So here are my top three clues that a frame doesn't fit:
- The vast majority of frames should have stems between 80mm and 110mm We don't even sell 130mm or 140mm stems. If you need a stem that long your top tube is too short. By using a super-long stem you are also putting too much weight forward and compromising the bikes handling. Very short stems may be useful on city bikes, but even those are a compromise.
- 15 to 30mm of seat post setback is all anyone should ever require, even with a Brooks saddle. Needing more means that either the top tube is too short or, more likely, the seat tube angle is too steep. There are those folks who convince themselves that having their seat way behind the BB allows them to apply more power. But that sort of turns your bike into a semi-recumbent. You end up loosing the ability to spin.
- An extra-long seat post on a conventional level-top-tube frame indicates a seat tube that's too short. I'm still in the "fist-full of post" school of fit.
I'll post my simplified frame fit guidelines soon. But for know I just want to emphasize that fit is more important than any other characteristic in a frame. I don't care how famous the builder is, how special the tubing, how beautiful the lugs. If it doesn't fit you well then it's not worth riding.
"fit is more important than any other characteristic in a frame"
ReplyDeleteI agree.
"If it doesn't fit you well then it's not worth riding."
I disagree. I imagine you're just being hyperbolic here, but I have to stand up for crappy bikes. I fell in love with cycling riding a bike that didn't come close to fitting.
A proper fit was the 2nd best upgrade I ever made. The best, by far, was getting on a bike in the first place.
If your bike doesn't fit, by all means get one that does. But, in the meantime, keep riding. It's worth it.
How did you get Jan Ulrich to pose for a photo?
ReplyDeletemw
In my youth, I raced on a Colnago that didn't actually fit me. The top tube was too long; I was riding a 90 mm stem on it. That compromised the handling of the bike.
ReplyDeleteEven on my day-ride bike, I like a stem of 110-120 mm because I like to have responsive steering and I have rather short arms to go along with my fairly short torso.
It's interesting that you mention frames that are too large at the beginning of the post but then go on to discuss characteristics of frames that are too small.
ReplyDeleteWhat do you consider to be the disadvantages of a too large frame? Is it only the obvious potential for testicular damage to the rider equipped with them?
Amen!
ReplyDeletetimely post. i recently got a used bike that is probably too small for me. for now, its the bike i have and got a 120 mm stem to make it more comfortable. +1 to the post saying that the best upgrade is getting on a bike in the first place!
ReplyDeleteam looking forward to your post on frame fit guidelines... will help as i continue my search for my next bike to replace the one i have now!
I'd love the bike that fella is sitting on in the photo for my daughter... what is it and is it available somewhere?
ReplyDeleteWasn't "Fistful of Seatpost" an old Clint Eastwood spaghetti western ?
ReplyDeleteWasn't "Fistful of Seatpost" an old Clint Eastwood spaghetti western ?
ReplyDelete6/21/10 8:55 PM
Yup....
'Go ahead, make my seat cluster!'
In my early days, I ended up with a frame too small because the bike shop couldn't imagine putting anybody on a frame over 61cm.
ReplyDeleteFor my physique, the fit wasn't terrible, and a 59cm top tube is okay with a 110mm stem. BUT, I had to put a Technomic stem on it to get the bars up within 2cm of the saddle.
I guess its horses for courses.
ReplyDelete'Fit' depends on the bike's intended purpose, BUT also the fashion of the time in which it was built. If you think that VO frames and the whole American neo randonneur thing is not fashion/aesthetics driven then I would suggest you are deluding yourselves.
For example, short top tubes and long stems were a very fashionable look on British TT bikes of the 70's and 80's.
Dave Moulton seems to think they work and plenty of people rate his frames.
http://www.prodigalchild.net/Bicycle6.htm
I'm 6'2", pretty normal proportions, and my favorite bike has a 61 cm c/c seat tube and a 57 cm c/c top with a 130 mm stem, this leaves me with 140mm of seatpost from the rails of a brooks pro select to top of seat lug.
The bike handles brilliantly. Its excellent for anything quick and agressive and comfortable for a 100 miles.
Dave moulton wouldn't even put someone 2" taller on a frame my size, which by your standards is too small and by any modern standards too big.
Go figure.
