AdventureManCO 

Preface: I ride about a 56cm. I may be picking up a 'too small' bike (looks around 50cm give or take) which is obviously too small, right? However. I've been on a quest the last year or so to try to find my 'correct' size. It turns out 'correct' can mean a lot of things, and it seems like there is quite the willy-nilly approach to sizing, given the application - French fit, race fit, and what not. What initially got me thinking about this was a couple years ago when I picked up this little Novara Randonee which is probably about a 52cm. Again, obviously too small. But the bike had a tall stem, and the saddle raised up high enough for me. It was actually really comfortable. I stopped riding it because I got a weird feeling in my knee when I rode it.

However, I've been playing around with geometry and adjustments a lot recently (via the Guerciotti and Huffente in the other thread), and just for kicks, I took a look at the Randonee again. Re-adjusted the saddle, and have been riding it. No knee pain (which makes sense, if the saddle/crank relationship is identical to other bikes I ride). So it got me thinking...just what is 'too small'?

I sort of get the feeling that seat tube length means nothing, apart from standover. You can simply adjust the seatpost higher, and it adjusts along the same angular plane of the seat tube angle, so if that was taller, it wouldn't change a thing. Where it seems like it matters a lot more is in top-tube length, and overall wheelbase length, where a shorter wheelbase would create more toe overlap, and a shorter top tube would necessitate a longer stem, which changes steering.

Case in point: I've been looking up bike pictures recently, and here are a few that I've found that are interesting:






Both of these are Miyata 1000s. Probably both around 50cm. Look at the saddle, and then look at the stem. There are plenty of people that would look at these two bikes and say 'too small!' for the rider. But these people are riding these bikes. Are they wrong? Are these bikes too small for the rider? Is there too much toe overlap? Is steering negatively affected? Is having a shorter top tube somewhat looked more favorably on a touring bike, where it may be considered a less aggressive position?

I'm going to try to make this 50cm bike work. If it doesn't, it is an easy pass to one of my kids, or potential trading material in the 'frame doesn't fit pass-around game' thread.

I'm also paging campfire as his Bianchi Grizzly is setup the same way - small frame, higher seatpost and stem -




If anyone else rides a bike in this configuration, with a small frame/shorter top tube, and higher saddle and stem, I'd be interested in your thoughts.

Wildwood 

Why ride the wrong size?
Only comment I could think of.

FrejusFlyer

I usually ride a 54/55 and the bike setup has a certain feel to it. I also have a "too small" 50cm Masi that I ride all the time. For some reason the position on the Masi feels very natural and puts me in a nice aggressive position without feeling crunched up. I have most of my personal records on the smaller bike riding in this position. I also, without a doubt, climb much better in this position vs being more stretched out on my "correct" sized frames. It does make you wonder about fit. If you're looking for a laid-back tourer or cruiser, I wouldn't recommend the smaller sized frames.
A photo of the small Masi next to a virtual 55cm frame.

AdventureManCO 

But what is wrong, and why?

DanseMacabre

The modern measurements with stack and reach are really what things "should" be. The bottom-bracket is the start of a bicycle here. Relative height of the handlebar is the stack. Reach of that handlebar (IIRC) is the reach. That way, if the seatpost of two bikes have different angles, you can still easily compare the sizing.

For myself, I like a bit low and long, I have short legs, long body and I guess long arms. Looking at your 2 photo's, you might like high and short. Cyclocross bikes might be nice for you (not for me).
In some way it is about feel. If I am on a bike with a 53cm toptube, I feel locked up or cramped. If I am on 58cm toptube, I feel like my arms are stretched out with locked elbows.
I prefer lower bikes relatively, 57cm cc gives me a handlebar that sits too high.

edit: oh, about those stems. With a quill stem you add flex in the wrong place. With an ahead set there are added risks over 3 or 5 cm.

JoeBass

I normally ride around a 53-55cm bike, but I came across a nice 45cm (!) 3Rensho and decided to see if I could make it work. Long story short- It works, but it does put me in a very aggressive position. The positive is better aerodynamics and I’ve set some personal records on this bike. I’ve also done lots of metric centuries and one imperial century on this guy with no issues. As long as you’re flexible enough to deal with it. I mean, after all, this is just the kind of saddle to bar drop you’re going to see on a serious modern racer’s bike.

70sSanO

I’m not a fitter, but for me everything revolves around bottom bracket to saddle position to bars. In theory I would like to be balanced so my weight is not too forward or set back too far.

Going to a smaller frame for me means more setback in a seat post and, ideally, a corresponding amount longer stem. But in reality getting close after getting the saddle where I like it is probably fine.

For those so inclined, bottom bracket does take into consideration crank length to some degree.

John

chain_whipped

No rules and don't listen to these old farts. Lol
- Look what the modern day 'compact frame' evolution has done.
- The 'professional' to OlYmPiC fitters and coaches all have completely changed from what was customary from the 1980's and prior.
- Components are available for every conceivable means in making a small frame work for a larger stature. Crank lengths to bring you down from a longer seat post to giraffe necked stems, bar configurations and width purposes.

