Body Geometry products are scientifically developed ... - Specialized

WWW.SPECIALIZED.COM/BODYGEOMETRY 

Body Geometry products are 

scientifically developed and proven 

to improve performance and 

comfort for a better ride.

Body Geometry saddles were conceived in 1997 to address the 

problem of Erectile Dysfunction related to disturbances in male blood 

flow while cycling on traditional bicycle saddles. Specialized's founder, 

Mike Sinyard, enlisted the help of Dr. Roger Minkow, an ergonomics 

expert who had designed pilot seats for United Airlines, as well as 

weight training equipment for the US Olympic Gymnastics team. 

Minkow designed the first Body Geometry Saddle with a V-shaped 

cutout, theorizing an increased blood flow because of reduced 

pressure between the pubic bones. Minkow's premise was that the 

internal pudendal arteries (and nerves) were being compressed 

against the pubic bones by the dome of the traditional bicycle 

saddle. This theory was substantiated in the medical literature by 

Urologists, including Dr. Irwin Goldstein of the Boston Medical Center. 

After designing the initial Body Geometry Saddle, prototypes were 

sent out for testing by both athletes and media, including writers 

from Bicycling Magazine. The tests were very positive and in 

September 1998, the first Body Geometry Saddle was given the 

highest award that Bicycling Magazine gives for products. 

Figure 1: TcO2 correlates with penile blood flow measured by Doppler 

In 1997 there was no direct way to test male blood flow while a 

cyclist was actually riding a bicycle. The only tests available were 

stationary tests with the rider sitting on a bicycle saddle, or on a 

chair. These initial tests showed a clear decrease in blood flow while 

sitting on the bicycle saddle, but the relevance of the information 

was in question. 

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BODY GEOMETRY 

STORY 

BACKGROUND 

AND TIMELINE 


The first field test of the initial Body Geometry concept was held at 

The Great Tour of Strength in Norway, a 540km single-stage race. 

The incidence of ED at this event in years past was published in 

ACTA Scandinavia in 1997 and shown to be 13%. Because of the medical 

data derived from this race, Minkow chose this as the first testing 

ground for the BG Saddle. Riders given BG saddles to use during the 

race were found to have a lower rate of ED, as well as a decrease in 

observed perineal numbness. 

In the years that followed, more efforts were focused on finding a 

more quantifiable method by which effectiveness could be measured. 

It was in 2000 that Dr. Frank Sommer, a German Urologist, developed 

the first method of measuring internal pudendal blood flow while 

cycling. He measured the blood flow in the arteries using a Dopler 

Duplex device and correlated this with Transcutaneous Oxygen 

measured at the Glans of the Penis, establishing a direct correlation 

between the two. Dr. Sommer then perfected testing Transcutaneous 

Oxygen by gluing a plastic ring on the Glans, filling the ring with fluid 

and measuring the Oxygen concentration in the fluid while riding. 

This led to exact measurement of the Internal Pudendal Blood Flow 

in real time: the first actual riding tests that could accurately measure 

blood flow. 

Figure 2: Perineal compression during cycling appeared to be responsible 

for some cases of Erectile Dysfunction (Sommer, Eur Uro Suppl. 1999)

Minkow first visited Dr. Sommer's laboratory in 2002, where he 

was able to measure the actual blood flow in the Body 

Geometry Saddles. Using this data and numerous trips back 

with updated models and prototypes, Minkow altered the 

angles of the cutouts, the densities of the polyurethane foam, 

and the placement of the window in the front section of the 

saddle. By this, Minkow was able to maximize the rider's blood 

flow on each saddle. 

Figure 3: Saddle 

design and Penile 

Blood Flow 

(Sommer: 

European 

Urology 41, 

2002) 

Since then, Minkow has tested every BG saddle design in Dr. Sommer's 

laboratory and has continued to optimize the shapes of the saddle 

itself, the shapes of the cutouts, the position of the window, and 

padding density. While blood flow in non-BG saddles has been 

measured at levels as low 5%, BG saddles have measured up to 100% 

in published comparison tests in German Cycling magazines. 

BLOOD FLOW 

COMPARATIVE RESULTS 

Tour Magazine. In April, 2004 Tour Magazine (Germany) performed 

tests on a number of saddle designs of their choosing. Note that this 

test and the those subsequently performed by Mountain Bike 

(Germany) were done in a “enthusiast” riding position on a road bike 

with that the rider's hands on the brake hoods. (This 60° position is 

also equivalent to most enthusiast rider's hands on the grips of XCclass 

mountain bikes.) The test results shown here were done with a 

volunteer Tour editor as the test subject. Although different riders 

will tend to show different results, Dr. Sommer confirms these values 

are typical and that the percentage values are representative of his 

results with the other test subjects. 

