Position question for the masters

[cinelli]

Since this forum is fortunate enough to have the
expertise of professionals such as e-richie, David Kirk,
and of course the Serotta masters, I am curious on
a fit and adjustment issue:

When a custom frame is built for a customer based
on his measurements, do custom builders design the frame
to have the seat mounted midway on the rails? Standard
length stem (for that size frame)? Offset seatpost? Do
the builders make recommendations on saddle placement and
stem length?

I ask this question because you see a LOT of custom-built
frames that the owners have very short or very long stems.
I also see a lot of NICE bikes with minimal seat tube projection
or the saddle very far forward on the post. Just curious :confused:

[David Kirk]

I hesitate to be the first to answer this if for no other reason that I'm shy about the term master.

I can only speak for myself. When I design a frame I have a seatpost in mind ( offset or straight up) and the saddle is meant to be in the middle of the rails.

I also have a given stem length and angle in mind and share that with the customer.

Dave

[zank]

When I design a bike for a customer, I do just that; I design a bike rather than a frame and fork. I start with a position (saddle height, saddle setback, reach and bar drop) and work back to the frame.

I know ahead of time what saddle and post the customer would like to use so that I choose a seat tube angle that results in the setback that I want with the saddle mounted on the center of the rails. This is done to allow for maximum adjustment later on if necessary. It also looks correct. I prefer setback posts. Center mount posts usually result in a slack seat tube angle, which may require a longer chain stay.

I also know what stem the customer would like to use and at what angle so we can determine the appropriate HT extesion and spacer height for the given reach, bar drop and desired standover clearance. The stem length is chosen based on a bunch of factors.

As for seat post extesion, I build along the lines of what Douglas describes as the French method. I prefer less seat post showing and fewer stem spacers to more post/more spacers. Just my aesthetic preference. But, the bike is designed in this manner to begin with.

Maybe some of the bikes you are seeing are second-hand? The second (or third, etc) owner may be so thrilled with finding their gem that they make it work for them. Just a thought.

[Dave]

Although I'm no master, I've used enough saddles to know that there is a lot a variation in the location of the saddle rails and the shape of saddle. These variations create a significant difference in the position of the saddle on the seatpost for a given rider position, relative to the BB.

Even if a custom is fit with the seatpost setback and saddle preferred by the customer, at some point that saddle will no longer be made and the search for a new one begins. The result might be a saddle that's comfortable, but no longer centered on the seatpost. That and position changes that have evolved over the years may account for less than perfect looking custom bkes. For a custom to look perfect, you either have to know the frame dimensions you desire, or trust the fitter/designer to predict the perfect fit and not alter it, once the bike is built.

I always tell people that an accurate fitting requires the saddle that will be used on the finished bike, a post with the same setback, the same handlebars, the same pedal/shoe combo and the shift/brake levers that will be used. Otherwise, the finished product might not fit as perfect as desired. If the fitter doesn't realize this, then he's not real sharp.

[cpg]

I, like DK, don't like the term master and by no means want to see this response as an admission that I see myself as a master. I don't and I'm not. As a matter of fact, I've always found the people that see themselves as masters are generally the farthest from this unattainable goal. With all that said, most builders design the frame and fork around the parameters that you said. Unless the builder is selling a complete bike the choice of components the customer chooses to use is out of his/her hands. This might lead to the issue that you've noticed. Once the frame and fork go out of the frame shop the customer can put on whatever they wish.

Curt

[cinelli]

Just to clarify, if I ordered a custom frame made
to my exact measurements, my correct position
should fall in a somewhat neutral setback/stem
relationship....ie: no 14cm stems or saddle at the
exteme limits of the rails.

[dirtdigger88]

I hesitate to be the first to answer this if for no other reason that I'm shy about the term master.
Dave

Dave- is someone calls themselves a master they are most likely not- if their peers call them a master they probably are-

Nuff said

Jason

[e-RICHIE]

Since this forum is fortunate enough to have the
expertise of professionals such as e-richie, David Kirk,
and of course the Serotta masters, I am curious on
a fit and adjustment issue:

When a custom frame is built for a customer based
on his measurements, do custom builders design the frame
to have the seat mounted midway on the rails? Standard
length stem (for that size frame)? Offset seatpost? Do
the builders make recommendations on saddle placement and
stem length?

I ask this question because you see a LOT of custom-built
frames that the owners have very short or very long stems.
I also see a lot of NICE bikes with minimal seat tube projection
or the saddle very far forward on the post. Just curious :confused:


saddle centered in offset (what are the non-offset posts
for anyway???) seatpost. stem proportioned for "the rest
of the bicycle" (no 11cm stems on 59cm frames...). no,
none, nada, never 90 degree stems.
hey - thanks for reading.
e-RICHIE
mister, not master

ps bid high bid often
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=2904&item=7162689103

[weisan]

ps bid high bid often
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=2904&item=7162689103

why no "Buy It Now" Price? Very disappointed. :rolleyes:

[cinelli]

Many thanks for the replies from some
of the true MASTERS of American framebuilding.
The knowledge base on this forum is amazing.

[davids]

saddle centered in offset (what are the non-offset posts
for anyway???) seatpost. stem proportioned for "the rest
of the bicycle" (no 11cm stems on 59cm frames...). no,
none, nada, never 90 degree stems.
hey - thanks for reading.
e-RICHIE
mister, not master

Why not 90 degrees?

89? 91?

[e-RICHIE]

Why not 90 degrees?

89? 91?


because it's not an elegant solution.

[Tom Kellogg]

During the fitting process, I need to take in the entire picture. As much as possible, I will make sure that the saddle is in the middle of the rails and the stem length is such that a small change one way or the other will keep the bike's center of gravity in the neutral zone. Once I am done, the customer will have a bicycle that is not at the limits of any fit adjustment.

Sounds pretty simple, but as noted in previous posts, there are a lot of component variables; rail location on saddles, post setback, stem lengths and angles, bar reach and drop, pelvic structure ... This is why a personal interactive fitting with the customer's chosen components is so critical. In many cases, those exact components are not available for the fitting, so I have to compensate for the differences.

I do not limit my customers aesthetic choices re: head tube extension, stem angle, post length showing, etc. As long as they like the way it will look and there are no mechanical or functional drawbacks, then I am willing to go with it. I will spend considerable time explaining the various options available in arriving at a given bar height relative to saddle height. Usually, it comes down to what the customer finds visually acceptable. For some, the choice is easy, for others, it is a chore. For still others, there is no way to get their saddle / bar relationship where it needs to be and look just as they would have hoped. Sometimes, life sucks. In this case, we will try to minimize the things that offend their sensibilities as much as we can.

Hope this helps. Take care.

[weisan]

Diggin' up a useful thread a while back...