Optimum Cycling Position

[Jdsk]

Just thinking about this whilst having a post grass mowing ice cream.
Surely optimum is optimum? Personal opinion has no involvement. Optimum must mean the most efficient position for maximum use of power.
Of course most of us, including me, screw that by incorperating so many personal requirements be they compensating for a knackered back or the desire to look at the view or wear sandles. We all chose sub optimum in some things I bet.

If it means anything then optimum (or optimal!) has to be optimum for something, and at some point that thing has to made explicit. But it doesn't have to be "use of power", it could be low drag, or comfort, or avoiding a specific pain, or how long you can keep riding, or enjoying that view. : - )

And most often it will be a compromise between many outcomes. And a compromise between the different compromises needed on different rides.

Understanding how adjusting the bike affects as many as those outcomes as possible will save time in finding that compromise.

Jonathan

[[XAP]Bob]

"Optimum must mean the most efficient position for maximum use of power. "

And that will change based on the duration of the power required, the amount of power required etc...

[bjlabuk]

"Optimum must mean the most efficient position for maximum use of power. "

And that will change based on the duration of the power required, the amount of power required etc...

Sure. And that is why pros change their positioning during a ride, as far as they are able to do without a spanner or a hex key!

[kylecycler]

"Optimum must mean the most efficient position for maximum use of power. "

And that will change based on the duration of the power required, the amount of power required etc...

Sure. And that is why pros change their positioning during a ride, as far as they are able to do without a spanner or a hex key!

Eddy Merckx even carried a spanner or hex key to adjust his saddle height during a race...

http://stevetilford.com/2012/11/21/fett ... ke/merckx/

[mattheus]

Great pic!

Merckx was a special case. After his back injury he was never comfortable on the bike, and tweaked his seat-post mid-race to minimise the pain:

"
The closest I have come to death was when I had my crash at the Blois outdoor vélodrome in central France in September 1969. I’d just won the Tour de France and I was racing behind my pacer, who was on a Derny [a custom-built motorbike]. He crashed into another bike and was killed. I hit him at full speed. I flew through the air, landing head first. I had nothing on my head – just sponge and leather. I twisted my hips and injured my back and I was never the same. I was always in pain, and still have treatment on my back every two months.
" Guardian Interview

[kylecycler]

Great pic!

Merckx was a special case. After his back injury he was never comfortable on the bike, and tweaked his seat-post mid-race to minimise the pain:

"
The closest I have come to death was when I had my crash at the Blois outdoor vélodrome in central France in September 1969. I’d just won the Tour de France and I was racing behind my pacer, who was on a Derny [a custom-built motorbike]. He crashed into another bike and was killed. I hit him at full speed. I flew through the air, landing head first. I had nothing on my head – just sponge and leather. I twisted my hips and injured my back and I was never the same. I was always in pain, and still have treatment on my back every two months.
" Guardian Interview

I didn't know that, just that he adjusted his saddle 'on the move'. Suppose it doesn't really apply in 'normal' circumstances, then, unless you have an injury.

Still might not do any harm trying out adjustments on a ride, though - I don't think you ever really get a proper sense of position unless you go for a long ride. That certainly applies to saddle pain. I've never had saddle sores or residual pain after a long ride but always after about 40-50 miles I start to get saddle discomfort/pain. Been through a fair few saddles, followed 531colin's fit guide but never really resolved it.

I think I've been riding with too much saddle setback, though - that was the only thing that differed from Colin's figures (can't remember what they were but he mentioned his saddle setback once on here and mine was further back compared to his and we're the same height). I've fixed it since, just haven't been on a long ride to try it out.

[531colin]

.....................
Still might not do any harm trying out adjustments on a ride, though - I don't think you ever really get a proper sense of position unless you go for a long ride. That certainly applies to saddle pain. I've never had saddle sores or residual pain after a long ride but always after about 40-50 miles I start to get saddle discomfort/pain. Been through a fair few saddles, followed 531colin's fit guide but never really resolved it.

