[dawgcatching]

I got a bike fit today, and my fit has changed quite a bit from my last. First off, the fitter recommended that I move the saddle forward, to within 1cm behind the pedal spindle. It was at least 1.5 cm from the KOPS position (rearward). Second, he noted that I am *VERY* inflexible: I only have a 65 degree extension ability when comparing the angle of my lower leg to the upper, when extended while on my back. Also, I can't bring my leg more than 70 degrees from flat (again while on my back) whereas 90 degrees would mean the leg was perpindicular to the ground. Therefore, he told me to start at a femur-tib/fib angle (with foot at approximately 5:30 in the pedal stroke, relaxed) of 35 degrees (he said the typical numbers are more like 25-32 degrees, but I can't get there until I increase flexibility).

Anyways, what all of this means is this: I currently have my seat slammed all the way forward on a Zero-setback Thomson post, and am about 5mm behind KOPS. He recommends raising my seat 2mm per week, and 8mm of increase will put me about 27 degrees on my femur-tib/fib angle, therefore increasing my power as I become more flexible.

The problem is this: As I raise the seat 2mm, I need to move it forward 1mm if I want to keep the same position relative to the spindle, correct? So, I will need to get some sort of triathalon post with a set-foward position (because currently I am as far forward with the seat as allowed)? Is this weird-it doesn't sound right. I have never seen a standard road bike with a set-forward position-most of the bikes I see of racers have alot of setback (I am guessing at least 3cm behind the KOPS position). Maybe I just have a super-long tib/fib and short femur. Or maybe something else is going on?

 

[Truth Hurts]

"Maybe I just have a super-long tib/fib and short femur. Or maybe something else is going on?"

.........or maybe the bike doesn't fit you. Is this a new bike?

TH

 

[C-40]

Sta??

What is the seat tube angle? If it's in the 72-73 degree range, this might be possible, but if it's steeper, it's hard to imagine needing a straight up post with the saddle all the way forward. You may also need to consider a change of saddle. Some models have very limited travel.

I'd try taking a second measurement on KOP. Different methods of measurement yield different results. Some say to use the boney protrusion below the kneecap and others say to use a measurement off the side of the knee that more closely approximates the true pivot point of the knee. This method often suggests an even further forward position. I'm curious whether your fitter also suggested lengthening the stem to match the forward movement of the saddle. A third method, recommended by Andy Pruitt is to use the front of the knee and drop the plumb bob to the front of the crank arm.

As for the relationship of saddle height to fore/aft position it's approximately 3 to 1, since it's proportional to 1/cosine73 = 3.4. If you raise the saddle 8mm, then it would need to be moved forward only about 2.5cm.

Has you fitter suggested stretching exercises? Sounds like you need some. Lack of flexibility is not a permanent condition.

 

[ewitz]

Switch to a longer saddle. Try the Arione it is a few cm longer than standard.

 

[Dinosaur]

Longer saddle might be the answer..

Switch to a longer saddle. Try the Arione it is a few cm longer than standard.

I needed a soft saddle after coming back from fracturing my hip and purchased a Fizik Rondine. It's 148x286. The nose puts you forward, the rails are set differently than "normal" saddles. I could not get it to dial in with my Colnago. I put it on my Klein when my Colnogo was down for repairs. The Klein is too large for me (61 and I ride a 59). The Fizik made a big difference. It's long and wide, but the Rondine is a tad too soft for me (now). Another saddle that might work is a San Marco Regal. It's long and wide (148x280). A little on the hard side...Unfortunately the Fizik Arione's are too expensive for me to try one..unless the original poster can find a used one on ebay...

And for the original poster I don't use kops to set my saddle. I set my saddle a certain distance behind the center of the bb. Depending on which saddle I am using it makes a difference of about 5mm. My usual setting is 7mm tip of saddle behind bb. If I go forward me knees will start to bother me, too far aft and my lower back will start to hurt..

I like what Peter White says about bike fit http://www.peterwhitecycles.com/
Click on "How To Fit A Bicycle". I find it's more about balance. kops is a relatively new concept in bike fit. When I came back to cycling when I retired 7 years ago, I had never heard of 'kops". In the old days guys just set their saddles 2 1/2 to 3 inches behind their bb and went by how it felt. I think the change is because of the steeper st angles. The common sta way-back-when was 72o-73o. Saddle are different also which compounds the situation.

