Road Bikes Are A Pain

Quite a few times lately I have been made aware of folks who really want to be biking, but when they go out and get a bike they end up feeling uncomfortable and then feel like trashing their bikes to get a new one or lose interest in cycling all together. "Road bikes are uncomfortable!"

Those are some pretty drastic measures and the pain can quickly spread to the bank account. There are smarter ways of going about looking for a bike than simply trial and error.

On the sidebar I have a few posts about geometry and material, but more importantly comes the subject of fit.

Anyone who is shopping for a bike should get fit by a professional. I don't want to offend anyone, but Giant seriously sucks at fitting and I would recommend going elsewhere for a professional fit. A proper fitting bike doesn't just mean a more comfortable experience, but it can also mean the difference between actually riding the bike and laying around the house with an injury.

I still stand by my belief that for road riding (predominantly riding on paved roads) a type of drop bar road bike is ideal as opposed to a mountain bike, although some flat-bar urban commuters can work well as urban assault bikes, but they are still configured with road bike geometry. Therefore, I am going to keep this post to road bike fitting.

3-2-1- Contact

The rider has three major contact points with the bike. The location and relation of these points is integral to determining fit--The seat, handlebars, and crank/pedals. If these points are not in the right place then riding a bike can be a heap of pain as it will not be ergonomically correct for the rider. When I see riders on a poorly fitting bike I always remember when my grandfather, who was a very stubborn man, went to a yard sale and picked up a set of gloves. He realized they were two lefties. Rather than go through the hassle of taking them back, he decided to simply wear them anyway. This resulted in a serious case of tendonitis on his right hand because his thumb was spending too much time under stress. The same thing can happen on a poorly fit bike.

The Crank

The crank length determines how large a circle the rifer makes with each rotation and varies between riders. Most cranks typically run between 165mm to 175mm in length. Most people fall into the 170mm-172mm range. I have heard of one method for determining the crank length being 18.5% of the distance from barefoot of the floor to the top of the femur. All numerical calculations are just suggestions. Some personal preference comes into play as some riders might like to spin faster with a smaller crank. Once you get this measurement figured out you can get your saddle height figured out. The Seat Tube length plays a factor here, but it is more aesthetic within a certain range. The ST will, however, determine stand-over height; a key element of the fit.

Saddle Sores: "Hey, your seat is too low!"

Damn, if I don't see more low saddles in Taiwan. I see more people going down the road with their legs sticking out at weird angles, weaving all over the road at no speed.

The proper saddle height allows the rider to stretch the legs out to their optimal extension to maximize the rider's efficiency. On a good ride you just don't want to waste energy on a poor stroke. Luckily, a poorly adjusted saddle usually makes itself known through a very obvious knee pain.

The saddle should be level. A forward tilt pushes the rider into the bars and an up-tilt pulls them off the back. For a basic start to the fitting process the saddle should be high enough so that you can just touch the floor with your tip toes. When pedaling your knee should be slightly bent. The balls of your feet should be over the pedal axle and you should not rock in the saddle.

The seat is a very personal preference. A saddle should match the rider's "sit bones", those little pointy parts of the pelvis that stick out when humans curl their legs. Although a rider may have a real fat ass... their sit bones may be quite narrow. The skeletal frame makes this determination rather than the amount of mass. Women typically need a wider seat due to the difference in reproductive physiologies.

A saddle can also be adjusted forward and back to achieve different feels and fits. It determines the size of the cockpit. A good cockpit on a bike should be a little stretched out and opened to allow for better breathing. Some seat fittings can be tuned to be more or less aerodynamic. More importantly, it balances the rider behind the bottom bracket. The balance will play a huge part in comfort and efficiency. It is important to know the length of the Top Tube to be sure your body can comfortably fit on the bike without being too stretched out or scrunched up.

A totally upright position your head, knees and feet are inline and the body is balanced. Now imagine someone turns on a wind machine. You will need to bend forward to stay balanced. As you bend your butt moves back. This is similar to riding a bike. If you are too upright you waste valuable energy battling wind resistance. You will work more and fatigue faster. A totally aerodynamic position is generally not comfortable to all but circus contortionists. A good tradeoff results in an bent position, bent, and balanced.