I think I've been riding with too much saddle setback, though - that was the only thing that differed from Colin's figures (can't remember what they were but he mentioned his saddle setback once on here and mine was further back compared to his and we're the same height). I've fixed it since, just haven't been on a long ride to try it out.

I find a sort of unholy alliance between saddle setback and reach; its difficult for me to get a flat bar bike long enough, so I find myself sitting right on the back of the saddle to get enough reach, even though the saddle setback is "right". I suppose if a bike were too long, you could slide forward and sit on the saddle nose.
(My B17 narrow nose is about 80mm behind the BB axle these days....getting further back as I get older)

[531colin]

My legs differ in length by one and a quarter inches.
Where does that put my saddle height?
My right knee moves not in a nice, vertical up and down plane, but in an outward arc as it lifts.
My leather saddle has been moulded into a lopsided shape.
I get along fairly well on my bike, so my conclusion is that the body can adapt well to less than theoretically ideal movements.

Thats a big difference in leg length.
I'm glad that you get along pretty well, but I'm going to sound a note of caution.
Cyclists get a lot of knee injuries, and yet cycling (even on an exercise bike) is often recommended for rehabilitation after a knee injury. The resolution of this paradox lies in the realisation that most cycling injuries are "over-use" injuries, that is they are caused by repeating the exact same movement thousands (millions?) of times.
My right bum bone makes a deeper dent in the saddle than the left bum bone, because I lean the bike to the left as I ride. (I may have other peculiarities as well.)
I guess that you drop your hip on the side with the shorter leg, and the saddle sags more that side as a result.
Your right knee moving in an arc on the upstroke is probably less of a worry than if it moved in an arc on the downstroke, ie under load, but I would guess that its your left leg thats shorter, and as you drop your left hip towards the bottom of the stroke this throws your right knee out on the upstroke.
I would encourage you to think about taking steps to try to even out your pedaling a bit.....stuff like a shorter crank for the shorter leg, and/or a built-up pedal or built-up cleat for the shorter leg.
If you Google "Steve Hogg asymmetry" you will find plenty of reading matter.

[Mike Sales]

My legs differ in length by one and a quarter inches.
Where does that put my saddle height?
My right knee moves not in a nice, vertical up and down plane, but in an outward arc as it lifts.
My leather saddle has been moulded into a lopsided shape.
I get along fairly well on my bike, so my conclusion is that the body can adapt well to less than theoretically ideal movements.

Thats a big difference in leg length.
I'm glad that you get along pretty well, but I'm going to sound a note of caution.
Cyclists get a lot of knee injuries, and yet cycling (even on an exercise bike) is often recommended for rehabilitation after a knee injury. The resolution of this paradox lies in the realisation that most cycling injuries are "over-use" injuries, that is they are caused by repeating the exact same movement thousands (millions?) of times.
My right bum bone makes a deeper dent in the saddle than the left bum bone, because I lean the bike to the left as I ride. (I may have other peculiarities as well.)
I guess that you drop your hip on the side with the shorter leg, and the saddle sags more that side as a result.
Your right knee moving in an arc on the upstroke is probably less of a worry than if it moved in an arc on the downstroke, ie under load, but I would guess that its your left leg thats shorter, and as you drop your left hip towards the bottom of the stroke this throws your right knee out on the upstroke.
I would encourage you to think about taking steps to try to even out your pedaling a bit.....stuff like a shorter crank for the shorter leg, and/or a built-up pedal or built-up cleat for the shorter leg.
If you Google "Steve Hogg asymmetry" you will find plenty of reading matter.

Thank you for your concern and advice.
I am afraid that your diagnosis is wrong and so your advice is irrelevant.
I have been learning about my hip since I damaged it fifty years ago.
After ten years on crutches I discovered the bicycle. In spite of my hip state it was a liberation, even though my pedalling action has upset the odd purist. I tried built up shoes and wedges long ago.
The problem has got worse and I am back on crutches, but I have not given up hope.
My point was that the human body can adapt itself to the most unlikely difficulties, so that the odd 5 mil. of crank length is of little matter.

