dirtman

I'm putting this here because all of my bikes are and likely always will be 'vintage'.
I'm 6ft 3in tall with a 36" pants inseam.
I've always ridden a 63cm frame, it gives me about 2" of stand over clearance in flat shoes.
The problem I've always had was being able to get full or even close to full leg extension when pedaling.
With a 63cm frame, I've got the bars and stem set as high as I can get them within reason, and the seat up about 6" above the mark.
It gives me okay leg extension but not perfect on the down stroke of the pedals.
I have a 69cm Raleigh Technium I trash picked a few years ago, I never gave it much thought about riding it due to its condition and size.
The other day I dug it out, pumped up the tires, fixed a couple of cables and gave it a try. I can only sort of stand over the frame, (an unplanned dismount could be painfull).
But with the seat up almost all the way, (The way I found it, and its stuck there), I found it one of the most comfortable bikes I've ever ridden.
Now, with all that said, I'm well over the bikes weight limit at over 350 lbs or so and I had to pump the tires up to 110 psi to get them to hold my weight. I was waiting for the rim sidewalls to blow out.
But my 64 year old knees didn't even ache after a nearly 5 mile ride on that thing. Something I've not done on a road bike in 25 years.
If I ride my old Nishiki International around the block so much as once, my knees hurt for a week and feel like their going to explode.
What I find is that so long as my leg is not bent more than 90 degrees on the down stroke I don't get knee pain. On my Nishiki, my knees are almost always bent 90 degrees or more even if I jack the seat post all the way up.
I was always taught that proper frame size is a frame you can straddle with 1" of stand over clearance on road bikes and 3" on all other bikes.
I also no longer can ride using the lower part of the drop bars, so most of my bikes got straight bars years ago, doing so alleviated the problem of my arms and fingers falling asleep.
It also kept my beer gut from hitting the top tube. Down tube shifters never did work for me, even when I was 240 lbs with a 32" waist size my chin would smack the top tube trying to reach down to the shift levers on a tall frame. The Technium is no exception to that even today. Arm are about 3" too short to reach the shift levers.
Going to straight bars and thumb shifters also cures this issue.
I don't ride road bikes these days, I've been looking to find a suitable older solid frame mountain bike to set up for street use or even a tall cruiser.

Anyway, what is considered 'proper fit' on a bike these days" How are you supposed to know what frame size you should be riding?

RobbieTunes

First, forget about stand over. Don't stand over. Ride.

Next, realize your static point: crankset. Doesn't move.
Next, reaching the bars comfortably, and this is top tube length.
That determines your useable frame size.

After that, fore and aft are: stem length (most important), seat post setback, saddle position (tweak).
After that, height rear is seat post length; height front is stem rise. Both tweaks.

I stick to these points consistently, remembering three basics:

1. Look down and see the front hub. (top tube length, stem reach, seat post setback, saddle position). The remaining variable here is bar reach, C&V bars don't help much here.

2. Arms flexed/bent a bit in both the drops and on the hoods. (top tube length, stem reach, seat post setback, saddle position). You see the pattern by now...

3. Legs nearly extended, but not quite, at the bottom of the pedal stroke. Seat post height and to a little extent, crank arm length.

All sizing is trial and error, but you can really narrow it down by getting a fit done at a shop that is not going to sell you a bike. There are also "sets" of measurements out there that you can do and apply charts. Always have two people measure you at least twice, and take the average.

There are also types of fits, from relaxed and more upright (that is getting more and more popular), to the Merckx fit that stretches you out.

So, start with the right top tube length for you and go from there. Simple, huh?I

seypat

Robbie bringing the wisdom, as usual. One thing I would add. When you find a fit that works, take some measurements and write them down. You have something then that you can transfer and use to set up any bike.

himespau 

If bending your knees hurts too much, can you get a slightly taller seatpost and shorter cranks on your other bikes so that your knees ever get so high that you pass 90 degrees? I'm about an inch shorter than you (and prefer a 63-65 cm frame as well) and I've only ever used 175 mm cranks, but it seems like a shorter crank might mean your knees don't come up as much. What about gearing? Are they roughly the same between the two bikes? If the technium has lower gearing, maybe you're just not putting as much pressure on your knees.

