DefUnct

Hi,

Got a bit of a bike fit question, or rather looking for insights as to whether my reasoning seems sound. I have quite long legs for my height and a large +ape index (Height 176cm, arm span 188cm, inseam is a touch over 86cm)

On my Trek 1000, which is a 56cm frame, the drop from saddle to bars is reasonable visually (but still seems more than most) but i feel a bit stretched out, even with a 9cm stem. Although i can sit up more and it is my tourer, i find that even long term riding on the hoods can make me feel a touch stretched.

On my Wilier, i went for a slightly smaller size (cca 54 i think, it was their size M) and although i have a larger drop (approx 12.5cm) from saddle to bars, it feels more comfortable, even in the drops and with a 11cm stem. It also feels that my arms don't have to stretch too far forward. Would i be right in thinking that's because my short torso doesn't have to reach so far, and my long arms make up for the large drop?

I know it depends on what you want to do, but overall, it is better for someone with long legs / arms to have a smaller bike but with higher saddle / longer stem, or larger bike with lower saddle and short stem?

Either way i love riding both of them (although i may turn the stem on the trek over, to increase the up angle to make it a real tourer).

Campag4life

One thing I have learned is many believe they are somehow different. Reality is, you don't have long legs for your height. Your arms maybe a bit long....what is your dress shirt sleeve length?

Bike fit as it turns out is largely elective. Some guys like to ride a bit more upright like me...and others want to be slammed. Upright guys....I am more up and out can use the drops a lot....I am in the drops 50% of the time...because I like the drops and so compared to most club riders, I ride as low if not lower because with their big drop, riding the drops isn't as comfortable. See it everyday on the road.

A 56 will put you more upright. Honestly reach isn't much different between a 56 and 54 but drop sure is. Look up any stack and reach geometry chart. The higher the handlebar, the closer it is to your shoulder joints and why greater reach is tolerated with a taller head tube.

There is no teacher better than trial and error. Unless a pro fit includes testing with a power meter, the rest is aerodynamics and comfort. You need to decide what feels best. Own about 3-4 stems...flip them up and down. Move your saddle fore and aft to find the sweet spot for power, ability to get aero and balance weight on your hands.

Having been at this for decades and an inveterate tinkerer, road bike it is an enigma wrapped in a conundrum.

Good luck.

rpenmanparker 

OP, your legs are slightly long for your height. "Normal" (i.e. average) is about 47.5%. (Keep in mind that cycling inseam is longer than clothing inseam. For clothing the normal ratio is about 45%) You are at almost 49%. So your observations are quite sensible. But for your height, most 54 cm frames would be just right for the average man. And that is working pretty well for you. So apparently you aren't too far away from normal. The 56 cm frame was likely recommended to you or chosen by you on the basis of seat tube length according to the notion of long legs must need a long seat tube. As you have discovered that is wrong, because except in a custom or endurance style frame that long seat tube comes with a long top tube. But your discovery that a smaller frame with a taller seatpost allows you to reach down to the bars comfortably without having to stretch out your arms forward is a well-known, if somewhat modern concept. Our own RollCNY practices this same fit principle and is a strong proponent of it for guys built like you. If you PMed him, you might find him willing to discuss this with you in detail.

My advice to you is to choose your bikes on the basis of top tube length (short) and head tube height (also short), not seat tube length or the related nominal bike size. Even better would be stack and reach, both also short. As you have observed, you want your arm length to be reaching down, not out. Your 54 seems to be working, but some 52s may even be right for you, and despite your owning a 56 cm bike, that would only be one size below "normal", not two. The numbers tell the tale.

Campag4life

Robert,
We pretty much emphatically disagree. In fact, putting the OP on a 56 based upon his leg length is the entire premise of bike sizing that goes back three decades. Leg's dictate fit more than torso. Why is that? For the reason I stated. A higher head tube shortens reach. And further...OP's long arms compensate for shorter torso in terms of reach anyway...even tho the OP has less than 1 std deviation longer legs for his height. Longer legged riders...I am one...do better on taller frames than smaller frames for the reasons explained.
If the OP rides a 54 he ends up with mega drop and for the average non racer, this is not as comfortable a geometry with a lot more weight on the hands, more neck extension etc.

