Professional Trainers: Saddle Height Question

You don't say what type of bike you are riding, Road, MTB, TT, Tri, etc.

My local Gym has a bike fitting service, their tips may be a help to you:
http://www.trysport.com.au/main_training_bikefit.htm
and http://www.trysport.com.au/frameset_training.htm

You may be pedalling with your toes down, thereby rendering your measurements less relavent. I find I am 1cm low, but this depends on seat width, however, I am trying to gradually increase my height. Also try bringing the seat forward a little to increase the effective seat tube angle.

Cheers
George

Quoted post said:

Originally posted by gclark8
You don't say what type of bike you are riding, Road, MTB, TT, Tri, etc....You may be pedalling with your toes down, thereby rendering your measurement less relavent. I find I am 1cm low, but I am trying to gradually increase my height. Also try bringing the seat forward a little to increase the effective seat tube angle.

The application/bike is general road training/racing. As far as foot position, I tend not to be an 'ankler', so that may play into it. The seat tube angle of my bike is 74 degrees, so moving the seat any further forward will have me in a TT position. The seat position feels comfortable where it is presently.

Quoted post said:

Originally posted by Ted B
It seems like I'm the one who usually breaks out the measuring tools and goniometer to assist persons in improving their fit, but now it's my turn...

When I set up my present bike, I recall using a goniometer to set the saddle height to right around 150 degrees between femur and tibia. I brought the bike in to the LBS right around that time, and never bothered to really scrutinize the settings.

In giving things a check, I discovered that my saddle height is about 1 cm higher than the most liberal of the analytical models.

This has not caused me any physical distress whatsoever over the past few months, and my power is good. My flexibility is also good, and I don't expect this to become a physical issue. However, I usually deal with saddles being too LOW, and now mine seems to be set slightly in the other direction. I realize that a saddle set too low will compromise efficiency. I also understand that raising the saddle reduces motion of the femur.

Am I losing anything in my case, or is it simply a matter of flexibility at this point? My usual references don't offer much insight on this side of the coin.

Hi there.

As you probably know, inseam isn't always the greatest way to determine seat height. For most its pretty good but some people have considerable discrepancies between the length of their thigh length vs. their shin length as compared to the norm. This means that the calculated seat height for each individual isn't always accurate.

Many good cycling fit books will now quote measurements in terms of leg angle as opposed to seat height calculation for this exact reason. Hence, I wouldn't worry about the fact that your seat is set higher after taking the appropriate inseam measurements.

In addition to this a 74 degrees seat angle is a little more aggressive which brings you a little closer to the bottom bracket. This too will raise your calculated seat height by just a bit.

If the knee/plumb-line test indicates that your knee is directly over the pedal spindle when the cranks are at 3:00, then I'd be confident that you are set up great.

Quoted post said:

Originally posted by Ted B
It seems like I'm the one who usually breaks out the measuring tools and goniometer to assist persons in improving their fit, but now it's my turn...

When I set up my present bike, I recall using a goniometer to set the saddle height to right around 150 degrees between femur and tibia. I brought the bike in to the LBS right around that time, and never bothered to really scrutinize the settings.

In giving things a check, I discovered that my saddle height is about 1 cm higher than the most liberal of the analytical models.

This has not caused me any physical distress whatsoever over the past few months, and my power is good. My flexibility is also good, and I don't expect this to become a physical issue. However, I usually deal with saddles being too LOW, and now mine seems to be set slightly in the other direction. I realize that a saddle set too low will compromise efficiency. I also understand that raising the saddle reduces motion of the femur.

Am I losing anything in my case, or is it simply a matter of flexibility at this point? My usual references don't offer much insight on this side of the coin.

i don't believe in any 'magical' numbers or formulas for *accurately* setting saddle height. however, a good ball-park figure is to use 100 % of greater trochanter height for the distance between the top of the saddle (where you contact it) to the top of the lower pedal when it is inline with the seat tube. this is a reasonable starting point. after this it's trial and error!

ric

I have looked into changing my seat height a number of times and have looked into a number of theories. My coach told me that he has had similar experiences and feels that the seat should be as high as possible before u feel that u lose power.Obviously thid will take some trial and error, and is obviously only a subjective measure and doesnt really give u a starting point, but it is basically what u r aiming at in your changes. There are many factors that contribute to the optimum seat height but if you are trying to describe it in a subjective manner i think this is the best definition.