Having the seat this low is fine for basic riding around at a leisurely rate. However, if you do any long-distance riding or anything with higher-intensity than 25%, you'll end up with knee problems. Knees can safely transmit the highest loads when they are straight, bone-to-bone. Bent-knees transmit loads through the ligaments. And when bent, they have a lot of wobble and will load the ligaments unevenly.

Even with a rotated "comfort bike" position, seat-height should still be the same (seat to pedal). Close to full leg-extension at the bottom of the stroke to keep the loads off the knee ligaments. There's various online guides to measuring seat-height and adjusting it optimally. They all will place your seat-height at about 100-109% of your inseam. It's typically safer to be on the too-high side rather than too-low as knee and hamstring injuries aren't as common with extra height as it is with being too low.

As for red-light stopping and starting, you'll find with practice and experience, that getting off and on the seat will actually be faster. Stopping is irrelevant because whether you get off or stay on the seat, there's no longitudinal travel anyway. Starting off the seat with one foot on the ground and one foot in the pedal with crankarm up & forward lets you transfer ALL your weight from the ground foot to the foot on the pedal. This is an instant 0-3mph jump with just half a pedal-stroke and you're across the intersection as the other folks are tippy-toeing trying to balance themselves on the seat trying to shift their weight from the ground foot onto the saddle.

Hi,

Clearly on a pedal forward bike the seat "height" is not the
same as a normal bike, but like recumbants, the height and
seat position fore/aft should combine to give the same
optimum leg extension through the bottom of the stroke.



One would assume the large* seatpost angle gives the fore/aft
movement also required for smaller / larger riders of the bike.

rgds, sreten.

* Or is it small compared to normal seatpost angles ? I think so.
Still its large in the sense of being less vertical than usual.

This is wrong. At the bottom of your pedal stroke, your leg is still slightly bent and your ankle is not extended. You don't have to lean far at all to reach the ground on a modern road bike by simply extending your leg and ankle, especially if you're above average height and the BB Height is proportionally small compared to others.

I stand by my original comment. For riders of anywhere near average height riding bikes with a normal bottom bracket height a proper saddle position will require you to lean the bike awkwardly far over to remain seated with a foot on the ground. If you can reach the ground comfortable while seated, either your saddle is too low or your bike and body proportions are out of the ordinary.

Either you are high, or your seat is too high.



These guys all appear to have normal fits. Notice how little distance is between the foot and ground on the rider in blue? Many pro fitters say you have a 30 degree bend in the knee bottom of pedal stroke. A 32" leg bent at 30 degrees has an effective length of about 28". Simply straightening your leg gets you 4 more inches, then extend your ankle for 1 or 2" more. Does it look like the rider in blue has 5+ inches to go before he can reach the ground?

I agree, with typical BB height he top of the pedals is about 4" off the ground. If the bike is fitted via the heel on pedal with leg straight method, that means that the rider can use his ankles to reach the ground, with his foot at the same angle as a woman wearing 4" heels. That may be OK if you're used to wearing 4" heels, but most people find this a somewhat tenuous foothold.

Add to that that we're talking about a straight down distance and you really want to reach out to the side for good support.

So while it's possible to toe down from the seat, most people with a correctly adjusted saddle will prefer to get off it while waiting for a light to change or whatever. Even after almost 50 years riding I still love to find a bit of curb when stopping for lights.

I'm pretty much average in fit and I agree. I can touch my foot to the ground pretty easily at a stop. I usually get off the saddle though because it's easier to have my entire foot flat on the ground if I have to wait a long time. But most riders don't have to lean way over to do. it

I agree that just touching your foot to the ground isn't that difficult but getting it far enough out away from the bike to have a stable standing position is and doing that while seated is a problem for most.

In any case there's no advantage to staying in the saddle. If done properly one still has one foot on a pedal, the other foot on the ground, and it's easier to have a stable start straddling the frame rather than a tippy start from the saddle.

Hi,

No. Its essentially correct and pointless arguing about.

I can tiptoe from the saddle but never do. Being
average build on a very average bike, IMO anyone
who can do better probably has a too low seat or
is very different to most of us in some respect.

Falling over over to one side to stay on the saddle
seems pointless to me, probably because I never
do it, seems to me you'd tend to wobble starting.

I only stay in the saddle with a convenient kerb.

rgds, sreten.

Well, with seat-height at 100-109% of inseam, you will still have bent-knees at bottom of stroke due to a slightly extended ankle. Any seat-height less than 100% of inseam risks knee and hamstring injury. There's been a trend in the past 20-years of lower seat-heights, going from 109 to 103-104% of inseam, but I doubt there's any pro rider sitting lower than 100% of inseam.

And if you look at ANY start-line before a race, there are ZERO riders sitting on their seat with their tippy-toes on the ground. It's just not stable, not efficient and looks clumsy. Especially if you wobble and fall over while starting.


https://coachlevi.com/images/menscracestartline510.jpg

And if you must stay in your seat at lights, learn to trackstand:

https://2.bp.blogspot.com/-4GkUQatXiD...rackstand.jpeg

There is so much specious and beside the point arguing going around here. . .

For crying out loud, Mr. OP, you're trying to coax people who've never seen you on a bike to fix you. Bite the bullet, go to a shop, and get a basic fit to find out how normal people sit on a bike like yours. And if it's the wrong bike, the fitter will tell you that. And if it doesn't solve your problem, it's medical, so see an orthopedist.

