Go Back  Bike Forums > Bike Forums > Road Cycling
Reload this Page >

Why the Ass-O-meter is flawed....

Notices
Road Cycling “It is by riding a bicycle that you learn the contours of a country best, since you have to sweat up the hills and coast down them. Thus you remember them as they actually are, while in a motor car only a high hill impresses you, and you have no such accurate remembrance of country you have driven through as you gain by riding a bicycle.” -- Ernest Hemingway

Why the Ass-O-meter is flawed....

Old 01-15-14, 05:24 AM
  #1  
Voice of the Industry
Thread Starter
 
Campag4life's Avatar
 
Join Date: May 2007
Posts: 12,572
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 1188 Post(s)
Likes: 0
Liked 8 Times in 8 Posts
Why the Ass-O-meter is flawed....

Most of us know that fit which is always debated on the 41 is a riddle to many of us and even a work in progress for pros.
3 pts of contact on the bike and if you get is wrong, can lead to pain and discomfort. Get it right and it transforms the riding experience.
And of course some days we get it right better than others. To me saddle setback and pelvis position on the bike is key. Inadequate saddle setback and pelvis rotation translates to too much weight on the hands and really destroys comfort and power to the bike.

Even though the following article is a self promotion for SMP saddles, an insightful article about pelvis geometry worth a glance if you haven't seen it:
https://www.stevehoggbikefitting.com/...ll-about-smps/

Hogg is a prolific writer on bike fit and one of my favorites as he writes with great clarity. Probably the large majority of those who ride a road bike don't understand pelvis geometry included Mr. Hogg when starting out which was a refreshing admission for a bike fit expert which btw I believe him to be. Reality is a pelvis is a pretty complex structure and most of us who haven't been initiated wouldn't understand how it relates to a saddle on a bicycle. Saddle width is often equated to the distance between ischial tuberosities or what are generically referred to as sit bones. This is an inaccurate oversimplification however. The pelvis as it rotates forward in terms of saddle contact narrows dramatically. So choice of saddle is probably more of a function of your pelvis rotation or lack thereof than any genetic distance between your ischial tuberosities or so called sit bones.

So sitting armchair fashion on an Ass-O-meter isn't going to tell you what your best saddle width is going to be for riding. There are other soft tissue issues as well when it comes to saddle shape that Hogg mentioned as well.

Words are an inadequate substitute for a picture and the third, top view picture is the best picture I have seen which illustrates how the inferior ramus of the pelvis is the true contact to the saddle when in a proper pelvis tilted forward riding position which straightens the lumbar region of the back and promotes torso tilt conducive to minimizing air drag. Cobb also speaks frequently about this in his videos which I also find informative.

Last edited by Campag4life; 01-15-14 at 06:54 AM.
Campag4life is offline  
Old 01-15-14, 05:32 AM
  #2  
Speechless
 
RollCNY's Avatar
 
Join Date: Jun 2011
Location: Central NY
Posts: 8,842

Bikes: Felt Brougham, Lotus Prestige, Cinelli Xperience,

Mentioned: 22 Post(s)
Tagged: 1 Thread(s)
Quoted: 163 Post(s)
Likes: 0
Liked 39 Times in 16 Posts
Bigger flaw in my opinion is Specialized's inability to understand numbers. If you used a 143mm original Romin, Specialized recommends a 155mm Romin EVO. What is the point of knowing you take a 143 if every model labelled 143 isn't actually a 143? As soon as I discovered that, I grabbed a spare original series, and won't look at them again.
RollCNY is offline  
Old 01-15-14, 05:39 AM
  #3  
Voice of the Industry
Thread Starter
 
