Considerations When Transitioning To A Bike Of A Different Geometry, pp. 56-59
Kate’s writing about her cycle-fit for a new-to-her TT bike and the experience of transitioning to the new geometry of TT from road bike.
November 2021
The most significant contact point that you can get right on your bike is the saddle. If your bike fit is correct, your saddle will be taking the largest percentage of your weight and will be offering optimum support. If support is inadequate, too much weight will be going through some of the rider contact areas on the saddle or through other contact points, creating problems.
The saddle that comes with your new bike is, like most mass sold items, designed to generically fit people of the average size/build of the bike purchased and simply finishes the bike within a price point. It is not the best saddle for you.
The saddle carries most of the weight of the body. As the pelvis is not that large, it has only a small amount of contact area with the saddle. This contact is not like sitting in a chair. It is essential that your choice of saddle enables the most contact area available. This means that widths in different parts of the saddle are important. It is crucial that you select the best saddle, in shape and design, for your individual build. If the saddle is not wide enough to support the pubis, riders twist to one side causing uneven loading, knee angles change causing loss of pedalling efficiency and potential shear forces. Get it right and the saddle increases comfort, efficiency, and performance.
Saddle design is also important for good rider biomechanics, which is key to maximising efficiency. Consider what shape of saddle best suits your riding style and sporting aspirations. The right saddle for you will provide stability. Being stable avoids the power output drop and performance or riding deterioration which instability causes. Stability creates the opportunity to improve power, speed or aerodynamic position.
The wrong saddle can cause a range of other issues from simple discomfort to saddle sores or vascular problems. Saddles that cause a ‘hotspot’ result in riders shifting weight to the other side for relief. As a result, as they do so they place extra stress on the knees as they then track differently, placing unnecessary shear forces on joints. Repeating that thousands of times in a ride or race increases the risk of injury.
A poor choice or poorly positioned saddle results in riders shifting on the saddle to get comfortable. As a result, each shift causes a break in the pedalling rhythm. Each break in rhythm causes a loss of time. Research has found that at elite level each shift causes a time loss of approximately 3 and 1/2 seconds and is a lost quality pedal stroke. This means that not only is there a time penalty but also a negative energy cost.
The saddle is possibly the piece of equipment that most affects your aerodynamics. If a rider can’t hold an optimal position, the aerodynamics of the rider will effect drag coefficient negatively. For example, this will result in loss of gains made from expensive deep section wheels or other purchases. Riders and triathletes will discuss aerodynamic gains all day. However, the bigger gains are stability, comfort and efficiency. When you have stability you create the opportunity to improve power, speed or aerodynamic position.
If you cannot rotate the pelvis anteriorly it will be difficult to maintain an aero position or to be riding in the drops. Therefore the often-seen option of lowering the base-bar or slamming handlebars is not a positive choice. Without stability on the saddle it’s difficult to hold a quality aggressive or aero position.
Triathletes often wish to stay aero for as long as possible but if the saddle doesn’t suit the rider, it’s hard for them to rotate the pelvis anteriorly. This rotation is important to create that necessary stability in the position. An uncomfortable saddle will limit ability to maintain that position due to discomfort caused and pressure on nerves and blood vessels. This results in posterior rotation of the pelvis to relieve the pressure, coming back to the base bar position and toughing it out in a poor position. This can cause excessive loading on the lower back which in turn affects the whole of the posterior kinetic chain. For triathletes, any problems created on the bike section can also later cause problems on the run when loading on the body and the damaged area increases dramatically.
There are some differences to consider between female/male pelvis size and width. Females generally have wider pelvises. However it’s important to consider yourself as an individual rather than making gender assumptions. It’s about finding the right saddle for you as a rider. What is the width of your pelvis? This is measured by the distance between the ischial tuberosities, the ‘sit bones’.
Other questions might include: Do you need more stability? Do you genuinely have the flexibility to use a certain type or model of saddle?
Knowing how you load your saddle is important. Do you load to the front, middle or rear of the saddle? Knowing this helps in saddle choice. You may need to ensure sufficient leg clearance to stop your knees angling out or poor rotation of the pelvis and increased positional shifting.
Once you have the right saddle, also getting the height of the saddle right is essential. Power transfer is never going to be optimum if it is too high. Saddle height being too high, perhaps to emulate what the rider perceives to be the optimum position, can lead to the rider having to tilt the saddle nose down to reduce unwanted pressure. In turn this causes instability as weight slips forward, increasing pressure on the front of the pelvis and causing discomfort. It can also place too much weight forward affecting, shoulders, back, arms or hands, and lead to other issues.