It is uncomfortable, but it's done. The USCF published a training guide a couple decades ago. The photo at the last chapter (called "Questions") was of The Great On (Eddy, of course), waiting for the race to start, sitting on the saddle, one foot clipped to the pedal and the other solidly, but on tiptoe, planted on the ground, patiently signing an autograph for an attractive female fan.

After I saw that I lowered my saddle a bit and increased the setback.

I understand that many pros are riding with less setback these days.

People try to make rocket science out of pedal height, but the truth is that there's no proven formula. We used to use higher saddles decades ago, but back then we were also ankling through the pedal stroke. Ankling is done less now and most ride with high cadence with little ankle movement. OTOH, the ankle can be set at a variety of positions, with each person being slightly different.

The differences in ankle angle make for different effective leg lengths. After 40+ years I've come to the conclusion, that if the seat is within the target range, riders unconsciously use ankle angle to dial it for their own pedaling motion, so any small "precision" adjustments are quickly compensated for and negated.

..or some do the reverse and if the "right" saddle height does not match their effective ankle rotation they move the saddle to accomodate the difference. I routinely take a lower saddle height because I pedal with less of an angle to the ground than most, even when at the bottom of the stroke.

Absolutely, and you're a classic example of why formulas don't wok except for finding a starting place. Whether you adjust the saddle to accommodate your ankle angle, or adjust the ankle angle to adapt to the saddle height is chicken and egg. I suspect a bit of both happens,which might explain how a good rider can jump on a borrowed bike, that's only a rough match to their own and still ride about as well as if no change were made.

I can't think of any saddle height rule that isn't really just a starting point. I like to start with the heel just touching the pedal, as Bill Kapaun gave. If my knees hurt, I raise the saddle about a mm at a time until I start to get hip rocking (abrasion in my groin, bad news!!!). Then lower it down until the pain (after healing!) does not start up again. THEN start working on saddle fore-aft position and tilt.

I wish I could do that.

I only stay on the saddle when I have something to lean against, like a light pole with a crossing button. Otherwise I find it easier to start standing over the top tube with my left foot clipped in. That way you can thrust yourself forward and onto the saddle and clip the other foot in easily and quickly. Staying on the saddle you can't thrust forward and you balance isn't very good to get a good start.

Very helpful discussion! Thanks to everyone for their input. I raised my seat to the highest it could go, which is also about the highest I can do to pedal naturally, without fully extending the leg at the lowest of the pedaling cycle. It makes great difference: feel much more comfortable in pedaling, much less knee stress when going uphill. I can't reach the ground with my toe while seated, even leaning slightly, but I'm not going to lower the seat back (until new problems occur), because then my lap would be near horizontal again at the top of pedaling.

(Btw, yes, I often avoid getting off the bike at red light by timing it so the light becomes green when I rolled to the intersection, behind or next to a stopped car.)

I don't know how they do it in Manhattan, but around here nearly everyone stops out of the saddle with one foot on a pedal and one on the ground. It is a very smooth motion after some practice, you just slide off the front of the seat as you stop, keeping the pedal that still has a foot on it in the forward, roughly horizontal position. When it is time to go, just shift your weight from the foot on the ground to the foot on the pedal and let the motion lift you back onto the saddle. There should be no "busying with dismounting and mounting". The only riders you see staying seated at stops are kids on their "street" bikes and little old ladies on beach cruisers. It always amazes me how many people you see riding in the bar stool position (seat too low and too far back). Those same riders are the ones who complain that they can't go fast and their legs/butts hurt after just a few miles.

Bike fit isn't a great mystery. Set the saddle height so that your leg is just a few degrees short of locking out at the longest part of the stroke (just a few degrees in front of the bottom of the stroke). As mentioned, some people measure saddle height as where the leg just locks out with the heel on the pedal spindle, that places it about right when you ride with the ball of your foot on the pedal. The fore/aft position of the saddle should put your knee cap roughly over the ball of your foot/pedal spindle when the pedal is in the forwardmost position. This is just a starting point but it should get you riding fairly comfortably. Don't start tweeking the measurements until you have ridden for a while, and then only change one adjustment a few mm at a time. If you have been riding in poor position for some time, it will take your body a while to get used to riding with a properly fitted bike.

I went with Sheldon Brown's dictum re seat height. He had posited that the appropriate seat height (in his experience and view) is where you have the seat at the highest level that precludes hip rocking. And it has worked beautifully for me. I am a little bit leary of seat height formulas, as I am not proportionally apportioned. I am 5' 10" tall, but my cycling inseam is a full 34"(86.36cm).

And I believe wholeheartedly in Sheldon's dictum, as I have experimentally tried my saddles lower and higher, but it did not work either way.

The rider in blue is leaning to his left making the pedal closer to the ground.

During my ride today I observed other people on the bikes. I get the impression that my bike's crank arms are longer than theirs. One of the guys, when at the top of the pedaling cycle, his lap was still some 45 degrees angle to horizon. Mine is just a little short of being horizontal, and my leg-to-torso length ratio is greater than average.

That's one of the things that have annoyed me about stock bikes. The large ones tend to have too-short of crankarms while the small ones tend to have too-long crankarms. Some pros even get custom cranks made longer than what's available on the market, in the 190-200mm range!