Seat Height Formulae

[Wannabe]

I need to know, quite urgently, THE BEST method of determining the correct seat height AT HOME. I can only get to a professional to do my bike setup towards the end of the month, and in the interim I need to get my seat height as correct as possible, ASAP.

Linnega, Widget, Scotty, all you boffins out there, please help this ignorant soul, I cannot continue to suffer like this any longer.

[Underachiever]

Inside leg (cm)*109% - crank length (cm)

So for 84 cm inside leg:

84.0*1.09-17.5 = 74.06 cm = top of saddle to centre of BB

[Wannabe]

Tx Underachiever.

From where on the saddle do you measure. I can recall somebody mention something about 120mm or 220mm from the most rearward point on your saddle.

[Canaris]

your feet should reach the pedalssmileys/smiley36.gif.

the quick fix is to be able to place your heel on the pedal, when your leg is fully extended.

The second check is to go and ride with a mate watching your hips to see whether the rock.  (the should not)

If your knee is bent more than 30% on the downstroke, your feet are massive or your saddle is to low.

Fore and aft position of the saddle also has an effect on its height.

Crank length also influences the angle of the knee at 6 and 12 position.  ( a knee should never be bent (under pressure/strain) for further than 90%.

 

[Wannabe]

With my inseam of 88cm, 172.5 cranks, my approx seat height should be 78,67cm. Correct or not?

Reason I'm asking is that at the Jock I got bad cramps at the outside of my legs, starting at the knee, going up to the hips. Quads and hammy's was ok. Had no power when climbing. Got advice to lift saddle, as it was too low. Lifted it 1.5cm, legs slightly bend at downstroke, hips not rocking.

At Nola, power was back during climbs/drags. From about 80km started to cramp on inside of legs (in "V" next to crotch) and Quads. Hammy's also started to tighten up. My deduction is that my seat is too high now. What say you clever people? (or do I need more time to get used to new setup)

[MichH]

Wannabe, when I had my setup done, they checked a few things:

When clipped in, straighten one leg so that the leg follows the angle of the upright tube. Heel should be slightly down

Put pedals parallel to the ground. The line from just behind your kneecap (measure on the side of your leg) to the middle of the pedal should be perpendicular to the ground.

Hope this makes sense

[SwissVan]

Simple quick check is the heel on pedal method:<?:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

Sit square on the bike in your full cycling kit (helmet not necessarily requiredsmileys/smiley2.gif), one leg clipped in the other not, place the pedal on the unclipped leg side in the 6 o clock position, place heel on pedal, saddle height should be adjusted so that the leg is straight and the heel of your shoe just lightly touches the pedal. (Hope that one leg is not considerably shorter than the other).

 

This is height would be just a starting point, you then need to adjust the saddle height according to your feelings, do a few hill repeats riding at a medium to hard effort and make small adjustments (2-3mm) at a time until it feels right. Under load you should feel that you are pedaling efficiently and smoothly.

 

Have a read at this post by Steve Hogg on cyclingnews.com Fitness and Questions section

 

http://www.cyclingnews.com/fitness/?id=2004/letters08-09#Kne e

 

[Icycling]

Trry www.wrenchscience.com

[Sir Fed]

wannabe, dont be in a rush to move your saddle by more than 5mm at a time. You are likely to pick up even more injuries by making radical adjustments.

I use the inseam x 0.886 formula. This is then measured from the centre of the BB to where you sit on the saddle (that bright shiny part, hopefully in the middle somewhere). That would give you a 77.96cm measurement which is 7mm lower than what you arrived at above. So you can see that there are a lot of theories and if you try them all you will probably end up with sore knees or worse.

If you are within 5mm of the various theories, I would advise leaving it as is until you can get professional advice and even then, make sure that you are able to go back to them if you still dont feel comfortable.

[Wannabe]

Thanks Guys and Gals, advice taken to heart.

Will see if I can get comfortable setup in meantime. Next Race is Lost City, so I have some time.

[CVANC]

What I look for after setting the saddle height is that the rider have a flat forefoot and slightly heel up position at the bottom of the pedal stroke, without over-extending behind the knee or rocking in the saddle to do it.

You can also rely on a specific upper and lower leg angle of anywhere from 28 - 35 degrees. It is also important to look at a rider's pedaling dynamics - the key is to be able to apply force all the way down through the pedal stroke, without dropping the heel at the bottom and delaying the time it takes to begin pulling back and up on the pedals on the upstroke.

If you?re setting your position up for mountain biking, you might be up to a centimeter below your optimal road position to allow for riding slightly over the saddle on bumpy terrain.

[Cois]

Ek het al die metode van CVANC en Sir Fed "I use the inseam x 0.886 formula" gebruik, en ek moet erken die een van Sir Fed werk die beste vir my bergfiets en die metode van CVANC het die beste gewerk die tyd toe ek nog padfiets gery het.

 

 

 

Maar dit is die belangrikste om na jou liggaam te luister. As jy 'n trainer het kan jy jouself voor 'n spieel plaas en dan kyk hoe jou setup lyk. As jy op die fiets rondbeweeg is jou setup nie reg nie. Ek het persoonlik gevind dat as ek heeltemal stil sit en trap (sonder dat ek my heupe in die peddals in gooi en my skouers rond gooi) verbruik ek die minste energie, en moeite.

 

 

 

Hoop dit help.