Pompiere

Definitely this. For years, I had experimented with different stems, bars, seat positions. When I bought a new bike a few years ago, it was comfortable right out of the box, so I copied the critical dimensions to my other bikes. I guess I got lucky, but now all my bikes are comfortable all day long.

due ruote 

https://www.bikeforums.net/fitting-your-bike/

There is a whole subforum on the topic of bike fit.

It's hard for me to imagine you still having a 90 degree bend in your knee on a 63 frame with the seatpost all the way up, but I am not in a position to dispute the claim.
Photos are always good. If you can manage to post a couple with you riding different bikes, it would surely help the discussion.
Is knee trouble an ongoing condition, or does it just arise with cycling?

dddd

I think that you will only find your best fit when the available adjustments make it possible to raise and lower your saddle freely in either direction.

Same goes for all other fit-parameter adjustments, such as handlebar height and reach, and saddle fore-and-aft.

Having a saddle slid rearward to accommodate a too-short seatpost will tend to over-stress the saddle rails and the seatpost, and will have you tending to push off the rear edge of the saddle under forceful pedaling. So better to center one's mass favorably above the bottom bracket such that very little push or pull force is needed at the handlebar to hold a comfortable fore/aft position on the saddle.

If you can put the more-comfortable bike in front of the less-comfortable one, perhaps a visual read can be made as to what the primary comfort-improver is?

Longer, stronger seatposts are available in plenty of sizes, as many are made to be used on mountain bikes having shorter frames.

I took this picture some years ago in order to compare two different bike frame's geometry. The main thing was that one bike's bottom bracket was positioned directly behind the other's, so that the angles and dimensional differences were made visually apparent.

StanSeven

Thread from C&V

philbob57

The rule of thumb (BITD when C & V was modern) was seat tube 9"-10" less than bike inseam, not pants inseam. If your pants are made to be 1.5" less than bike inseam, that means a 63 cm frame is 8 cm too small, by that heuristic. You can solve the stem height problem by using a Nitto Technomic quill stem. That should be a lot cheaper than a new frame.

Robbietunes is probably a better rider than I am. I've come down on the top tube on a too big bike, and I'm not going to own a bike that's too big for me again.

dirtman

What I'm finding as I get older is that the better fitting 63cm frame is harder and harder to mount, especially if the seat post it higher than I can straddle. Which is definitely the case with a super sized seat post. To make the 63cm frame work, I need to raise the seat about 9" above the seat tube, but that's far too high to swing my 64 year old leg over. I think all my cranks are 170, I tried 165's once but they didn't make much difference other than changing my gear selection choices. I've always preferred a shorter reach stem that's raised up as far as i can get it. Bars lower than the saddle don't work for me, I don't bend that way, not now, not ever.
At my age, straight bars are the only option, and it solves the shifter reach problems.
On the 69cm Technium, I can barely get on the bike, I sort of lean the bike way over and step over the top tube, or get on next to a step. Once on the bike, the top tube height isn't ideal but its doable. The saddle height still needs to be jacked way up. Luckily that's where its stuck. If I had to stop suddenly and dismount, I'd likely have to sort of fall off the bike to one side since I can't 'hop' off he back at my age.
At my age and size, nothing happens fast, and I've come to the realization that drop bar road bikes are in my past, not future. But I have to solve the leg position thing if I'm going to keep riding. I'm not sure how to get a pic. I don't use a cell phone and my only camera uses film that I'm not even sure I can still buy.

