Re: My thoughts on seat position, crank length, and cleat position

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tlarwa wrote:
> Well, almost. I have a 33" inseam (838mm) and use a 175 crank, which is
> ~20.8%. My saddle height is 737mm, which is what your formula works out to
> as well, but that is to the top of the seat clamp (or to the saddle rails),
> NOT to the top of the saddle surface itself. That dimension is a full 50mm
> higher. I can't imagine riding that much lower, if that's what you are
> suggesting. Hmmm...


So your distance from pedal spindle to seat-top is about 115% of
inseam? I wouldn't even be able to reach the pedals with a setup like
that. Is your inseam measurment accurate? Are you particularly limber,
such that a very straight knee angle and extended foot isn't a problem?

Joseph

 

[Rebecca Morris]

For another data point, I also tried using a longer crank. I have an inseam
of about 96 cm, so I tried a 190 mm crank. This is a bit shorter than the
formula, but I was afraid that a longer crank would have too little ground
clearance on turns. I started out with a 175mm crank.

The longer crank felt good for a while - especially on climbs - but I
eventually (a few months later) had a lot of calf pain in both legs. I
tried different seat heights and cleat positions, but nothing solved the
problem. I went back to the 175mm cranks and the pain subsided.

I then decide to try the 190mm cranks again and very quickly had the calf
pain back. I then gave up. Leg pain was one of the warning I heard about
long cranks. They were right.... for me....

I may have been slightly faster on climbs with the longer crank, but my
average speed never changed much - maybe 3-4 minutes out of a 4 hour hilly
ride.

In the year since the change back to the 175mm crank I have been changing my
cleat position and seat height in an effort to optimize my position. I now
have the cleat on the ball of my foot and the seat is at about 108%. I plan
to try 109% when I get a new seat - the old one has started to bother me.

Based on what I have heard from the coaches comments (web page searches) the
bicycle manufacturers' offering, and my own experience, I suspect the
scaling may be more like the square root of leg length rather than linear
with leg length. Moment of inertia scaling?

Anyway, that is my story. Good luck with your experiments.



Bob Morris


<[email protected]> wrote in message
news:[email protected]...
>
> tlarwa wrote:
>> Well, almost. I have a 33" inseam (838mm) and use a 175 crank, which is
>> ~20.8%. My saddle height is 737mm, which is what your formula works out
>> to
>> as well, but that is to the top of the seat clamp (or to the saddle
>> rails),
>> NOT to the top of the saddle surface itself. That dimension is a full
>> 50mm
>> higher. I can't imagine riding that much lower, if that's what you are
>> suggesting. Hmmm...
>
>
> So your distance from pedal spindle to seat-top is about 115% of
> inseam? I wouldn't even be able to reach the pedals with a setup like
> that. Is your inseam measurment accurate? Are you particularly limber,
> such that a very straight knee angle and extended foot isn't a problem?
>
> Joseph
>

 

[[email protected]]

Rebecca Morris wrote:
> For another data point, I also tried using a longer crank. I have an inseam
> of about 96 cm, so I tried a 190 mm crank. This is a bit shorter than the
> formula, but I was afraid that a longer crank would have too little ground
> clearance on turns. I started out with a 175mm crank.
>
> The longer crank felt good for a while - especially on climbs - but I
> eventually (a few months later) had a lot of calf pain in both legs. I
> tried different seat heights and cleat positions, but nothing solved the
> problem. I went back to the 175mm cranks and the pain subsided.
>
> I then decide to try the 190mm cranks again and very quickly had the calf
> pain back. I then gave up. Leg pain was one of the warning I heard about
> long cranks. They were right.... for me....
>
> I may have been slightly faster on climbs with the longer crank, but my
> average speed never changed much - maybe 3-4 minutes out of a 4 hour hilly
> ride.
>
> In the year since the change back to the 175mm crank I have been changing my
> cleat position and seat height in an effort to optimize my position. I now
> have the cleat on the ball of my foot and the seat is at about 108%. I plan
> to try 109% when I get a new seat - the old one has started to bother me.
>
> Based on what I have heard from the coaches comments (web page searches) the
> bicycle manufacturers' offering, and my own experience, I suspect the
> scaling may be more like the square root of leg length rather than linear
> with leg length. Moment of inertia scaling?
>
> Anyway, that is my story. Good luck with your experiments.
>

What height were you using with the 190's? Perhaps an intermediate size
like 180-185 would do the trick, if you aren't satisfied with the
175's. Do you still have the 190's? I have some 180's, maybe we can
swap?

