RSS Feed
About this blog

Welcome and thanks for visiting the VeloFit Revolution blog.  I'm Eric Bowen, the owner of VeloFit Revolution at  Revolution Bike Shop , located in the north san diego county coastal city of Solana Beach, CA. To learn more about my services, please use the navigation links at the top of the page.   

Follow VeloFit Revolution

Email Newsletter icon, E-mail Newsletter icon, Email List icon, E-mail List icon Sign up for our Email Newsletter

Follow BikFit on Twitter

Eric's rides
« Cleat Placement: Fore/Aft Position | Main | Road Handlebars: A Bike Fitter's Perspective »
Monday
May022011

Performance Geometry: Why a road bike with racing geometry may not be the best fit

Sexy racing bikes featured in ads and displayed in shop windows are hard to ignore. These are the bikes the professionals ride.  These are usually the lightest bikes. These are often the bikes with the hot paint jobs. These are the bikes that seem to feature all the latest and greatest technological advances. If you want “the best,” you are probably going to be lusting after one of these machines. Unfortunately, top of the line racing bikes are also the ones that won’t be the best fit for most roadies. 

The problem 

So, what exactly is it about racing geometry that can cause sizing/fitting issues? The root of the problem is the head tube length on many racing bikes can be too short for many cyclists.  Specifically, the shorter head tube length of most of these bikes can create a situation where the saddle to handlebar drop (saddle height over handlebars) is too severe.  Many will describe the sensation as being too “hunched over” the bars or too stretched out on the bike. The potential issues and discomforts arising from these fitting issues are beyond the scope of this article, but if you’d like learn more about this topic, you can refer to these previous articles: 

Reach to the handlebars - guidelines

Reach to the handlebars - solutions  

The solution 

Rather than the typical racing geometry, many roadies would be far better served by bikes featuring geometries referred to as “Performance,” “Comfort,” “Sportive,” or even “Relaxed.” These bikes all have one thing in common – they feature sloping top tubes combined with a longer head tube, usually about 1.5 cm to 4 cm longer than the racing model of the same size.  Some of these designs will also sport a slightly shorter effective top tube, which helps shorten reach to the handlebars, and a longer wheelbase and chainstays, which provides a more stable and forgiving ride.

Want to know how much of a difference a longer head tube can have on your reach to the handlebars? Here’s a very important rule of thumb: 

For every 1 cm difference in head tube length and/or stem spacers, your reach will change by 3 mm. (reach being the distance from the nose of the saddle to the center of the handlebars at the stem). The shorter the head tube, the longer the reach. 

Saddle to handlebar drop (saddle height over bars) guidelines 

If you want to know how to measure your saddle to handlebar drop, this Park Tool link will show you how: (scroll down to item B – Saddle Height Over Bars) 

As a general rule, I strongly suggest keeping the saddle to handlebar drop in the 0 – 10 cm range* - shorter cyclists tend to be at one end of the extreme, and taller cyclists at the other.  Based on hundreds of fits, I have found that the average fit male (5’9”, 1.75 m) will usually be comfortable in 4-8 cm range and the average fit female (5’5”, 1.65 m) in the 1-5 cm range. 

Not all cyclists will need, or want, a saddle to handlebar drop that falls within my guidelines. A drop of greater than 10 cm might come into play if any of the following apply:  

  • You have long arms for your height (arm span is 5 cm/2” greater than your height)
  • You have great flexibility and are super fit (i.e. skinny)
  • You race, or are an experienced cyclist who is used to low/aero positions  

*[I’ve written an entire article on how to choose the correct size of road bike, which can be found here. If you are on a frame that is either too large, or too small, it will often necessitate a saddle to handlebar drop that is at the extremes of, or outside, my general guideline.] 

An example of racing vs. performance geometry 

At the bottom of this article I’ve listed some of the major brand’s performance/comfort/sportive geometry style of bikes.  Let me illustrate the differences between one of those, and a racing bike from the same company:  

A.  Felt F Series (racing geometry)

Size, 54 cm

Top tube – 54.5 cm

Head tube – 12 cm

B.  Felt Z Series (performance geometry)

Size, 54 cm

Top Tube – 54.5 cm

Head tube – 16 cm 

Assuming both bikes have the same length of spacers between the stem and head tube, bike A is going to put the handlebars 4 cm lower than bike B.  Based on the rule of thumb I mentioned earlier, bike A will also have about a 1.2 cm longer effective reach than bike B (4 cm head tube difference x .3 mm = 1.2 cm). 

