Road Bike Groupsets

We are living in the information era, where experience, skills and know-how are just a mouse click away. So with the right tools and knowledge, it is relatively easy for someone who does their own bike maintenance to build a bike, especially if you have a fair amount of experience with bike maintenance. However, relatively new riders or those who usually drop their bike in at the mechanics for a service, might prefer to get a mechanic to do their build.

Make sure you buy the correct size road bike. Choosing the wrong size can lead to uncomfortable riding and can even lead to injuries such as strains as well as muscle sores. For an in-depth look at road bike sizing, check out our Ultimate Road Bike Size Guide blog.

Yes! Modern electronic components are reliable and weatherproof. Manufacturers recommend avoiding powerwashing and fully submerging your electronic groupset fitted bike - However, most people avoid doing this with a regular cable-shift / mechanical bike anyway.

Yes, but... Make sure the flat-bar shifters will work with road derailleurs. Either use gear shifters designed for flat-bar road bikes or you might need to also swap to MTB transmission. Brake lever 'throw' and leverage could also be different with flat-bar brake levers compared to drop-bar lever braking. Online searches & youtube are good to confirm compatibility - the chances are, if you are thinking about doing something with a bike, someone has already made a youtube video about doing the same thing.

Gear shift levers are designed to work with specific derailleurs, cassette and chain. The best way to ensure that your bike performs at its best is to use matching groupset components. There are some exceptions though, for example, Shimano 11 speed 5800, 6800 and 9000 work together, as do some Sram and Campagnolo groups. Always check compatibility online if you are unsure.

For those getting into road riding, an entry level road bike costing less than £1000 would suffice. For many riders, a mid-range bike can offer a great mix of high performance at a relatively affordable price point. Mid-range bikes are a key market for the bike industry, meeting the mass market demand has led to some great bikes to be had in the mid-price sector. There is generally a bigger jump in performance from entry-level to mid-range, than from mid-range to top end bikes.

A good entry level road bike is likely to feature an aluminium frameset, components from a known groupset manufacturer and branded wheels & tyres.

Mid-range road bikes feature a carbon or aluminium frameset, a mid-range groupset (for example Shimano 105 / Ultegra, Campagnolo Potenza / Chorus, Sram Rival /Force)

High-end road bikes feature a premium carbon frame, a top tier groupset and a high quality wheelset. Finishing kit components, (bars, stem, seatpost, saddle etc) will be branded and hi spec.

Yes, flat bars can be installed on road bikes, however they would need new gear change levers & brake levers, as flat bars are designed for mtb style shifters and levers. A good way to test whether this would be a good option is to ride a lot on the tops (of drop bars) with hands positioned on the flats, out from the stem, obviously this isn’t as wide as with a flat bar, but it would give an indication of reach fit.

No. Cable discs offer some of the benefits of hydraulic discs but can’t match the modulation and power of a hydraulic system. Cable discs do offer a lower cost and easy maintenance alternative though, as a cable disc system uses regular cable pull levers and cables.

No. Road bike wheels for disc brake road bikes are not compatible with rim brake bikes. Also, some disc road bikes which came out before through axles became standard used quick release hubs. Some modern wide rim wheels might not fit on older bikes with less clearance.

Disc brakes offer more powerful braking and smooth modulation. Disc brake bikes feature through axle mounting for the wheels, this provides a more solid connection between the wheels and frameset. However! Many riders don't need powerful braking and don't want the extra weight of hydraulic bisc brakes, in addition riders with rim brake race wheels might want to keep using them.

Electronic gear change systems have become more common during the last few years. Instead of using powerful springs to operate derailleurs, small motors move the derailleurs.Either wires or wireless technology are utilised to implement the gear shift. Electronic gears make shifting easier, but not necessarily more reliable or more accurate. Gear shifting reliability and accuracy are reliant on clean, well adjusted derailleurs & cables, as well as clean, non-worn cassette & chain.

Road bike chainsets tend to come with 2 chainrings. The options of chainring sizes are usually; Compact - 34 50 chainrings, Semi compact - 36 52 and the classic race option, 39 53. More and more riders are choosing compact and semi compact chainsets which allow for smaller gear ratios for easier, faster pedalling over climbs.

Yes, there are warning lights on the junction box of Shimano Di2. In the event of the battery fully running down, the front derailleur stops first, at that point there's still usually around 100 shifts of battery power for the rear derailleur. Modern batteries last so long, they can be taken for granted and not checked regularly - it's a good idea to check the battery life indicator every few rides.

Solid Green light - 75 - 100%

Flashing Green light 50 - 75%

Flashing Red light 25 - 50%

Solid Red light 0 - 25%

Yes. Providing stock is available, you can select options such as crank length, cassette ratio, bottom bracket type and derailleur cage length, this allows a good level of customisation for your new build.

Yes, it is more cost effective to buy a full groupset rather than individual components. Buying a groupset from Merlin allows component options too (providing stock is available), so it is also easier to get exactly what you would like.

This is a largely personal choice on which most bike riders have an opinion. Different manufacturers provide their own options for all types of bike riding, each manufacturer has their own particular slant on each component and the technology of how they integrate together. While some riders prefer the solid clunk of Campagnolo, others prefer the cutting edge technology of Sram Wifi or the smooth, effortless performance of Shimano. Campagnolo supplied the winning (disc brake) groupset for the 2021 TDF winner, Tadej Pogacar (UAE Team), recent Shimano and Sram wins suggest that at the top end of road racing at least, there isn't too much to choose between manfacturers.

This depends on how long your legs are, typically taller people have longer legs. Smaller riders would be better suited to shorter 165 - 170mm cranks, average size riders usually go for 172.5 - 175mm and larger riders usually choose 175 - 180mm. Cranks are available in 2.5mm increments from 165mm to 180mm although some sizes can be more difficult to find, especially at the shorter and longer extremes..

Manufacturers recommend using complete groupsets to get the best performance from their components. However, it can be possible to replace Shimano road group components of the same generation, such as Dura Ace 9000, Ultegra 6800 and 105 5800. (A 105 5800 front derailleur could be substituted for a Ultegra 6800 front derailleur). There may well be other examples of cross compatibility, although when you try to mix between manufacturers this is less likely to work because different manufacturers use different amounts of cable pull for shifting.

To fit a braze-on (not clip-on) front derailleur to a frame without a braze-on / tab, you will need a front derailleur / mech clamp. Front derailleur clamps are available in different size options to fit most frames - 28.6, 31.8 and 34.9mm. These sizes correspond to the diameter of the frame seat-tube.

It is usually cheaper to buy a full bike because the manufacturer has the economies of scale purchasing components, and they can usually do this more cost effectively than the individual. However! If you want a specific build that the manufacturer doesn’t offer or if you want to use your existing wheels or components you have sitting collecting dust in the garage, it may well be cheaper to build your own.

This depends on the groupset and the chainset. The big groupset manufacturers recommend using all their components in a groupset, however some smaller manufacturers such as Hope, Rotor and DMR make chainsets which integrate with various different groupsets.

We always recommend following manufacturers instructions for fitting any component. The Youtube channels of Park Tools and GCN Tech have very indepth and comprehensive advice for completing all sorts of jobs on bikes, these are also worth watching particularly if you are inexperienced or unsure.