'Fist full of seatpost'? isn't that a 50's reaction to the over small pre War bikes, which in turn were replaced by more aggresive Italian geometry and taller posts longer stems in the late 60's?
The most quoted aspect of frame size is the seat tube length/stand over height and I think its possibly the most irrelevant, it can so easily be corrected with a longer/shorter post or taller stem (if you're still using quils). If you are hitting your gonads on the top tube then perhaps you don't know how to stop a bike properly ;-) Top tube length/weight distribution are so much more important.
Your mileage will almost certainly vary, so keep drinking the New Brand (TM) Koolaid.
Simon
If it feels good, ride it!
ReplyDeleteFit is a big deal and, sadly, despite every effort to codify, it it remains an art. The single hardest thing in the business is to fit someone to their first bike. After that it's easier but the first one, if done improperly, can kill bike love in the rider.
ReplyDeleteI like to go for a ride with some one before making them a frame. At the least I want a video, along with the spec-seat tube, top tube, and stem, along with some body measurements. So far, although I've pretty much stopped building, every body that I've made a frame for has been very happy, in some cases 1200 km brevet happy.
Like I said, art.
Or, as we used to say in Hollywood, Art makes sandwiches in Studio City.
Phil Brown
I'm looking forward to your simplified frame fit guidelines. I hope it helps reduce the sales of snake oil custom fittings. There are several simple sets guidelines that give a good starting point for fit, and fine tuning is always a matter of personal preference, experience, and conditioning. The more scientific a fitting appears the more it should be avoided.
ReplyDeleteI cannot agree more that a large number of people are riding bicycles that fit poorly.
ReplyDeleteSome people seem to be the Emperor in new clothes. Probably best to let them be?
Frame fit is about “good-enough fit” not “perfect fit.” Lots of ways of fitting a bike will work well. A body changes over time (because of use, age, and injury), flexibility varies among riders at all levels, and the what one is used to riding makes a huge difference--not to mention the various types of riding styles and conditions. That's why different fit methods, models, and schools have been successful over the years even though they don’t agree with each other.
ReplyDeleteMy method is to follow the school of thought on fit that focuses on your type of riding and then just ride, ride, ride. Make adjustments as needed.
What a pandora's box you opened.
ReplyDeleteimo, conventional wisdom on frame sizing runs out of steam for people over 6 feet tall.
The same extends to crank length. Why you can not readily buy a bike with a crank over 175mm defies logic.
Agreed. I am over 6 foot and cobbled together the right parts to fit me. Actually, if you are really tall or really short, you have to just work stuff out. Some of us are all legs, others all torso. I love all my old tall steel frames even if some flex a little. Still ride OK.
ReplyDeleteWhat most people seem to miss regarding bike fit is one simple and undeniable fact ... we all have different bodies. Not just in arm/leg/torso dimensions, but also in weight distribution. Most classic AND modern bike fit methods are really meant for athletic builds - people who are flexible and fit. They don't necessarily work for those who aren't built like a "cyclist". A very slender person with little upper body mass is going to feel very different than a person with a great deal of upper body mass (muscle or otherwise) on the same bike, even though they may have the same physical dimensions. I may be wrong here, but I believe it is very important to achieve a "balanced" position for the rider, which may mean a very different bar height, stem length, seatpost setback, and so on, to bring the weight distribution of the rider and bike into proper place. If the bike fit methods also included placing the front and rear wheels over a pair of scales to measure weight distribution, we might just have a more useful process for a wider variety of body types.
ReplyDeleteAll that aside, I agree that we should just shut up and ride ... but I don't believe it should be uncomfortable and painful.
The problem about bike fit is that it isn't an event but a process. If it isn't right at first you-or the shop owner-has to keep trying and change parts to make it work.
ReplyDeleteSadly it takes time and money and few shops or, more important, customers, want to make the effort.
By the time a rider gets to a frame builder he's usually got his fit problems worked out and knows what works or doesn't work.
Phil Brown
To add to the confusion, fit is a moving target also. When i started road riding I felt quite awkward coming from a flat-bar background. I had the shop flip the stem up, now I flipped it back down after a few months.
ReplyDeleteI hope your discussion will be based more about cause and effect of the various frame measurements than which size fits whom.
keithwwalker said:
ReplyDelete"What a pandora's box you opened.
imo, conventional wisdom on frame sizing runs out of steam for people over 6 feet tall.
