Saddle Position

Hi,

I've just measured 4 different saddles and the rails are a different length, and in a different position relative to the front or back of the saddle, and the actual saddles are all different lengths. That suggests to me that measuring from the tip of the saddle to the center of the stem (or the setback from the tip of the saddle to the BB) is relative to the make and model of saddle. So, my question is does a bike fit and frame design depend on knowing the measurements of the actual saddle thats going to be used, or is there a better reference point than using the tip of the saddle?

Many thanks,

Quote:

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Originally Posted by DrByrne

Hi,

I've just measured 4 different saddles and the rails are a different length, and in a different position relative to the front or back of the saddle, and the actual saddles are all different lengths. That suggests to me that measuring from the tip of the saddle to the center of the stem (or the setback from the tip of the saddle to the BB) is relative to the make and model of saddle. So, my question is does a bike fit and frame design depend on knowing the measurements of the actual saddle thats going to be used, or is there a better reference point than using the tip of the saddle?

Many thanks,

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The measurement is simply a starting point. Most would mention that saddle model when making the commitment to a new or duped design.

This is why bicycles are adjustable

Quote:

---

Originally Posted by DrByrne

Hi,

I've just measured 4 different saddles and the rails are a different length, and in a different position relative to the front or back of the saddle, and the actual saddles are all different lengths. That suggests to me that measuring from the tip of the saddle to the center of the stem (or the setback from the tip of the saddle to the BB) is relative to the make and model of saddle. So, my question is does a bike fit and frame design depend on knowing the measurements of the actual saddle thats going to be used, or is there a better reference point than using the tip of the saddle?

Many thanks,

---

What Rich said.

When folks order a custom bike they generally do say what saddle will be used.

FWIIW and only that I measure from the back of the saddle.

Quote:

---

Originally Posted by DrByrne

Hi,

I've just measured 4 different saddles and the rails are a different length, and in a different position relative to the front or back of the saddle, and the actual saddles are all different lengths. That suggests to me that measuring from the tip of the saddle to the center of the stem (or the setback from the tip of the saddle to the BB) is relative to the make and model of saddle. So, my question is does a bike fit and frame design depend on knowing the measurements of the actual saddle that's going to be used, or is there a better reference point than using the tip of the saddle?

Many thanks,

---

Here's how I deal with this as it's how I start my fitting process (center of the handlebar to saddle tip).

There are 4 critical measurements I take:

1. Center of handlebars to saddle tip.
2. Saddle tip to center of seat post/saddle rail connection point.
3. Saddle Length
4. Center of bottom bracket to top of saddle

I will also request stem type and rise +/- and saddle type and what the intended saddle will be for the new build (whether the same or different).

I will also request images of the bike from the side and a close up of the saddle/seat post from the side.

All of this is a starting point to see where the client presently is and if there are any discrepancies that I'm seeing (i.e. a large amount of saddle to bar drop/rise, saddle positioned all the way back on its rails, etc.) These measurements and pictures are weighed and compared with the measurements from their person checking overall height, inseam, and arm length to see if there are any discrepancies here as well (long/short torso compared with long/short arms, long inseam compared with torso length, etc.).

Once all of this is understood, when I'm initially setting up the drawing, I will pull from a 1:1 archive of 2D drawings I've created of saddles. If I do not have that particular saddle, I'll go about getting critical measurements to create a new drawing of that specific saddle for my archive. I've found that is pretty much the only way to accurately draw a bicycle.

Pro-Tip: Always have the critical parts you plan to build around BEFORE you start your drawing. That way you can take measurements and recreate drawings if necessary. For example, I have a huge 2D/3D archive of Paragon Machine Works parts. Head tubes, dropouts, braze-ons etc. Tube profile drawings including reverse engineered drawings of my radius seat tubes I make in-house in addition to my chainstays. Stems, handlebars, water bottles, standard bottle boss placement templates, chainrings, cranksets, droppers, hydraulic calipers (ISO and Flat Mount) etc. Fork blades, suspension forks, steerers, crown assemblies. You name it, I either have it or I've drawn it.

Hope that helps!

Easy.

I don't consider it at all but rather a line parallel with the ground from the center of the stem cap to the center of the seat post.


But then again, I use actual chain stay length too.......


- Garro.

That answers my question and a lot more to think about. Thanks everyone.