Campag4life's Avatar
 
Join Date: May 2007
Posts: 12,572
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 1188 Post(s)
Likes: 0
Liked 8 Times in 8 Posts
Originally Posted by RollCNY
Bigger flaw in my opinion is Specialized's inability to understand numbers. If you used a 143mm original Romin, Specialized recommends a 155mm Romin EVO. What is the point of knowing you take a 143 if every model labelled 143 isn't actually a 143? As soon as I discovered that, I grabbed a spare original series, and won't look at them again.
Roll, we will have to disagree here. Width sizing has its place as a singular metric as flawed as it is. Singular indices or metrics never fully define something as complex as agreement between two topographical surfaces...both of which subject to rotation aka a human pelvis while riding and a fixed bike saddle that can be adjusted. Also pretty impossible to combine a quantifiable entity like saddle width with a quality like saddle shape or form comprised of a myriad of dimensions, angles and radii. That is the reason for example many pros who ride a 143 Toupe may prefer a 155 Romin...a Romin rides more narrow because in front view is more convex than the flatter side to side Toupe. So words and experience have to be used in conjunction with a single side to side measurement which quite right doesn't tell anywhere near the whole story about sizing. Also sorry to say this but my opinion is your position on choosing the original series because of any sizing convention is ridiculous. Most prefer the Evo to the original including me. Just get the size you need. A number is just a number and has to be used in context with other saddle attributes most notably shape. To me Specialized makes the best saddles but I haven't ridden all of them.

Last edited by Campag4life; 01-15-14 at 07:04 AM.
Campag4life is offline  
Old 01-15-14, 08:10 AM
  #4  
Senior Member
 
Wesley36's Avatar
 
Join Date: Jul 2009
Posts: 1,001
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Campag4life
Saddle width is often equated to the distance between ischial tuberosities or what are generically referred to as sit bones. This is an inaccurate oversimplification however. The pelvis as it rotates forward in terms of saddle contact narrows dramatically. So choice of saddle is probably more of a function of your pelvis rotation or lack thereof than any genetic distance between your ischial tuberosities or so called sit bones.

So sitting armchair fashion on an Ass-O-meter isn't going to tell you what your best saddle width is going to be for riding.
I would say that you are setting up a false opposition here. Choice of saddle should be informed BOTH by pelvic rotation and the distance between the sitz bones. If one was to oppose them, knowing pelvic rotation and not sitz bone distance is more useless than knowing sitz bone distance but not pelvic rotation. Ass-o-meters do what they are supposed to do, but it is a case of garbage in - garbage out. Why, for f's sake, would one sit armchair fashion on an ass-0-meter? You are right, it is a quick way to get a meaningless number, but that is not the fault of the ass-o-meter.

If it is going to be a meaningful exercise, one needs to adopt a position similar to the one on the bike when sitting on the ass-o-meter, for the reasons you have outlined. This does not mean discarding ass-o-meters, it means using ass-o-meters properly and interpreting the information correctly.
Wesley36 is offline  
Old 01-15-14, 08:10 AM
  #5  
Speechless
 
RollCNY's Avatar
 
Join Date: Jun 2011
Location: Central NY
Posts: 8,842

Bikes: Felt Brougham, Lotus Prestige, Cinelli Xperience,

Mentioned: 22 Post(s)
Tagged: 1 Thread(s)
Quoted: 163 Post(s)
Likes: 0
Liked 39 Times in 16 Posts
Originally Posted by Campag4life
That is the reason for example many pros who ride a 143 Toupe may prefer a 155 Romin...a Romin rides more narrow because in front view is more convex than the flatter side to side Toupe.
I absolutely agree, and am not saying that the metric should cross models. But within a model, when you place one year's 143 with the next year's 143, wouldn't you expect them to be similar? How is someone to know that this model upsizing increased? If you wear a size 34x34 pleated front Docker, do you expect to have to test fit the next year's size 34x34 pleated front Docker? If you went flat front, sure. It's a different model.

It is a small beef really, and I am not taking anything away from Specialized saddles. There is no number that measures 143 on a saddle per se. It is a saddle made for a 143 bottom. So if the replacement model needed to be made 148mm wide to fit the same 143 bottom, label it a 143. I don't care what the true width is. I care that it will fit just like last year's model with the same name, same size labelling.

