Saddles and Bike Fit

Comparison of the rail clamping regions of three saddles:  the Specialized Avatar, the Brooks Team Pro, and the Selle Italia Turbo. The Brooks Team Pro has the same rail configuration as the Brooks B17, and the other two saddles are meant to be representative examples of typical, modern saddles. The measurements are in centimeters, not mm as shown in the picture. The picture is from Tallrider on Bike Forums (@drtallrider on Instagram).

I have been testing my resurrected Hetchins to see how rideable it is. When I started this project, my big concern was if the frame was simply too large for me. Had that been the case, it would have been a deal killer. Good news, I realized within minutes of picking up the bike that the frame, though large, is quite rideable. Of course, issues sometimes appear on longer rides that would not have been noticed on the 3 mile ride home from the bike shop so I decided to ride it 100 miles or so before making any big decisions. One decision that could not wait was what to do about the saddle. The saddle from the Centurion donor bike, despite being a Brooks, was a cheap model which I found uncomfortable. I borrowed a Brooks B17 from my Bianchi Specialissima, put it on, and went for a 5 mile ride, only to find that the B17 was positioned too far forward. I had run into a similar issue just over a year ago when I transferred the B17 from my Surly Cross Check to my Bianchi Volpe in preparation for my first metric century, replacing the (rather uncomfortable) modern saddle that came on the Volpe. When I did so, I found that the B17 felt too far forward. This surprised me at the time, and to understand why this was, I got on line only to find this was a known issue with the B17. As can be seen in the illustration at the top of the page, the shape of the rails underneath the Brooks B17 has two potential problems:

1. The part of the rails where the seatpost attaches is very short front to back, providing virtually no front to back adjustment.
2. The clamping area is relatively far back on the saddle, resulting in a more forward than normal saddle position.

This problem is sufficiently well known that special "long setback" seatposts are manufactured specifically for the ever popular Brooks B17 saddle.

Why would Brooks design their saddle this way? One thing to bear in mind is that the design of the B17 remains unchanged since the 1890s when it was first introduced, so perhaps this problem results from bicycle geometry evolution. I would have to say, though, that my experience so far does not support that. I have put B17s on four bicycles, two modern and two vintage, and it worked out of the box on two, one vintage and one modern but was too far forward on the other two, again, one modern, one vintage. My 1960 Bianchi Specialissima originally came with a Brooks B17, so perhaps it is no surprise that a (new, replacement) B17 worked on it. After my first 200 kilometer brevet ride, which I rode on my 2010 Surly Cross Check, I developed saddle sores, so before the second one, I replaced the Surly-provided saddle with a Brooks B17, and it fit fine too. When I transferred that saddle onto my 2006 Bianchi Volpe, however, it felt too far forward, the same experience I just had with my 1967 Hetchins.

What accounts this this bike to bike variation? Two factors that spring to mind are differences in the seat tube angle of the frame and differences in the setback on seatpost that came with the bike. Normally seat tube angle is a piece of information provided by the manufacturer, but because all my bikes are older, that was not an option for me. I could measure this angle, but getting measurements that are sufficiently accurate for potentially small differences seems problematic. Measuring the setback on various seatposts seems easier, and I may do that at some point, but have not yet done so. So, as of today, I don't know exactly why this saddle fit fine on two of my bikes but is too far forward on the other two.

What does it mean to say  that the seat is too far forward? How is that determined? To begin with, I have to confess to being quite ignorant about bike fit, I have always adjusted my bikes by how they feel. When I had the problem with the seat feeling too far forward on my Volpe, I assumed the problem was the distance between the seat and the handlebars, e.g. that I might have been able to correct it by purchasing a longer handlebar stem that would move the handlebars forward, away from the seat. It turns out this is incorrect. (I have noticed on bike forums that I am not the only one with this misconception.) The issue is the positioning of one's body relative to the crank and pedals. Thus, the correction I made on the Volpe, changing the seatpost, was the right one, moving the handlebars would not have solved the problem. I believed the seat was too far forward not due to any measurements, but only because it felt too far forward. I did worry if this judgement was subjective; I have had the experience of a bike feeling like it fit perfectly one day and badly the next despite not changing anything in between. So, my first response when the B17 felt too far forward on the Volpe was to try to get used to it. Only when that didn't work did I change the seatpost.

What could I have measured? What is the proper position of the saddle relative to the crank and pedals? Conventional wisdom, summarized by the acronym "KOPS", is Knees Over Pedal Spindle. According to this rule, with the cranks parallel to the ground, a plumb bob extending from the knee should pass through the spindle of the pedal. However, not everyone agrees this is optimal. Besides theoretical objections, there is the observation that triathletes often ride bikes with the saddle very much farther forward than that. Who is right? To my knowledge, there is little definitive scientific evidence on this subject, so perhaps my approach of putting the saddle where it feels best is not such a bad idea, especially given my interest is not on maximum speed and efficiency, but rather on a fun, comfortable ride.

Someone whose advice I have come to trust is the late, great Sheldon Brown. Although he died in 2008, much of what he said retains its value and as a result his website is being maintained and updated by his disciples. Of all the things I read in preparation for writing this post, his article, Revisionist Theory of Bicycle Sizing. was the one I found most helpful. This is what he says:

"On a bicycle, much of the rider's weight should be carried by the pedals, but if your saddle is too far forward, your legs alone can't support your upper body, so you'll wind up leaning on the handlebars too hard. ... Different cycling styles involve different amounts of pedal force. Racers obviously apply more force to the pedals, more of the time. The usually recommended position for a racer is the "KOPS" position, which usually works out well with seat tube angles in the 73°-75° range. For recreational riders, who don't tend to pedal as hard or as much of the time, a more relaxed position, with the saddle farther back is likely to be more comfortable. As the saddle goes back, the handlebars will generally move back and up to avoid an excessively sharp bend in the torso."