On a 63cm frame, with the seat post about 3" above the top tube, I can stand flat footed on the bike over the saddle. IN this position, my knees are just slightly behind 90 degrees at the bottom of the stroke, and uncomfortably bent at the top of the stroke.
One problem I also have is that if I set the bike up with a short enough reach to fit me, my knees hit the bars and turning becomes a real problem.
Also, at over 350 lbs or so, I've always had some concern as to how long the seat post and stem are. I've broken my more than my fair share of seat posts, stems and cranks over the years.

due ruote 

I don’t know a thing about recumbents, but I am wondering if that’s something worth looking into. Maybe someone with experience will chime in.

woodcraft

It sounds like you are trying to have your feet on the ground while on the saddle, which will not be good for you knees or for generating power.

For a good saddle height starting point, pedal backward with heels on the pedals, without the hips rocking.

If it's hard to get your leg over to get on the bike, , lean the bike to the side so the top tube is lower.

On a road bike, one normally has to get off the saddle to stand- say at a stop sign.

RobbieTunes

I'm 5'6" and I was riding a 59cm Ironman Carbon in my first metric, cramping after 40 miles. We get to a stop light 1/4 mile from the finish, with a police officer directing traffic, and I simply fall over.

"Why didn't you unclip?"
"It was my hip and elbow or the grapenuts."
"I see, good choice. Now get out of the intersection."

dirtman

For a good saddle height starting point, pedal backward with heels on the pedals, without the hips rocking.

If it's hard to get your leg over to get on the bike, , lean the bike to the side so the top tube is lower.

On a road bike, one normally has to get off the saddle to stand- say at a stop sign.[/QUOTE]

The problem isn't getting over the top tube its getting over the saddle.
For me, to make most bikes ridable, the saddle has to be way high. I usually seem to need maximum distance between the saddle and the cranks to get proper leg extension.
If I can get a bike adjusted so as my legs are near totally extended at the bottom of the stroke and not hitting the bars or my chin on top I can ride a long time without pain.
The problem is usually to attain this I need a huge frame with a long seat post that's nearly impossible to straddle.
I used to own an older Panasonic MTB, in a 24" frame, I replaced the SR seat post with an extra long model and did the same with the stem. I could barely straddle the frame, and getting up onto
the saddle was a reach, but once up and moving the bike felt great.
The frame broke at the dt to bb connection on that bike and it went away a long time ago. What I'm finding with a lot of newer bikes is that the cranks are higher off the ground than most older bikes, making it even harder to attain the proper distance between the cranks and saddle.

With all the things going on lately I never did buy a bike, and likely won't any time soon the way it looks so I have plenty of time on my hands to look around and find something that really fits.
I liked the fit of the first Schwinn I looked at, the Mesa Runner. I also looked at a 23" High Sierra that was a few years newer, that bike had cantilever brakes, a chromoly frame, and Biopace chainrings.
It was a clean bike, the guy was asking $360 firm. The problem is that it didn't fit me like the Mesa Runner did. Something was different about the riding position and the bike didn't feel right underneath me.
It was as if I was too far forward on the bike. When riding it, I felt as if I was looking down at the front of the front wheel, not over or behind it as if the top tube was a lot shorter. It also had a more vertical angle to the head tube.
The Mesa Runner was a much more comfortable bike to ride. On the Mesa Runner, my head was behind the point of the handle bars not over or ahead of it as on the High Sierra. I also had turning issues with my knees on the High Sierra, I had to lean rearward and open my legs wide to clear the handle bars to make a slower speed turn of any type and I had to be very conscious of not banking my knees on bar shifters.
Remembering back, those were a lot of the same reasons I sold the one I had years ago.
I couldn't tell not having the two models side by side whether the difference in ride position and feel was due to the frame angles or measurements or the type of bars and stem, or the forks, or a combo of all the above.

Carbonfiberboy 

The biggest problem with the OP's issue is that they're 6'3", over 350 lbs., probably about 60 y.o., and out of shape. Conventional wisdom may not be applicable. Be that as it may, get on and off the bike any way you can. Lean the bike way over, that works usually. If that doesn't work, lay the bike down flat on the ground, step one foot over it, reach down and stand it up. When I'm totally exhausted and crampy, laying the bike down flat is the only way I can stagger off it. Nordic skiers can just fall down flat in the snow. Cyclists don't have such an easy option.