The same extends to crank length. Why you can not readily buy a bike with a crank over 175mm defies logic."
Which conventional wisdom, though? There's the rub. 1950s? 1970s? 1990s? Current?
I'm not sure there are very many folks that really need road cranks longer than 175. I have a friend that is 6'5" (is strong like bull...) and he does tend to use 180s, but that's what, 99th percentile American male height? In my shop, I get average-sized male customers asking for 185 mm cranks, or for 160 mm ones. Same size person in both cases!
Our positions on a bike evolve to fit our personal needs, and then we try to apply that position to different bikes with stems, saddle setback, etc.
ReplyDeleteWouldn't it be enlightening to ride 3 or 4 identical bikes in different frame sizes, with each adjusted for your favored riding position?
keithwalker wrote:
ReplyDelete"What a pandora's box you opened.
imo, conventional wisdom on frame sizing runs out of steam for people over 6 feet tall.
The same extends to crank length. Why you can not readily buy a bike with a crank over 175mm defies logic."
I agree with your first paragraph, but let me tell you about 180mm cranks. I am 6'4" and when I ran across a used 180mm crankset I happily went for it after reading so much about longer cranks for long-legged people. I am pretty disappointed with them and will go back to 170mm soon (or at least 175mm). When I went from 170 to 180 I was stunned by the difference one little centimeter makes. It is almost impossible to spin those cranks fast! The difference in cadence is incredible. Unfortunately, I don't have a computer on that bike (it's a city commuter/errands bike) so I don't have numbers to back this up, but it definitely doesn't feel right.
everyone has a fit theory.
ReplyDeleteBy your criteria my beloved Super Course isn't close to a 'proper' fit, but you'd be wrong. After years of experimenting I've come to realize bicycle fit is such a personal thing that anyone who offers advice on how much seat post should be exposed or how much extension my stem should have is just clueless. Everyone is different, bike frames basically get you in the ball park, seatposts and stems come with different setbacks and extensions for a reason.
ReplyDeleteSince the 6 footers are chiming in I will too on for all us 98th percentile types.
ReplyDeleteOne reason I started making frames was that I am 6'3" with short-32" inseam legs-and a long torso. For years I rode a Colnago with-for Colnago-a giant top tube of 60cm and a 13cm stem. When I started making my own I settled on 61x61 which is about the longest frame a normally sized tube set will make. Any longer and you have to use a piece of 4130 for the top tube.
And I like a conventionally styled frame, parallel top tube, no extended head tube, just the thing for an old mossback like me.
You may look me up at Phil Brown Cycles.
Phil Browm
Phil Brown said:
ReplyDelete"Since the 6 footers are chiming in I will too on for all us 98th percentile types.
One reason I started making frames was that I am 6'3" with short-32" inseam legs-and a long torso. For years I rode a Colnago with-for Colnago-a giant top tube of 60cm and a 13cm stem. When I started making my own I settled on 61x61 which is about the longest frame a normally sized tube set will make. Any longer and you have to use a piece of 4130 for the top tube.
And I like a conventionally styled frame, parallel top tube, no extended head tube, just the thing for an old mossback like me.
You may look me up at Phil Brown Cycles.
Phil Brown
6/23/10 12:17 PM"
Phil:
That sizing sounds right on (to me, anyways) for your body dimensions. I am 6' 2" with a 33" inseam and probably a 'regular(?)' torso for my height, and I tend to ride about a 62/59, depending on BB height, seat tube angle, and drop....
The (mostly anonymous) posters breaking bad on Chris' theory appear to be missing a crucial point.
ReplyDeleteVO is selling bicycles.
Individual customers may ultimately disagree with what V-O believes is a good fit.
Without some detailed information on V-O's fit philosphy, you may as well just throw a dart at the size choice.
"The (mostly anonymous) posters breaking bad on Chris' theory appear to be missing a crucial point.
ReplyDeleteVO is selling bicycles.
Individual customers may ultimately disagree with what V-O believes is a good fit.
Without some detailed information on V-O's fit philosphy, you may as well just throw a dart at the size choice."
