Recently I was contacted by a customer who was concerned that my bikes using a 24” front wheel/700c rear wheel design were flawed. Wouldn’t the design put pressure on the neck and shoulders because the 24” bicycle wheel made the front of the bike lower than the rear?
Ah, if were only so simple as throwing a 24” bicycle wheel on a bike designed for a 700c wheel. If one picture is worth a thousand words, then four pictures must be even better.
1). Here’s a bike with 700c front and rear wheels.
2). If the 700c front wheel is replaced with a 24” wheel and no other changes made to the bike, the picture below shows how it would look. Not only is the bike very low in the front, but the brake pads are far above the wheel. The rider would definitely feel not only pressure on her hands and shoulders, but she would feel the thrill of no front brake!
3). If the 700c wheel and fork is replaced with a 24” front wheel and fork, braking is restored, but the bike still “points down.”
4). Here’s the right way to do it. The head tube on this bike is much longer than on the bike using twin 700c wheels. This keeps the front of the bike in the proper position so the top tube is horizontal again and the rider is in a normal position. Compare this to the first picture.
Bottom line: When a bike with a 24” front wheel is build this way, there is no design flaw. If the rider feels as though she is bearing too much force in her arms, the solution lies in tweaking the stem and handlebars.