Bike fit - read this and apply: How can I fitting my bike

Bike frame fit basically isn't a thing. There's stack and reach, but those are more advanced concepts than called for here. Basically a frame is the right size when it's possible to apply all my fit instructions and not need some weird thing like a 130mm stem or a 50mm setback seatpost to make it work. Go to a large bike shop and get them to mess around with you, looking for the right frame size with the above objectives in mind..

When you stop, you don't put both feet on the ground. and you don't stay in the saddle. You come off the saddle, put one foot down and leave the other on the pedal. I like to put the right foot down in the US, the left foot being more likely to get run over. If you're using platform pedals, you flick the pedal up to the proper height with your lazy foot, push off with the down foot and start pedaling.

dirtman

My weight apparently is a lot higher than I thought, I got weighed at the doctor's office a few weeks ago and weighed in at 435 lbs.
To give a better description of my build, I'm 6ft 3in tall, 64 years old, with a 36 in inseam, 44 in waste, and I wear a 2xl t shirt.
I have a bit of a gut, but am mostly big all over. At my lightest in my teens when I first hit my max height I was 165 lbs and riding daily.
At age 20 and still riding daily I was 260 lbs and I stayed at that weight till my early 50's.
I have arthritis in my hands, elbows, shoulders, knees, and ankles. I've had several leg and foot injuries over the years that give me some pain, and I've had breathing issues
since I was in my 20's. I've been putting off double knee replacement for 10 years because I'm not convinced it'll solve enough of my issues to make it worth while.
I also had double hernia surgery 5 months ago and am waiting for an appointment for a third repair.

Fit wise my number one issue is leg extension. I've been to a couple of bike shops, one refused to fit me to a bike saying I was too heavy, another didn't have any bikes my size and said they don't order bigger bikes, they don't sell.
I also have zero intention of buying a new bike, anything I buy will be older. I don't like the new bikes and zero interest in owning one.
I'm most comfortable on something like an old three speed, but I've tried that in the past and tires and wheels are an issue and finding one larger enough is pretty tough. This area also has fairly rough roads, and rougher shoulders to ride on, so narrow wheels aren't likely my best choice.

Carbonfiberboy 

You realize of course that all of your physical problems are because of being 200 lbs. overweight, right? Fix that and you fix everything.. Well, I suppose not anymore, but you might think about limiting your further losses. I mean really! It's not that hard to lose 4 lbs. a month, 50 lbs. a year, 4 years and you're way more OK than you are now. It's calories in, calories out. The easiest way to cut calories is to eat smaller portions. No desserts, no snack foods in the hours. "Eat food, mostly plants."

This thread is not about bike fit.

KeepPedaling

Good info about bike fit! Thanks!

dirtman

I eat very little meat, mostly due to cost. I have never eaten 'junk' food or fast food. If I eat meat, its usually fish. I can't possibly eat any less. For example, yesterday I ate 2 eggs and an onion for breakfast, I didn't get a chance to eat again till 7pm, and I had a can of baked beans over some rice. That 12oz can of baked beans and cup of rice will be my dinner for three days. All day long though I drink lots of homemade iced tea. I make iced tea in gallon jugs, using 1 tbs. of sugar per gallon. My only weakness food wise would be a seafood buffet, but I'm generally too cheap to do that anyhow.
I spent most of the day on the roof of my garage ripping off the old shingles and re-tar papering it. If the weather stays clear, today and tomorrow I'll be hammering on new shingles. Last week I re-shingled my house, rebuilt the front wall on my camper, and took apart my one tractor for a repaint. Right now I feel like I got run over by a bus. On the scale, I gained 2 pounds in the last three days.
A week ago I had to dig out my last set of clothes that I hadn't worn in 5 years, all my 2xl shirts and 44" pants.
What bothers me about working around the house is that I live by myself, and have had issues falling down over the past few years. I fell through my side door onto my porch last fall. I somehow tripped a half step away from the door and crashed right through both doors. Luckily I sort of rode the door down and didn't get hurt. But I spent the whole night gluing the door and frame back together and re-hanging the door.
I get up around 4am every day, and turn in around 8pm most days but I find myself falling asleep by mid noon. I dozed off working on my roof last week. I was in the middle of a row of shingles near the top and nodded off. The last I remember was that I was one neighbor come home from work, which is usually around 5pm. The next thing I remember is waking up and its almost completely dark and dead quiet. The funny thing is I think I sort of woke up, looked around and dozed off again for a bit. I climbed down the ladder, put my stuff away and when I finally walked into the house it was after 8:30 pm. The cold is what woke me up, the temp had dropped from 65° to bout 45° and I was only wearing a t-shirt and a pair of sweat pants with no shoes or socks. I didn't lay down on the roof, I just sort of nodded off sitting there leaning on my right elbow.
When I came inside, I grabbed a hard boiled egg and a glass of iced tea, took a shower and went to bed. I was back on the roof and finished the job by noon.

