat whilst riding, Mechanical levers have a more ‘natural’ shift feel compared to electronic shifting
CONS OF MECHANICAL SHIFTING
– Shifting is not as precise/flawless as it relies on cables being in perfect working order, Cables are always needed and can take more time to install depending on the frame
Rim Brake vs Disc Brake
All bicycle brakes work the same way, by touching brake pads against a wheel surface. The difference between rim and disc brakes is where the braking force is applied. With rim brakes, the braking force is applied to the rim of the wheel, whilst a disc brake applies force to a metal disc rotor close to the middle of a wheel.
There are two different types of disc brake systems that can be found on a road bike, hydraulic or mechanical disc brakes.
Hydraulic disc brakes work in the same fashion as motorbikes and cars, via the use of hydraulic brake fluid. When the brake lever is pulled, a plunger is activated at the master cylinder. This pushes fluid through a hose, to the caliper at the wheel. The pressure of the fluid operates pistons in the caliper that causes the brake pads to clamp to the disc rotor. Hydraulic disc brakes are often found on higher level bikes.
Mechanical disc brakes work via the use of cables and in a similar fashion to traditional rim brakes. When the brake lever is pulled, it pulls a braided stainless steel cable which is then used to apply braking force to the disc rotor. Due to their simplicity, mechanical disc brakes are typically found on entry-level bikes.
Rim brakes have been around for a very long time. Although that may no longer be the case in a few years’ time. In recent years, with the advancement and rapid evolution of disc brakes, some bike manufacturers have decided to cease rim brake bikes and produce only disc brake models.
Looking to purchase a new bike in 2021/2022? What is the better option for you? Rim or disc brakes?
It all comes down to personal preference. Rim and disc brakes are both capable of doing the job.
In summary, go for disc brakes if:
• You ride or commute a lot in winter/bad weather
• Bike weight is not your top priority
• You want or will have only one bike to use all year round
• You have a little extra money to spend and want the best braking you can buy
Listed below are the full details of the pros and cons of disc and rim brakes.
PROS OF DISC BRAKES
Better braking power: Disc brakes allow a rider to stop over a shorter distance with more control.
Faster riding: Due to greater braking power and trust, a rider can brake fractionally later with disc brakes.
Wet weather braking: Disc brakes perform a lot better in wet conditions. With rim brakes, there is a very slight delay when the brake pads touch the wet surface of a wheel rim. Rim slippage from wet brake pads contacting wet rim brake wheels (especially carbon rims) can be a real hazard. On the other hand disc brake performance is generally unaffected in wet conditions.
Reduced wear on wheels: All rim brake surfaces (including aluminium) will wear down over time from all weather conditions, reducing the stopping power and life of a wheel. From the heat generated from constant braking, carbon rim brake surfaces are especially vulnerable to damage and can cause tyre/tube problems even with a chance of tyre blowout.
Disc brakes remove the heat and friction wear from the rim and places it on the disc rotor instead. A disc rotor can easily be replaced at a fraction of the cost compared to a new wheel.
Better tyre clearance: Rim caliper brakes are approximately limited to the 28mm tyre range. Disc brake bikes don’t have this limitation and can therefore fit much larger tyre size which can increase grip and comfort.
CONS OF DISC BRAKES
Maintenance: Rim brake parts and braking pads are relatively simple to swap. In comparison, changing disc brake pads and/or discs can be more challenging for some as it requires bleeding if it is a hydraulic system.
Cost: Disc brake components, groupsets or complete bikes are more expensive than rim brake counterparts. Although in the near future, once disc brakes become more common and technology improves, the price difference should reduce.
Weight: Disc brake framesets tend to weigh more (up to 500g). Disc brakes also weigh more than rim brakes, a negative for cyclists who are concerned about bike weight.
Parts aren’t transferable: Disc brakes parts can’t be transferred to rim specific frames and vice versa. Frames and disc brake wheels aren’t transferable as the wheel hubs are different and the fork needs to have brake mount tabs to accommodate disc brakes.
Disc brakes can be dangerous: When riding with a group of riders who have a mixture of disc and rim brake bikes, it can potentially be hazardous. Riders with disc brakes can leave it later to brake compared to rim brake users, which can potentially cause an accident.
There is a perception that disc brakes are dangerous in a crash due to the spinning rotors. However there is a lack of hard evidence to support this at the present moment. Disc technology is constantly improving and the rotors are now much more smooth and rounded.
Gear Options and Ratios
The gearing/gear ratios that you have on your bike has a significant impact on how fast and far you ride.
Gear ratios are the combination of the number of chainrings on the front of the bike and the number of teeth on those chainrings, as well as the number of cogs on the cassette and the number of teeth on those cogs.