Source: testing conducted with Tour magazine editor, April 2004. 

Comparison samples of racing and/or anatomic saddles selected and 

provided by Tour magazine. Results in order of performance. 

Stabilized Blood 

Saddle Brand and Model Flow Value1 Specialized BG Pro Road 89.3% 

Terry Fly Max 75.8% 

SQ Lab 611 72.6% 

Selle Italia SLK Gel Flow 71.6% 

AX Lightness 65.9% 

Selle Italia SLR 65.4% 

Selle Italia Flite 65.1% 

Selle San Marco Arrowhead 54.3% 

Selle San Marco Aspid FX 53.3% 

SDG USA 52.7% 

WRC1 Extreme 50.0% 

Tune Speed Needle 41.4% 

Fizik Alliante 40.3% 

Fizik Vitesse 39.6% 

SaddleCo 36.2% 

Terry Butterfly RS Women 32.8% 

Fizik Arioni 27.5% 

Selle San Marco Rolls 6.5% 

1 After five minutes’ cyling at a comfortable pace. 


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Additional independent studies were done by Mountain Bike 

Germany based on the new blood flow measurement techniques, 

showing a wide array of saddles measured against each other. 

FURTHER TESTING 

In May 2004, Dr. Minkow conducted supplemental tests in the 

more aggressive 30° “racing” or “aero” (rider with hands on the 

dropped part of a road bar, equivalent to an extreme XC MTB 

racing) position. Previous studies had found this position restricted 

blood flow significantly more than the neutral (on the brake 

hoods) position. 

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In addition, five different racing and/or anatomic-type saddles 

were chosen and a test rider cycled for seven minutes in the aero 

or race position. The results were as follows: 

Saddle Brand and Model Stabilized Blood 

Flow Value 

BG Avitar (2005 road racing model) 54% 

Selle San Marco Aspid 35% 

Selle Italia Flite 25% 

Selle Italia SLK 25% 

Selle Italia SLR 9% 

We now have a far more complete view of effectiveness, thanks to 

these new testing methods. As a result, Body Geometry saddles 

address all aspects of ergonomics, by accounting for not just 

perceived comfort, but also scientifically-documented men's and 

women's-specific pressure relief requirements. Additionally, Body 

Geometry saddles do so without forcing a rider to compromise their 

personal requisite levels of saddle performance: BG technology and 

benefits are available in models to suit recreational riders and 

professional racers alike.

DESIGN ASPECTS 

COMFORT 

MATERIALS 

The most obvious and most common method of achieving comfortable 

saddle designs is the careful use of different materials. However, 

addressing comfort issues by simply increasing the amount of 

padding is rarely effective, and sometimes can even be detrimental 

to comfort and safety. In fact, in January 2004, in Drs. Sommer and 

Minkow's first presentation of their blood flow laboratory protocol to 

journalists, Body Gometry saddles were compared to even thickly 

padded saddles, and it was found that the softest, most padded saddles 

restricted blood flow more than any other type of saddle. Every 

Specialized Body Geometry saddle utilizes unique blends of multidensity 

foams and, strategically located gel pads, and advanced 

composite bases engineered to have specific levels of flex to suit the 

saddle. Optimal use of each of these materials aids comfort and can 

contribute to the design of an ergonomic saddle, but materials alone 

are insufficient - the design itself must be ergonomic, and the materials 

must be utilized to support that design. 

WIDTH 

Men and women who ride bicycles are all different sizes. When sitting 

on the bicycle, the pelvic sit bones (ischial tuberosities) contact the 

saddle. As the rider's pelvic width increases, the rider generally needs 

a wider saddle. Likewise if the pelvis is narrower, the saddle that the 

rider feels comfortable may be narrower. However, the dimension of 

the pelvic bones has absolutely no relationship to the dimensions of 

the rider (Height, weight, etc.). The only way to understand the 

pelvic width and therefore determine the correct width saddle to ride 

is to measure the ischial tuberosities. This is done with a special 

measuring tool developed by Carl Bird of Specialized. Riding position 

for both men and women also plays a factor. The more aerodynamic 

a riders position, the narrower the pelvic contact, since the pelvic 

bones are in the shape of a triangle with the wider part in the rear. 