Of course everyone has their own little theory about bike fit and it can get very confusing. No way of telling what it right. I'm kinda from 'go by feel approach'..I'd say if you had no problems with your old set up, why change?

 

[peabody]

don't follow the KOPS

meathod, when in the drops pedaling with a fair amount of resistance on the flats
you should be able to remove your hands from the bar and just teater to the point
of falling forward. if fall forward immediately then slide the saddle back until the teatering
point. most people are too far forward.

 

[C-40]

no concensus on that...

There are certainly a lot of opinions, including those of sports medicine experts like Andy Pruitt who disagree.

The idea of pushing the saddle back until you can ride hands-off would have those with weak midsections wanting the saddle further back than even a setback post would allow. The other downside to this idea is poor weight balance on the bike, with the front end too light for the best cornering.

I've done a fair amount of experimenting over at least a 3cm range in the last few years and found no advantage to positioning the saddle far back, even for climbing mountains. I've since switched back to a more normal position, with my knee less than 1cm behind the pedal spindle. More weight on the front of the bike (about 45-46%) makes for improved high speed cornering on a mountain descent.

 

[Dinosaur]

That's what I found also..

I used to ride with my saddle pushed way back. I think I'm about 1cm back in the kops position. Having a long saddle means you can scoot aft or forward depending on what you are doing. I think saddles play a big role. I'm a big guy at 210+ and I found the most comfortable saddle for me was the little skinny, narrow, lightly padded, lightweight, San Marco Aspide. It just dials in with my seat post and I like the way it fits my rear. I can set this saddle almost dead center in the index scale in the rails and it dials in with the way I set my saddles..the problem was I had to go through a ton of saddles until I stumbled on this one...funny I can mess with my bike in my garage using a measuring tape and a level to get everything just right, but I can go for a ride and make a slight change just by feel and get it better..

And for what it's worth for anyone..if you are having no problems with your set up, don't start messing around with anything as you might end up right back where you started..

If it ain't broke don't fix it.

 

[dawgcatching]

What is the seat tube angle? If it's in the 72-73 degree range, this might be possible, but if it's steeper, it's hard to imagine needing a straight up post with the saddle all the way forward. You may also need to consider a change of saddle. Some models have very limited travel.

I'd try taking a second measurement on KOP. Different methods of measurement yield different results. Some say to use the boney protrusion below the kneecap and others say to use a measurement off the side of the knee that more closely approximates the true pivot point of the knee. This method often suggests an even further forward position. I'm curious whether your fitter also suggested lengthening the stem to match the forward movement of the saddle. A third method, recommended by Andy Pruitt is to use the front of the knee and drop the plumb bob to the front of the crank arm.

As for the relationship of saddle height to fore/aft position it's approximately 3 to 1, since it's proportional to 1/cosine73 = 3.4. If you raise the saddle 8mm, then it would need to be moved forward only about 2.5cm.

Has you fitter suggested stretching exercises? Sounds like you need some. Lack of flexibility is not a permanent condition.

The bike is a Look 585, but I haven't been professionally fit in about 3 years (which is when I started riding) so my fit has changed alot since then, as my muscles have developed and I became used to pedaling a bike. The STA on the 53cm is something like 73.75, which is pretty standard.

Yes, I am doing stretching exercises, starting yesterday!. The idea is to loosen up the hamstrings so that I can raise my saddle to a more suitable height. Currently, my BB to saddle height as he set it up is 76.0cm, and my cycling inseam is 85.5cm, which puts my saddle on the low side currently. I have never been able to touch my toes, so it is time to do something!

When my fitter measured the knee/pedal spindle measurement, he put my knee touching the top tube and held the plumb from the side of the knee. He had my foot relaxed and about the 5:30 position (he said it was effectively the bottom of the stroke, vs. the standard 6:00) Part of the reason of the change was to get me spinning: he had me hooked up to a computer that reads power output, and both my max torque and spin were very, very choppy. With the changes, my spin became smoother, my power evened out between the two legs (before the changes, it was 45% output left leg, 55% right leg), and my max torque point moved to a more normal 105 degrees.