A great place to start fitting the saddle is to put the saddle in the forward most position that allows the rider to take his hands off of the bars and maintain the body position without straining or feeling fatigue. You should not feel like you're about to fall forward when you let go of the handlebar. If the position with the hands on or off the bars feels neutral to your back muscles you know that you aren't using your arms to support your body. If you are not balanced, your arms and shoulders will get tired on a long ride. Try to balance roughly 55% of your weight rear and 45% forward.

So A Cyclist Walks Into A Bar:

Handlebar position also depends on a rider's needs and goals. For drop handlebars the size should equal the distance between the ends of the clavicle. I am a size 42. A shorter, more upright stem brings the bars closer for comfort and a more upright position to view the road far ahead. Low bars allow for a more aero position and a long stem helps with control at higher speeds. A rider should have the elbows slightly bent on the hoods and not locked. Handlebars should be even and not pointed up or down. That is not a great way to adjust the reach to the levers and brakes.

Even after a fit some riders need to fine tune their position. Here are a few helpful links to help.

----------------------------------------------------------------------

A good fit calculator can be found at Wrench Science and at Competitive Cyclist.

The late Sheldon Brown lives on the interwebs and has a wonderful piece about pain. His entire site hosted by Harris Cyclery is a great source of info.

An Alternate take on K.O.P.S. (Knee Over Pedal Spindle) sizing.

Gearing and other calculations can be found here.

Passing Geometry

Understanding Bike Geometry When Choosing A Bike:

I know the word, but what does it mean?

Size:

ST (ct) Seat Tube.

The seat tube determines the height of the bike or your frame size. This is generally measured from the center of the bottom bracket to the top of the top tube.

TT (cc) Top Tube Center to Center.

This is also known as the “effective top tube”. This measurement ranges from the center of the seat post to the center of the steering tube. This measurement determines the rider’s cockpit size and reach. The TT (cc) measurement is important to understand so that the rider will not be too stretched out or scrunched up. Most riders can feel when they are too stretched, but often make the mistake of getting too scrunched and not allowing a good position for proper breathing. Good breathing technique is vital for climbing and hard rides.

TT (hz) Horizontal Top Tube.

This is the actual length of the top tube. On compact frames this measurement may be longer than the effective top tube.

ST angle: Seat Tube Angle.

The angle of the seat tube is measured in relation to the ground, and tends to fall somewhere between 68 and 75 degrees.

A frame's seat tube angle determines the position of a bike's saddle related to its bottom bracket. Since the bottom bracket is the axis around which the bike's cranks and pedal rotate, this affects the orientation of the rider's legs and body in relation to the bike. Seat tube angle also influences how the rider's weight is distributed between saddle and handlebar.

A steeper seat tube brings the bike's saddle more into a vertical line with the bottom bracket, thrusts the rider forward into a more aerodynamic position, situates more of the rider's weight on the handlebars, and so the rider employs more of the hamstring muscles. Triathlon bikes often have steep seat tubes, because they're built exclusively for speed and tend to be ridden by people who are strong runners (and therefore have well-developed hamstring muscles).

The shallower the seat tube, the further the bike's seat is pushed behind its bottom bracket. This is a less aerodynamic position, but it also puts more demand on the thighs and glutes (which tend to be well developed in cyclists), and places more of the rider's weight on the saddle, to increase rider comfort.

A steeper seat tube makes a shorter seat tube for a frame of a given size, and making for a stiffer, more responsive feel. A shallower seat tube requires longer chain stays which can allow for grater comfort over rough terrain.

The steeper seat tube enables a more direct transfer of power through the rider's legs, although a shallow seat tube angle puts the rider in a better position to exert power during low cadence riding, such as seated climbing.

HT Angle: Head Tube Angle

Most head tube angles vary from about 69 degrees (when 90 degrees is perpendicular to the ground) to 75 degrees. In general, the steeper your head angle (closer to 75 degrees) yields quicker and more responsive the steering. Responsiveness can be explained by the following:

a) - A steeper head angle allows for a more weight-forward riding position, placing the body and head closer to the front of the bike, allowing the rider to see the road ahead sooner.

b) - A more upright head angle allows the front wheel to be tucked down under the rider, thus easier to steer.

c) - With the rider's weight more aligned with the turning angle, the bike will turn with more subtle weight and shoulder shifts rather than large arm movements.