EDIT: And when did words like travel and label lose the second lowercase "L" when you add "ing". I was taught labelling and travelling, and Mr. Spellcheck disagrees. He also seems to not like being called Mr. Spellcheck.
RollCNY is offline  
Old 01-15-14, 08:17 AM
  #6  
Voice of the Industry
Thread Starter
 
Campag4life's Avatar
 
Join Date: May 2007
Posts: 12,572
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 1188 Post(s)
Likes: 0
Liked 8 Times in 8 Posts
Originally Posted by RollCNY
I absolutely agree, and am not saying that the metric should cross models. But within a model, when you place one year's 143 with the next year's 143, wouldn't you expect them to be similar? How is someone to know that this model upsizing increased? If you wear a size 34x34 pleated front Docker, do you expect to have to test fit the next year's size 34x34 pleated front Docker? If you went flat front, sure. It's a different model.

It is a small beef really, and I am not taking anything away from Specialized saddles. There is no number that measures 143 on a saddle per se. It is a saddle made for a 143 bottom. So if the replacement model needed to be made 148mm wide to fit the same 143 bottom, label it a 143. I don't care what the true width is. I care that it will fit just like last year's model with the same name, same size labelling.

EDIT: And when did words like travel and label lose the second lowercase "L" when you add "ing". I was taught labelling and travelling, and Mr. Spellcheck disagrees. He also seems to not like being called Mr. Spellcheck.
I understand your point, but now if you move away from the actual width of the saddle to define size, then you abandon that convention and move on to another. This is in fact the same conundrum with frame sizing. Sloping top tubes has created 'virtual' or effective sizing because seat tube length is no longer relevant. So manufacturers use both....virtual sizing...and generic sizing, i.e. S, M, X, XL...even M/L for some manufacturers like Giant.
I believe the uptake is...no single metric does a good job defining something as complex as size because size is comprised of many dimensions. So maybe it would be best for Specialized to simply abandon a numeric value for width and use S, M, L etc. No doubt they have considered this.
Campag4life is offline  
Old 01-15-14, 08:23 AM
  #7  
Senior Member
 
lsberrios1's Avatar
 
Join Date: Jul 2012
Location: Atlanta GA
Posts: 2,844

Bikes: '13 Spech Roubaix SL4 Expert

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 297 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by RollCNY
I absolutely agree, and am not saying that the metric should cross models. But within a model, when you place one year's 143 with the next year's 143, wouldn't you expect them to be similar? How is someone to know that this model upsizing increased? If you wear a size 34x34 pleated front Docker, do you expect to have to test fit the next year's size 34x34 pleated front Docker? If you went flat front, sure. It's a different model.

It is a small beef really, and I am not taking anything away from Specialized saddles. There is no number that measures 143 on a saddle per se. It is a saddle made for a 143 bottom. So if the replacement model needed to be made 148mm wide to fit the same 143 bottom, label it a 143. I don't care what the true width is. I care that it will fit just like last year's model with the same name, same size labelling.

EDIT: And when did words like travel and label lose the second lowercase "L" when you add "ing". I was taught labelling and travelling, and Mr. Spellcheck disagrees. He also seems to not like being called Mr. Spellcheck.
So you are saying that the 155mm saddle might not actually be 155mm? I have not measured so I don't know but I thought that is what it meant. I am a 155mm in Romin Evo and Toupe. I have not found another brand that makes a 155m saddle. Selle Italia has a system for measure that indicates their widest saddle at 143 (I think). So if I ride a 155 in Specialized, what would be the equivalent in say, Selle Italia or Fizi'k? I am running into this because I don't want to put a Specialized saddle on the new bike, but if it is the only choice then so be it...
__________________
Cat 6 going on PRO....
lsberrios1 is offline  
Old 01-15-14, 08:25 AM
  #8  
Voice of the Industry
Thread Starter
 
Campag4life's Avatar
 
Join Date: May 2007
Posts: 12,572
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 1188 Post(s)
Likes: 0
Liked 8 Times in 8 Posts
Originally Posted by Wesley36
I would say that you are setting up a false opposition here. Choice of saddle should be informed BOTH by pelvic rotation and the distance between the sitz bones. If one was to oppose them, knowing pelvic rotation and not sitz bone distance is more useless than knowing sitz bone distance but not pelvic rotation. Ass-o-meters do what they are supposed to do, but it is a case of garbage in - garbage out. Why, for f's sake, would one sit armchair fashion on an ass-0-meter? You are right, it is a quick way to get a meaningless number, but that is not the fault of the ass-o-meter.

