There are some things we can learn about our bikes if we will just pay a little attention. I’ve heard it expressed as “feeling your bike’s pain”.
If you feel your bike continuing to move forward even after you have hit the brakes, it’s possible that your rims just need to be cleaned. However, there is a real possibility that your brake pads should be replaced. Take a look at your brake pads every once in awhile so you can gauge how much life is left in them. Many of today’s brake pads have a wear indicator in the form of a line or pattern. And even if you have had the same brake pads for years, and they look like new, they should be replaced as they can harden and reduce your braking poser.
If you feel your chain jumping from gear to gear or just refusing to move from one gear, it could be a couple of problems. Your cable to the rear derailleur may need to be cleaned or adjusted or both. Use a chain lube (something with a Teflon base) to help the cable move freely. If the cable has too much slack you may have to shift twice to get into the next gear. If it’s too tight, when you shift once the derailleur may move more than one gear.
If you feel something moving around inside the head tube, or feel resistance when you turn the handlebar, pay attention. The headset controls your steering, and can throw your bike off balance when it is out of adjustment. Lift your bike by its seat, and tap the front wheel on the ground. You quickly should be able to ascertain if it is loose. If your handlebar doesn’t turn easily, the headset is too tight.
If you feel your brakes drag and your shifting feels sluggish, your brake cable may be dirty and/or dry. Use some chain lube on your cables where they enter the housing.
If you “feel” any of the above “bike pains”, pay attention. If you are mechanically inclined take the necessary steps to correct the problem. Otherwise, get your bike to your favorite bike shop and get it fixed. Letting these types of problems go, only creates worse and more expensive problems in the future.