General Cycling Discussion - How much "wriggle room" in fitment?

I'm looking at a new (to me) roadbike. Two year old bike with less than 1K miles on it, for about a third of the new price.

The frame is a small and measures to be the exact correct size for me (18').

However, the reach may be a bit short. That, I suppose, can be tweaked with a different handlebar stem and perhaps a bit of fore/aft adjustment in the saddle.

Anyway, how much wriggle room (away from dead on specs) should one tolerate in bicycle fitment?

Thanks in advance,
Rick

About 5mm.

I'm not sure there's a single answer to this question.

If you can make the fit work, then the frame size doesn't have to be ideal. I've found the stem and saddle position can be moved around such that you're essentially able to go up a single frame size. It's harder to scale down. My 56cm bike has a 140mm stem on it that makes it feel like a 58cm.

On the other hand, you have to look at what those adjustments do to your biking mechanics. I'd look at whether moving the saddle back and the stem/bars forward to increase reach would put my knees in the wrong place relative to the pedals. Is stretching it out going to put much more weight on my arms and wrists?

If you can make the changes without introducing different fit issues -- ironic as you're making the changes to address fit issues -- then it's probably fine.

"Knees in the wrong place relative to the pedals."

Reading that comment I take that there must be a proper alignment for the knees.

Can you say a bit more about that matter?

I'm far from being an expert, but from what I can tell from web surfing, there are enough different opinions on perfect fit that "exact correct size" is meaningless. Likewise, there are different opinions on proper alignment for knees. Plus, the answer will depend on the type of riding you do.

Personally, I'd start by trying out the same frame in the next larger size, to see how it fits. I'd also pay attention to where the seat and stem are with regard to the limits of adjustability. If the stem is already relatively long, you may not have many choices for finding a longer one.

"Knees in the wrong place relative to the pedals."

Reading that comment I take that there must be a proper alignment for the knees.

Can you say a bit more about that matter?


Knees have to end up over the top of your pedal spindle + or - a little bit. Frame size will not effect this as all road bikes have around a 75deg seat tube angle. So now top tube length and stem length along with bar reach to a smaller degree is what will determine your reach to the bars. Make sense?

I'm not sure there's a single answer to this question.

If you can make the fit work, then the frame size doesn't have to be ideal. I've found the stem and saddle position can be moved around such that you're essentially able to go up a single frame size. It's harder to scale down. My 56cm bike has a 140mm stem on it that makes it feel like a 58cm.

On the other hand, you have to look at what those adjustments do to your biking mechanics. I'd look at whether moving the saddle back and the stem/bars forward to increase reach would put my knees in the wrong place relative to the pedals. Is stretching it out going to put much more weight on my arms and wrists?

If you can make the changes without introducing different fit issues -- ironic as you're making the changes to address fit issues -- then it's probably fine.
Thanks.

Do I take accurately from your comments that it is better for a frame to be on the small side (as opposed to being too large)?

Depending on which fitment scheme I read (and compared to my body measurements) the size Small frame (44.50 cm) is either just right for me, or slightly on the smallish side of correct. If I'm going to err one side or the other from perfect in buying a used bike, I definitely want to err in the better direction!

Weather permitting I'm going for a lunchtime ride today to see how I like this bike. Last week I rode the same route on a bike that was 54 cm, so the feel of the ride may be the real test.

On the 54 cm bike I felt a bit stretched out and kept wanting to be a bit more upright. Then I rode my junker mountain bike for several miles on a dirt road and realized the discomfort was not so much from being stretched out as being over stuffed... I kept having to sit upright to feel like I could breath properly.

So it may be this gut I'm carrying is the real source of my discomfort, meaning I need to worry less about frame size and more about just riding...

Do I take accurately from your comments that it is better for a frame to be on the small side (as opposed to being too large)?

There are many schools of thought on frame fitment. You should google and read up on them. I personally prefer to err on the side of too large, instead of too small. If your frame is too small, then the seat will end up much higher than the handlebars. This is good if you are a professional racer, but bad if you are me. In fact, this trend is relatively new even among professional racers.

From the sounds of it, "too big" for your would be a frame that you could not comfortably stand over. It sounds like you have a long torso and won't have to worry about the frame being too long.

PS- There is not complete agreement on the whole knee-over-pedal fitment dogma.

There are many schools of thought on frame fitment. You should google and read up on them. I personally prefer to err on the side of too large, instead of too small. If your frame is too small, then the seat will end up much higher than the handlebars. This is good if you are a professional racer, but bad if you are me. In fact, this trend is relatively new even among professional racers.