If it is going to be a meaningful exercise, one needs to adopt a position similar to the one on the bike when sitting on the ass-o-meter, for the reasons you have outlined. This does not mean discarding ass-o-meters, it means using ass-o-meters properly and interpreting the information correctly.
not sure what you mean by false opposition. Did you mean false premise or supposition?
Good point about how to sit on an Ass-O-meter. Btw, have you done this? When sitting in a forward rotated position on a Ass-O-meter do you really get 2 distinct points? I would like some proof of that. Seems to me the inferior ramus where one really sits on a road bike saddle is in effect, two converging boney rails or protrusions. I am quite sure they would not leave a clear demarcation of sit bone spacing when sitting in a proper pelvis forward rotated position.
Therein leads to the further myth about correlating an Ass-O-meter measurement to actual saddle width. How much side to side distance should one leave to each respective edge of the saddle to each touch down of the pelvis to the saddle. 5mm? 10mm? This isn't quantifiable with any sort of science.
Campag4life is offline  
Old 01-15-14, 08:27 AM
  #9  
Senior Member
 
George's Avatar
 
Join Date: Jul 2006
Location: Katy Texas
Posts: 5,668

Bikes: Specialized Roubaix

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 92 Post(s)
Liked 51 Times in 30 Posts
So I got fit by one fitter using the ass meter and he put me on a 130 Romin EVO.I could feel it pushing my sit bones apart. So I went back and got a 143 Romin Evo. Much better, but it just didn't feel right. Then I tried the 143 Toupe, which felt the best. My butt is telling me I like flat. Then I tried the SLR Max Flow. I said to myself this is finally it. I kept reading about saddles and I came across A San Marcos Regal'e, that sounded like something to try. So I seen one on sale at Performance and bought it. Man did this saddle work great for me. The saddle is a 148 mm wide and it feels great. So much for the ass meter, lol.

After 2500 miles on the saddle, I don't know what happened on yesterdays ride, but I could feel I was getting warm on my left sit bone and I blame it on my new shoes. I lowered the saddle by 3 mm for the sole difference and moved the left cleat forward as I had on my Specialized Comp shoes. When I got home I looked and I didn't have a mark on me. So I don't know what's going on . Maybe it was just my pedaling or just not use to the shoes yet. I bought the Giro Factor shoes and I find them to much more comfortable than the Specialized. I contribute that to a better fit for me. I didn't put the one vargus wedge in I had in the right shoe, but I didn't have any pain either, so I feel alright.

I cant ride today, but I'll have to watch to see what I'm doing different, to see what's causing the sit bone to heat up. You would think if it was heating up, I would be red or had some kind of chaffing or something.

Anyhow the saddle feels great and I'll have to make some adjustments, because of the new shoe's. The all carbon shoes feel great.
__________________
George
George is offline  
Old 01-15-14, 08:35 AM
  #10  
Voice of the Industry
Thread Starter
 
Campag4life's Avatar
 
Join Date: May 2007
Posts: 12,572
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 1188 Post(s)
Likes: 0
Liked 8 Times in 8 Posts
Originally Posted by George
So I got fit by one fitter using the ass meter and he put me on a 130 Romin EVO.I could feel it pushing my sit bones apart. So I went back and got a 143 Romin Evo. Much better, but it just didn't feel right. Then I tried the 143 Toupe, which felt the best. My butt is telling me I like flat. Then I tried the SLR Max Flow. I said to myself this is finally it. I kept reading about saddles and I came across A San Marcos Regal'e, that sounded like something to try. So I seen one on sale at Performance and bought it. Man did this saddle work great for me. The saddle is a 148 mm wide and it feels great. So much for the ass meter, lol.

After 2500 miles on the saddle, I don't know what happened on yesterdays ride, but I could feel I was getting warm on my left sit bone and I blame it on my new shoes. I lowered the saddle by 3 mm for the sole difference and moved the left cleat forward as I had on my Specialized Comp shoes. When I got home I looked and I didn't have a mark on me. So I don't know what's going on . Maybe it was just my pedaling or just not use to the shoes yet. I bought the Giro Factor shoes and I find them to much more comfortable than the Specialized. I contribute that to a better fit for me. I didn't put the one vargus wedge in I had in the right shoe, but I didn't have any pain either, so I feel alright.

