Alan K

I normally use a 54cm or 55 cm frame and once tweaked for my convenience, they work well for me. Long time ago, we bought a 50cm frame bike for one of my children. When I tried to use it even after raising the seat and handle car, it just didn’t feel righ for me. I personally wouldn’t go lower than one or two cm below what I think is my optimum size.

Andy_K 

This is basically what I do, but I'm a nerd so I have a spreadsheet that tells me what stem length I'll need. I set the saddle height to a fixed measurement about the bottom bracket, then use a measurement from the bars to the tip of the saddle to set the saddle fore/aft position. Then I ride and tweak as necessary. The idea is that if the relative position of the saddle, bars, and bottom bracket are the same, the "fit" will be right.

That still leaves some room for differences in handling and so on based on the bike's geometry and where your weight is relative to the wheels. The fit method above is all about properly distributing your weight over the bottom bracket, but on a smaller frame you'll get more weight over the front wheel. Also, stem length can have a noticeable effect on the steering. Handling is affected by a lot of factors, but I think this is one of the biggest reasons to avoid frames that are way too small. The other reason is aesthetics. I kind of prefer the look of a tall stem and bars near the height of the saddle, but there's definitely a point where it starts to look goofy.

When I moved from modern bikes with compact geometry to vintage bikes with level top tubes I didn't understand how to translate bike size, so I started out buying bikes that were on the small end of what I could ride. Then I gradually went bigger until I hit the upper limit of what I could stand over. Lately I find that my problem is having enough seat post exposed to get my workstand clamp on it. I think I need a smaller clamp.

I've posted the range of what I've used before, but I'll do it again since it's on topic.

My lower limit was this Pinarello Gran Turismo, which was advertised as a 54 but was actually more like 53.



Or this Gitane Gypsy Sport, which was maybe a bit smaller.



Those were both comfortable enough and fun to ride, but they look a bit goofy.

My biggest bike is this Colnago, which I think is about a 59. I can stand over it if I'm wearing shoes, but I can polish the top tube while doing so.



Bringing it back around to the Pinarello above, what I really loved about that was the color. I came to terms with it being too small, and kept an eye out for a replacement in that color that was my size. Eventually one turned up.

non-fixie 

Another data point: Bernard Thévenet, during a 1975 TdF time trial. Not sure if he had a special bike for that.

jamesdak 

Actual for me the main guiding force has been my bad knees and damaged lower back. Hence why I keep everything the same. For sure the bikes feel and handle differently but if they were all the same that would ruin some of the fun, LOL! Every now and then when I do back to back rides on different bike I may notice a handling difference as I swap bikes but this sensation is usually gone within the first mile. I don't race and hardly ever am pushing any of the bikes to there handling limits. When I do, for sure I prefer certain bikes over others. I totally agree with the last part. That's why several of the bikes that I loved riding were easy to pass on, they just looked wrong because of how I set them up to ride.

jamesdak 

Throw out the rules, live dangerously!!!!

thinktubes 

Rode with a 140mm stem for a bit - learned about #1 😅

repechage

looks visually balanced, impressed on the Campagnolo and Japanese rear mech working well.

panzerwagon 

Was wondering myself.. probably deserves its own thread.

geeteeiii

I can feel comfortable on a wide range of sizes, as long as the top tube is around 55-56cm. I prefer larger than smaller. I have long legs and short hands. I think my ideal frame would be 57cm c-t ST and 55cm c-c TT so i could have a stem with a decent length to maintain handling. Felt really good on a zero setback seatpost with 56cm TT, but most vintage post sadly have setback so i run them all the way forward.

panzerwagon 

There’s a window of reasonable fit that spans too-cramped to too-tall, but it narrows as we age and become less flexible.

Another factor might be the length of your femurs relative to your inseam. I have longer femurs so prefer slightly more saddle setback, which reduces the amount of stem length to play with on a given frame. Can place more limits on a too-large frame as opposed to a slightly smaller frame. Ideal tends to come closer to a square dimension frame.

That said, I still prefer slightly too large than too small primarily due to stability of a long wheelbase.

panzerwagon 

bikingshearer 

BITD, it was reported that Thevenet rode a stock PX-10 in 1975 and a stock PY-10 in 1977. This may have been Peugeot sales hype; by 1975, he was more than well-established enough to have his frames built by someone else.