One of the reasons I like having a forward cleat position is to make
sure my calf muscles get in on the action. I have somewhat muscular
(and thus heavy) calves that would be a waste to just be moving around
even in small circles. (I can only use certain bottle cages on the seat
tube or else they rub). The efficiency of moving them in larger circles
with longer cranks remains to be seen, but looks good so far.

Where was your calf pain, and what sort? Are you a spinner? What sort
of build do you have?

Joseph

 

[Rebecca Morris]

My entire calves hurt on both legs no matter what I did. I'm about 6'4" and
185 lbs, so I'm a bit lighter than most my height. I usually turn the
cranks at about 70-75 up hill and about 88-92+ on the flats.

Definitely not a muscular type.

I tried moving the cleats back when using the 190's, but more than a little
back hurts the smoothness of my pedal stroke. With the 175's I like the
cleats at the ball of the foot.

I still have the 190's - they are a triple from High Sierra along with a BB.
Are the 180's a triple? The bike is all set up for a triple and I don't
want to change.


<[email protected]> wrote in message
news:[email protected]...
>
> Rebecca Morris wrote:
>> For another data point, I also tried using a longer crank. I have an
>> inseam
>> of about 96 cm, so I tried a 190 mm crank. This is a bit shorter than
>> the
>> formula, but I was afraid that a longer crank would have too little
>> ground
>> clearance on turns. I started out with a 175mm crank.
>>
>> The longer crank felt good for a while - especially on climbs - but I
>> eventually (a few months later) had a lot of calf pain in both legs. I
>> tried different seat heights and cleat positions, but nothing solved the
>> problem. I went back to the 175mm cranks and the pain subsided.
>>
>> I then decide to try the 190mm cranks again and very quickly had the calf
>> pain back. I then gave up. Leg pain was one of the warning I heard about
>> long cranks. They were right.... for me....
>>
>> I may have been slightly faster on climbs with the longer crank, but my
>> average speed never changed much - maybe 3-4 minutes out of a 4 hour
>> hilly
>> ride.
>>
>> In the year since the change back to the 175mm crank I have been changing
>> my
>> cleat position and seat height in an effort to optimize my position. I
>> now
>> have the cleat on the ball of my foot and the seat is at about 108%. I
>> plan
>> to try 109% when I get a new seat - the old one has started to bother me.
>>
>> Based on what I have heard from the coaches comments (web page searches)
>> the
>> bicycle manufacturers' offering, and my own experience, I suspect the
>> scaling may be more like the square root of leg length rather than linear
>> with leg length. Moment of inertia scaling?
>>
>> Anyway, that is my story. Good luck with your experiments.
>>
>
> What height were you using with the 190's? Perhaps an intermediate size
> like 180-185 would do the trick, if you aren't satisfied with the
> 175's. Do you still have the 190's? I have some 180's, maybe we can
> swap?
>
> One of the reasons I like having a forward cleat position is to make
> sure my calf muscles get in on the action. I have somewhat muscular
> (and thus heavy) calves that would be a waste to just be moving around
> even in small circles. (I can only use certain bottle cages on the seat
> tube or else they rub). The efficiency of moving them in larger circles
> with longer cranks remains to be seen, but looks good so far.
>
> Where was your calf pain, and what sort? Are you a spinner? What sort
> of build do you have?
>
> Joseph
>

 

[[email protected]]

Rebecca Morris wrote:
> My entire calves hurt on both legs no matter what I did. I'm about 6'4" and
> 185 lbs, so I'm a bit lighter than most my height. I usually turn the
> cranks at about 70-75 up hill and about 88-92+ on the flats.
>
> Definitely not a muscular type.
>
> I tried moving the cleats back when using the 190's, but more than a little
> back hurts the smoothness of my pedal stroke. With the 175's I like the
> cleats at the ball of the foot.

Does it feel right? Or do you still feel like giving longer cranks a
try?

> I still have the 190's - they are a triple from High Sierra along with a BB.
> Are the 180's a triple? The bike is all set up for a triple and I don't
> want to change.

My 180's are Campy double. But if you don't plan on using the 190's
anymore, I might be interested in buying them for my mountain bike.

Joseph