So after all that, here is the Zombie's Guide to Subjective Bike Fitting:

1) Adjust the saddle height so that your leg is almost straight at the most extended part of the pedal rotation.

2) Adjust the forward-back position of the saddle so that it is comfortable. This might require changing the seatpost.

3) Adjust the forward-back position and height of the handlebars until they are comfortable. This will require changing the stem.

So what should I do about my Hetchins? One approach is to purchase a long setback seatpost. Another is to purchase a more modern saddle. I definitely wanted to try these solutions before purchasing components that might or might not work, and to that end, I moved my Brooks Cambium C19 from my Public Bike to my Hetchins, and that solved the "seat too far forward" problem. (It also felt reasonably comfortable.) The Brooks Cambium comes in various widths, C19 being the widest, which I have on my Public Bike because conventional wisdom states that the more upright the seating, the wider the saddle should be, and my Public Bike has a fully upright seating position. I assumed that the C17 size would be about the same width as my preferred Brooks B17 and thus more appropriate for the Hetchins, as it is a road bike with a more aggressive seating position, so purchased that. When I tried it, the front-back position was fine but the saddle felt very hard. I tested it for rides of increasing length, and at the end of a 23 mile ride, concluded the C17 is just not comfortable for me on that bike set up as it is. So, I solved one problem but created another, a story which is beginning to come up frequently on my Hetchins restoration project. I plan to blog about the comfort of different saddles in a future post, but in order to make the Hetchins comfortable to ride, I was back to trying a B17 saddle with a long setback seatpost, which I borrowed from my Bianchi Volpe. This worked great! With this seat and seatpost, the Hetchins is comfortable for at least 39 miles, the longest ride I have tried on it so far. With no sign of discomfort at that distance, I am guessing it is as comfortable as any bike I own. Problem solved! Or at least that problem.

What other issues remain with my Hetchins? To begin with, calling this bike a Hetchins might be a desecration of the Hetchins name. Rather than building up this frame with a set of components carefully selected to create an optimum bike and to match the characteristics and features of the frame, I built it up from components that came from (and thus were selected for) a completely different bike, a 1970s Japanese Centurion. I did it this way so I could test the frame size at reduced expense, but the downside is that some Centurion parts might be less than optimal in their new home. This kind of mismatch is responsible for many of the issues that affect the rideability of my Hetchins (Hetchurion?) For example:
1) The downtube shift levers slip. The shifter levers from the Centurion are held on by a clamp, and on the Centurion frame, there is a small braze-on on the downtube to keep this clamp from slipping. The Hetchins frame lacks this braze-on, thus the slipping. Instead, the Hetchins frame has braze-ons for shift levers mounted in the ends of the handlebars.
2) The gears are not as low as my old body needs in the hills of California.
3) Shifting into the largest cog (lowest gear) on the freewheel is not as smooth as I would like. When I find myself on a hill, I can have difficulty getting into that gear. I am getting a bit better at this with practice, but if I could make it work more smoothly, I would.
4) Gebhard, after he completed the build of this bike with parts from the Centurion, warned me that the rims and spokes from the Centurion were made of soft metal, and might not be very durable. In fact, after 120 miles of riding, the spokes are still making creaking noises. In my experience such creaking noises are common on a newly built or aligned wheels, but that goes away fairly quickly, way before 120 miles. Thus, especially in the context of Gebhard's warnings, I find these noises disquieting. It is possible that these "soft" wheels would work for me, as I am a very low power rider. However, my son has expressed interest in using this bike, and he is a much more powerful rider than I, so it might be wise to proactively rebuild these wheels with sturdier spokes and rims.

In addition to the above, my Volpe wants its seat and seatpost back, so I should purchase a new Brooks B17 saddle and setback seatpost. On the other hand, although I had previously posted that the brakes on the Hetchins grabbed, this problem has gone away with time presumably as a result of the brake pads wearing in, thus, this is no longer a problem.

When the downtube shift levers first slipped, I took the Hetchins back to Gebhard, and he repositioned and tightened them. He also readjusted the rear derailleur, but it still doesn't work the way I'd like. We talked about the above issues, and discussed some possible directions we could take. The good news is that I learned he has access to a large selection of vintage-compatible parts, making this project much easier. The bad news is, as I have thought about this project, I have ended up back where I started when I first brought the rebuilt Hetchins home. I'm still not sure what I want to use this bike for, so I am not sure what I should do to it. What Gebhard and I discussed was replacing both the front and rear gears (new freewheel and crankset) to provide a low gear of 25 inches, as low as any bike I own, as well as putting on bar end shifters, the seatpost, and saddle. The derailleur would have to be changed as well as the derailleur from the Centurion will not handle this gear range, but I have a derailleur which might do. As I have thought about it, this set of upgrades does make sense, in that it makes the bike generally rideable, but I still want to think about it a bit more. For example, if I wanted to save some money, I could leave the crankset as-is and just replace the rear gears, giving me a low gear of 33 inches, low enough for most rides that I do, and depending on how I use this bike, that could make sense.