Pro and cons, surely enough reads and arguments to just say screw it and go try at.

PS. I've seen many riders even touring with smaller frames, and they like the extra clearance, plus room for a top bag, etc..
Many a pro riders downsized as well. Tri / tt folks as well. Smaller triangle stiffness, shrink the body up a bit to break the primary aero drag, etc.. The UCI is a stickler on much of those issues because its THE key ingredient of being fast, figuring it out for a competitive edge.

merziac

I think it can depend on so many things.

FITness, fitness, physiology, tolerance, mindset, stubbornness, ailments and lack there of, sun, moon, tides, etc, yada, yada, blah, blah, blah.

And it seems a big one for many whether you ever raced or not, I never did.

I rode too small bikes most of my life and made them work, thought they were fine until I finally got some that were big enough.

The big ones are so much better, I can push a higher gear much further and most importantly I can get up many hills without digging into the basement.

Which is very good at this stage as I have been banged up a bit from bikes and MC's, riding the bike now helps keep a lot of that in check, a very good thing.

For me it is truly amazing the difference, YMMV.

chain_whipped

I recall Hampston had mentioned he was fitted and was racing too large a frame. When Eddy Merckx came aboard team 7 Eleven, he transitioned him to a smaller size. Think about that era and then go further back when Merckx was racing, his fitting!

smd4

AMCO, I think I found a bike you might like:

3alarmer 

...smaller frame, shorter top tube, etc.

randyjawa 

If I have to ride a bike that is not quite the right fit, I choose larger over smaller. In fact, larger is, as often as not, as or more comfortable than just right. I know that sounds silly but it is a reality that I am aware of.

ScottCommutes

I'm no expert, but my experience has been that the taller you are, the more options you have. I am 6' 3", and I ride a bike with 26" wheels, an undersized frame, and a very long seatpost and stem. This looks goofy, but the upside is a smaller bicycle - easier to find a frame, lighter, better turning radius, shorter length, better maneuverability indoors and in traffic, etc. I commute and don't ride super aggressively, so this works for me.

Kontact 

Compact frames aren't smaller, they just have shorter seat tubes for a given size. Most sloping top tube bikes today aren't actually compacts, since they also have taller head tubes.

ridelikeaturtle

I think what you need is an "endurance" bike. There's a wonderful little thread here, where so many people have so many important things to say about it.

https://www.bikeforums.net/road-cycl...plish-you.html

LOL Happy Holidays!

merziac

Fully agree with this, I seem to need maximum extension for harder and longer riding, not that I ride very much of either.

I always think of "legging it out" on this, a term that describes it to a T, for me.

Kontact 

Most of the photos in this thread aren't small frames adapted to fit like a larger bike, but large people riding very small bikes. I would imagine that many of them either have really long legs for their height, or are riding with their arms pointed straight down.

My personal experience is that I should be on a 50cm and have owned 49-52. For whatever reason, the long stem or something else that made that 49 fit like the other bikes made it feel odd to me. But maybe that was just something particular to that frame's geometry. A 50 I had also with a long stem didn't feel that way to me. But none of that is as extreme as going from a 56 to a 50.

RCMoeur 

Some of us never had much of a choice and often had to make do with too-large frames, as that was all that was available at the time.

This might explain my affinity for cantilever-frame cruisers - they fit me well, although many of them aren't exactly made of 753.

Does this help AMCO's predicament? No, as it's the opposite. But it gave me a chance to again comment about not being blessed with excess height.

MeadMan2

Back in the day, I used Greg LeMond's size chart to determine bike size. He wrote that if you fall in-between two sizes, go with the smaller frame. I have ridden a 52 cm frame since & will not go larger. Of course at 85, my torso has shrunk so a shorter stem & also I have a harder time getting my leg over the top tube.

repechage

yeah, and he raised his stem for his big Giro win.

Robvolz 

I’m confused because bike frames are like shoes, they create sizes and make the numbers on a bell curve, knowing the average shoe size (example) is 9.5 - do they make more of those and less size 7 and 13s.

just wait. The right size 56 will come along.

I think I’m done, my collection is what I want and everything fits me.

but there on the “Are you looking” thread was that early merckx corsa in size 56 for $100. If I was in LA, I would have done it.

use search tempest to find what you are looking for.

52telecaster

The older I get the taller I ride but, every once in a while I set up a too small mixte with a long seatpost and stem and it feels fine.

genejockey 

Because you can only find the 22" version of the bike you really want. So, you get a 330mm seatpost and a 135mm stem.

The problem is, 10cm of bar drop is about all I can manage for rides > 2-3 hours, and even with the stem at minimum insertion, this has 11 cm.

non-fixie 

BITD, 11-15cm of exposed seatpost was considered correct, and seatposts and stems were manufactured to match.

So, I prefer 63-64cm frames so I can be comfortable and use the vintage parts I like.