I cant ride today, but I'll have to watch to see what I'm doing different, to see what's causing the sit bone to heat up. You would think if it was heating up, I would be red or had some kind of chaffing or something.

Anyhow the saddle feels great and I'll have to make some adjustments, because of the new shoe's. The all carbon shoes feel great.
In bold...common lament and debunks the validity of an Ass-O-meter as any basis for correct saddle width. Lets say saddle width is only 60% of the equation anyway and the rest is shape and firmness.

A tip if you are getting asymmetric pain or loading side to side on your sit bones. Rotate your saddle one side or anther to change the load distribution. You can play with tilt as well. Posture and pelvis rotation really affect saddle pressure points. As John Cobb talks about a lot, rotating your pelvis properly forward takes pressure off of tender sit bones.
Campag4life is offline  
Old 01-15-14, 08:36 AM
  #11  
Senior Member
 
Wesley36's Avatar
 
Join Date: Jul 2009
Posts: 1,001
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Campag4life
not sure what you mean by false opposition. Did you mean false premise or supposition?
Good point about how to sit on an Ass-O-meter. Btw, have you done this? When sitting in a forward rotated position on a Ass-O-meter do you really get 2 distinct points? I would like some proof of that. Seems to me the inferior ramus where one really sits on a road bike saddle is in effect, two converging boney rails or protrusions. I am quite sure they would not leave a clear demarcation of sit bone spacing when sitting in a proper pelvis forward rotated position.
Therein leads to the further myth about correlating an Ass-O-meter measurement to actual saddle width. How much side to side distance should one leave to each respective edge of the saddle to each touch down of the pelvis to the saddle. 5mm? 10mm? This isn't quantifiable with any sort of science.
False opposition - you took two elements of a fit, then put together an argument as to which part is better. It is a false opposition, because it is not "either/or", it is "and". You need to account for pelvic rotation AND sitz bone distance. Either parameter is less meaningful without the other, but your initial post makes it sound like we should choose one over the other. So it sets up a false opposition - these two parameters are not contradictory, both should be elements of fitting a saddle.

And yes, this is exactly how I used an ass-o-meter, and yes, there are definitely two distinct points. In terms of the physiology of how the pelvis interacts with the saddle, scroll down near the bottom of this, there are even fun pictures:

https://www.cervelo.com/en/engineerin...-saddles-.html
Wesley36 is offline  
Old 01-15-14, 08:40 AM
  #12  
Senior Member
 
Wesley36's Avatar
 
Join Date: Jul 2009
Posts: 1,001
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Campag4life
In bold...common lament and debunks the validity of an Ass-O-meter as any basis for correct saddle width. Lets say saddle width is only 60% of the equation anyway and the rest is shape and firmness.
And there you go again. You really need to add the concept of "and".

If one isolates it from all other input, then yes, an ass-o-meter would not give meaningful information. Just like if you scrape the numbers off of your ruler, it will cease providing meaningful data when you hold it beside something. People misusing ass-o-meters does not mean that ass-o-meters do not work.

Fitting a saddle is a dark art, and subject to a great deal of trial and error. There is no shape that works for everyone. That said, taking into account things like sitz bone distance AND pelvic rotation AND seat height etc etc gives us a better starting point than just grabbing random saddles and slapping them on your bike.
Wesley36 is offline  
Old 01-15-14, 09:23 AM
  #13  
Decrepit Member
 
Scooper's Avatar
 
Join Date: Aug 2005
Location: Santa Rosa, California
Posts: 10,489

Bikes: Waterford 953 RS-22, several Paramounts

Mentioned: 71 Post(s)
Tagged: 0 Thread(s)
Quoted: 634 Post(s)
Liked 68 Times in 57 Posts
The ass-o-meter patent shows the need to elevate your feet to make an angle between your upright trunk and your upper leg roughly simulating your seating position on the saddle (~30° - 45° for aero, ~40° - 75° for more upright). Your sitbone distance will vary depending on the angle as shown on the patent drawing. And, yes, you get two small, distinct impressions from the sitbones; the distance between them is easily measured.