We're supposed to have rain today, so I'll likely spend the day inside painting my kitchen and front door area where I fixed a few hair line cracks in the plaster over the winter and didn't want to paint in a closed up house over the winter. Before Saturday, if the weather allows me, I want to till and lime my garden to get ready for planting. I do a 15x30ft garden each year. I plant mainly tomatoes, lettuce, squash, okra, peas, green beans, and beets. I eat mostly salads all summer long with a couple of eggs for breakfast every other day.
My problem is my arthritis and old injuries make it hard to exercise, which why I want to get back on a bike, and to save some money on gas. I've been out of work since I was 60 due to an inoperable hernia, the doctor wouldn't give me a return to work letter and I was let go. Soc. Sec. don't cut it so I do odd jobs and build things to sell in my wood shop. I do have a tread mill, an old Schwinn Airdyne stationary bike, and a Bowflex that someone gave me a few years ago. I do fine on the bowflex but the treadmill and Airdyne are hard to deal with. I've fallen on my face a few times on the tread mill, and the Airdyne is too hard to pedal, not at all like a real bike. I also have a 12ft row boat that I take out on a nearby lake when I can. I can row with two oars just fine, I can go all day with no issues My forearms and biceps are still very strong so long as my hands don't start going numb. When they do I turn around and go from pulling to pushing the oars for a while to keep moving.

I was walking about two miles each morning but it was causing a lot of foot pain. I tried the special shoe thing and all but that got expensive wearing a size 17 1/2 shoe. If its warm, I sometimes still walk, but I go barefoot which causes me less foot and lower leg pain. I now carry a cane or walking stick since I've tripped and fallen a few times lately. The last time I bruised my ribs pretty bad when I fell on some big rocks trying to get out of the way of a truck that was driving on the shoulder towards me.

One of the problems I've had is that I don't know when to turn back when I go walking, I get out away from home and find I'm totally exhausted by the time I get home, or in such pain that I can't do anything else the rest of the day. I find myself getting winded with severe pain in my legs and feet about half way back most days. If I were on a bike, I'd at least have the option of coasting some of the way to get home.
I also find that if walk any other time of the day other than right after breakfast I get light headed and feel weak. If I eat right before, I'm usually okay. My doctor said I should walk, shouldn't do anything overly strenuous, but I'll go stir crazy sitting around the house. The latest virus going around is what has me stuck in the house due to the lock down and ban on going out. The only up side is that I'm getting a lot of projects done around the house that I've been putting off. I do find that my leg and knee pain isn't as bad if drink something like Propel or Gatorade but either one messes with my stomach pretty bad. I can barely stand the taste of Gatorade and all those drinks are high in salt.

The biggest issue with getting back on a bike is my hands and arms falling asleep, it even happens when driving a car sometimes. I take aspirin to help that but it don't stop it.
Second is the potential for knee pain.