Men's and Women's saddles created by Specialized now come in different 

widths so that riders can choose the most comfortable as well 

as the most medically safe saddle for their needs. 

WIDTH TESTING 

During blood flow testing, varying the width of the saddles created 

differing percentage of blood flow for male cyclists. Theoretically this 

is due to the difference in width of the pelvic bones: when comparing 

similar body types and sizes, women's sit bones are typically 1 cm 

wider than men's. With wider pelvic bone separation, the distance 

between the ischial tuberosities (sit bones) increases, requiring a 

wider saddle for support. If a rider with wider sit bones sits on a narrow 

saddle, the rider is not well supported and the saddle pushes up 

into the pelvis, compressing the internal pudendal arteries which lie 

in Alcock's canal against the pelvic wall. During women's testing, 

saddle widths changed the pressure map as well as the maximum 

pressure felt by the rider. Women with wider sit bones had less pressure 

with a wider saddle even though the central cutout and window 

remained identical. 

PRESSURE RELIEF 

With respect to the pressure saddles create, and the designs that can 

alleviate this pressure, men and women both have very unique 

requirements. Male cyclists have been shown to have an increased 

incidence of Erectile Dysfunction as a result of riding, something 

that's been shown to be true in hundreds of studies since 1984. The 

ED has been associated with constriction of the Internal Pudendal 

arteries in the region of Alcock's Canal, attached to the pubic bones 

of the pelvis. Female cyclists have been shown to have pain, numbness, 

urinary, and sexual problems as a result of riding. This is 

thought to be the result of both constrictions of the arteries (just as 

with male cyclists), as well as direct perineal pressure from the bicycle 

saddle. 


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MEN 

Through our studies, we now have a clear picture of the health and 

physiological impacts of bicycle saddles on male cyclists, specifically 

as it relates to the compression of the pudendal arteries. Because we 

can now accurately measure blood flow in male cyclists, we can 

accurately compare different saddle designs, and utilize this data to 

improve and optimize each BG saddle for its intended use. 

MEN'S BLOOD FLOW TESTING 

In January 2004, Drs. Sommer and Minkow presented their blood 

flow laboratory protocol to journalists from the USA and Europe. This 

presentation compared general types of saddles including soft, thickly 

padded traditional saddles, conventional race-type saddles, and socalled 

“anatomic” saddles designs. In comparing these general types 

of saddles, the journalists noted some surprising overall results that 

remained consistent regardless of the brands of saddles tested: 

• Soft, padded saddles restrict blood flow more than any other type. 

In general, the more padding, the more restriction. 

• Thinly padded racing saddles, while clearly less comfortable for 

most cyclists, performed better than soft “comfort” saddles in 

terms of blood flow. 

• Overall, anatomic saddle designs (with grooves, cut-outs, or 

relieved areas), offered the best performance (restricted blood 

flow the least). 

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PRESSURE RELIEF NEEDS ARE DIFFERENT 

FOR MEN AND WOMEN 

Women's perineal pressure is related to the anatomy of the perineum (area between the clitoris and anus). 

The cutout on the women's saddle is hour glass shaped as opposed to the V cut in the men's saddles. This 

specific difference in cutout shape is responsible to decrease in direct pressure for women. Because their sit 

bone width is wider than men's, only women with small sit bone width who ride predominantly in the aero 

position will require the narrowest saddle. 

Comfort saddles for women, ie. The Dolce, are deliberately wider because of the sit bone width increase in 

women. This saddle is also wider because it is presumed that women on this type of saddle will ride in a 

more upright position. Because the pelvic bones are widest in the rear or when the rider is upright, the 

saddle needs to be wider than a higher performance saddle which assumes a more forward leaning position. 

Blood flow for men is restricted in two places on the bicycle saddle, in the rear 1/3 of the saddles where the 

internal pudendal arteries are compressed in the vicinity of Alcock's canal, and under the symphysis pubis 

(front connection of the pelvic bones). The placement of the V cut takes into account the rear constriction 

and the window in the front alleviates the compression under the symphysis. 


Editors from various magazines then requested comparison tests 

between different saddles available in the marketplace (samples were 

provided by the editors). Dr. Sommer outlined the complexity of 

doing comparison tests in the following way: 

1. Each rider has a different baseline blood flow. Some riders have 

inherently higher blood flow (probably because of anatomical 

differences). 

2. Temperature affects rider's blood flow so that on different days 

the same rider may have different results. 