__________________
- Stan

my bikes

Science doesn't care what you believe.
Scooper is offline  
Old 01-15-14, 09:55 AM
  #14  
Senior Member
 
Join Date: Aug 2006
Posts: 2,501
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Likes: 0
Liked 42 Times in 22 Posts
The biggest flaw of the "ass-o-meter" is that it doesn't take into account personal preference and personal comfort. I use a very narrow saddle because I am not comfortable with most of my weight on my ischial tuberosities. I can't ride for 20 miles like this. I would prefer more of my weight on my peroneal area and it doesn't cause me any other problems after 30 years of riding daily. The Specialized saddle based on my "meter reading" is a terrible saddle for me.

Unfortunately, you can't pick a saddle with a ruler.
jrobe is offline  
Old 01-15-14, 10:14 AM
  #15  
Senior Member
 
UnfilteredDregs's Avatar
 
Join Date: Jun 2013
Location: NYC, duh Bronx.
Posts: 3,578

Bikes: Salsa Ti Warbird- 2014/ November RAIL52s

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 67 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by Campag4life
Inadequate saddle setback and pelvis rotation translates to too much weight on the hands
How do you know what too much weight on the hands is? I found the perfect saddle for myself, extremely comfortable...However, I do have hand issues from too many years playing guitar... (carpal tunnel, cubital tunnel...) and when I come off a good ride I do experience some numbness in my hands that I know is carpal/ pressure related... and if I absorb enough road chatter I get a bit of tennis elbow as well...

It is manageable and I am wondering if it's something I just have to deal with due to my history or can I really improve my cockpit? I have been professionally fit, and I do plan to go back with more input in about another 200 miles...

But back to the question... when on the hood or in the drops, how much weight should you be supporting there?

I am still working on posture, I make sure I arch my back, elbows bent...when I go into the drops, the same, and I schooch way back on the saddle...
UnfilteredDregs is offline  
Old 01-15-14, 10:34 AM
  #16  
Senior Member
 
Seattle Forrest's Avatar
 
Join Date: Mar 2010
Location: Seattle, WA
Posts: 23,208
Mentioned: 89 Post(s)
Tagged: 0 Thread(s)
Quoted: 18883 Post(s)
Liked 10,645 Times in 6,054 Posts
Don't tell Beth.

I have her convinced an experienced cyclist can fit her for a bike and for hiking shoes too, measuring by hand.
Seattle Forrest is offline  
Old 01-15-14, 10:52 AM
  #17  
Speechless
 
RollCNY's Avatar
 
Join Date: Jun 2011
Location: Central NY
Posts: 8,842

Bikes: Felt Brougham, Lotus Prestige, Cinelli Xperience,

Mentioned: 22 Post(s)
Tagged: 1 Thread(s)
Quoted: 163 Post(s)
Likes: 0
Liked 39 Times in 16 Posts
Originally Posted by Scooper
The ass-o-meter patent shows the need to elevate your feet to make an angle between your upright trunk and your upper leg roughly simulating your seating position on the saddle (~30° - 45° for aero, ~40° - 75° for more upright). Your sitbone distance will vary depending on the angle as shown on the patent drawing. And, yes, you get two small, distinct impressions from the sitbones; the distance between them is easily measured.

Thank you for this. Here is why:
Two or three years ago, the max saddle width Specialized made was a 155, as directed by the Ass-O-matic. Today, they make saddles up to 168. Did sit bones expand exponentially (or linearally at not a non-linear rate) to warrant new models in 168? My old reading led to a 143, and it worked perfectly. I bought a Selle Italia in 143, and it feels slightly narrower, but not uncomfortable. However, I would today be steered to a 155.

