The Difference Between Bike Fit and Bike Design
What’s a bike fit for? Well, obviously to get you more comfortable and/or faster on your bike. Some people make a distinction between bike sizing and bike fitting. The former is figuring out which size bike you belong on, from a finite set of choices, the latter is figuring out what your actual, best position on a bike, any bike, is. Many riders have been sized; fewer have been fitted.
If you have a good fit, you can take the numbers that describe your position and adapt a stock size bike to them. That might entail a different stem length or angle. It might involve spacers under the stem. It might call for sliding your saddle forward or back on its rails. An adjusted saddle height, maybe.
And, it’s tempting to say that, if you can achieve your fit numbers on a given bike, that bike is then a good bike for you, but here’s where we start to talk about bike design, because simply putting your hands, butt and feet in the right place in space doesn’t necessarily produce a good riding, comfortable, optimized bicycle.
You don’t need a custom bike to achieve your fit, but a custom build can make what goes underneath the best it can be, and that can make a huge difference to your riding experience.
What does that mean in real terms?
It means better handling, achieved by making sure your weight is balanced over the wheels, that your stem is neither too long or too short, matched to the right headtube angle, coupled with the correct fork rake.
It might mean making the frame stiffer or more compliant, by making the frame more compact or more open in its angles, or by choosing the right tube diameters, wall thicknesses and butting profiles to suit a rider of your weight, proportions and preferences.
So, there are all these subtle things about bike design that amount to much more than achieving an optimal bike fit. A custom bike, a term we use interchangeably with ‘designed bike,’ should handle better, and it should weigh what it needs to weigh for the person riding it, not more or less.
At Peregrine, we are master bike fitters, but we also understand the fundamentals of bike design. Our process is about guiding you to the best possible bike, whether it’s a production bike adapted to you and your unique needs, or a custom bike that delivers perfect fit and perfect performance in one package.
Some Signs Your Bike Doesn’t Fit You
The vast majority of riders adapt their bodies to their bicycles. They put up with discomfort in various parts of their bodies and think that’s just how riding a bike feels. Some of their discomfort is immediate, like a feeling of being over-stretched for example, while some others only appear over time. Maybe their lower back begins to ache after an hour of riding.
Here are some basic signs that might be telling you you need a bike fit (or a better fitting bike):
1) Neck pain. Do you get a stiff, sore neck from riding? That can indicate your handlebars are too low, or possibly too wide.
2) Shoulder pain? Again, that can be related to handlebar position, but if the soreness or tightness is focused on either side of your spine, in your shoulders, that can be caused by a bar that’s too wide. You may be allowing your head and neck to “collapse” between your should blades.
3) Knee pain? Knee pain indicates saddle position problems. Pain or soreness at the front of your knee, may indicate that your saddle is too low. If the discomfort is at the back of your knee, your saddle may be too high. Overextending your leg can also produce pain in the outside of the knee and in the IT Band.
4) Lower back pain? There are myriad causes of lower back pain on the bike. Many riders aren’t flexible enough to maintain the positions they ride in. Getting saddle height, bar height and reach right allows you to ride comfortably AND generate the most power. Lower back pain is particularly insidious because the causes can lead to spinal degeneration and longer term health issues.
5) Arm fatigue? It’s likely you’re over-stretched. Perhaps your stem is too long, but you might just be on a bike that’s too large.
6) Numbness? Hand numbness can come from too much weight on the front wheel, or some sort of nerve impingement, possibly due to narrow handlebars. Numbness in any of the areas that contact the saddle can come from riding the wrong saddle (too narrow/too wide), or from improper pelvic tilt (which can overlap with lower back problems as described above).
7) Foot problems? Maybe you have numbness in your toes or hot spots under your foot. Some of these can be addressed by adjusting cleat position, but proper alignment of the foot is often missing, and we have a lot of ways to address that, which is important because we expect to see problems of the foot to affect the knee eventually.
If you have any of these problems, we can help you, and this is just a partial list. Other signs that might not yet be producing discomfort are rocking hips, riding with straight arms, knees bowing outward. Come see us to find out how your riding can be, not just pain-free, but comfortable and, in the long term, healthier for your body.