Time-Trial-Triathlon-bike-fitting-head-on-position
Bike Fitting, Uncategorized

Why should I have a bike fit?

There are many people who ask “Why should I have a bike fit?”. So let me pose a question to you. Would you go down to Saville Row, or Carnaby Street in London and buy an off the peg suit, without even trying it on? Then expect it to be a perfect fit and wear it day in day out for work? No of course you wouldn’t!  So then why do so many of us spend a small fortune on N+1, the new bike, but NOT have it properly fitted?  Beats me (although I’ll admit it was something I was guilty of MANY times in the past)!

biike fit 3

The above was taken whilst at my Bike Fit Training at PhysioHaus in Newcastle where I was fitted numerous times. I also participated in many fits on other riders through this process.

The joy we derive from our cycling passion, is massively increased when we feel ‘at one with the bike’. A good fit delivers this.

In a previous post I talked in some detail about the differences between a specific time trial and triathlon fit.  But for now lets rewind right to the start. Why should I have a bike fit?

 

There are many benefits of getting the perfect fit on your bike

These are numerous and will only enhance both your performance and enjoyment. Below is an example list which I will then address in some detail once we cover the ideal bike fit ‘process’.

  1. Optimal power generation
  2. Reduction or removal of any pain in either neck, foot, back, shoulders, saddle or handlebar areas.
    1. Almost all of these ailments can be caused, or exacerbated by a poor position
    2. Protection of key muscles in multisport, e.g.: making sure your run muscles are not compromised by an extreme position on the bike
  3. Improved handling
  4. Optimised and improved aerodynamics
  5. Better race or performance results

 

The bike fit process

An ideal bike fit should contain all the following elements:

 Pre-assessment:
• What are your goals from the fit? Improved power? Comfort? Aerodynamics?
• Riding goals? What are they?
• How long have you been riding? What is your riding history? What type of riding?
• Have you been fitted before?

A Physical evaluation:
• Have you any past or pre-existing conditions that affect your riding?
• Basic measurements to determine saddle height, bar width, stem length.
• Physical analysis of your posture, feet position and foot arch height.
• Flexibility assessment. An off bike analysis and measurement of your current level of flexibility. This is to determine how extreme (or not) we would look to take your position (if relevant) in the fit.

Bike measurements pre-fit.
• What are your current bike key measurements? e.g.: Saddle height, saddle angle, handlebar width, stem length etc.

On bike analysis
• Starting with your existing position the fitter will take some angle measurements and determine initial areas of opportunity.
• Cleat set up. A review of your pedal cleat position for optimal comfort and power transfer.

Adjustment.
• The fitter will then make micro adjustments in a systematic way to ensure the optimal position. This may take only a few tweaks, or with a complex aero fit can be much more involved looking at head, hands, saddle and helmet position and even what helmets to wear.

Follow up.
• You should have the opportunity to go away and try the position and return to tweak if needed based on real life riding feedback.

 

Triathlon-bike-fit-position

 

Lets now revisit some of the key benefits you will get from a bike fit:

Power Generation

This is obviously critical as this is the biggest single determinant of how fast you will go. For example:
• If your saddle is too high you may be over extending your muscles in your glutes and calves and losing power at key extremes in the pedal stroke .
• If your saddle is too low its likely you will not be extracting all the available power from your muscles through the pedal stroke.
• Poorly positioned cleats will mean that the transfer of power from foot to pedal may not be optimised and you may get knee or other pain from a poorly aligned kinetic chain.
• Handlebar position, width and height will also affect your ability to maximise (or not) power generation.

 

Comfort

Being comfortable and feeling no noticeable pain (apart from your legs screaming at you when pedalling hard!) is the goal with a bike fit.

• Saddles are often the biggest area of problem. Saddle choice per se, is a massively personal choice. You will see many riders stick with a saddle or brand that they know and love throughout their career. It’s also important dependent on the type of riding you do.  On a TT or Tri bike, the riding style dictates that your hips rotate over the saddle to maintain the position. This means different types of saddle, such as the ISM Adamo below, or similar can be a good option for both comfort, aerodynamics and power generation.
ISM-PROLOGUE-adamo-saddle

An Incorrect saddle height, as well as affecting power generation, can cause discomfort due to incorrect pressure in the pelvic area.

Saddle position, fore and aft, can also cause problems in both the pelvic area (due to your position over the bottom bracket). It can also affect power generation for the same reason and also neck/shoulder pain due to either being over stretched or too scrunched up from the saddle to handlebars. Optimising weight balance between the key contact points (saddle and hands / arms) is key here.

• Stem and handlebar – position, shape and size
When fitting a bike the key measurement is top tube length, seat tube length is less important as saddle height can be used to compensate for this,  But top tube length can only be tweaked using stem length and generally there is much less options in this as the affect on handling with either a very short or very long stem come into play

Width of your handlebars. As a rule of thumb your bars should mirror the width of your shoulders. Most bikes come with 42cm bars (road bikes) these days, which is generally ok for most ‘average male riders’, but for either smaller or larger riders, or women, a different size may be needed.

Handlebar drop. These days (again on road bikes) most bikes have a shallow drop (about 10cm).  Older bikes can have much deeper drops.  Shallower is better as the difference between riding on the drops and hoods is reduced, reducing the impact on position and comfort.

Stem length. As mentioned above, this is the only real variable to affect reach.  Most bikes, TT bikes included, have 100-110mm stems.  It is possible to get much shorter and much longer stems, but these can have a negative effect on handling, either making it really twitchy (short) or less responsive (long).

 

Improved handling

A perfectly fitted bike will feel like an extension of you. You will specifically notice this when descending or in a racing bunch. A client of mine, who was a notoriously nervous descender reported the transformation in his skills after a bike fit. He was more confident, able to hold the lines and maximise the speed when descending as his handling confidence massively improved.

The same is true of bunch riding. You need to be so observant of the road, other riders and the parcours that anything but an optimal fit will hamper you.

 

Improved and optimised aero dynamics 

I have covered this area in detail in two previous posts, one on TT v Triathlon fit and also in a review of my experience with aerodynamic bike fitting in a wind tunnel. But to recap some salient points.

The key to going fast on a time trial or triathlon bike is based around a number of things:

• Absolute Power
• Power to weight (less important but still relevant)
• Efficiency of power transfer e i.e.: minimising power losses through the drive train by using the best possible drive train components and bearings.
• Rolling resistance
• Aerodynamics and how much (or ideally little) air you displace as you ride.

The final point here. Aerodynamics is the biggest ‘free’ element you can affect (without massive outlay or improvements in power) on your bike.

A truly aero position can be a compromise from your most efficient power generating position.  Just think of it simply, if you were to sit up, right above the pedals in ‘shopping bike style’ and give it all you have got, you may well be and feel more powerful than your position in the saddle. BUT I guarantee you will not be as aerodynamic!  So the challenge we have is minimising any power loss against the gains we make in your aero profile (as demonstrated by the top picture).

So when doing an aero bike fit our goal will be to balance these two things and ensure that you deliver the FASTEST performance. It’s not necessarily the most powerful rider who will win, it is the one who travels fastest through the air. And that’s a balance of all the 5 points above.

Here at Peaks we are fully qualified by the IBFI International Bike Fitting Institute  and are able to offer bike fits to suit. Also working in conjunction with our partners Aerocoach, we can offer aerodynamic track testing where we can validate your ACTUAL aerodynamic drag and help you optimise your position.  Book an Aerocoach session.

Contact us to learn more and book your bike fit appointment.

 

Thanks Andy

 

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