And the guy I worked with to get my first Romin, with the Ass-o-matic, was brilliant, or an extraordinarily accurate liar. He looked at my measurement, looked at my bike setup, and told me I was between sizes, and recommended the 143. He also specifically said (and I remember it because it proved to be accurate) that if I was intending to maintain or increase the amount of saddle to bar drop I had, I would love the Romin 143. If I intended to relax it, I should go to a Toupe or a Romin 155 (when 155's were 155's and not 168's). I loved the saddle, but hated it when I went to a less aggressive set up for a short duration.
RollCNY is offline  
Old 01-15-14, 12:56 PM
  #18  
Voice of the Industry
Thread Starter
 
Campag4life's Avatar
 
Join Date: May 2007
Posts: 12,572
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 1188 Post(s)
Likes: 0
Liked 8 Times in 8 Posts
Originally Posted by Wesley36
False opposition - you took two elements of a fit, then put together an argument as to which part is better. It is a false opposition, because it is not "either/or", it is "and". You need to account for pelvic rotation AND sitz bone distance. Either parameter is less meaningful without the other, but your initial post makes it sound like we should choose one over the other. So it sets up a false opposition - these two parameters are not contradictory, both should be elements of fitting a saddle.

And yes, this is exactly how I used an ass-o-meter, and yes, there are definitely two distinct points. In terms of the physiology of how the pelvis interacts with the saddle, scroll down near the bottom of this, there are even fun pictures:

https://www.cervelo.com/en/engineerin...-saddles-.html
Since you want to be precise, tell me precisely what torso and pelvis rotation angle you used when sitting on the Ass-O-meter to determine your optimal saddle width.

I believe you spoiled the foundation of the test. The test with the Ass-O-meter is predicated on sit bone spacing with the torso orthogonal to the where you sit. The resulting spacing is interpolated as shown in the diagram above based upon riding position.

Last edited by Campag4life; 01-15-14 at 01:01 PM.
Campag4life is offline  
Old 01-15-14, 03:56 PM
  #19  
Farmer tan
 
f4rrest's Avatar
 
Join Date: May 2008
Location: Burbank, CA
Posts: 7,986

Bikes: Allez, SuperSix Evo

Mentioned: 38 Post(s)
Tagged: 1 Thread(s)
Quoted: 2870 Post(s)
Liked 28 Times in 23 Posts
Campy, I read the same article, and agree with the premise that inferior ramus spacing is the more useful measurement -- once getting into a pelvis rotation similar to that on the bike.

I was able to measure by placing a dry paper towel over a damp paper towel on a low surface (toilet lid), crouching similar to riding position while hovering over it, and then briefly touching down.

It leaves two damp divets you can measure. If you repeat the measurement more upright, the space between divets increases as you have rotated the pelvis back,which widens the boney contact points.

My wide ass fits the narrow fizik well due to the rotation.
f4rrest is offline  
Old 01-15-14, 04:22 PM
  #20  
Voice of the Industry
Thread Starter
 
Campag4life's Avatar
 
Join Date: May 2007
Posts: 12,572
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 1188 Post(s)
Likes: 0
Liked 8 Times in 8 Posts
Originally Posted by UnfilteredDregs
How do you know what too much weight on the hands is? I found the perfect saddle for myself, extremely comfortable...However, I do have hand issues from too many years playing guitar... (carpal tunnel, cubital tunnel...) and when I come off a good ride I do experience some numbness in my hands that I know is carpal/ pressure related... and if I absorb enough road chatter I get a bit of tennis elbow as well...

It is manageable and I am wondering if it's something I just have to deal with due to my history or can I really improve my cockpit? I have been professionally fit, and I do plan to go back with more input in about another 200 miles...

But back to the question... when on the hood or in the drops, how much weight should you be supporting there?

I am still working on posture, I make sure I arch my back, elbows bent...when I go into the drops, the same, and I schooch way back on the saddle...
My suggestion is experiment with saddle setback and handlebar height. Oddly, more setback and greater distance to the handlebar and a slightly lower handlebar is many times the recipe for low hand pressure. This is very counterintuitive and goes right over the head of many amateur cyclists who ride cramped with a closer in handlebar with little saddle setback and the arms are in compression. If you move your weight more rearward and balance your body on the saddle better and move the bar away this will will take weight off your hands. Again, the opposite of what many do.
HTH.
Campag4life is offline  
Old 01-15-14, 04:26 PM
  #21  
Voice of the Industry
Thread Starter
 
Campag4life's Avatar
 
Join Date: May 2007
Posts: 12,572
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 1188 Post(s)
Likes: 0
Liked 8 Times in 8 Posts
Originally Posted by f4rrest
Campy, I read the same article, and agree with the premise that inferior ramus spacing is the more useful measurement -- once getting into a pelvis rotation similar to that on the bike.