From the sounds of it, "too big" for your would be a frame that you could not comfortably sand over. It sounds like you have a long torso and won't have to worry about the frame being too long.

PS- There is not complete agreement on the whole knee-over-pedal fitment dogma.

+1

At last, someone talking sense :D

The reach should be pretty well corrected with the proper stem. You really do not want to adjust reach with your saddle (or so I understand). The saddle should set you up over the pedals properly (according to the dogma I have heard but I don't want to start a religious debate).

Fit is a funny thing. It varies with the person, age, weight, fitness, usage and so on.

For example, if you are an ultramarathon cyclist and glory in 200 miles or more per day, the posterior goes first. The ultramarathoners I have known, tend to ride with the saddles on the low side. They lose a bit of power but they gain it in posterior endurance. Performance cyclists (people who like to ride really fast) tend to have their saddles on the high side so they generate maximum power and the posterior can just take its lumps.

Performance cyclists also tend to favor low handlebars for a more aerodynamic position and possibly for the coolness look. Cyclists who ride at more moderate speeds tend to prefer their handlebars to be at or about seat level.

For most people, finding the proper mix requires a bit of adjusting until they get it dialed in the way they like it. A good bike shop person can probably talk to a person and take their fitness and purpose into account in adjusting the fit from what is considered "ideal".

Since you are asking in General Cycling, the proper answer is that anything within a couple of centimeters is no problem. I also tend to err on the side of too large, since I am a fan of the "French Fit" or bars even with the saddle. This tends to be easier to accomplish with a larger frame.

If you had asked in Road Cycling, the pat answer changes to be that you have to be within 1 centimeter. You should also err on the side of smaller, since more drop is always good. ;)

If you had asked in the Racing subforum, then the answer is that no deviation is tolerable, since you got your measurements from a good professional fitter, and a good professional fitter is a god and should never be questioned.

The above are true to within +/- 5%

There are many schools of thought on frame fitment. You should google and read up on them. I personally prefer to err on the side of too large, instead of too small. If your frame is too small, then the seat will end up much higher than the handlebars. This is good if you are a professional racer, but bad if you are me. In fact, this trend is relatively new even among professional racers.

From the sounds of it, "too big" for your would be a frame that you could not comfortably stand over. It sounds like you have a long torso and won't have to worry about the frame being too long.

PS- There is not complete agreement on the whole knee-over-pedal fitment dogma.

I am of the other thought- If a frame is too large- Then back and leg ache is a possibility.

Two pics attached and they are of Giants compact frames. A Small and an Extra Small. Both fit me perfectly. The OCR is the Extra small frame and a change of stem to a high ridse stem and as you can see- the bars are up to saddle height. The TCR is the next size up, the small, and fits a bit better as I have the bars just below the saddle.

Unless you are talking a largely wrong size of frame- then frames can be made to fit. How much that will affect the handling though is open to debate.

And the OCR is my loaner bike that will fit riders from 5' to 5'8 with just adjustment of the saddle height and fore and aft position.

...

Weather permitting I'm going for a lunchtime ride today to see how I like this bike. Last week I rode the same route on a bike that was 54 cm, so the feel of the ride may be the real test.

On the 54 cm bike I felt a bit stretched out and kept wanting to be a bit more upright. Then I rode my junker mountain bike for several miles on a dirt road and realized the discomfort was not so much from being stretched out as being over stuffed... I kept having to sit upright to feel like I could breath properly.

So it may be this gut I'm carrying is the real source of my discomfort, meaning I need to worry less about frame size and more about just riding...

Interesting - I have a very similar problem. I have a 56cm frame and feel like I have trouble breathing with the fitting I got from a professional fitter. However, my stem gives me 4 choices for angle and when I went with a higher angle I ended up with back pain. Still haven't figured it all out.

Well I took the test ride.

Keeping in mind that I am in terrible shape, carrying 30 extra pounds, and at the very beginning of trying to rectify my last five years of sluggish living, the ride today was excellent. I rode this morning for just shy of 15 miles and up until I began to tire a bit the ride was pretty much effortless. The shifting and operation of the bike is flawless.

Then, after I began to tire out I was still able to manage my pedaling (perhaps cadance is the correct term?) to ease up a bit on the strain but stay at a steady pace.

At one point I stopped at a wide spot in the road shoulder and did a bit of adjusting on the seat angle and that helped with the weight distribution at my ... sensitive contact points. It will be a while before I can make peace with that seat.