I will re-check the saddle location tonight. My saddle is an SLR, which doesn't have that much fore-aft movement.

 

[C-40]

KOP recheck...

After reading Andy Pruitt's book, I decided to recheck my position using the front of the kneecap as he recommends. I was surprised to find the plumb line slightly ahead of the end of the crankarm! This further forward position hasn't hurt my climbing a bit. I do tend to spin a lower gear a bit faster on the climbs. That can't be bad for my arthritis damaged kneecaps.

 

[dawgcatching]

After reading Andy Pruitt's book, I decided to recheck my position using the front of the kneecap as he recommends. I was surprised to find the plumb line slightly ahead of the end of the crankarm! This further forward position hasn't hurt my climbing a bit. I do tend to spin a lower gear a bit faster on the climbs. That can't be bad for my arthritis damaged kneecaps.

So, Andy Pruitt's method is to put the foot at 6:00, and plumb down from the front of the kneecap? And, he is measuring over the end of the crankarm, not the spindle? What is the difference? The spindle and end of the crankarm should be in the same vertical axis, correct?

 

[C-40]

vertical axis?

I don't get why you would think the center of the pedal spindle and the front of the crankarm are in the "same vertical axis". The front of the crankarm is 1.5-2.0cm further forward than the center of the spindle. The exact amount varies from one crank to another.

Most often, using the boney protrusion below the kneecap is recommended as a starting point, projecting a plumb (vertical) line to the center of the pedal spindle.

Using the front of the knee as a starting point is further forward than the boney protrusion below the kneecap, but so is the front of the crank arm.

What I'm saying is that I don't get the same result using the two methods. All it points out is that either is just a ballpark reference, not a real accurate measurement that insures the best pedaling action.

Here's a link to some basics: http://www.coloradocyclist.com/bikefit/

 

[temoore]

I don't get why you would think the center of the pedal spindle and the front of the crankarm are in the "same vertical axis". The front of the crankarm is quite a bit further forward than the center of the spindle.

Most often, using the boney protrusion below the kneecap is recommended as a starting point, projecting a plumb (vertical) line to the center of the pedal axle.

Using the front of the knee as a starting point is further forward than the boney protrusion below the kneecap, but so is the front of the crank arm.

What I'm saying is that I don't get the same result using the two methods. All it points out is that either is just a ballpark reference, not a real accurate measurement that insures the best pedaling action.

Here's a link to some basics: http://www.coloradocyclist.com/bikefit/

I think the problem is that one of you is saying the pedal at the 6:00 position, in which case they do line up, but that would be the wrong position to evaluate, and the other saying 3:00 (or is that 9:00?) position, which is the correct position for this excercise.

 

[C-40]

didn't catch that...

Yes, all KOP measurements are done with the crankarm at 3:00 (horizontal).

 

[danl1]

KOPS is a 3:00 measurement, as others have noted. I'm not liking the sound of the advice you are getting, though I might not be hearing it right. But that's OK, because I don't think a lot of KOPS anyhow. If KOPS had merit, recumbents would be impossible.

KOPS is a weak measurement, at least as commonly used. It's usually used to define saddle fore-aft, even though you can easily go from forward to well rear of KOPS only with seat-height adjustments that are within the 'accepted' ranges for that measurement. Point is, KOPS is dependent on two variables, not just one as it's normally used. I like Keith Bontrager's take on the issue, though his method is fussy:

http://www.sheldonbrown.com/kops.html

My personal method (based loosely on Keith's theory) is how it feels when I really punch it seated, like honking up a climb. If the saddle is too far back, I get the sensation of feeling like I'm driving myself off the back of the seat. If it's too far forward, I hit the rivet when I start honkin'. Saddle in the right spot, the sit bones stay right where they belong. And that's the whole point, isn't it?

 

[C-40]

questionable fitting...

Well, the 585 does not have a slack STA, so I suspect your fitter subscribes to the more extreme forward position philosophy. If your fitter dropped a plumb line from the side of the knee to the pedal spindle, with the crank at the 3:00 position, that's liikely to suggest a more forward position. I'd check the weight balance of the bike, when your riding with the back low and your hands in the drops. I'd keep the front weight down to 45-46%.

