Handlebar Drop

I have a frame sizing chart on my website; it was formulated about 30 years ago from actual customer measurements and the frames that I built for them. Apart from a few minor updates, it has remained basically the same.

I am of the opinion that while bicycle frame design has changed, and to some degree riding styles change; human bodies remain the same. Therefore, the basic frame fit issues are the same as they have always been.

One question I find people are asking more and more is “How much handlebar drop should I have?” In other words the difference in height between the saddle and the top of the handlebars.

When I retired from framebuilding in 1993 handlebar drop was not even in the equation. The reason being that top tubes were level and the quill stem was placed at a height where the top of the handlebars were about 7cm. above the head bearing. (See picture above.)

The stem could easily be adjusted up or down a centimeter or so either way, and assuming the rider was on the correct size frame the difference between the seat and handlebar height was automatic. Head tube length had absolutely no bearing on anything.

It didn’t matter who built the frame or how the frame angles differed there was always the constant of the level top tube. If a rider switched from one 56-centimeter frame to another 56 from a different manufacturer, the handlebar drop remained the same. In fact the term handlebar drop was not even used.

All this has changed now with compact frames with sloping top tubes; the manufacturer can make the head tube as long or as short as they wish, thus effecting the saddle/ handlebar height difference. Adding to the problem, the new threadless steerers and stems are not as easily adjusted for height as the old quill stems.

Manufacturers are already listing their frames by virtual sizes rather than the actual seat tube length. I think they should also give the virtual top head bearing height. In other words, how much higher or lower is the head bearing compared to a level top tube frame?

Below is a preliminary handlebar drop column added to my frame size chart. I no longer have the luxury of actual customer measurements in front of me. I had to rely on memory and my gut feeling to come up with these numbers.

You will not find compact frames in all these sizes, but if for example, your size is a 57cm. but you can only find a 56 or a 58, set the reach and drop as you would for a 57.

Your input is appreciated, how does this compare with what you are riding? Bear in mind this is for a racing position; adjust accordingly if you want something for a more leisurely style of riding. Please post a comment

Toe Overlap: No Problem

There was a discussion recently on Classic Rendezvous Bike list; the tread titled “Toe overlap even on good bikes,” implied that toe overlap was a design flaw and one should not expect to see this on quality bikes. Toe overlap is a result of other critical design factors and cannot always be avoided especially on smaller frames.

When a framebuilder designs and builds a racing frame, his main criteria are to: (1.) Place the rider in a position where he can pedal with maximum efficiency, and (2.) Design the frame so the finished bike will handle at speed in the best way possible. If the result of the design is toe overlap then the builder can do little because to achieve toe clearance other aspects of the frame’s design would have to be altered.

For example the picture above shows my own bike. It has a small 52 cm. (C to T) frame and has about an inch of toe overlap. If I were to make the front end of the bike one inch longer to avoid toe overlap, I would have to do one of the four following things or a combination of all four.

(1.) I could make the seat angle steeper, or (2.) the top tube longer. (3.) I could make the head angle shallower, or (4.) the fork rake (offset) longer. The first two would effect my riding position; the last two would affect the handling of the bike.

Toe overlap is not a problem because riding and cornering at normal speed the front wheel never turns far enough for the toe to hit the front wheel. The only time it becomes an issue is when turning sharply at a very slow speed; doing a U-turn on a very narrow road for example.

Caution and common sense are all that is required when executing a tight U-turn. If you are turning left then your right pedal will be down for maximum ground clearance as you coast into the turn. By the time you need to start pedaling again you are already half way through the turn, and the right crank has to complete ¾ of a turn before the toe is opposite the front wheel.

By that time, you should be all the way around and the front wheel is straight ahead again. If you are not the coast again, or ratchet the crank back again on the freewheel.

Doing the same maneuver with a fixed gear is a little trickier; but it is a matter of timing. Go very slow and start to turn as the toe passes the front wheel; that way the crank has a whole revolution to go before it makes contact again. If the front wheel is still turned the next time round; straighten the front wheel so the toe clears, then turn sharply after it has passed.

Fixed gear and fenders (Mudguards.) is going to make this move a little difficult, but not impossible. With clipless pedals, you could unclip the outside foot and move your toe back to give more clearance. I sometimes get out of the saddle and simply point my toe downwards to give more clearance.

What you need to avoid is a situation where you get your toe on the wrong side of the wheel in a turn; if you do, try not to panic. Ratchet the crank back if you have a freewheel, or if you are riding fixed gear, keep going and let the toe pass the front wheel so you can straighten up again.

Lastly, I would like to point out that a racing motorcycle with narrow swept down handlebars; turning is restricted because the handlebars touch the fuel tank. Here is a machine that will go 200 mph plus, and restricted turning seems not to be a problem. Therefore, I maintain the opinion that toe overlap on a bicycle is neither a design fault nor a problem.

What does the length of your forearm and the price of fish have to do with stem length?

This method of determining handlebar stem length has been around for ever. My cycling experience dates back over 55 years and it was practiced then; actually it is not a bad guide and works for most people. Place your elbow against the nose of your saddle and if your finger tips do not fit behind the handle bars as shown above, then your stem is probably too short. If the bars are more than 2cm. away from the finger tips your stem maybe too long.

When I was racing I used a stem that placed my finger tips one centimeter from the bars; now as a mild concession to my aging body I’m using a stem a centimeter shorter. If you are wondering as I did for many years what the length of a persons forearm has to do with stem length? I will explain.