[531colin]

Mike, I'm sorry to hear of your continuing difficulties.
I hope I haven't upset you, thats the last thing I wanted to do.

[Mike Sales]

I hope I haven't upset you, thats the last thing I wanted to do.

Don't worry. I have seen many consultants over the years and not all made things worse.
My best doctors have two wheels.

[bjlabuk]

Just doing my own research on the internet of recent scholarly research papers on saddle height, knee angle etc. Alot of them are definitely aimed at the elite pro riders, way above my level or need. However, most of them emphasise the importance of seat height. Knee angle is also mentioned and should fall within a 25 to 35 degree angle apparently, though not sure how I would measure that angle unless I use trigonometry ?

https://www.researchgate.net/publicatio ... in_Cycling

Just emailed for a copy of this report.

These reports are obviously not for everyone. I am just out to keep fit, race against myself and my watch, and sustain as little injury to my ageing body as I can!

[mattsccm]

Alright my point was maximum efficiency is optimum. So what makes best use of your power. Wasted power is inefficient.
I know those who don't race disagree but what ever your cycling the optimum isn't down to what is comfortable as long as maximum power is achieved. Anything else if secondary. Maximum power in a specific postion for example is part of this.
Human preference is totally different to human performance.
I am most efficient head down buttock up as long as I am not too low. I can't hold that position for more than about 20 minutes but that's not important as the turn in a 10 mile TT comes before 20 minutes so discomfort is discounted. Couldn't do a 25 like that so that position wouldn't be optimum.

[kylecycler]

I find a sort of unholy alliance between saddle setback and reach; its difficult for me to get a flat bar bike long enough, so I find myself sitting right on the back of the saddle to get enough reach, even though the saddle setback is "right". I suppose if a bike were too long, you could slide forward and sit on the saddle nose.
(My B17 narrow nose is about 80mm behind the BB axle these days....getting further back as I get older)

75cm for me, Colin, although it was 80cm before I moved the saddle forward a few weeks ago - I've gone the other way! It's a flat bar Carrera Subway, 62cm virtual top tube with a 90mm stem. Saddle height is 73 cm - I might be able to go lower, although I can dip my heels when 'forcing the gear' as you suggest in your fit guide. I'm 5'10" and quite stretched out to the bars, but tbh I've got no issues with fit as such, feels fine and I don't get sore or stiff on long rides or anything, or sore knees, just a sore bum! I know I'm not alone by any means but it takes the pleasure out of going further than about 60 miles. Maybe I just need to man up, grin and bear it, although that's what I've been doing.

I've got narrow sit bones - 100 mm centre to centre - so I guess I need a fairly narrow saddle. Currently using a 150mm wide Passport Navigator, same as the Spa synthetic saddle, I believe, just differently branded. Maybe too squishy for me, though, I think I need something firmer or at least less grippy. Funny thing is, I've got an awful feeling that the original saddle that came with the Subway might have been the best of the bunch - it was no worse than anything I've tried since and might well have been better - I've been chasing my tail! Saddles are like golfers' putters - no rhyme nor reason to them - golfers have won championships with a putter they bought at a jumble sale and they don't know why it works for them either!

I'd fork out for a Gilles Berthoud saddle if I thought I could justify the cost - I've very seldom heard of anyone who doesn't get on with them - it would be like a lifetime investment. My Carlton Ten came with a B17 Narrow when it was new in 1977 so when I build it back up that's what I'll fit again, see how that goes.

[st599_uk]

My point was that the human body can adapt itself to the most unlikely difficulties, so that the odd 5 mil. of crank length is of little matter.

Isn't that one of the problems of bike fitting though? The body can adapt to the situation, so the optimal position for comfort/power transfer is hard to detect by feel. If it feels wrong, then you're a long way off. If it feels right, you're in a position that the body can tolerate, but not the best necessarily. And just because the body can tolerate it for 30 mins, doesn't mean it will for a 300k ride.