Inpd

Hi,

I've noticed an interesting double-think/tautology/etc on these forums.

So whenever a newbie posts on what bike to get a whole bunch of people start behaving like Chicken Little and tell him/her that unless he gets precisely fitted to the bike its going to be a big issue and greatly detract from his biking experience.

However, when someone takes the advise and does get fitted to a bike (i.e. https://www.bikeforums.net/road-cycli...correctly.html) and it doesn't feel great people start giving them advise like, "your LBS fit ... considered a starting point" and "There is no correct ...." and "Change your seat height ...".

Here's my example that getting the exact precise fit is not all that important. I bought a Dawes 50cm Lightening DLX because BikesDirect said it should fit someone 5"7 to 5"9 which seems small. But it fits we well. I used the Lemond Method of setting the seat height (88.88883% of inseam height) and have done 200 miles with no pain/aches etc. Low and behold I met someone with the 54cm version of the same bike and I asked to ride his bike. After I adjusted the seat a bit it was just as comfortable.

So is getting the right sized frame really that important? Sure I can't rid a 44cm or a 64cm bike but 50cm vs 54cm isn't very much of a different (barely half a thumb length) and its easy to fix with a few modifications of seat height or stem length.

AnkleWork

Maybe you get what you pay for . . . and some other stuff you don't want.

Delmarva

I've posted on several threads that asked for help in selecting a new bike. I don't recall anyone saying a precise fit kit was needed for a newbie. Rather I think the most common response is that bikes vary in frame dimensions and how controls are arranged so it is important to try more than one. And most folks say it is equally important to find a bike that is appropriately sized for the individual. A new purchaser may not realize they are cramped in or stretched out when trying a bike at the store. A good bike sales person can spot that.

On the other hand an advanced rider who puts on a lot of miles could easily justify the cost of a good fitting session. What one chooses depends on the individual situation. Your advice works for you but I would hesitate to recommend it for one and all.

fietsbob

Why not take test rides in person if in Doubt? the shop can adjust the component parts pick at point of sale if you need a different stem, saddle, pedals, etc.

jyl

I have and ride road bikes from 52 cm to 58 cm. As long as the seatpost allows adjusting to correct saddle height, and you are reasonably flexible with reasonable core strength, I think most of us can ride a fairly wide range of frame sizes in tolerable comfort. If you are willing and able to change out for higher/lower or longer/shorter stem, seatpost with more/less setback, bars that are deeper/shallower, then you can usually get the "touch points" to be the same on a bigger vs smaller frame. There will still be differences in geometry, and some riders will be more sensitive or discerning to those, and the type of riding matters too.

The thing is that newbie riders may not have that flexibility or core, they may be more prone to hand or arm discomfort, they may ride heavy in the saddle, and they usually aren't ready to immediately swap out components on their new bike, so it is best if they start out with the "right" fit or close to it.

My 52 cm bike is fine for anything up to 50 miles. After that, it gets cramped and uncomfortable. My 58 cm bikes are great for long rides, but don't feel quite as quick-handling. I recently built a 56 cm and, not surprisingly, it feels somewhere in the middle.

FastJake

Not sure why this was posted in Bicycle Mechanics, but ok.

How far did you ride the other guy's bike? One mile, 10 miles, 50 miles? Fit IS important but how important depends what you're doing with the bike. Unless it's way out of whack (like a 6'6" rider on a 50cm bike) you can ride pretty much anything around the block without pain or discomfort.

Obviously the saddle height can be adjusted to accommodate a large range of heights, but for me it's the distance from the seatpost to the bars that is critical and significantly less adjustable. I am getting rid of two of my road bikes because that distance is 66cm even with a short stem. At that length my hands become uncomfortable and eventually go numb after 30-50 miles of riding. However, on my bikes that fit me better that distance is 62cm and I can ride all day long (I did a 175 mile ride last weekend) and be totally comfortable.

So it's both. It's a starting point, and there is no scientific method that I'm aware of for getting "reach to the bars" correct. And for newbies going on shorter rides it doesn't matter very much. But for long distance riding it's a critical dimension which can cause ride-ending pain if it's wrong.

Seat-tube length and saddle height are way easier to set due to the Lemond Method that you mention. One measurement and it can be completely figured out within a couple millimeters. Reach, as far as I know, is not like that.

ThermionicScott 

Some people are more sensitive to small adjustments (like me -- I carry allen wrenches so I can make tiny adjustments mid-ride if needed) and if they're inexperienced, we try to steer them toward knowledgeable people who can get them in the ballpark, after which we can try to help further. There is no double-think except in your imagination.

dr_lha

You've put 200 miles on that bike already? How long was each ride? I find fit issues aren't a problem for a 20 mile ride, but for a 50-100 mile ride it starts to matter more. I'll freely admit here that I have never had a "bike fitting" though, but I have ridden bikes all my life so I know what needs to go where.