When I am determining frame size I take into account three body measurements:
1. Inside leg length (Often referred to as inseam.) measured crotch to floor without shoes.
2. Overall height.
3. Shoe size. (Length of foot.)
I do not require body length because I have overall height minus inseam. I do not require arm length because this is relevant to leg length and foot length combined.

Human bodies although all different do generally follow certain rules of nature. We have the same basic design and structure as most other animals on this planet except we walk on our hind legs while most others walk on all four. So it follows a person with long legs will also have long arms; short legs, short arms.

Four legged animals generally walk on their toes (and finger tips) whereas we stand and walk on our heels. So some people have a long body, but short legs and it is not unusual for a person with this build to have longer feet, and also longer arms. The long arms are not out of proportion if you consider the leg length is a combination of inseam plus the length of foot.

When pedaling a bicycle the toe is pointing downward at the bottom of the pedal stroke so the foot becomes an extension of the leg; which is why it has to be taken into consideration when determining frame size. The person with short legs, long feet needs a larger frame than their inseam alone would suggest. The larger frame with its proportionally longer top tube will also accommodate this rider’s longer body and arms

The length of the forearm is proportionate in length to the length of the foot; take one of your shoes and hold it against your forearm and you will see it is the same length as the distance from your elbow to your wrist. In other words the big bones in your forearm are the same length as your foot.

So assuming you are on the right size frame and your seat is set at the correct height; then chances are if you have very long feet then you will have a short inseam and a long body.

Because you have long feet you also have a long forearm and if you do this little elbow against the saddle trick it will show you need a long handlebar stem which will be right for your long body and arms.

A person with very long legs for their height will also have long arms but will have a short body and small feet relative to their height. Small feet mean short forearm and a shorter stem which will be right for their short body. Because this rider has long legs his saddle will be set high making a greater distance from the seat to the bars; this will accommodate his long arms.

There is another method for determining stem length which states: “A rider seated with their hands on the drops of the bars, will have the front hub obscured from view by the handlebars.”

This works in the same way; longer body calls for a longer stem and vice-versa. The only thing is that this method could be affected by the head angle of the frame and the length of fork rake. I prefer the length of forearm method because it is simpler. It works for most people but there is a small percentage that it will not. I always say if you are comfortable and happy with your current position, don’t change it. Go by the old “If it ain’t broke” adage.

And what does this all have to do with the price of fish? Nothing at all, but it got your attention.

A Different Thought on Frame Sizing

After measuring and studying hundreds if not thousands of customer’s measurements over the years as a custom frame builder. I came to the conclusion that although human bodies are all different; they do follow certain rules of nature.

Choosing frame size on inseam alone does not work across the board because for example it is common for a 6 foot man to have an inseam as short as 30 inches; and you can’t put a 6 foot man on a 51 cm. frame which is what his inseam suggests.

Tall people are not scaled up models of short people. Most of the height difference is in the legs; body length differs by a lesser proportion. If you have long legs then you also have long arms. Short legs; short arms. This makes sense since most animals are four legged; why should we be any different?

Leg length is a combination of the inside leg measurement plus the length of the foot. Length of the foot is important because when pedaling the toe is pointed downward at the bottom of the pedal stroke; so the foot becomes an extension of the leg.

People, who have a short inside leg measurement for their height, generally have longer feet. (Bigger shoe size.) It is as if they were designed as a much taller person, but their heel got turned further up their leg; making a short leg, long foot.

Imagine two people both six feet tall standing side by side; one has a 34 inch inside leg, the other a 32 inch leg measurement. Because they are the same height it follows the one with the shorter leg has a body 2 inches longer; he also has longer feet and shorter arms than the other guy. They can both fit on the same size frame, (59 cm. center to top i.e. 57 center to center.)

They will both have close to the same seat height, because the short leg guy has a longer foot so his seat needs to go higher than his inseam would suggest. They can also use the same top tube length and handlebar stem, because one has short body long arms; the other long body, short arms; making their reach the same. Minor adjustments in seat height and stem length may be called for.

It has occurred to me that with these compact frames on the market now and only available in small, medium, and large; customers are only ball parking frame size anyway. It has long been my opinion that frame size is linked to the overall height of the rider more than any other measurement because of the rules of nature I have just spoken of.

I have formulated this based on my own frame sizing chart. If you are 5’ 3” to 5’ 5” frame size equals Height divide by 3.3. For people 5’ 6” to 5’ 10” frame size = Height divide by 3.2 and if you are 5’ 11” to 6’ 4” frame size = Height divide by 3.1

A example would be someone 6’ 2” = 74” divide this by 3.1 = 23.87 in. (61 cm. measured center to top. i.e. 59cm. center to center. A person 5’ 7” = 67” divide this by 3.2 = 20.93 in. (53cm. center to top. i.e. 51cm. center to center.) The easiest way to convert from inches to centimeters is to get a tape measure with both metric and inches on and simply read across. If you don’t have a tape measure the formula is “inches x 2.54”

Reach which is top tube plus stem length; is frame size center to top plus 10cm. If you want something more accurate go to the chart on my website The chart was derived not by any mathematical formula but by records of custom frames built over many years. Most people find it pretty accurate. What I have put forward here in this Blog is an attempt to come up with a simple formula that comes close to this. If you are an experienced rider don’t change your position based on this alone because this is new thinking. It is intended as a place to start for a newcomer to the sport.

Feedback would be apprecated.