Big Feet

[LarryA]

Buddy of mine has large feet for his height - 5'9" and size 11. Inseam is proportional for his height.

The inside of his left knee is getting cranky. I did a quick check of his position and he is running his saddle 4-5 cm higher than the formulas suggest, and his cleats forward. I suggested he move the cleats back a little, and drop the saddle some and see if that makes a difference, but I haven't got clue 1.

Does anyone have any sense on how much/how little to adjust seat height to accommodate his foot size?

[Matthew Strongin]

Man that seems like a pandoras box without a ton of additional info, photos, etc. FWIW, I'm 5'9" and wear size 10.5-11 shoes and never think of myself as having larger than normal feet. Especially not from a bike fit standpoint.

[LarryA]

Could be that me being 5'10" and having size 8.5 feet are distorting my sense of normal;-)

No photos (he's now 5 hours south of here) but Inseam is 83.2, Cranks 172.5, setback 7cm, Nose to Bars 52cm, nose to Hoods 67, Seat Height 77 (measured through the rail centre and to the bottom of a book placed on the saddle), Saddle is nose down 2.5cm, Bar drop 4cm. Torso is ~45° when on the hoods and arms are straight and at about 90° from the torso.

I know fitting like this is futile, just trying to sort out if he's in the ball park.

[Crowemagnon]

(sucks air through teeth)

yeah ill bite, I’m making a habit of this so heres some seriously defensive language ; (fitting like this IS futile but having someone answer can help you minimise futility, even if just by realising you disagree with them)

context of me;
ive been fitting professionally at a rate of normally 5 people a week for a 2&1/2 years before that i studied industrial design including some basic ergonomics thinking and practice. i charge $150 for a bike fit that might take a few sessions, normally two of around an hour does the trick.. ive read and been taught a stack of fitting systems and don’t prescribe to any of them whole heartedly, some things work for some people. i encourage people to read about fitting and try and theorise how they could improver their own bike setup, or their ability to use it and how this could improve their riding.

i TEND to put cleats way further back, saddles further forward, and handlebars higher and Much further forward than the results of other bike fitters i see locally. After injury prevention, i think prioritising selection-survival for road racing is important, (its very very tough to win big solo breakaways, so best try and win sprinting with a flat-ish back from a small-ish group, having nailed your recovery in-between moments of unleashing-the-fury). i think hips being open and calves being used minimally for power generation are both great things that work really well for lots of people. i fit road cyclists across a full range of age and ability but know(, and probably do my best work for) fast men the best, as i see more of them than any other group. i fit lots of junior trackies competing up to a national level too, mostly male.

about six months ago i spent about 40 hours developing a calculator or four to come to the conclusion that things that were impractical for me to measure accurately (and i was trying quite hard!) can account for too much variation for a calculator to be any use at all.

BUT

if we make some assumptions, i can run you through as far as i got, and you can make your own guesses from there.

if;
a man is 175cm tall (5’9”) and they fit size US 11 (euro 41ish) shoes, he’s got a bit of room in there, (say his feet are 28.5 to 29cm long leaving 12mm odd in the end, and his total stack height is about 22-25mm and his cleats are setup somewhere around 10mm behind the ‘centre of the ball of the foot’ ( this is daaaaangerous chat right now…) and his foot is supported in a way such that he has support under his arch which is Very slightly invasive near the rear of his arch (navicular) while standing on flat ground in his shoes, and he’s a fast club rider/racer (comfortable getting hip bumped in a corner, can ride in a bunch at 40kmh for a couple of hours on the flat without imploding, knows how to eat) AND he has a middle of the bell curve (of the riders ive seen and fitted) proportion and flexibility and muscle distribution, rides 10 hours a week, 5 of which is structured sessions; and his inseam is 83.2cm, riding 172.5mm cranks,

Then;

if i imagine their bike got stolen and they had no reference for fit.

the best of my calculators (the one that was always closest to final position, were talking around the +/-1.5 cm mark for both saddle height and offset) would say;
start with a saddle pretty flat in shape maybe with a cutout that ran all the way through the nose, set it up almost dead flat in orientation, between zero two degrees of foreward slope (nose down) and saddle height as you measure it around 75.0cm - with about 4cm of setback.

i wouldn’t even look at the bar until he can pedal comfortably on the saddle without knee pain on an indoor trainer (up on the flats).

Pat.

[Too Tall]

Nice work Pat. Tom Kellogg taught me how to fit riders on bikes. I use no system other than a X/Y laser to ensure accuracy and a device for measuring knee / hip angle (when needed).

Larry, since the dust is off the discussion I just want to agree with sending him to a pro or someone twice your age for advice. This is rocket science.

[LarryA]

Thanks guys. He's here again next week so I'll have the "get thee to a fitting pro" discussion with him then. In the interim I'll suggest he do as per Pat's recommendations, as well as ensure he tells the fitter it was his own idea;-)

I do appreciate how difficult this is to do remotely, so value the input all the more.