Saddles are a hugely personal item of equipment. Spend the time to learn what suits you, get someone to assess your position critically. Get measured to have an optimum width to offer stability. Review your options regularly. Some manufacturers have test saddles you can borrow from retailers and others offer a 30 day trial or return. Time invested in getting it right will be rewarded with your goal of comfort with increased efficiency and performance.
Ian is a qualified cycle-fitter with over 10 years of experience working with age group and elite level riders/triathletes of all ages. He believes he is fortunate enough to have been trained by some of the best fitters in the business. His fitting knowledge is supported by his understanding as a Level 3 High Performing Triathlon Coach and a British Cycling Level 3 coach for Road, Time Trial, and MTB. He is an age-group athlete, has represented GB at Long Distance and Cross Triathlon, and has completed over a dozen multi-day long distance cycling events. He is always happy to discuss your needs in relation to fit and training. Please get in touch with any questions.
Well to be exact, behind handlebars and aerobars. As with all your contact points on the bike it’s important that your bike fit is optimised to enable a great position but not at the cost of comfort. If comfort is not there, then efficiency is affected and so, therefore, is speed.
I am sure most of us who ride a bike have experienced that feeling of pins and needles in the hands, often along the ring and little finger. You take your hand off the bars, make a fist, wave your hand around and the sensation reduces and disappears. Hands back on the bars, back up to speed, and a while later it is time to repeat the process. On each occasion, whilst you do this, you reduce your speed (not to mention the one-handed cycling and changes in ride posture/pressure on other contact points).
Clinically, this is known as Handlebar or Cyclist’s palsy. It is commonly associated with compression of the ulnar nerve. The median and ulnar nerves provide sensory innervation to the hand. Compression most frequently is in an anatomical space in the wrist called the Guyon’s Canal. Depending on your choice(s) of hand position on the bars and the setup of the front end of your bike, the numbness may also be experienced around the thumb, index, or middle finger. This will be compression of the median nerve and may be diagnosed as Carpal Tunnel syndrome. This is more common among mountain bikers and the cross -triathlon community due to the different handlebar configuration and hand position.
For triathletes, from novice to experienced, there then there comes the question of aerobars. Incorrectly set up aerobars increase the risk of ulnar nerve impingement at the Cubital Tunnel at the elbow. As the ulnar nerve travels from the neck to the hand, compression of the nerve may show symptoms along this path. Most often symptoms are numbness and tingling in the hand or finger of the affected side and difficulty in the application of finer motor skills i.e. changing gear in an aero position.
Handlebar Palsy can be split into four categories, with a fifth category to consider in relation to aerobars, according to where the compression occurs. Each has its own characteristics of sensory loss and/or motor weakness. While it is unusual for age group triathletes and cyclists to suffer motor impairments, any symptoms and their causes should be managed to avoid the risk of long-term chronic damage.
Research in this area over a number of studies indicates that this is an important issue for growing numbers of athletes riding on aerobars. Cross-referenced studies have shown increases between pre-event and post-event symptoms; and end of season symptoms have shown a further increase. Triathletes and Time Trialists should research or take advice on the best shape of aerobar design and configuration for their individual biomechanics.
There may be a range of reasons for the symptoms across all groups of riders including:
Due to the changes in how we train with the advent of turbo and smart trainers, a growing variety of platforms to train and race on plus virtual racing events, the prevalence amongst the triathlon and cycling community may be on the increase. Historically there is an increase in people experiencing symptoms over the winter months. This is most likely due to decreased changes in hand position; less movement of the hands generally and reduced fine motor movement demands. Training indoors may bring on symptoms due to factors such as wearing different gloves or moving less on an indoor trainer.
This condition can be caused by a poor bike set up/fit. I often see riders with stems slammed low to emulate a perceived quality aero position when the rider just is not capable of maintaining it comfortably, safely, or efficiently. As a result, weight shifts in different proportions around the contact points. The most common hand positions for symptoms are hands on the hoods or drops or by the gear shifters. Also, for those on aerobars, the general considerations for handlebars apply to the base bar but also consideration of the design of the aerobars and set up plus individual biomechanical limitations.
What can you do to relieve or stop the symptoms?
Most of us who cycle will experience this from time to time. It is about noticing it, reflecting on it, and making those changes to improve your position or riding habits to maximise your health and the riding experience.
Ian is a qualified cycle-fitter with over 10 years of experience working with age group and elite level riders/triathletes of all ages. He believes he is fortunate enough to have been trained by some of the best fitters in the business. His fitting knowledge is supported by his understanding as a Level 3 High Performing Triathlon Coach and a British Cycling Level 3 coach for Road, Time Trial, and MTB. He is always happy to discuss your needs in relation to fit and training.