"The 33"-Road Bike Racing - Your saddle height and inseam length?

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cbip
03-18-09, 06:24 AM
I am fighting some low back pain and have been trying to adjust my fit to help. I was just wondering what others saddle and inseam numbers were to compare. Also, if you know your drop from the saddle to the bars that would be great also.
My inseam is 34.5 and my saddle is set at 31 inches using Keo cleats which have a 7mm stack height. I think the saddle is ok maybe 1-2 cm high at most. I also moved my saddle forward yesterday after checking my knee over spindle set up. I was behind the spindle at the 9 oclock position so I hope that by moving my saddle forward it puts less stretch on my hamstrings and calves which I hope was what was the cause of my back pain, or at least a contributor.


MDcatV
03-18-09, 06:30 AM
I dont remember what my inseam is, but it's short, somewhere around 73 cm. my saddle height from center bb to top of saddle at its "sweet spot" is 67.5 cm

if you're actually having pain, you would be best served by:

- dr. or chiro visit
- stretching those hammies
- professional bike fit, pain + tinkering without a good baseline to start from is a recipe for a summer on the couch

ericm979
03-18-09, 07:09 AM
Moving the saddle forward will cause you to use your hamstrings and glutes less and quads more.
But it doesn't affect the calves much. To reduce the stress on them you can move the cleats back.

I'm 6' tall with a 35.5 inch cycling inseam. My saddle is at 78cm, but I tend to drop my heels when I pedal so it is a bit low. I'm about 1.5cm behind KOPS.

What's important is not what works for me but what works for you. I recommend starting from one of the formulas (i.e. LeMond) and moving things around one at a time to see what works for you. Make measurements and keep detailed notes. Or get a fitting.

Your problems may have nothing to do with bike fit- it could be that you have strained a muscle, have a back problem, need to stretch, or have a weak core.


YMCA
03-18-09, 07:09 AM
90.5 cm inseam
73 cm seat height

According to charts, I should be 79-81cm seat height, but I have adapted to this for various reasons and it works.

MDcatV - your inseam must be much longer. No way could you even reach the pedals with a saddle that high.

MIN
03-18-09, 07:35 AM
I've talked to many experienced fitters that say more often than not, LeMond's formula of inseam * .663 = [cleat to top of saddle] is a great starting point.

My inseam is somewhat short for my height - 5-10.5" with 32.5" - my saddle height is 73 cm (bb center to top of saddle). You'd have to back out the crank length to get to the Lemond number.

YMCA
03-18-09, 10:15 AM
^^^
actually Lemond's formula is .883 x inseam
seat height measured center BB to top cup of saddle

ex: 90cm x .883 = 79.5 or 80cm x .883 = 70.6

MIN
03-18-09, 10:52 AM
^^^
actually Lemond's formula is .883 x inseam
seat height measured center BB to top cup of saddle

ex: 90cm x .883 = 79.5 or 80cm x .883 = 70.6

I guess I've seen it both ways, now that you mention it.


LeMond's formula, from his former coach, Cyrille Guimard, establishes C-C size by the formula .65 x inseam length, which yields virtually the same frame size when you add the 1-1.5cm difference between C-C and C-T.

mmmdonuts
03-18-09, 12:11 PM
What's wrong with heel on spindle at BDC for a starting point? Much easier to get there than silly calculations to start with and still have to adjust later.

MIN
03-18-09, 01:14 PM
What's wrong with heel on spindle at BDC for a starting point? Much easier to get there than silly calculations to start with and still have to adjust later.

They are both doing the same thing - trying to get an ideal knee bend at BDC once the cleat location is set. Some people are more numbers oriented (like me.)

MDcatV
03-18-09, 02:20 PM
90.5 cm inseam
73 cm seat height

According to charts, I should be 79-81cm seat height, but I have adapted to this for various reasons and it works.

MDcatV - your inseam must be much longer. No way could you even reach the pedals with a saddle that high.

typo - meant 76, not 73. I havent bought a suit or been fit to a bike in a while though and I'm going from memory.

Longfemur
03-18-09, 03:02 PM
Heel on pedal is not the same as the LeMond method. It results in a considerably lower saddle height, too low for most people who ride a lot in a road bike position. If it doesn't give you a lower saddle height, it's because you are unconsciously lowering your hips to favour the leg you're measuring with.

cbip
03-18-09, 03:56 PM
I think my seat height is close enough to correct that my back pain is either too much saddle to bar drop or my saddle was too far back. Since I moved it forward yesterday I will see if the pain lessens or goes away. From my years as a golf professional I can promise you that the numbers don't lie, if they are attained by the correct method. I find it hard to belive that there are no science based fitting systems available at most bike shops to give accurate, use full information to fit someone on their bike.

