Measuring fit with new saddle

[kgreene10]

My body is finicky about fit. I’ve dialed it in with my prior saddle but need to make a change. I’m moving to a saddle that’s 23mm shorter and from a different manufacturer. Changes to the fit don’t seem / feel as simple as measuring BB setback and distance from saddle nose to shifter hoods 23mm linger. Presumably, where you sit on each saddle is what matters. Is there a sensible way to determine this?

[eddief]

trial and error. test rides where you give your body enough time to settle in to the new fit. bring an allen key. you'll say ahhh once it's right. and then probably adjust 5 more times after that.

[BdaGhisallo]

Put it roughly where you think it should go and go for a few rides with an Allen key and tweak it until you replicate the sensations in your butt and muscles that you got with the old saddle.

[Dude]

the closest i've been able to come is to "quantify" where your sit bones go on the old and/or new saddle. On your current saddle, measure that point from the front or back or wherever. Put some tape, mark it with a pen, whatever. Is the new one squishier than the new one? cool, subtract 1mil from your saddle height.

Lay the top of the old one on the top of the new one and transfer and adjust that measurement. old saddle might be 5cm from back, new saddle is now 6cm from back. Now you know at least the same point that youre adjusting for.

That's all you can really do as each saddle behaves differently. Some flex, some break down faster, some compress more. You can eliminate some of the guesswork, not all of it.

[OtayBW]

Figure out - as best you can - where your sit bones are and use that measurement instead of saddle tip....

[pdmtong]

take both saddles off and put them so their tops face each other and align them based on the thigh flare area.

thats the most basic way I know to then approximate the sit bone placements

[djdj]

Assuming they are roughly the same shape, measure from the widest part of the saddle to the bars or stem cap.

[Dave]

If the reach to the brake hoods is too far, i can feel it. It may take a few rides, but you can get it right. The more meticulous may have a measurement of the knee, relative to the BB, but I don't do that. I place the saddle back far enough that my weight is balanced over the saddle, so I don't have too much weight on my hands, even with a 10cm saddle to bar drop.

[uber]

agree with all of the above. One trick I picked up from Sacha White is to get on a trainer, pedals at 9 and 3, stand up on the pedals and balance your weight such that your fingertips are just touching the hoods and all of the weight is supported by your legs. Then, drop your butt straight down onto the saddle. Put the saddle where your sit bones land. It works really well for me.

[Nomadmax]

I'm a nut about bike fit. I have a sheet for every one of my road bikes. Of all the measurements I take and record, none of them involve the saddle nose because it's arbitrary when using different saddles.

All my measurements are from the 80mm wide point on the saddle, measured with calipers and marked with blue masking tape. Setback, saddle to bars, saddle to hoods, saddle to drops are all measured from that spot on the saddle. The only measurement that isn't measured there is saddle height, that's measured along the seat tube and terminates at the top of the saddle in the center of the seat post clamp.

By writing these measurements down, when you finally get something that works you'll have a starting point for another bike. Trail and error is great, just make a record of it so you aren't "re-trying" something that didn't work before.

[kohagen]

Figure out - as best you can - where your sit bones are and use that measurement instead of saddle tip....

Absolutely! If the new saddle is 23 mm shorter and you set your saddle position using the bar/saddle nose measurement, your reach will be about 23 mm shorter. Probably not what you want.

[tombtfslpk]

I'm a nut about bike fit. I have a sheet for every one of my road bikes. Of all the measurements I take and record, none of them involve the saddle nose because it's arbitrary when using different saddles.

All my measurements are from the 80mm wide point on the saddle, measured with calipers and marked with blue masking tape. Setback, saddle to bars, saddle to hoods, saddle to drops are all measured from that spot on the saddle. The only measurement that isn't measured there is saddle height, that's measured along the seat tube and terminates at the top of the saddle in the center of the seat post clamp.

By writing these measurements down, when you finally get something that works you'll have a starting point for another bike. Trail and error is great, just make a record of it so you aren't "re-trying" something that didn't work before.
A kindred spirit. I do pretty much the same thing. I use a piece of cardboard with a three inch wide slot cut in it (stays in the toolbox) and mark that location with a piece of masking tape on the saddle. Set the rear tire against a wall and measure to the bottom bracket. Set the saddle height from the bottom bracket with the saddle at zero angle. Measure from the wall to the tape I put on the saddle. Subtract that number from the wall to bottom bracket number and you have a reference for seat setback from bottom bracket. Use that same tape on the saddle to measure to the bars with your chosen bar drop.
Write that ALL down, every time. Saddle height, setback and angle, saddle to bar drop, saddle to bar distance, even saddle to hood distance. Make all of those measurements at the same floor space every time. All of this is invaluable if you own multiple bikes (don't we all).
Even if you're just helping a buddy work out fit issues, write it down. All those numbers come in handy.