I understand where you're coming from, but I disagree. I love what VO does, but I don't really care how they think a bike should fit me. Same as I don't really care what GP thinks about fit or anyone else. After 30+ years of cycling, I've got a pretty good idea of what works for me. It's great to see other opinions, but other than seeing what the latest thoughts on fitting are, I don't really put much stake in how other people think I should sit on my bike.
One person's "that doesn't fit!" is another person's "Just right."
According to current schools of thought, my frame is too big, according to others, too small. Meh. I'll ride what I like.
It ain't rocket science.
Not exactly anonymous,
Brian
I like "framebuilders" who are legends in their own minds.
ReplyDeleteAnonymous said...
ReplyDeletePhil Brown said:
My previous post snipped...
Phil:
That sizing sounds right on (to me, anyways) for your body dimensions. I am 6' 2" with a 33" inseam and probably a 'regular(?)' torso for my height, and I tend to ride about a 62/59, depending on BB height, seat tube angle, and drop....
I'm an inch taller and with one inch shorter legs and that puts me right outside of industry sizing. In this case 2 inches matters because it's right at the top of the sizing scale.
To perhaps further the discussion the human body will adapt to a slightly "incorrect" position pretty readily. Lots of people, especially if they mostly ride on the tops as may riders do today with brifters will feel OK on a slightly short bike.
It's an art, not a science.
Phil Brown
I become suspicious of fitting advice the minute that "spinning" is mentioned.
ReplyDeleteNot that I plug along at low cadences, but I like to sit well back. I didn't convince myself of anything, and I've had 40 years of road riding to experiment with. I have long thighs for my height, and I like to use them. I can go farther and longer powering the pedals at a moderate cadence than I can by spinning. When I position myself by modern racing-influenced standards, it just doesn't work for me. So, internet-based advice be darned, I sit well-back, on a long bike, with my handlebars up near saddle level. I have deep drops for when I need to get low. To each his own.
IMHO, the bike illustrated at the top of this post does not fit the rider properly, whether the bars and seat can be adjusted to be in the correct place or not. Many bikes used to be sold like this is the UK in the 1980s and before, but there are better ways to fit short riders, i.e., compact frames.
ReplyDeleteI would agree that many people ride bikes that do not fit them, and also that many frames have seat angles that are too steep. However, there are virtually no frames which vary by more than 1/2 degree from the norm (whatever that is assumed to be). Steep seat angles are easy to find, but <73 or 73.5 degrees on other than large frames is uncommon.
While this is so, seatposts with lots of offset will be essential for many of us.
I disagree about longer stems and their affecting handling.
ReplyDeleteIf using an Albatross bar for example, a longer stem is needed than for a drop bar. The higher the bars, the closer the bars come to the rider.
Many people ride stems too short.
Too long a stem put too much weight over the front wheel It's the weight distribution, not the stem itself that matters. Sports car designers try for 50/50 weight distribution because too much weight over the front or rear will degrade handling. It's the same principle on a bike.
ReplyDeleteim so confused about frame sizing.. im relatively new to the whole fixed gear/road bike scene so idk if im riding the correct frame size or not. i am 5'10 with normal proportions and i just recently bought a 54cm sized bike. i feel fine on the bike and i have about 1 and a half inches of clearance from the top of the frame to my crotch. but ive seen shorter people on bigger frames! the bike shop owners recommended the 54cm and my friends say to get a bigger frame.. what do y'all think?
ReplyDeleteI don't think I'm freakishly proportioned in any way, but I and I suspect many others will find your sizing ideas questionable. I've been riding the same fit for 40 years, including 6 to 7 cm bar drop from saddle height, 7cm saddle setback, tip of saddle to center of bars at 57 to 58 cm- all done on frames with 56 or 57 cm top tubes with 12 or 13 cm stems. I can generally make just about any frame from 56 to 60 cm seat tube C-T work for me, and get all of my fit dimensions perfect with proper setup- so your thoughts on 15mm to 30mm saddle setback and an 80mm to 110mm stem just aren't going to work for some folks- unless they like being all 'scrunched up'or unless they are on the far end of the normal distribution having shorter arms and/or torsos. I say forget about the $200 or more 'pro' bike fit, and the $20,000 computerized bike fitting devices. Just pull out your copy of the old Greg Lemond book with its sizing charts, and put a coffee table book in your crotch to size yourself- then go out and ride a lot.
ReplyDelete