I have read that, when Merck was on the Peugeot team 10 or so years earlier, he was on stock PX-10s, He commented a few years later that he did not think highly of their descending characteristics. (He said this as part of an answer of why he had attacked Roger Pingeon on a descent in a race.) So maybe Thevenet was on an actual Peugeot, maybe not. Either way, I'm sure his wins did not hurt Peugeot's sales.

repechage

back then, I would expect a lighter gauge tube set.

repechage

Merckx did ride a provided Peugeot at the onset of his tenure there. Simpson introduced Eddy to Masi, he rode those painted as Peugeot, Merckx was soon also doing that.
This would continue when He moved to Faema. Merckx was pretty smart or well advised, he started riding bikes painted as Eddy Merckx, years before he had any license agreements.
forward thinking.

repechage

A comment on fit, I have my saddle set basically identical on my bikes. I do have the bar position vary a bit, some days one just does not feel as flexible. Higher and shorter reach is the way to go.
does not take much, 15mm is quite a bit.

Kontact 

Especially looking at the hood height, these bikes all display greatly different fits. How can you compare them?

Piff 

Like other long legged and short torso-d people who ride vintage bikes, I'm somewhat forced to ride smaller bikes. Hate it, to be honest, trying to find a road bike with a 59cm seat tube and 55cm top tube is, uh, dang near impossible. I make a ~55cm square frame work with a 80mm stem slightly higher than traditional and a compact handlebar. It is a touch squirrelly compared to when using a 100mm stem and traditional drops, but it works.

Classtime 

Lots of old man approaches here. Good motivation. I put extra effort into increasing range of motion today.

squirtdad

Look at late 80's miyatas in 89 the team, 1400 and 914 had 58 cm x 55.5 cm .... which is closer to your 59 x 55 https://www.ragandbone.ca/PDFs/Miyat...logue%2089.pdf

and if all else fails Kirk Frameworks | Custom Bicycles

Piff 

Oh you wonderful, terrible, influence you

​​​​​​I've been wanting to try out a STB road bike for a while now!

squirtdad

Merry Christmas, happy to help, the link to the catalog will show you a lot of years of models and geometries STB came out in 1986 i am pretty sure.... 84 team was double butted, 85 team was triple butted, but not spine triple butted

mstateglfr 

This is quite the question for the c&v crowd since so many bikes posted here thru the years are what most would call 'ill fitting' at best.

As someone who rarely fits a mass produced c&v frame without some obvious esthetic concessions, this is not a glass houses sort of observation as I recognize many of my own c&v bikes have been too small.

I am convinced so many of the small bikes exist for one or more of these reasons...
- someone used to fit the bike and they now need an upright position due to age or injury, so they slap a technomic stem on and crank the bars back so the brake levers face the sky.
- they need a lower top tube to feel safe or to easily mount/dismount, but they also don't want to own a new fangled sloping top tube bike.
- it's a grail bike that is in a close to correct size, but clearly not correct size so some goofy adjustments are made in order to enjoy the grail bike.
- some people genuinely don't understand how a bike should fit, and they ride a bike that is too small(or big) out of blissful ignorance.


Very few of my c&v bikes stay with me for more than a year, even when I really like them, because they don't actually fit without modifications and I don't feel like riding bikes that see too small for more than that time before I move em on and try something else that is going to also be too small.
I have 0 interest in technomic stems as a long term solution for a frame that is too small.

But hey- if people want to ride a small frame because it's a bike from their youth they can now afford or whatever, more power to em. An often ridden bike that is too small and has goofy fit concessions is better than a properly sized bike that is rarely ridden.

jamesdak 

Ummm...... Saddle height and setback all the same. Reach from centerline of saddle to centerline of the stem's clamp are the same. Like I said originally the variety is the saddle to bar drop and the bars. The knees need precise placement but fortunately even with lower back limitations my flexibility is pretty good most days. I'd absolutely hate to try and run the exact same bars on all the bikes I have. The only constant there is 42cm widths although a couple are different. So I certainly would not call them greatly different myself. But I guess you would, LOL! It's all good!

I will say sorting out lever placement on the various bikes is something I do consider. A lot of times I'll set the levers and then ride them for some miles to see about the hand comfort. Lot's of difference from old school levers and modern ones in terms of how I like them placed for comfort.

I'll purposely vary saddle to bar height on some bikes according to if they are more purpose built. Like I prefer the bars higher on my main climbing rides, more comfortable to me.

I am curious to see how things go now with both knees replaced. The legs are straighter and I noticed after the first one that the one leg was a lot closer to the top tube on the top of my stroke than the other one.

Piff 

I'll have to take a trip through the catalogs again, I really had no idea Miyata made some with such short top tubes. I like the geometry of the 718a or the 512 from that year....72 degree heatube, 415mm chainstays, and nearly the same seattube to top tube ratio. Nice sport touring frame.

jamesdak 

Or....we can play with this another way. You're right, they are all completely different and yet none of it matters as they feel fine under me.

And as another data point we can figure in my silly 19mph game where no matter how the bike fits me I'm still running pretty much the same speed on all of them. How's that for blowing up the theory that " too small bikes are bad"?

Now excuse me as I step away to get on my indoor recumbent bike with it's saddle way too low. Still trying to break up some stubborn scar tissue.