I trash picked an old Raleigh Sprite over the weekend. I found it while walking the other day. I wasn't going to bother with it but its a ladies frame and its super tall. The seat goes high enough to really work for me and I can push myself up on the seat with my arms. I pumped up the tires on it adjusted the chain, oiled it up and took a short ride on it around the block, about 3 miles or so this morning before the sun came up. Right now my right knee feels like its going to explode. It'll go away but it'll take a while. It hurts to put weight on my left foot, and right knee so bad that I'm hobbling around with two canes. I'm sure a lot of it is due to the worn out leather saddle that's covered in duct tape, and its got two different kinds of pedals on it. The right side has a small oval rubber pedal, the left side has a steel rat trap on it.
The tires are likely original, (Its still got the old Dunlop style valve stems and "Raleigh Record" branded white stripe tires. The rear rim is true side to side but has a pretty bad flat spot. The bike creaks real bad when I'm riding.
Some of it is from the rear wheel, the rest likely from the seat and cranks. The left side crank arm is missing its cotter pin, and it won't move. I put my weight on it and it don't budge.
I put 70 lbs in the tires, about 15 psi more than they call for but its what it took for them to look right under my weight.
I was ok while riding the bike, but realized the minute I got off it my knee was going to be an issue today. I barely got from the bike to the door to get back in the house. I left the bike leaning against the porch since I couldn't walk from the shed to the house with my knee hurting the way it is. When it gets this way its fine so long as I don't straighten it.
It used to happen years ago when I rode too. Having a taller frame and tall seat post that let me get better leg extension all but eliminated the problem back then. The bad part is that I don't feel it till I try to stand up off the bike.
Its one of the reasons I stay on the saddle at stops, I can't trust my knees to be there if I'm hopping down off a tall saddle. I do find that riding this Raleigh ladies frame give me a bit more confidence that I'm not going to nut myself coming off the saddle, and I've got the option of coming down on either or both feet if needed, not just having to choose one. I favor my left knee when riding but my right leg is stronger even though its in pain. If I ignore the pain, I can still push the bike pretty hard. Right now though, I don't trust this bike, its pretty rough and the missing crank pin is bound to fail. I'm just hoping it works loose so i can get it all apart to service the bottom bracket and put some fresh cotter pins in it. The tires are old, but they seem fine, a flat tire isn't the end of the world and if they fail, I'll replace them then. If I keep riding this for now, I need to find a better rear rim. I don't think this one is saveable. The flat spot is sort of two flat spots over about a 12" area opposite the valve stem. I can try to unlace the wheel and pound it back into shape but I doubt I'll have much luck and its a lot of work and time that may not get me anywhere. I just as well find a better back rim to swap the hub over too.
The brakes on it leave a lot to be desired too but I'm also not going very fast. its the few downhill runs on the way home that got my attention. The bike sort of ran away down one hill for about a half mile or so, I had to resort to dragging my feet to slow down enough to turn onto my street through an intersection that's always covered in loose sand. If it weren't for calloused feet, and what little stopping the old brakes did give me I'd likely have run through someone's stockade fence or into a van parked across the road there. The brake pads say John Bull on them and are hard as stone and they make an awful grunting sound when the brake are applied.
I may take them off and try to sand off the glazed layer or find something to soak them in to soften them up a bit. I can't believe I didn't break a brake cable trying to slow that thing down.
I also need to remember to take some rubber bands with me next time to tie up my beard. When the wind was to my side, my beard kept trying to wrap around me face and into my eyes.
I didn't have the beard when I rode a bike last. When I'm on my motorcycle, I tuck it in my jacket and the sides of the helmet keep it down on the sides.

Chr0m0ly 

I wonder if wrapping and ace bandage around the knee before walking or biking might help, just to keep everything in alignment when your working it.

And for the bike mounting, I mount from the pedal, not the ground. I stand over the top tube, put a foot on the pedal, and as the pedal moves down, the bike starts moving and I raise my butt into the saddle. With your foot on the pedal you get 3 or 4 inches higher than the ground.