saddle height measurement

granda

so i know how high my saddle should be but where do you measure to on the saddle front,middle,or back or in line with the seat tube

Ryder

Good question - I measure in line with the seat tube, so the middle or whatever is directly above the seat tube

Cee-Jay-Cee

Saddle height when setting up a bike is generally taken from the top of the pedal with the crank lined up with the seat tube so it's safe to assume you measure the point of the saddle in line with the seat post.

Beasty

That does not make sense though as you will get different results depending on how far back or forward the saddle is compared with the seat post. To be consistent it should be measured to the same position in the saddle (the middle). Normally the measurement will be taken from the centre of the BB/cranks then adjusted for crank length/pedal combination.

Lumen

granda wrote: »

so i know how high my saddle should be

How do you know that?

Lumen

Beasty wrote: »

That does not make sense though as you will get different results depending on how far back or forward the saddle is compared with the seat post. To be consistent it should be measured to the same position in the saddle (the middle). Normally the measurement will be taken from the centre of the BB/cranks then adjusted for crank length/pedal combination.

Or just measure to each end and average them out.

But what happens when you change saddle to a noseless one? :pac:

I have combo flat/SPD pedals and I can feel a difference depending on which side I'm using, which may be in part because of changes in sole depth.

granda

Lumen wrote: »

How do you know that?

i had a bike fit done last year but after a bit of disassembly and cleaning i was putting everything back on and had a thought about where exactly do you measure from.
i have always done it along the seatpost line from the bottom bracket but was thinking that this could be wrong and want to get other peoples thoughts on the subject

Cee-Jay-Cee

Beasty wrote: »

That does not make sense though as you will get different results depending on how far back or forward the saddle is compared with the seat post. To be consistent it should be measured to the same position in the saddle (the middle). Normally the measurement will be taken from the centre of the BB/cranks then adjusted for crank length/pedal combination.

But if the saddle is level then it's fore/aft position doesn't really make that much of a difference as the point in line with the seat post should be at the same height as anywhere else on the saddle. If the saddle is tilted then use the highest point.

Beasty

CJC999 wrote: »

But if the saddle is level then it's fore/aft position doesn't really make that much of a difference as the point in line with the seat post should be at the same height as anywhere else on the saddle. If the saddle is tilted then use the highest point.

The seat is set back from the BB. The further back it goes the longer the distance from the BB - it does make a difference and you are supposed to lower the saddle slightly as you move it back to compensate for this

mp31

granda wrote: »

i had a bike fit done last year but after a bit of disassembly and cleaning i was putting everything back on and had a thought about where exactly do you measure from.
i have always done it along the seatpost line from the bottom bracket but was thinking that this could be wrong and want to get other peoples thoughts on the subject

I would have thought details from the bike fit would have this sort of informaton to enable you to do a self refit. Why not go back to the person who did the bike fit for you and ask them?

clog

I got a bike fit from Aidan Hammond. From the spec sheet I have in front of me and from memory he measures from centre of bb along the seatpost line to a parallel saddle. (I had more setback on one of my bikes and I think he may have altered the line slightly through the mid point of the clamp)

granda

mp31 wrote: »

I would have thought details from the bike fit would have this sort of informaton to enable you to do a self refit. Why not go back to the person who did the bike fit for you and ask them?

i have all the measurements just not the exact position the saddle height was measured from and also it was more of 'where do other people measure it from question' which seems to have brought forth a few different answers but it seems the general opinion is along the length of the seatpost which is where i measured it from myself

Lumen

One day I'm going to buy/make myself a goniometer.

Maybe it would be possible to have a device which clips on to the thigh and shin and measure knee angle dynamically.

edit: I think what I'm looking for is a cheap, reliable, "single axis electrogoniometer".

or maybe this: http://noraxon.lunarpages.net/products/sensors/dts-mech-goniometer.php

Ryder

goniometers cost something like 10e on amazon.....in fact, reminds me that I need tio get one.

Beastys measurement to the middle of the saddle makes sense as changes in fore aft position and height can be incorporated into one number, but the key probably is to use the same measurement that your original fitter used.....anyone know how irishfit do it? got a fit done 3 years ago but now live abroad so havent been back since

Cee-Jay-Cee

Lumen wrote: »

One day I'm going to buy/make myself a goniometer.

Maybe it would be possible to have a device which clips on to the thigh and shin and measure knee angle dynamically.

edit: I think what I'm looking for is a cheap, reliable, "single axis electrogoniometer".

or maybe this: http://noraxon.lunarpages.net/products/sensors/dts-mech-goniometer.php

I made one from two lengths of 25mm wide batons about 60cm long and used a butterfly nut at the pivot point that allowed me to lock it once I had the angle measured. Once I had an angle taken I drew it out onto a sheet of paper and measured it with a protractor. My current saddle height/position gives me approx 40 degree angle.

Lumen

CJC999 wrote: »

I made one from two lengths of 25mm wide batons about 60cm long and used a butterfly nut at the pivot point that allowed me to lock it once I had the angle measured. Once I had an angle taken I drew it out onto a sheet of paper and measured it with a protractor. My current saddle height/position gives me approx 40 degree angle.

Excellent. That's presumably the minimum angle (at slightly before TDC). Did you measure the max angle (at slightly before BDC)?

I guess they'll have the same relationship unless you change crank length.

Cee-Jay-Cee

Lumen wrote: »

Excellent. That's presumably the minimum angle (at slightly before TDC). Did you measure the max angle (at slightly before BDC)?

I guess they'll have the same relationship unless you change crank length.

I just measured at the bottom I had thought that I wasn't get a proper leg extension despite my saddle being quite high and so decided to measure it to satisfy myself.