Reynolds 

FWIW, I'm 172cm and my inseam is 83cm, on the long side, and a 54 or 55 fits OK for me.

Campag4life

OP...if you want a comfortable fit...trend your fit in the direction of what Rivendell espouses. Now, to me there are much better bikes for the cash out there...Rivendell owner's will disagree ...but have a perusal of the following:

Learn About Bikes with Rivendell Bicycle Works

rpenmanparker 

Sometimes new ways of doing things are discovered, and that is true in cycling as in everything else. Both Roll and the OP here have discovered a "new truth", that (at least some) short-torsoed folks can be more comfortable with their long arms reaching down instead of forward. Their sSmaller frames, assuming standard, general purpose racing frame proportions, can work very well for them. As Roll says, if he bought a frame that fit his legs, the top tube and head tube would both be way too long. He could reach the bars, but his head would be way too far rearward for good weight distribution, and he might have trouble getting the saddle to bar drop that he needs. Basically this idea has the middle of the cycling body, the torso, fitted to the middle of the bike, the top tube. I would never have come up with this, but multiple folks are attesting that it works. Makes sense to me.

I will say that I employ the same thought process but in the opposite direction...and without thinking about it until now. At only 5'7" I ride 54s. Always have. My steelie is actually a 54 C-C, so it is really a 55.3 C-T. Why? Because I have a long torso. My inseam to height ratio is a little under 47%. Not much under average, but some. Actually it never occurred to me until now. Many folks my height would be on a 52. But I need more top tube and head tube than a smaller frame would provide. Even with the 54.8 to 55.5 cm top tubes on my frames, I still need 100-110 mm stems and about 25 mm of spacers. If I rode a 52 cm frame, I would need a 120 mm stem at least and might not be able to get the bar height I prefer. What would be the point of that?

So on both ends of the inseam to height ratio distribution this unusual way of looking at bike sizing seems to work. Maybe not for everyone, but it appears to be a valid alternative for some folks.

With regard to your statement:
"...higher head tube shortens reach..." Well, not exactly. If you will put your bars at a certain height through tall steerer or tall head tube, it is all the same. With horizontal 1" top tube, lugged steel frames, all this stuff was much more predictable. The shortening effect of the taller top tube in a larger size on reach was neutralized by moving the whole front end of the bike forward or steepening the head tube angle. Nowadays there are lots of complicating factors that work with and against the effects of each change you make to one area.

Fiery

That sounds like a reasonable assumption in your case.

I notice that taller riders typically seem to have proportionately more drop and less reach than shorter riders. Taller riders also seem to have proportionately longer limbs on average. This would seem to be confirm your idea. However, the beginning and the end of it is still personal preference. Some people simply find it more comfortable to reach out, while others prefer to reach down. Who will prefer what doesn't necessarily relate to one's body proportions.

I think you're doing it right. In the end, you know best what feels comfortable. It's great that you have two bikes with different sizes and positions, so it's very easy to experiment

RollCNY

Robert,
I appreciate you trying to share my experience, but you are not doing it well. I have short legs, long torso, and long arms, and my fitting style corresponds to C4L's. He is long legged, so he sizes taller for his height. I am short legged, so I size down for my height. He finds "endurance geometry" head tube lengths comfortable, where I find them unfavorably long.

I use short head tubes and high amount of saddle to bar drop to achieve a comfortable reach. The bike I tour on has about 5.5" of saddle to bar drop and a 120mm stem. My hybrid had about 4.5" of drop and a 130mm stem.

There was a thread some time ago that nicely pointed out the differences in people's proportion. It asked about the best way to tighten a rear QR skewer. My answer was to push down on the saddle with your chest, hold the lever in one hand, tighten the nut with the other, and flip the lever open and closed as you go. I quickly found out how few people can reach both sides of their rear axle in that position, and all sorts of people who have never met me told me that my saddle was definitively too low. Proportions obviously vary.

With the OP being close to "normal" morphology, assuming his measurements are correct, I would size frame conventionally, and get dialed in with seat post setback and stem length. I am no expert, but his numbers don't seem highly disproportionate.