ThermionicScott 

Good point. Sometimes you don't realize there is a fit issue until you're a couple hundred km into a ride, and that's why fit doesn't seem to matter for folks who never go on long rides.

modelmartin

Bike fitting is probably good for those who don't have the ability to figure it out themselves. That is not a criticism or a cut. Some have the ability and some don't. I am fortunate that I have been able to figure out my own fit and it works well for me. I do a fair number of 50-150 mile rides and aside from tired legs I feel good afterwards (I am 58).

Having said that I detect a sort of reverence for the bike fit experts out there similar to them being holy men ( and women). I totally see how important they are for highly competitive racers, triathletes, etc. and it does take a lot of expertise and knowledge.

Since i am quite comfy on my bikes I think i will pass on the fitting experience.

Wilfred Laurier

I am one of the posters who regularly points out what I think are ill fitting bikes, but I have never said that there is one correct frame size for anyone... there is a range of sizes in most bikes that will fit most riders - one or two sizes that fit almost equally well, and probably one size up and one size down from those can also be used without problem, but are possibly not ideal.
The details I see that set alarms ringing are usually weirdly set up bikes - seatpost jacked or slammed, weird super long stem (or stem turned backwards) or 14" of spacers. These are often indicators that the rider had or is having trouble getting the bike to feel comfortable.
My personal concern is very tall riders who have never had a bike that fits properly, and so don't know what it feels like. I am 6'5" and many bikes are not available in a size that I could get comfortable on without swapping in non-standard parts, but there are loads of big people riding bikes in a 'Large' size (usually on a bike where XL was not an option) with seatposts out past the max extension line, and 12" of saddle-to-bar drop.
From my own experience, while there is no 'correct' size, just a reasonable range, when you are outside that range, all the long seatposts and riser stems will still likely result in a bike that is not comfortable.

no1mad 

Neither am I.

Welcome to the "Fitting Your Bike" forum .

Inpd

Thanks Mods for moving my post.

I had intended it to go in the general road bike forum. In that forum whenever a newbie asked what bike to get the inevitable answer is that you need to go to a LBS to get fitted. But my experience is that as long as your somewhat close there is a ton of ways to adjust the bike to make it fit.

For example, I mentioned I have the 50cm version of the Dawes Lightening DLX and my friend the 54cm version. I road mine 15 miles and then road his 15 miles. With the slightly larger frame I need to move the seat forward and down a little but it was just as comfortable as mine and I road about the same pace.

Carbonfiberboy 

Some people are more sensitive or have a less conditioned core. I can ride anything on which I can reach the pedals, but I have a very strong friend who has to have everything just exactly so or she can't ride strong. People are all different.

Bandera

Using a well proven fitting method for a "baseline fit", as opposed to just guessing and making it up as you go a long is a very efficient.
That being said the system was designed for competitive riders and will produce a Classic road race fit, if you go through the process.

The Guimmard/Le Mond system starts with the proper frame size and proceeds from there: it is essential to get it right.
No element of fit is independent of another but the proper frame size is the key: a waste of time, effort, calculation and $$$$ otherwise.

That being said for plootering about and short distances anything that feels good is good enough.
For high power output, precise handling/descending/sprinting in the tight confines of a peloton a precise fit is essential.

Never buy the wrong frame size.

PS: 200 total miles vs. a 200 mile ride will prove an entirely different kettle of fish........

-Bandera

Inpd

Thanks Bandera, I really do appreciate your comments. The major changes in the frame size are the height and the C2 length (reach). But does it really matter if one gets a 54 or a 50cm sized frame? In this particular bike's case the difference in the C2 length (seat post to stem) is just 2 cms along with a height difference of 4 cm. Does 2cm and 4cm really make that much difference.

Bandera

To me it certainly does.
All of my road bikes from 1977-2013 are 55.3-57cm with an identical 56cm TT.
Works for me in FG, Rando-ish, Race and Endurance configurations.

On modern machines w/ "compact" sizing the Classic fitting systems give way to TT measurement as the "baseline" for fit.
Research more and talk w/ experienced local club cyclists but most important: Seat Time, ride the miles and adapt.

-Bandera

Wanderer

Ask for opinions, and that's exactly what you get.

Andrew R Stewart 

(Bold added by me) Moved the seat down and forward of what? From where your friend had it (nice friend to let you screw around with his set up) Or relative to the BB? One issue with alking about fit is the terminology and the references not always being the same.

I do agree with what many are saying. There is a range of bike sizes that can get acceptable/even same fits. The less experienced the rider the less fit sensitive they tend to be. Some are more fit focused then others given the same experience.

But i'll also add that there is a difference with fitting goals. Some fits are for comfort others solve power/aero challenges. And lastly, the perfect fit (whatever that means to the OP) will change as their goals and body change over the years. Andy.