At any rate, I'm going to bite on this bike. It came to me through the grapevine from a late 20's something club rider (mechanical engineer) who has taken immaculate care of it. I'll stick a folding set of allen wrenches in a seat bag and keep after the tweaks until it is spot-on.

Thanks to all for the feedback.

I think my first big "make it mine" purchase might be pedals and a pair of shoes...

Here's my 2 cents worth of advice:

Don't decide on your bike fit philosophy based on internet postings. If you don't already know what you need or what you prefer of the infinite possibilities, have someone who does know check you out on the bike. But, you should just assume from the outset that there is no such thing as dead on spec. Even if there was, there's as much wiggle room as that provided by the adjustment range of the saddle and the handlebars (both vertically and horizontally). So, what you want is to get a bike that is in the general ballpark.

However, there certainly are different styles or kinds of riding. They can affect how you would setup your bike, and in turn, that can affect what frame size you should choose. Do you want to cruise along at low speeds with high handlebars, or do you want an efficient road riding position? The one caution I would suggest is that despite multiple arguments people have for higher handlebars, it's not something you would automatically want even if you seek comfort. If you plan on riding a lot, and you want to get wherever you are going at a decent speed, you may prefer bars at least a little lower than the saddle. You need to be bent over in order to make the most efficient use of all the muscles that can be recruited to propel you on the bike.

Well I took the test ride.


At any rate, I'm going to bite on this bike. It came to me through the grapevine from a late 20's something club rider (mechanical engineer) who has taken immaculate care of it. I'll stick a folding set of allen wrenches in a seat bag and keep after the tweaks until it is spot-on.

Thanks to all for the feedback.

I think my first big "make it mine" purchase might be pedals and a pair of shoes...


If you did 15 miles and the only pain was butt ache- then it will fit you. You will have to get that saddle right but don't change it for about a month and try to adjust it for more comfort. The bike will gradually be tweaked over the next few rides but sounds as though you could be making a good choice.

Now on tools whilst riding- I have a "Wedge" (small tool bag under the saddle) that contains a Mutitool- spare tube- puncture repair kit and a couple of tyre levers. On the bike I have a water bottle and a pump. Don't skimp on the quality of the pump. This is all I carry for a 100 mile ride- so bear in mind that you can keep the necessities down to a minimum.

Now that I have a bit more time to type, let me throw in my personal experience.

My current bike is a much older Novara Aspen, pre-MTB days, probably closer to the current Novara Buzz in frame design. In particular, the top bar slopes but not a huge degree. I got it because I'm short (5'6"), I wanted a standover height that wouldn't castrate me, and I figured - perhaps naively - that the sloping top bar would get me more standover room without sacrificing the other important fit dimensions. I ordered it without trying the fit, because they didn't have my size in stock, and the next size up was good except for the standover being too borderline. This was pre-web, so I couldn't look up the geometry or do much other research.

I've never been really happy with the fit. Although REI has an excellent customer satisfaction policy, I was too invested emotionally in the bike to exchange it. Whether it was because I spoke to the wrong person or stem choices really were much more limited back then, I don't know, but early on they didn't have any suggestions about improving the height of the handlebars. It was ok when I just used it recreationally, but when I started doing a lot more fitness cycling a couple of years ago, the hand pain and numbness began.

As I've been trying more bikes this time around, it became clear to me that I should err towards the larger size. Nowadays I have the advantage of steeper top tubes, so the standover isn't as compelling an issue as it was back then. The first bike I tried was the Novara Metro, in a small, and then immediately tried the medium. There was no comparison. Even though the medium felt much taller to me, once I got on it, it was far more comfortable. It turns out that I'm getting the Cannondale Adventure 3, but the guy who sold it to me almost suggested that I try the large.

Generally-speaking, unless you're a racer or want to ride like one, there is really no downside to choosing a frame which is at the taller range of what you can stand over (assuming a level top tube). This makes it much easier to set the handlebars higher for one thing (even if you don't want them as high as the saddle, it's still hard because the industry caters to the racing image). It also tends to open you up so can breathe properly. Just my opinion maybe, but I always find that most people end up looking like a circus bear on a tiny bike. First, the bike industry made road bikes shorter horizontally, and then they made then more compact vertically. It makes for very funny-looking little bikes with big people on them.

If you did 15 miles and the only pain was butt ache- then it will fit you. You will have to get that saddle right but don't change it for about a month and try to adjust it for more comfort. The bike will gradually be tweaked over the next few rides but sounds as though you could be making a good choice.