Roll

rpenmanparker 

I am horribly embarrassed. And I am painfully aware that this is not the first time I have made the mistake. I could have sworn that you were both long in the legs and the arms and short in the torso. I was sure that I remembered that your case was an example of doing something unusual, but what you are describing now seems quite normal, the same thing that would have been arrived at by just standing over the top tube in the old days. For some reason I keep thinking that there is a growing interest in a counterintuitive sizing method these day. I guess that prejudice is what keeps me making this same mistake. Must be all in my head. I apologize to all concerned for the misinformation. In future I will just put this topic off limits for any replies by me.

Campag4life

In bold Robert for the record is patently false. Just so you know in fact, this is the entire premise of Rivendell's fitting philosophy. Effectively I ride his fit philosophy on a carbon Roubaix and his sizing convention corresponds with my best fit. The taller the head tube, the longer the top tube has to be to accommodate the same 'body reach' i.e. distance from rider's shoulder joints to hoods and drops. I believe you are referring to the metric of reach on a geometry chart which has little relevance other than a 'relative' distance...knowing what value in addition to stack which provides the best overall fit. This isn't body reach. Body reach is the combination of stack and reach including sta on a geometry chart. That is the reality not what you wrote. I understand that really few can combine stack and reach into a paradigm. Most can only consider a single variable....you for example top tube. But the taller a head tube is...the closer the handlebars are to the shoulders and either a longer top tube and/or stem is required for equivalent body reach.

PS: if there is a flaw in frame sizing convention used today, it is the metric of reach. This term reach while not independent of a rider's reach to the handlebars is only relevant when combined with stack and seat tube angle. In that sense, the term reach is a misnomer because that metric in isolation does not represent a rider's true reach to the handlebars.

Campag4life

Your atonement will be 10 lashes with a worn out 9 speed chain. You may wear body armor if you like but size up and not down.

gsa103

That's interesting morphology, since usually limb lengths scale together.

My personal experience agrees with the OP & Robert's observation. As someone with a long torso/short limbs, I needed to size up and shift to a sloping top tube bike for clearance.

The key thing is how you balance on the bike and keeping your weight properly centered. Extending the bars forward may actually increase weight on the hands since extending the arms increases the lever. On a rider with a shorter torso, a shorter top tube allows a similar arm angle, the only thing is a lower handlebar to allow the riders arms to not feel crunched.

Campag4life

Limb lengths generally scale together but not always.
Extending bars forwards rarely increases weight on a rider's hands. I will try to explain why. A rider with bars low and close in is generally performing a push up when riding a bike. Some have the core strength for this. Many however are better served with the hands more out in front because now the body is effectively transformed from performing a push up....to that of a hammock. Instead of arms being in pure compression i.e. more straight down, there is a greater element of tension versus compression in the arms which is much less fatiguing for many...me in particular.

RollCNY

Yes, my morphology is unusual, and the CC fit calculator nicely highlighted it. After painstaking measurements and data entry, it recommended something like a 690mm effective top tube and a 180mm stem. And that was the most relaxed fit.

If I were French, my last name would be Magnon.

RollCNY

I also find it funny that the Breezer Venturi that has been the subject of so many threads in the past 6 months would actually fit me nicely in the largest sizes, with its long length and very short headtube. I wouldn't even need the stack of spacers and high rise stem that ships with it.

rpenmanparker 

Oh compadre, jus' dooo eeet.

wheelreason

I fail to see the humor...

Dan333SP

Hot... But how does it ride? I'd recommend a new thread with some thoughts.

wheelreason

I can't ride it until my blue anodized cable ends arrive. I'm seriously considering selling it after reading some of the other Venturi threads. Owners seem to get as wacky as JB.

DefUnct

Wow that opened up a lot of discussion and i really value all the inputs and information. To be honest the Trek was my first bike and i picked the size based on what i read at the time. After my experiences with it, when the time came to pick a new bike and i went for the Wilier, the size was based on what i had learnt from riding the Trek and from all the new information i read that wasn't the mainstream this height = this fit (or similar).

I will say that for the trek, the stack is higher, as Campag4life says, but i have my saddle pushed all the way forward (as far as it can go) and still feel a bit stretched. On the Wilier, although the drop is bigger, the bars are horizontally closer and my saddle is set at a mid-point, giving me space to play with either way should i want to play with setup - that's despite having a longer stem than on the trek.

Will look into Rivendell fitting, have not seen / heard of that before - thanks a lot!