Andrew R Stewart 

This reply is an excellent example of what I just mentioned. There are numbers without the complete picture. What does a 56cm top tube have to do with the stretch between the seat and bars? With no saddle tip set back (or at least the seat tube angle and post set back) or stem length the top tube number is but a data piece floating around with no foundation. Andy.

Bandera

Andy,

You know perfectly well that fitting is a complex process, describing in exacting detail the setting up of just this one machine using the Guimard/LeMond system would take a very long paragraph and serve little purpose in answering the OP's question.



Detailing the different requirements for "the complete picture" each of four bikes would take much longer to no real purpose.
Using a well proven fitting system will provide each of us with our unique baseline fit, using mine will duplicate my Vitus not your bike.

The answer to the OP's question:

Yes, it does matter to me.
All of my machine's frames are within a 2cm conventional C-T size range, share the same TT length and are optimized for their intended role: FG, Rando-ish, Race and Endurance configurations.
Selecting the proper frame size is essential to achieve an optimal fit for competitive/high mileage riders. It is the starting point for well proven fitting systems for good reason, it matters.

With the advent of "compact" and sloping tube frames TT length is the new default frame measure, getting that right is essential.

-Bandera

GravelMN

+1 for several of the above responses.

Sure there is a range of frames and geometries that will work for a given purpose for a given individual. A frame a couple of cm on either side of your theoretical "ideal" size can be made to accommodate you with adjustments in saddle and handlebar position, possibly involving changing a seat post and/or stem. The shorter and less intense the ride, the further off of an ideal fit you can be without discomfort. I can tolerate my wife's commuterized rigid MTB for a few miles of casual riding even though the frame is 3" too small and the saddle to handlebar reach is so short that I would be sitting almost completely upright. I'd look like a bear on a tricycle but I could do it with no ill effects, but that doesn't make it a good fit.

As you start to expect better performance over longer, more intense rides, the need to be closer to your ideal fit becomes greater. As a recreational/fitness rider, my bike frames are as close as possible to my ideal within the limits of what the manufacturer offers. I had a basic fitting at an LBS followed by small tweeks from time to time. Stems, seatposts, bars have been swapped for what works best for me. So you could say my bike fit is pretty close to ideal considering that everything is off the rack.

Now if I was a pro who lived on my bike and my livelihood depended on my performance, my bike fit would require a lot more analysis and much closer tolerances.

Some people can tolerate variations further from the "ideal" than others. A fit 20-year old with no orthopedic problems or previous injuries might be able to get away with a wide range of frame sizes and fits. Someone a bit more seasoned with neck, back, hip, knee, or ankle issues might find that even a cm here or there makes a big difference.

Most of the posts I have seen said that a LBS or home fitting using standardized measurements and relationships is a starting point that may require some additional adjustment to find the best adjustment for that individual. Many others, including some of mine, have said that, if you are having pain, numbness or other problems, a good analysis of bike fit is a good place to start when correcting the problem. I don't see that as "the sky is falling" or double think. Bike fit is important, the more you ride, the more important it becomes.

bikemig 

Top tube length matters. Yes there are other variables but with the right top tube length I can make most bikes work. Without it I can't.

Revisionist Theory of Bicycle Sizing

RR3

Thems big words.

It is not really double-think but cognitive dissonance spewing forth from riders who sincerely want to help but don't know crap. Who does not want to help a Newbie with shoulder pain, lumbar pain, foot pain, ulnar nerve myopathy, or sore bummies. Many of these ailments can be caused by poor fit.

With all due resect, 200 miles total is not much of a test for the 50 cm nor is a spin around the block for the 54 cm.

I notice a couple mm difference in saddle height.....for instance, I have two models of shorts and I need to lower the saddle when riding the thick padded ones IF I am doing a long ride. I suppose the chicken littles that you reference have experienced lasting and lingering pain from ill fitting bikes or know that a better fit absolutely will result in more performance and those who know something (unlike those who know crap) consider a good fit to be a good investment and is indeed universally accepted as ultimate truth. If you don't think poor fit will decrease performance and may cause discomfort, you know little. How to get the fit correct is up for debate. How much a good fit helps is up for debate.

A 52 cm might be perfect for you on the Dawes; thus, the 50 might be a touch small and the 54 a touch big. A 2 cm change is frame size from ideal is not much and can be accomodated easilyt. My custom rando bike is 59.7 cm CT and my racing bike is a 58 cm. The pedal to saddle distance is identical on both. The setback is similar and established for balance. The race rig is more slammed and the saddle to stem drop on the rando bike (60 mm) vs 100mm on the race bike is differnt for reason. The geometry and setup certainly effect handling and comfort. There is a lot of bad fitting info out there and that might be the double-think...jus sayin.

twodownzero

I'm 5'5" and my pubic bone is 788mm off the ground. Try being me and standing over a 54 cm bike and you'll understand the importance of fit.