Some riders will turn the crankset slower with a larger gear ratio to achieve a certain power output or speed, whereas some riders turn the crankset faster with a smaller gear ratio, to achieve the same power output.
It all comes down to gear ratios, pedaling efficiency and terrain, as well as rider style, experience, fitness and preference.
You need to ask yourself, what type of gearing is the most efficient for you? Do you prefer to spin an easy gear with a higher cadence or push a larger gear with a slower cadence?
The available gear ratio choices
Road bikes have either a single, double or triple chainring. Single chainrings have become more common on road bikes in recent years. Two chainrings are the standard for road bikes. Triple chainrings are often seen on recreational, entry-level and touring bikes.
1x (single chainring – 50T): Single chainrings are becoming increasingly popular in road cycling. A front derailleur isn’t needed with a single chainring, which therefore means less maintenance and cleaning, less weight, simple gear changes and a greatly reduced chance of dropping the chain.
However compared to a double chainset, you will have a smaller gear range (therefore requiring a larger/higher speed cassette to ‘rectify’ this), greater gaps between gears, a shorter chain and cassette lifespan and a greater amount of mechanical energy loss because of the severe chain angle (AKA cross-chaining).
2x Standard (53-39T): Bigger gears which allows a rider to generate more speed or power, but you need to be able to turn the gears to get the most out of them. A standard chainset is usually the preferred option for racers, strong cyclists or those who live mainly in flat areas.
2x Semi-Compact (52-36T): Is a relatively new but increasingly popular chainset. The teeth number has ‘the best of both worlds’, a standard and compact chainset. A semi-compact chainset is more suited to strong climbers, hilly areas, sportive riders as well as racers and riders who want a wider range compared to other available chainsets.
2x Compact (50-34T): Provides the smallest gearing on a double chainset. A compact chainset is more suitable for those who live in hilly areas, prefer a higher cadence or are inexperienced/less fit. It is especially ideal for new riders.
3x Triple (50-39-30T): As the name suggests, it has three chainrings. It has slowly been phased out due to the preference of a double chainset with a higher speed cassette.
Other Options: There are other, less common options such as a 46-36T or a 48-32T setup, but these are much more suited to very steep climbs or steep offroad hills.
There are many cassette options available from each manufacturer so that you can fine tune your gearing.
Manufacturers are currently making 8, 9, 10, 11, 12 and even 13 speed cassettes with a wide range of teeth options. In case you are unsure, 11 speed means that there are 11 sprockets on the cassette. As the speed of a cassette increases: the number of sprockets increases, the step between each sprocket can be decreased and it can also allow for a wider gear range, which is beneficial for both hilly and flat terrain. A different chain size will be needed for each speed.
The most common cassette options are 11-25T and 11-28T, where the smallest sprocket has 11 teeth and the largest sprocket has 25 and 28 teeth respectively.
The greater the number of teeth on each sprocket, the smaller the gear ratio, which therefore increases cadence, making it easier to pedal but with less speed output. A lower tooth number on each sprocket results in a higher gear ratio, making it harder to pedal but increases speed output at the cost of reduced cadence.
Below we discuss three cassette teeth options and what they are ideally used for.
11-23T: This ratio is ideally suited to flat rides or races, allowing small step changes between each sprocket.
11-28T: Most bikes are now supplied with this ratio, which allows for a good number of gears for flat and hilly rides, with a relatively equal step change between the sprockets.
11-32T: This ratio is ideally suited to hilly rides, allowing larger step changes between each sprocket.
Crank Arm Length
Crank arm length tends to vary depending on rider height/leg inseam and the size of a bike. Sizes usually range between 165mm to 180mm. Comfort and efficiency are the two main factors in determining the ‘correct’ length of a crank arm for a rider. If you are having knee, hip or lower back problems whilst riding, then it is important to check your crank length as well as the usual factors such as frame size, seat height and your flexibility.
A good method that tends to work well in determining the appropriate crank length for a rider is:
Crank length (mm) = 1.25 * Leg inseam (cm) + 65
Longer crank arms: Requires greater force to turn the crank but creates more torque due to increased leverage. It is harder to maintain pedal efficiency compared to a shorter crank arm. Ground clearance is also reduced.
Shorter crank arms: Requires less force to turn the crank but creates less torque due to less leverage. A rider’s cadence will therefore be higher. It is easier to maintain pedal efficiency compared to a longer crank arm. Ground clearance is also increased. If a rider is having trouble producing power on flat roads but is fine when riding up hills, then it could be a sign that the crank arms are too short.
If you want to delve into much more detail on crank length and how to choose the correct crank arm length for you, CyclingTips have published an extensive article and GCN have made a good video.
View the specifications, reviews and the weights for every road groupset from every brand.