from Rookie’s keyboard,
Hello, friends
It’s time for my Sunday post. Today, I will present you my take on pursuit bike frames – a somewhat obscure part of the cycling industry – but quite interesting nonetheless.
Let’s go.
As the name suggests pursuit frames are designed for a track cycling discipline known as pursuit racing. There are two forms – individual and team.
In the first case, two riders start from a stationary position at the opposing ends of a track.
Since the track has a circular shape, the two riders are effectively chasing each other. The race continues for 4 kilometers (2.5 mi) for men and 3 kilometers (1.9 mi) for women. The faster rider or the one that “catches” the other wins.
Team pursuit is similar. The main difference is that one team is chasing another. Each team is made of 4 members.
Pursuit bikes have very aggressive frames with a massive saddle to handlebars drop which allows the riders to assume a maximally aerodynamic position.
In the world of cycling, drag is a major problem because it increases the effort required to accelerate and maintain speed.
Most of the drag is created by the rider’s body. Road and track bikes are designed to make the rider’s back as horizontal as possible to the ground to minimize drag and increase speed and/or reduce the effort needed to maintain it.
Since pursuit events are fairly short and performed in a controlled environment (an indoor velodrome), the frames designed for that discipline can afford to be maximally aggressive.
The geometry of a track frame has the following properties:
Lower front end
The handlebars of a pursuit bike are positioned maximally close to the front tire. Many classic pursuit bikes even have the handlebars mounted on the fork’s crown.
Forward sloping top tube
The low position of the head tube necessitates a top tube going down rather than up. As a result, pursuit frames have forward slopping top tubes that appear “weird” in the eyes of the “uneducated” crowd because standard bikes have the exact opposite top tube style.
Low Bottom Bracket
Pursuit frames have relatively low bottom brackets making the handling of the bike more stable thanks to the lower center of gravity.
The Advantages
- Supreme Aerodynamics
As already mentioned, pursuit frames’ main purpose is to reduce the drag created by the rider’s body. They excel at that task at the expense of comfort.
- Lightness
The simplicity of track frames results in a clean and light product.
- Cool Points
Truth be told, one of the main reasons why recreational cyclists buy pursuit frames is the coolness factor. Pursuit frames look fast and unique. Consequently, many cyclists ride similar bikes for appearance rather than performance.
The Downsides
- Uncomfortable
In the world of cycling, you cannot have maximum comfort and speed at the same time as the two collide. Since pursuit events are fairly short, all ideas of comfort are thrown out of the window in the name of speed.
The frames come with a single riding position that requires a lot of flexibility. In some cases, even road cyclists won’t be able to pedal from such extreme angles. Many recreational cyclists will have a hard time even getting into that position.
If the frame is old-school, and the handlebars are mounted near the fork crown, the rider will feel as if they’re about to flip over the handlebars.
Consequently, pursuit frames are not a recommended choice for people with back and neck pain.
- Dangerous In Traffic
Riding a pursuit frame in traffic is a bad idea for the following reasons:
Reduced Visibility
Pursuit frames put the rider’s back in a very horizontal position. As a result, it becomes more difficult to see and be seen.
Forward Weight Shift
Pursuit frames put more of the rider’s weight on the front tire. The weight shift increases the chances of going over the handlebars and makes it more difficult to lift the front wheel if necessary.
Thin Tires
The tight and compact geometry of track bikes results in very little tire clearance.
In some cases, the user won’t be able to safely install even 25mm tires. On the track, this isn’t an issue, but on the streets, wider tires help by softening the ride and making it easier to overcome obstacles. Also, a wider tire is less likely to get trapped between the rails of a water drain.
Non-Friendly To Accessories
The minimal tire clearance and the lack of eyelets on pursuit frames make the installation of accessories such as fenders and water bottles frustrating.
Rear-facing Dropouts
Like other track bikes, pursuit frames have rear-facing dropouts. Rear-facing dropouts are ideal for fixed gear drivetrains because they secure the wheel better and make it easier to tension the chain.
However, the absence of a derailleur hanger does not allow the installation of a rear derailleur by default. If the user wants to use gears, it will be necessary to use an aftermarket solution such as chain tugs with a built-in derailleur hanger.
Different size wheels?
Some old-school pursuit bikes have a smaller wheel at the front (650c). The goal is to make the bike even more aerodynamic by dropping the front closer to the ground.
The downsides of having a smaller front wheel are twitchy steering and the necessity to carry two tubes.
Another problem is finding the same tire and rim models in both sizes.
Note: Some road bikes designed for women have a smaller front wheel too. The goal is to eliminate toe-overlap (hitting the toes with the front wheel when making a turn). Of course, toe-overlap is an issue on all bikes, but it amplifies when the frame is smaller.
There are two prime candidates for a pursuit frame:
- Track cyclists who participate in pursuit disciplines
At the end of the day, the main reason for the existence of a pursuit bike is to reach maximum speed in pursuit events. Technically, it’s possible to compete in a pursuit event with a regular track bike, but on the highest level where every millisecond matters, a rider with a dedicated machine will have an advantage.
- Recreational riders who find pursuit frames aesthetically pleasing
The world of cycling is surprisingly visual. Hence why very often cyclists purchase bikes as well as accessories based on appearance rather than function.
That said, a pursuit frame is too non-functional to be a cyclist’s main ride. Pursuit bikes are dangerous to ride in traffic and very uncomfortable even for moderately long rides. Therefore, it makes sense to purchase such a bike only as an addition to a collection rather than a main unit.
Pursuit Appearance Without The Uncomfortable Geometry
The attractiveness of pursuit frames makes them desirable, but the effect is offset by the lack of comfort that the geometry comes with.
To capitalize on the interest, some companies and custom frame manufacturers make pursuit-looking frames that don’t have the extreme angles of an actual pursuit bicycle. To achieve this effect, the frame is made with a forward sloping top tube, but the saddle to handlebar drop isn’t nearly as extreme as the original. That said, one cannot tell the difference between a “posing” pursuit bike and a real one without looking closely.
Until next time,
Rookie
Leave a Reply