As for your saddle height, it doesn't sound low to me, but it depends on the accuracy of your inseam measurement (most people measure on the low side). The angle of the foot greatly affects saddle height. If you pedal with the heels up quite a bit, then it will be higher than someone like me who pedals without a lot of heel rise.

FWIW, I'd never use a straight up post with a 73.75 STA. Most riders woudl use a setback post on this frame. I'd also say that you picked a small frame for someone who has low flexibility. Your sadddle height is 4cm more than mine, but your frame (and head tube) is less than 3cm taller. You've either got to use a lot of spacer or a high rise stem to get the bars up very high. I can tolerate a 9cm height difference, so I only need 1cm of spacer with an 84 degree stem.

Has your fitter also suggested that the stem be raised when you raise the saddle more? Perhaps the aextra height difference won't bother you, but it't something to keep in mind.

 

[dawgcatching]

I think I am confusing myself here. I re-thought the process, and he did indeed do the KOPS measurement at 3:00. He did the tib/fib to femur angle at 5:30 or so, with my foot slightly relaxed. He noted that in this 5:30 position, my heel was lower than normal (the angle of tib/fib to femur was 35 degrees) hence the "you may want to raise your seat 2mm per week as you become more flexible".

I can't remember if the KOPS position was measured from the top of the kneecap or the bony protrusion. I will have to re-check it on my trainer at home tonight. Still, as C40 pointed out, the saddle seems VERY far forward, and it at least 2cm further forward than I was riding last year.

Also, my saddle to bar drop is 9.5 to 10cm or so, and I ride with shallow classic bend bars. I can ride in the drops w/o a problem, but not for hours on end. Usually I am down there only for short bursts or when descending. I am currently riding a 110 stem, but last year it was a 120 later in the season (with the same frame). The bike acutally handles better than any I have yet owned: I feel glued to the road. I had a 70-mile race last weekend (as part of a stage race) with 7500 feet of climbing, and lots of hairpin descending turns, and the bike felt perfectly balanced.

 

[acid_rider]

can you elaborate?

The idea of pushing the saddle back until you can ride hands-off would have those with weak midsections wanting the saddle further back than even a setback post would allow. The other downside to this idea is poor weight balance on the bike, with the front end too light for the best cornering.

I've done a fair amount of experimenting over at least a 3cm range in the last few years and found no advantage to positioning the saddle far back, even for climbing mountains. I've since switched back to a more normal position, with my knee less than 1cm behind the pedal spindle. More weight on the front of the bike (about 45-46%) makes for improved high speed cornering on a mountain descent.

I do not understand.
C-40, does it mean that *currently* you ride in fore/aft saddle position of -1cm where if you are in the drops riding hard-ish in say 53/16 pushing 90rpm and then if you were to let go off the bars with both hands (to, say, move up to hoods) you will collapse forward at once? And do you find your performance improved as a result of moving forward?

thanks

 

[flying]

Also, my saddle to bar drop is 9.5 to 10cm or so, and I ride with shallow classic bend bars. I can ride in the drops w/o a problem, but not for hours on end. Usually I am down there only for short bursts or when descending. I am currently riding a 110 stem, but last year it was a 120 later in the season (with the same frame). The bike acutally handles better than any I have yet owned: I feel glued to the road. I had a 70-mile race last weekend (as part of a stage race) with 7500 feet of climbing, and lots of hairpin descending turns, and the bike felt perfectly balanced.

This is confusing as you said you were not flexable yet have 3.5 - 4" drop between saddle & bar tops?
Bottom line though is your statements about a 70 mile race with 7500' of climbing. If it felt that good why worry? Formulas get you close but only you can say what feels right for you.

 

[C-40]

???

You need to read the post from Peabody, that I was responding to. I said nothing about how my current position affects my weight balance over the bike. I've never done the test, as posted by Peabody. It's worthless, IMO.

What I was saying is that I've used a far-back position and got nothing special from it. It may allow you to apply more torque and get up a steep section with an under-geared bike, but it can also reduce your cadence. Substituting lots of torque for cadence is hard on the knees, can overburden the leg muscles and inadequately train the cardiovascular system. After moving the saddle to a more normal position, I spin better and the bike handles better.

Read my other posts and you'll note that I mentioned three ways to measure KOP and none will produce the same result. That's why I say it's a ballpark measurement.