Fixing excessive saddle to handlebar drop 

Many cyclists I fit are on bikes that are about one or two sizes too big.  In the case of a racing style of geometry, this can be a real problem, as both the top tube is going to be too long and the head tube can also be too short. Using the same Felt F bike from the example above, the next size up from the 54 cm is a 56 cm, yet it’s going to have a head tube that is only 14 cm, and that’s still 2 cm shorter than the 54 cm Felt Z!  If your correct top tube length should be 54 cm, and you instead end up on a frame like the 56cm F series race bike, you may very well have a total effective reach that is perhaps 2.5 cm too long; that is going to be a problem. 

Trying to make a bike fit by using a short stem and/or a stem that has a steep positive rise are both potential workarounds for frames with short head tubes and/or top tubes that may be too long. My definition of a short stem is using one that is more than two centimeters shorter than the one that came with the bike. My definition of a steep rise is using a stem with angle greater than 12° - the stem positioned so that it’s angled upwards, as opposed to being flipped (referred to as a negative rise) so that the stem is somewhat level with the ground.  Both workarounds are compromises and can have a negative effect on a bike’s handling characteristics, not to mention its aesthetics - road bikes with short stems for their size and/or stems with extreme upward angles simply don’t look right. I’m not a bike snob, but this is one instance where I am somewhat “old school.”  Also, I’m not a fan of placing any more than 4 cm of spacers between the stem and head tube in an effort to raise the handlebars, especially for carbon steerer tubes; it’s not safe.  

Conclusion 

Below is a list of bikes featuring longer head tubes for a slightly more upright, back saving riding position. Make no mistake, these are not cruiser bikes, and can certainly be used for racing. In fact, many professionals are now opting to race on these types of bikes. Depending on the components and wheels selected, many of them can be built up to be super light (sub 15 lbs., 6.8 kg for a 54 cm). In the next few years I believe the industry is going to start “getting it,” and will start marketing these bikes with the same zeal as their full blooded racing machines. 

Of course, a custom built bike will usually be the best option for a perfect fit, especially for those with disproportionate lower and upper bodies.  

Lastly, if you are interested in the Look 566, Felt Z/ZW, Colnago Ace, or Bianchi Infinito/Dama, do get in touch with me.  My bike shop partner, Revolution Bike Shop has access to all these brands, and can ship globally; they are also a dealer for custom builder Guru

Bikes with Performance, Comfort, and Sportive Designs* 

Look 566

Felt Z /**ZW

Colnago Ace

Bianchi Infinito / **Infinito Dama

Guru Evolo (see link above)

Cervelo RS

Cannondale Synapse /**Synapse Women

Specialized Roubaix / **Amira

Giant Defy Advanced /**Avail Advanced

Trek Madone 5 & 6 Series (H3 Geometry) /**Madone WSD

Scott CR1/**Contessa

Jamis Xenith Endura /**Femme

Time NXR Instinct

Merckx EMX-3 /**EFX – 3 

Lapierre Sensium/**Sensium 100L

Lynskey Sportive (Titanium)

BH Speedrom / **Cristal

Moots Vamoots (Titanium)

Litespeed Xicon (Titanium) 

*This is not intended to serve as an exhaustive list of all such bikes. If you know of others that should be included, please email me (velofitter@yahoo.com) and I’ll add them to the list.

**Women’s version.  

Reader Comments (1)

Very nice article, my work with the Tour de Cure brings me into contact with many recreational riders that have been fit to a racing geometry and have lots of issues. The industry leads everyone to believe they can achieve 'pro' results with a racing bike, i.e. top of the line, when a sportive bike would probably give them the same results with greater comfort.

May 5, 2011 | Unregistered CommenterSDVeloSocial

PostPost a New Comment

Enter your information below to add a new comment.

My response is on my own website »
Author Email (optional):
Author URL (optional):
Post:
 
Some HTML allowed: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <code> <em> <i> <strike> <strong>