You Gotta Have An Angle:

ROAD BIKES

Bikes with the steepest angles are the dedicated road racing bikes, which have angles averaging 74 degrees for both the head and seat tube. Racers want quick, agile and efficient machines, geared towards speed with comfort being a bonus if you get it. A steep head tube angle means that most of the rider's weight will be evenly distributed between legs and shoulders. A racer has to be in good shape to ride with more weight on the shoulders with eyes focused directly on the road in front rather than the trees and mountains.

Touring / Sportive/Recreational Road Bikes:

Steep angles allow for a very efficient ride. You can get racing angles to fit this category as well. In this category however, you get the luxury of having a slightly slacker HT angle for a more upright position, better for taking in the scenery, watching for cars ahead, and a little less interest in controlling the bike. In a more upright position, more weight gets transferred to the sit bones, which is usually more comfortable.

BB drop: Bottom Bracket Drop

If you were to draw a line horizontally between the front and rear dropouts and a perpendicular line through the center of the bottom bracket. The distance between the center of the bottom bracket and the first line, measured along the second is what is known as he "BB drop, which measures how far below the axles the bottom bracket sits.

Mountain, cyclocross, and track frames bottom brackets tend to be quite high (mine is 65mm). The reason is to keep stones, dips, roots or a severely sloping track from causing a pedal strike, hitting the chain rings or frame. The bottom bracket in these bikes is built up and way from these dangers which could end a ride or a season in a hurry. A higher bottom bracket also shortens the chain stays and down tube of a frame, which are put under the greatest stress under riding conditions, which translates into a stiffer, more responsive feel.

The advantage of stiffness and safety come at the cost of stability; the lower the bottom bracket, the lower the bike's center of gravity, for a more stable ride. Touring and commuter frames often have a lot of drop, to be more practical than concerned about winning a sprint. Many good road bikes tend to have medium BB drop for the best of both worlds.

CS: Chain Stays. The chain stays run from the bottom bracket to the rear dropouts. This can be measured as "actual" or "effective" length due to the fact that the bottom bracket drop will increase or decrease the length of a frame's chain stays without changing the position of the wheel.

Most models tend towards shorter chain stays. Short stays makes them stiffer and minimize the flex and therefore adds greater power transfer from the pedal stroke. This shortens the wheelbase for a snappier feel and low speed turning. It also puts more of the rider's weight over the rear wheel for optimized traction. Mountain bikes use short chain stays to better dig in to fight up loose climbs.

A longer wheelbase with longer chain stays makes a more stable bike at higher speed. The long chain stays add more flex. They push the rider forward off the rear wheel to add to the comfort of the ride. These bikes will often have a more shallow seat tube angle; great for seated climbs and women's bodies. The longer stays also allow greater tire clearance for larger tires to be used and making it easier to remove the wheel. Another added benefit of longer chain stays is that they will keep the rider's heels from hitting a rear pannier rack. This is generally why you see commuter and touring bikes with longer chain stays.

SO: Standover.

This is how high the top tube will be from the ground. This measurement may vary based on tire size. Some companies measure this differently, so it is good to double check before ordering.

HT Length: Head Tube Length

This may vary to allow for greater aero position.

WB: One fundamental measurement is wheelbase. The WB is calculated either by measuring the center of the hubs or the center of the spot where the wheels meet the ground; these distances must be equal (assuming the wheels are round!). A longer wheelbase should make a bike more stable in a straight line but less agile in turns. It may make a bike feel more comfortable or smoother due, in part, to the flexy stays.

Stem: Stem length is a completely adjustable parameter to adjust the feel of a bike. Most stem lengths are selected based on fit, but a rider can opt for a longer stem with a forward seat position to create slower, more stable steering, or the opposite effect with a shorter stem. Stems may vary from 130mm to under 90mm.