One of my favorite Georgena Terry witticisms goes something like this: “if we were all 3 inches tall, we would be riding bicycles with appropriately sized wheels.” Why the cycling industry has shoved 700c down everyone’s throats has mainly to do with the racing fad we are all now recovering from, and little to do with what is the right sized wheel for a given rider and a given application.
Currently, the cycling industry is going through another fad: wheel and tire size crazes – 650b, 29er, and super fat, to name a few.
When frames are built, the wheel size and tire width must be determined in advance. A small frame cannot properly contain a large diameter wheelset without serious comprises in the frame geometry. Placement of the rear brake bridges and length of the fork blades determine how much clearance a frame will have with the wheel size it was built for. By using long reach brakes, it is possible to convert a frame built for a larger wheel size to a smaller size. But why is this even necessary in the first place? Why aren’t bikes for smaller riders automatically built with appropriately sized wheels?
Well, partly this is because Americans have demanded the lowest price possible when it comes to purchasing just about anything. To achieve this low price, bicycles must be manufactured anywhere but here, where our wages are astronomically high relative to manufacturing-based countries such as China and Taiwan. We also have labor laws, environmental regulations, and lots of red tape which help to drive up the cost of manufactured goods relative to that of other countries. While I am glad we protect our workers and the environment, consumers don’t seem to care and we quite happily purchase many of our goods from other countries where such laws do not exist.
These factors contribute to the “one size fits all” wheel diameter phenomenon. In order to produce bicycles at a price point that the consumer demands, it is much less expensive to equip them all with the same wheel size, regardless of the frame size. The result on a smaller frame is that the head tube angle will be slackened to allow room for the front wheel to clear the downtube and help reduce toe overlap (all manufactured forks have the same rake – so there’s no extra cost there except to cut the steerer to different lengths). And, on really small frames, there might not be much of a headtube at all, because the manufacturer has determined that the only thing a shorter rider cares about is standover height. A super slack head tube of 69 degrees with the standard 45mm of fork rake is going to be a handling mess for a road or commuter bike. The bike will have lots of wheel flop, so arriving at an intersection and slowing down will feel very unstable and it will be hard to keep the bike upright at slow speeds. Instead, the smaller frame should be designed to accept smaller wheels, allowing for normal rake and trail to allow for good slow and high speed handling, and for an actual head tube which will help to improve the overall comfort of the frame.
All riders should measure their bikes by top tube length, not seat tube length. If you look at photos and drawings of cyclo-touring bikes from times past you will see that there is very little seatpost showing – these bikes are tall relative to the rider, at least by today’s standards. And, they often used smaller wheel sizes, which would help to lower the saddle height relative to the ground. By riding a taller frame you can get the stem higher relative to your saddle, and these older bikes had lower bottom bracket heights, making it possible to put your toe down at an intersection, rather than dismounting. Unfortunately, modern cycling “wisdom” tells everyone to have at least 1″ of clearance between your crotch and the top tube. Why? Well, apparently cyclists of the mostly young and male variety often somehow crash land on the top tube, causing serious and sometimes lasting injuries to their private parts. However, if you are riding in a way that allows you to crash on the top tube, you are probably taking unnecessary risks. And, it wouldn’t matter whether the top tube is 1 inch below your crotch or 3 inches below your crotch. This kind of accident would require you to have lost control of the bike while still straddling it, such as attempting jumps and other tricks that our culture has decided is a good thing for young boys to try. A greater standover height can also be achieved by using a lower bottom bracket, so you could still have a tall frame and the “requisite 1 inch clearance” on the top tube if a lower bottom bracket were the norm.
However, worse and more prevalent injuries can be caused by riding bikes with too long top tubes. Smaller riders often select bikes with short seat tubes only to be confronted with a super long top tube (this is another way the manufacturer crams a 700c wheel into a too small frame). Riding a bike with a too long top tube can cause neck and lower back pain, arthritis and hip degeneration. This kind of injury happens over time and can also be exacerbated by doing super long rides even on a bike that fits correctly.
Some smaller riders prefer to ride mixte frames. These frames are much stronger than typical “women’s frames” because they have a sloping top tube which extends all the way down to the rear dropouts. This makes for 3 rear stays instead of two, and helps to offset the greater flex of the head tube away from the seat tube under acceleration. This solves the problem of standover height, but unfortunately does NOT address the problem of having a too long top tube. Why? Because mixte frames were produced in smaller runs, there are limited choices as to the headlugs which provide for a predetermined sloping top tube angle, forcing the manufacturers of mixte frames to produce them with relatively long top tubes. Peter Underwood has an interesting discussion of this topic here. He also argues that these long top tube lengths on mixte frames were the result of builders wanting their mixtes to conform to their “norm” for top tube length – which was 21 inches (53.3 cm) for custom builders. The 1930’s Peugeot pictured above has an effective top tube length of 56 cm!! While this super long length is slightly offset by the upright bars, this is a bike that could only be comfortably ridden by a person at least 5’6″ tall. The other mixte frames currently in my shop all have effective top tube lengths of 53 cm. This is way too long for a small rider, generally speaking. That is one reason I discourage small riders away from non custom mixte frames, unless they are mainly going to do casual riding in an upright position.
The solution is to design a bike frame in a logical way such that the frame dimensions are proportionate to the small riders’ anatomy. This naturally includes using smaller wheels. Such a frame can have a nice big head tube, and will be bigger overall, which will produce a much more comfortable frame and riding experience.
You can find such frames if you are diligent. The bike shown above is my Terry which I purchased as a frame and fork. It is not a custom frame but one I picked up on eBay which was a leftover NOS from the 90’s TIG welded with Tange tubing. It has great geometry with no compromises so it handles well in all conditions, and has absolutely no toe overlap.
Unfortunately, buying a new complete bike for a small rider will not be so easy. There’s no point in trying to find such a bike at your LBS. The best thing to do is order a bike from a well regarded shop such as Rivendell, Georgena Terry, or your local custom builder. These builders automatically design their smaller frames proportionally and with smaller wheel sizes such as 26 inch, 650c or 650b. One thing I have learned is that I prefer riding frames with steep angles – 73 or 74 on the seat tube, and since I like a low trail bike I prefer a steep head tube angle combined with a lot of fork rake. As far as I know, no one has researched whether steep angles are more comfortable for smaller riders, but I like the feel of having more of my body closer to the front of the bike.
The vintage line up in smaller frames works best if you can convert a small frame to 650c or 650b, or if you can find a small frame originally built with smaller wheels, such as the ALAN depicted at the top of this post, which was designed for 24 inch wheels. Until more small riders begin demanding appropriately sized bicycles and wheels, nothing will change. So, if you do stop in to your LBS, let them know that you could be a good customer if only their suppliers would provide the kind of bike which is safe and comfortable for you to ride.