Longfemur
03-18-09, 04:13 PM
I find it hard to belive that there are no science based fitting systems available at most bike shops to give accurate, use full information to fit someone on their bike.

No such thing because there's too much individual variation and choice involved, riding intensity, riding style, etc. Even the most perfect professional fitting will likely need some fine tuning after actually riding.

There's a lot of misleading advice on the web about slamming the saddle all the way back. My guess is that this was based on using a B17 saddle. Because of how its saddle rails are, you had to have it all the way back on the rails to get a knee-over-pedal fit (since the saddle was originally designed for bikes that had a much slacker seat tube than what is common today). It just doesn't apply to modern saddles on modern bikes (unless the bars are higher than the saddle). When someone does that, they end up pedaling from way behind the bottom bracket, and with road bike drop bars, the bend at the waist ends up being too sharp. It's a position for pedaling a cruiser, not a road bike. Also, the "LeMond" formula is not meant for a way back saddle. It would put the saddle too high. So, too far back could have been your problem.

bigfred
03-18-09, 05:00 PM
93.5cm inseam, bb-saddle 83.0cm, 180 cranks, 51 shoe, da spd-r pedals,

mmmdonuts
03-19-09, 06:38 AM
The point I was trying to make with heel on spindle is that all methods are a place to start. There is no single formula that would work for all or even most people. So why mess around with formulas if they all need adjustment after the bike is setup. The best fitting systems seem to be the dynamic ones but even those might need tweaking after a few rides in the real world. You can go to three different qualified professional fitters and there is a good chance that you'll get slightly different fits from each. So where does that leave us? To me it's that fit is about ending up within a range that is comfortable and efficient with some room for adjustment to favor power over comfort or efficiency or vice versa as the needs dictate. You can use any method to start but don't be a slave to the numbers.

No?

Cyclists and golfers have a lot in common.

Longfemur
03-19-09, 07:07 AM
The numbers just give you a place to start, that's all, same as the more traditional rules of thumb. Then you ride and see how it feels. There's no other way.

brundle_fly
03-24-09, 03:48 AM
You foot should be flat,not on tip toes at the bottom of the pedal stroke.I have found anway,this gives increased power

Sike100
03-24-09, 04:36 AM
inseam: 98cm
bb - seaddle: 87,6 cm with 177.5 cranks

determined by bikefitting

YMCA
03-24-09, 07:03 AM
inseam: 98cm
bb - seaddle: 87,6 cm with 177.5 cranks

determined by bikefitting

Shaq, is that you?

wanders
03-24-09, 08:18 AM
Shaq, is that you?

Call me Bill.

http://www.bobkestrut.com/images/walton.jpg

Longfemur
03-24-09, 08:49 AM
Formulas are just a rough starting point at best. There's no way for any seat height formula to take in pedaling style, intensity of effort, and most importantly, the saddle setback you need because of the length of your thighs. The farther back you are, the lower the saddle has to be. And that's not even taking into account other things like the thickness of your shoes, the stack height of the pedals, the length of the cranks. Even the height of your handlebars affects the saddle height that works best for you, believe it or not.

The best you can do is to try the heel on pedal method and at the other extreme, the so-called LeMond formula (which actually has nothing to do with Greg LeMond as such). The heel method will probably be too low, and the LeMond method may or may not be too high for you. So, try different heights in between and see what feels best. The higher you are, the more power you can put down, but on the other hand, you are limited in this by the need to actually be able to ride on that saddle, and too high starts limiting your ability to spin smoothly. It's a compromise, and most people whose living does not depend on winning bicycle races should probably err on the side of comfort.

At a good saddle height, you need to be able to ride in all hand positions, including the drops. The drops is where you see if your position is right, because if your saddle is too low, you will feel like your knees are coming up too high (and you may even start to pedal by flaring your knees out at the top).

Sike100
03-25-09, 12:23 AM
Shaq, is that you?

How did you know my name?? Pssst! :-)


Anyway, back on OT.
I never liked Lemond formula. Better formula for me was 107-109% inseam length, seaddle-pedal distance.

Regards,
Sh.q

BarracksSi
03-25-09, 05:31 AM
I am fighting some low back pain...

Right there makes me wonder if saddle height is less of a problem than the reach to the bars. That is, whenever my saddle height was off, I felt it in my legs; but whenever my reach was wrong, I felt it in my back.