Put simply, a rigid bike is a bike which has a solid frame, with no suspension of any kind. With the prevalence of complex suspension systems, rigid bikes are becoming an increasingly rare breed, particularly at competition level events, but there are still many environments in which the rigid bike thrives, and there are numerous reasons why you might want a rigid bike over a heavily suspended one.Before we look at the advantages and disadvantages of rigid bikes compared with suspension bikes, let's examine where you might find them, and what they're usually used for.
Most kids' bikes use rigid frames. Children don't tend to weigh much so they wouldn't get the most out of suspension frames. Additionally, kids outgrow bikes so fast that it can be expensive to constantly invest in suspension bikes.
BMXs are always rigid framed, since the length of the forks on a BMX would only allow a couple of inches of suspension travel at the most, and would therefore be pointless. Suspension forks would also make the BMX heavier at the front, making it unstable.
For reasons similar to BMXs, trials bikes usually have rigid frames. There are exceptions, but most trials riders like the direct control offered by rigid frames.
Road Bikes & Couriers
Couriers and commuters depend on the reliability of their bikes to get them where they're going without hassle. Rigid bikes allow them to do just this. In fact, cycle-couriers (who are amongst the most knowledgeable cyclists out there) very rarely ride suspension bikes.
Very long distance bikes - referred to as 'tourers', rarely have suspension (except in the seat-post, but even these can still be considered rigid bikes).
Cyclocross is a racing discipline in which very fast, lightweight bikes race over a mixture of terrains, both on- and off-road. Although rigid cyclo cross does allow suspension bikes in certain circumstances, the vast majority of cyclo cross bikes are rigid framed.
Time Trial Racers
With the emphasis on speed and with no obstacles or uneven ground with which to contend, Time Trial bikes are always rigid.
Cheaper bikes, like those available from high street chains, often keep the costs down by using rigid forks instead of suspension forks.
So it's clear that any kind of on-road or on-track cycling events require a rigid framed bicycle, and in the real world people who use their bikes every day, like couriers for example, also choose rigid bikes over suspension bikes.
Why? Well, bikes with rigid frames offer a number of advantages over suspended bikes, not least of which is the cost. Rigid bikes save money by doing away with all the high-tech components like oil-filled shocks, and thereby cost less to make, and less to buy.
But that's not all. By removing all of these components, rigid bikes also remove the possibility of their failure. As such, rigid bikes are more reliable than full suspension bikes. There are no weak links or pivots like there are in complicated suspension linkages. As long as the welding is good, a rigid frame will live longer than a dual-suss bike. Rigid bikes are also unanimously lighter in weight than their suspended counterparts - there are less materials used in the construction of rigid bikes and therefore less weight.
Weight & Reliability
The reduction in weight and reliability make rigid bikes ideal for light off-road duties and essential for road riding. What's more, rigid forks are more responsive than suspension forks, which means that cyclists who need precision over smooth ground - like BMXers, trials riders and dirt jumpers to a lesser extent - will find it easier to use rigid forks.
Then there's the power delivery. Bikes with rear suspension lose energy in the transmission - some full suspension designs cause slight variations in the length of the chain. Additionally, full suspension bikes loose energy during the powerstroke of the pedal - making them notoriously difficult to pedal up hills or to accelerate very fast because they bob and duck. Rigid bikes don't suffer from these maladies; almost 100% of the energy you apply to the pedal will make it to the floor via the rear wheel, providing your bike is set up well.
Suspension vs. Rigid
Such is the quality of modern suspension systems however, some lightly suspended forks can work wonders if you're going to encounter any rough stuff on your travels. For anything other than tarmac riding, you'll benefit from a few inches of suspension travel. But for on-road riding, if you're commuting to and from work for example, then you should look seriously at a rigid bike. You'll save money, save weight, save on repairs, get fit and go fast. And if you're torn between the comfort of a dual suspension bike and the robustness of a rigid bike, then here's a tip: get a rigid bike and buy a suspension seat post - you get the best of both worlds.