3. Different riders have more sensitivity to arterial constriction, so 

that in some cases a rider will sit on a saddle and the arteries 

immediately constrict, then expand to give a baseline blood flow 

that is stable after several minutes. 

• Other riders will have less immediate drop and stabilize faster. 

• In almost all cases, blood flow stabilizes between the 5 and 7 

minute mark. 

4 Anatomical differences exist so that a particular saddle may 

provide one rider with more blood flow than a different-sized rider. 

Dr. Sommer emphasized that while more blood flow is obviously 

better, any value of more that 50% is reasonable to consider safe for 

most cyclists.

WOMEN 

Women cyclists have not yet been studied to the extent that men have. 

While there are hundreds of medical studies linking men's problems and 

bicycling, there is only one study describing women's problems, written 

by Dr. Irwin Goldstein's group in Boston. In the study they attribute pain, 

numbness and sexual dysfunction in women cyclists as being a result of 

direct pressure from the saddle. 

In an effort to create more comfortable and safe saddles for women, 

Minkow studied women cyclists at The Boulder Center of Sports Medicine. 

The riders inserted TekScan sensors in their cycling shorts to accurately 

measure perineal pressure in the sensitive soft tissue areas. These measurements 

showed enormous differences between saddles and showed 

that the Specialized saddles had in many cases 1/4 the pressure of the 

competition. 

The issue of women's saddles has not been able to be addressed using 

blood flow measurement, because thus far there has been no physical 

way to attach the Oxygen measuring device to the vaginal wall. In 

2005, Minkow devised a testing method to show direct pressure on the 

women's anatomy. Using TekScan sensors placed inside the shorts of 

women volunteers, pressure on the soft tissue was measured while riding. 

Perceived pain was directly correlated with increase in pressure on 

a colored pressure map, allowing saddle design to be correlated with 

pressure mapping. BG women's saddles showed in some cases only 1/4 

the pressure of traditional saddles in the perineal area. 


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PERFORMANCE 

Experience driven designs 

In addition to the advanced Body Geometry design elements, each 

saddle is developed to suit specific types of riders and environments, 

based on the experience that any rider is seeking. 

Toupe: Competitive Road, Track 

Alias: Competitive Road, Track 

Avatar: Endurance Road, Ergonomic Road, 

Fitness/Commute 

Rival SL: Competitive XC, Freeroad 

Rival: XC Trail, Aggressive ATB 

Indie, 

Indie Sport: XC Trail, Aggressive ATB, Freeroad, 

Ergonomic Road 

Jett Women's: Women's Road, Women's ATB 

Dolce, 

Dolce Gel: Women's Road, Women's ATB, Women's 

Comfort 

BG2 Sport: Comfort Street, Comfort ATB 

Milano, 

Milano Gel: Comfort Street, Comfort ATB 

BG Comfort, 

BG Comfort Plus: Comfort Street, Comfort ATB 

WEIGHT & MATERIALS 

Every BG saddle blends a range of optimal materials and construction 

methods to achieve optimal levels of comfort, weight, and durability - 

again, factors that are dictated by the experience that the intended 

rider is seeking. Competitive riders will appreciate the unparalleled 

weights we achieve utilizing carbon fiber shells, hollow titanium rails, 

micromatrix synthetic cover materials, and ultralight thin-profile foam 

padding. Those seeking added comfort on longer rides will find 

solace in our judicious use of gel padding on select models, putting 

further damping and shock absorption between the rider and the 

road or trail. Women will appreciate our unique padding shapes and 

densities, available in a range of models to suit nearly any female 

cyclist. And those seeking greater comfort and shock absorption for 

more recreationally-focused riding will appreciate the BG models that 

utilize denser padding and additional gel inserts, maximizing comfort 

for those who value it most. 

Roger Minkow, MD 

Roger Minkow is a medical doctor who began 

designing ergonomic products in 1984. At that 

time he designed the workout equipment for the 

US Olympic Gymnastics team, and then went on 

to design the pilot's seats for United Airline's 

767's in 1988. During this time he was the Co- 

Medical Director of the San Francisco Spine 

Center and a medical researcher in the field of 

Spinal Surgery. Dr. Minkow began working with 

Specialized in 1997. 

Since then, he has designed the ergonomic components 

for the Body Geometry Saddles, Gloves, 

and Grips. Together, Specialized and Dr. Minkow 

have revolutionized and re-educated the cycling 

industry towards a more scientifically-grounded 

approach to component and apparel design. 


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Body Geometry products are scientifically developed ... - Specialized

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