What i really like is despite all the discussion and science behind it all, i think we all seem to agree it comes down to personal preference and also having the time and patience to learn and experiment what works / doesn't work for you.

Dan333SP

I'm not sure why or when it happened, but the Venturi managed to become the next in a long line of Bikeforums memes, up there with guads, drope the hamer, dial it up to 400 watts, baby bike bolts, ect.

I'd ride it with pride. I'd also get a Dawes for longer rides, because the Breezer can't handle daily centuries.

Maelochs

(Summary at the end for the (tl;dr) crowd)

OP ... I have committed the cardinal sin of not reading all this because ... I also have a shorter torso and ride a much smaller frame than people would expect given my height and inseam.

Forget all the measuring systems, standard deviations, etc. I used the Competitive Cycles bike fityles bike fit web page (Bike Fit Calculator | Find Your Bike Size | Competitive Cyclist), did all my measurements, measured all my bikes (all different frame sizes and geometries,) and sketched out many frames based on the dimensions listed on their websites, and no matter what, came to the conclusion that I need a smaller frame to get a shorter top tube. A taller head tube helps because, as rpenmanparker notes, it is better to reach down than far forward, and a taller top tube tends to (I said "Tends To"; I know there will be someone who will find a contrary example just because) bring the bars a little closer to the seat, as it is sloped back a little.

Basically, I learned that no measurement system and no fit system and no algorithm fits absolutely every person perfectly, and there is nothing so important as experience. There are people (some of them post here) who will tell you to set up your bike according to some preconceived system of proportions, despite the fact that it hurts to ride that way. There are some who will tell people that their bikes are the wrong size, even after those people have put hundreds or even thousands of miles on the bikes with great comfort and pleasure.

I am a tad over six feet (what's that, 185 cm?) and I usually fit best on a 56-cm frame ... depending on the length of the head tube. Endurance-style frames I can go up some, because of the taller head tube. You might be right at home on a normal-geometry 54, or even a 52 ... and I can guarantee you no matter what, unless you bike looks like some people Think it should, they will tell you how wrong you are doing it.

Campag4life raises an interesting point. I think though that you shouldn't really be putting that much weight on your hands anyway. (Unless of course you are touring, where you won't necessarily be pedaling hard and will be in the saddle for a long time.) In any case, you shouldn't ever be holding yourself up with your arms as if doing a push-up. But that can all be adjusted easily and cheaply with various length stems. Head tube and top tube length are fixed; if you don't get those right it could be much harder to make everything else fit.

I find that with my short torso, if I have to reach long, I have to bend too far at the waist even though my arms can stretch the distance. This seems to pull my center of gravity forward a tiny bit which makes me want to slide back on the saddle which puts the bars even farther away. I'd rather ride with my arms slightly bent and a little forward, than almost straight and way forward; this enables me to keep my pelvis tilted properly, keeps me stable on the saddle, and doesn't leave me hurting after an hour's ride.

Cliff Notes: Don't pay attention to all the people's theories if they contradict your experience. Short-torso people seem to be more comfortable on smaller frames with shorter top tubes and more exposed seat post---but ignore what I say, too, if it doesn't seem to fit you. Ultimately, you will ride the bike so you need to figure out what fits you.

rpenmanparker 

Something is wrong if your saddle is not at the same place on both bikes...with respect to the bottom bracket. If the seat tube angles of both bikes are the same, and your seatposts both have the same setback, then the saddle should be in the same position on the clamps on both bikes. You aren't supposed to use saddle position to adjust reach.

Maelochs

This is absolute.

As fart as I know the first thing to do when sizing a bike is to set the saddle set-back so that your knee at the top of the stroke is about over the pedal spindle. Height and setback have to be set pretty much together due to the slope of the seat tube ... so when the saddle is about where it needs to be, your knee is about over the spindle at the top of the stroke and still slightly bent at the bottom.

Everyone will vary slightly to suit different body proportions and fitness/flexibility levels, but almost everyone will be pretty close to this.

After that, do the rest, but if the seat/BB position isn't right. something else will go wrong----inefficient pedaling, pain, injury, general discomfort while riding ....

If you cannot reach the bars comfortably with the seat where it is supposed to be, get a shorter stem. Don't move the seat----it will hurt you in the long run.