22.08.2023 | Reading time - 28 min(s)

Gravel VS Road Bikes

Written by Edinburgh Bicycle Cooperative

Posted in: Gravel/Cyclocross, Road Cycling

Gravel bikes are one of the hottest new styles of bikes to come out in the last few years. At an initial glance, road and gravel bikes look very similar so gives rise to the question; what are the differences between gravel and road bikes? We will have a look at this question and then go on to list some of the best gravel bikes available at the moment and the benefits of each one.

Contents and Quick links to sections

What are road Bikes?
What are Gravel Bikes?
Differences, at a glance
Best gravel Bikes

Intended terrain

Road bikes are designed with smooth tarmac in mind to be as efficient or as fast as possible between between A and B. As the tyres are relatively narrow, this means that any sort of gravel or loose surface will be a no-no but, that being said, some road bikes nowadays are being supplied with wider tyres for some light gravel riding.

Shape and riding position

A road bike will have drop handlebars and will be available in different frame geometries (shapes). Endurance road bike geometry will give a more upright riding position (shorter reach and higher handlebars) that will be more accessible and comfortable for a lot of riders that want the efficiency of a road bike but the comfort to allow them to ride longer distances. The downside of a more upright position is that it is not quite as efficient due to being in a less aerodynamic position and a less optimal position for firing the leg muscles - but for the people who are looking for a long distance, comfortable road bike, this is an acceptable trade-off. For those don't want to sacrifice speed, there are race road bikes.

Race road bikes tend to have a longer reach and a lower front end to put you in a more aerodynamic position so saving energy and adding to the efficiency. For many people, this position might not be particularly comfortable as it relies on more core strength and a higher degree of flexibility particularly in the hamstrings and lower back but, my word, you will be fast!

Tyre clearance and tyre size

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Classically, on road bikes, the clearance between the tyres and the frame and forks would be minimal in order to use less material in the frameset to allow the bike to be lighter and stiffer; hence adding to the efficiency of the bike.

Lately, some endurance bikes will come with clearance to allow full mudguards or even wider tyres for added comfort. In the past, road bike tyres were 23c or 25c but now you will see up to 32c compatibility, even on a race bike. Recent studies have shown larger tyre widths give less rolling resistance than the 25c tyres.

Tyre style

On a road bike, you will only really see 'slick' tyres as these give the best grip on tarmac and have the least rubber displacement, again, to increase the efficiency of the bike. 'Hybrid' tyres are available which are slick on the middle of the tread for when you are on the road but with a knobbly edge for if/when you go on light gravel to give you more grip on loose surfaces (just make sure that you have enough clearance in the frame for these wider tyres). Just be aware, though, that the more gravel the tyre, the less efficient you will be on the road.

Mudguard and rack compatibility

The general rule with road bikes used to be that they are not designed for excessive parts to be fitted to preserve the efficiency of the bike but even this is being relaxed in favour of having something a bit more versatile. Some endurance road bikes will have mounts for racks and the clearance for mudguards (the person behind you will thank you on a group ride in the wet). Race bikes will generally not have the mounts for racks but will allow some type of mudguards to be fitted.

Gearing

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As a road bike is generally designed for riding on smooth roads and tarmac, the gearing and particularly the derailleur does not need to be so robust as, in theory, it will not get bounced around so much so road gearing can concentrate on being as smooth as possible. But, British roads being what they are, road bikes are now starting to borrow technology from gravel bikes where the derailleur is more robust and does not bounce around so much on rough terrain. A great example of this is the Shimano GRX groupset that comes with a 'clutch' mechanism so you can turn it off on smooth surfaces for smoother shifting or turn it on when it gets rougher (most of us just keep it on because our roads are definitely not smooth).

Frame material and general frame info

Road bikes will generally have the lightest frames possible and will use the least amount of material to produce a safe and efficient bike. As they are not being used for gravel road riding, they do not have to reinforce the frame with extra material for extra bumps and jumps. Which frame material manufacturers use will have an impact on the characteristics of the frame.

Aluminium Alloy

Aluminium alloy is a relatively cheap and easy material to manipulate and manufacture and you will see this on less expensive bikes. In order for Aluminium to be strong, it has to be stiff so you will feel a bit more road buzz which will make longer rides a bit tougher on your hands, arms and shoulders. Aluminium is great though as it is relatively efficient for a low price.

Carbon composite

You will pay a bit more for a carbon composite frame but this is because it is a bit harder to manufacture and the raw ingredients are a bit more costly. But you certainly get what you pay for... carbon composite is a man-made material and because of this, it can be given different qualities in different parts of the bike - e.g manufacturers will likely make the bottom bracket and downtube of the frame very stiff to limit extra movement when you pedal so as to concentrate all of your energy towards propelling you forwards (efficiency again) and not wasting energy bending the frame. Carbon composite forks and rear seatstays will likely have some compliance built in for extra comfort and to dull the road buzz. You will find various different levels of carbon so as you spend more money on a carbon frame, you are likely paying for more stiffness and more efficiency.

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Steel

Not as common as aluminium or carbon but you still find some steel road bikes on the market. Steel is excellent as it is exceptionally strong and comfortable. The reason it is so comfortable is that steel can flex but still retain its strength so dulls even large vibrations from the road. The trade-off to steel is that it is a bit heavier than other materials but the ride quality is amazing even over poor tarmac surfaces and you sacrifice some pedalling efficiency due to the bendy frame but really, you are buying a steel frame for comfort and strength. You will find different grades of steel and the more you spend, the lighter and more comfortable the frame will be.

Titanium

Like steel, titanium road bikes are quite rare but are incredible at what they do. All of the positive characteristics of steel but are amazingly lightweight. Trade-offs are that you lose some pedalling efficiency from the bendy frame and they are quite expensive to buy - titanium is quite a complicated material to manufacture and weld as this needs to be done under specific temperatures and pressures.