Now on tools whilst riding- I have a "Wedge" (small tool bag under the saddle) that contains a Mutitool- spare tube- puncture repair kit and a couple of tyre levers. On the bike I have a water bottle and a pump. Don't skimp on the quality of the pump. This is all I carry for a 100 mile ride- so bear in mind that you can keep the necessities down to a minimum.
I have an older wedge type bag similar to the larger one in your picture that came off of a Specialized MTB before my college kid took off with the bike to school. So I can manage a bit of storage space.

I'm assuming you are speaking of a very small hand-held pump. Who is the manufacturer and ultimately, do you have a picture? :thumb:

Here's my 2 cents worth of advice:

Don't decide on your bike fit philosophy based on internet postings.

That's the best advice in this whole thread. :) I'm certainly not an expert on fitting, and I should have prefaced my remarks as such. It all comes down to "if it works for you, then it works."

My comment on the knee position over the pedals is just that -- my comment. For my body on my bike, I notice knee pain if I don't have the knee roughly over the pedal spindle at the bottom of the pedal stroke. This means my saddle fore/aft position is essentially fixed wherever I need it to be to get the knees in this spot. This means that any reach issues I want to address basically happen with the stem length (for a given frame size).

FWIW I had no idea there was knee dogma. It's just what works for me.

BookFinder, glad the bike fits. At the risk of kicking off another long thread, I'd say that when it comes to making adjustments, little tweaks can make a big difference. You might want to give yourself time to get used to any change you make before deciding it does or doesn't work (assuming it doesn't cause pain).

I have an older wedge type bag similar to the larger one in your picture that came off of a Specialized MTB before my college kid took off with the bike to school. So I can manage a bit of storage space.

I'm assuming you are speaking of a very small hand-held pump. Who is the manufacturer and ultimately, do you have a picture? :thumb:

Pumps- If you can make one fit- then the Frame pumps- the ones that fit the length of the top tube or from the Bottom bracket to the top tube are the best to get. It has to fit though- otherwise it will be lost at the first rough bit of road.

Modern pumps are smaller buit not many will get you to 100psi for road tyres. One exception is the Topeak "Morph" series. They come in many forms- but I have a Mini Morph on my main bike. It is like a mini Track pump and has a pullout foot -a hose to connect to the valve and can get to 140 psi--eventually. Only problem with the mini morph is that it does not put a lot of air into the tube at one stroke but it does get there. I also have a Road morph on the other bike but this is a long pump and will not fit all bikes.

Topeak make good pumps but the "Morph" series are superb. Attachment is of the MINI Morph but for small frame bikes- this is a small pump that works.

http://www.topeak.com/products/Mini-Pumps

So this morning I get up and my left knee is barking at me. Not growling or snarling, but definitely barking.

The knee has a history that can be summed up in six words: "Used to drive a big rig."

The knee was one of the things that put me out of the OTR driving job. (Hey - I'm a former Marine, and have been a construction worker, school teacher, and professional counselor. While I can't exactly explain it, I think I enjoyed the driving job more than any of the others.)

Anyway, after several years of only occasional twinges of pain, this knee issue has caught my attention today! It hurt sharply this morning, and has subsided somewhat, but I now feel a need to explore that topic in relationship to this purchase.

So I have two questions:

1. What in the personal body build vs fitment tweaks can I do to minimize the knee pain?

2. Would cycling shoes and clipless pedals help with that issue?

Thanks again to all for the feedback.

There are many schools of thought on frame fitment. You should google and read up on them. I personally prefer to err on the side of too large, instead of too small. If your frame is too small, then the seat will end up much higher than the handlebars. This is good if you are a professional racer, but bad if you are me. In fact, this trend is relatively new even among professional racers.

I think that part of the "art" has to do with how you use your bike. Most of the effectiveness research has to do with Olympic caliber athletes. That'll give you one answer. Grant Petersen has a quite different take for his "everyman" bikes. Which do you think is closer to you?

I tend to like bikes that are about a size larger than is generally recommended for a person my size because I want the taller head tube and higher handlebar position.

I thought I should clarify my position on bike fit. Attached it a photograph of my bicycle. I would consider this 56cm frame to be one size smaller than my 5'11" frame would take for a "French" fit, but one size larger than the current trend for "roadies." It is about perfect for how people were sized 30 years ago before everyone elected for a frame that was one size too small to save weight. YMMV

I think the guidelines here (http://www.rivbike.com/article/bike_fit/choosing_a_frame_size) are good ones.