I was able to measure by placing a dry paper towel over a damp paper towel on a low surface (toilet lid), crouching similar to riding position while hovering over it, and then briefly touching down.

It leaves two damp divets you can measure. If you repeat the measurement more upright, the space between divets increases as you have rotated the pelvis back,which widens the boney contact points.

My wide ass fits the narrow fizik well due to the rotation.
Good comments thanks. What this thread reveals is as stated in the thread subject, the Ass-O-meter just isn't very useful. Many if not most don't find a correlation to what that gauge measures and preference for a give saddle width. This is for a variety of reasons. I believe the Ass-O-meter is a semi desperate attempt to add some science to something that is hard to quantity...saddle comfort. I do credit Specialized however with their significant contribution to saddle design by their width sizing. Width is perhaps thee most important single parameter when it comes to saddle selection but there are many contributing factors to what makes for a good saddle on a 4 hour ride. I thought Hogg's article is excellent and why I shared it.
Campag4life is offline  
Old 01-15-14, 04:50 PM
  #22  
Rubber side down
 
Clipped_in's Avatar
 
Join Date: Mar 2011
Location: Teh Quickie Mart
Posts: 1,769

Bikes: are fun! :-)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Liked 225 Times in 105 Posts
Originally Posted by Campag4life
...More setback and greater distance to the handlebar and a slightly lower handlebar is many times the recipe for low hand pressure. This is very counterintuitive...
Yes it is, and my experience supports your ideas. However, you have to be careful to insure that you are not compromising optimum pedaling position in the process. Some people do better (from a pedaling power perspective) in a more saddle forward position. It is a balancing act, and it is easy to passively exclude important variables.
Clipped_in is offline  
Old 01-15-14, 06:43 PM
  #23  
Senior Member
 
UnfilteredDregs's Avatar
 
Join Date: Jun 2013
Location: NYC, duh Bronx.
Posts: 3,578

Bikes: Salsa Ti Warbird- 2014/ November RAIL52s

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 67 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by Campag4life
My suggestion is experiment with saddle setback and handlebar height. Oddly, more setback and greater distance to the handlebar and a slightly lower handlebar is many times the recipe for low hand pressure. This is very counterintuitive and goes right over the head of many amateur cyclists who ride cramped with a closer in handlebar with little saddle setback and the arms are in compression. If you move your weight more rearward and balance your body on the saddle better and move the bar away this will will take weight off your hands. Again, the opposite of what many do.
HTH.
I was actually thinking along those lines as I was riding today...effectively you're moving your CG rearward, so more weight at the seat...??

Last edited by UnfilteredDregs; 01-15-14 at 09:31 PM.
UnfilteredDregs is offline  
Old 01-15-14, 08:35 PM
  #24  
Lover of Old Chrome Moly
 
Myosmith's Avatar
 
Join Date: May 2011
Location: NW Minnesota
Posts: 2,949
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 143 Post(s)
Likes: 0
Liked 23 Times in 17 Posts
Ass-o-meter is just a tool that gives you a guideline to use as a starting point. The only true test of a saddle is comfort and sitbone width is just one of many variables.
Myosmith is offline  
Old 01-15-14, 10:01 PM
  #25  
Senior Member
 
Spiduhman's Avatar
 
Join Date: Nov 2007
Location: CenCal - SLO
Posts: 710

Bikes: S2, Wilier GTR (Arr), Giant VT, Myata 3-10

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Likes: 0
Liked 6 Times in 3 Posts
San Marco Aspide Arrowhead "gelaround" in 130 - it fits me.

The particular model was discontinued, so, thanks to Nashbar, I've some spares.

When the spares wear out, then it'll be time to re-analyze.


It's like shoes; the size, width, style, model all "count" - so does the last, material, and the artisan.

I've slimmed down quite a bit over the last ten years, and also moved to a more aggressive and comfortable position, hence a "130 mm" saddle is now just the thing, and the replaced saddles are each a bit wider going baaack in tiiiime.
Spiduhman is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.