This is the first article in a series of blog posts where we’ll look at some common technical aspects of cycling.  Brett Flemming – Bike Gallery’s General Service and Training Manager – kicks off things with some tips and pointers about brake pads and rims.

Congratulations year-round bike commuters, you’ve almost made it through another winter! And this year, the weather gods surely put the winter back in winter time. After braving the harsh weather and road conditions of the last couple months, now is a great time to check your brake pads and, more importantly, any rim wear your bicycle might be experiencing.

a cross section of a rim with a sidewall that features substantial concavity. (click on image for larger view)

Yes, the brake pads on most bikes (except for bikes that use disc brakes) rub on wheel rims made of aluminum.  Aluminum is a great material that is very corrosion-resistant and lightweight, providing better performance and more nimble bike handling. Unfortunately, aluminum does wear away when exposed to the rubbing of brake pads and the road grime and dirt that inevitably collects on them while riding in winter. So it’s a good habit to regularly check the outer sidewalls your rims for “concavity”, which is an indicator of how much wear your rims have suffered (see photo). As a rims wears out, the sidewall of the rim will gets slightly thinner and slowly start bending outwards under the pressure of the tire, causing the sidewall to morph from a flat surface to a concave surface.

A failed rim, featuring a partly separated sidewall. (click on image for larger view)

If left unchecked, the rim may ultimately fail – a section of the rim’s sidewall might literally blow off under the pressure of your tire – possibly causing an accident. If you are not sure how bad the rim wear is on your bike, just drop into one of our stores for a free evaluation. Bike Gallery’s service estimates are always free so while you’re at it, you might as well get your full bike checked and get an estimate on other repairs that might be due. In addition,  our service folks are able to schedule this free service to minimize the disruption to your daily bike commute. Just drop by or give them a call.

Checking your brake pads for wear is also critical. Even on a newer bike, your braking power will get seriously compromised when your brake pads are worn out. As brake pads wear out, they tend to become increasingly misaligned with the rims’ sidewalls (sometimes even diving underneath the rim), resulting in poor braking power. Beyond a certain point, things get even worse when the metal pad holder inside the brake pad or the metal housing of cartridge-style brakes gets exposed and start skidding on your rim, without providing any braking power. You might hear a squealing or scratching sound when this happens, but don’t let it come that far. Metal rubbing on metal is very bad and it’s easy to do serious damage to your rims in a short time!

a worn-out brake pad (on the left) vs. a new one. Note how the grooves on the left are almost completely gone. (click on image for larger view)

So how do you check your brake pads? Just look at them from above and below and look to see if the “grooves” are still visible. All brake pads are equipped with grooves which, when worn through indicate the brake pad is at the end of it’s useful life and must be renewed. Changing bolt-on brake pads (the ones pictures in the photo) may seem simple, but they must be very firmly attached while being held in not less than five planes of critical alignment. a good job to entrust to your local Bike Gallery service department… if your bike has cartridge style brakes with “insert” style pads it is pretty easy (and safe) to renew the pads yourself. If your bike does have bolt-on brake pads, ask for an upgrade to cartridges when we change your brake pads, so you can save money next time you wear out your brake pads.

We know that many of you rely on your bikes for transportation and we’d like to keep you riding safely. If you have any other questions, don’t hesitate to contact us or visit one of our stores and learn more. Many of our stores also offer free monthly maintenance clinics. Check our clinics page for a complete list of times and locations.

You can do it yourself or bring it to us, but no matter what, do check the condition of you rims and brake pads regularly. It will make your ride – and that of everyone elses you share the road with – a safer one!