Rim wear- a frequently missed opportunity

I frequently encounter bikes with neglected rim braking surfaces. Rim brake surfaces are a “wear item” that typically take many years to use up. Years of riding and dragging brake pads across a rim’s surface take their toll on the rim. Of course, the pad is softer and wears down faster, but pads wear down the rim as well, and the process goes faster when you add dirt and grime to the mix. I explain to my customers that riding a bike with dirty rims is like dragging sandpaper across the rim every time you brake. Unfortunately, it is often too late for an older bike with a lot of (dirty) miles and the rim must be replaced

If you have ever seen a rim crack in this way, you know how ugly it can be. Rims are under a lot of pressure from the inside as the tube tries to force the rim’s vertical walls apart. If the side of the rim is compromised, that wheel is a ticking time bomb. It could crack slowly and gently, or explode catastrophically and hurt the rider. That makes for a very unhappy customer if you were the last person to put a wrench to that bike and sign your name to the work. Even worse, it could be a liability to your shop if someone is injured and they feel you are responsible through negligence. I have refused to work on some bikes because of worn rims. I make it clear to the customer that I will not work on the bike unless they replace the rim (or more likely, the whole wheel). When explained rationally and with great care, the situation can benefit the shop and the customer.

For example, a few weeks ago a customer came in from out of town with their teenager’s bike, presumably to drop the kid off in town for college. The bike had recently been worked on by another shop in their home down and was still having problems. I investigated a problem that was unrelated to the front wheel, but noticed some major issues with it as I pursued my habit of inspecting every bike I touch.

I found that everything about the front wheel was in trouble: the tire had a wear line that ran around the sidewall from a misaligned brake pad rubbing it thin, the hub lock nuts were loose so that the hub came out of adjustment in my hands, and the rim surface was worn so thin that tiny cracks were forming in it. The worst part about it was that the hub bearings has clearly been recently overhauled and packed with fresh grease. This indicates that a professional bicycle mechanic had done a poor job adjusting a hub on a wheel with a compromised tire, cracked rim, and left it in that shape without a word.

why bother repacking a hub that is laced to a dead rim?

tiny cracks in side of rim- this is a ticking timebomb

a customer's bike should never have left a shop with a tire looking like this

Now a word about critiquing other shops’ work: this is a situation to be handled carefully. It is certain that your own hands make mistakes from time to time and others notice. Maybe it was a customer, maybe it was another mechanic. Customers’ perception of one mechanic’s work affects their perception of bicycle mechanics in general, just like any bad behavior in any other profession tarnish the image of everyone in that profession.

So take care not to throw the other shop under the bus. I often find it tempting to do so, hoping that customers will avoid the offending shop in the future and boost my perceived expertise in the process. The reality is that harshly criticising another professional’s work is unprofessional in itself and it drags the name of all bicycle mechanics through the mud. A sense of solidarity within the profession must prevail, but only insofar as you can honor this and still give the customer a good value for services for which they are paying.

I explained to this customer that the tire had been compromised, the rim was worn out and likely to crack, and that the hub needed further adjustment anyway, a fact eclipsed by the fact that the rim was rolling on borrowed time. I sold the customer a new tire, rim, rim strip, and applicable service charges associated with that. The customer was happy with my thoroughness and honesty, but I somehow felt like I lost in the end.

The delicate balance I was obligated to honor (and hopefully succeeded) was that of giving the customer at least what they need, if not what they want, while building, or at least not damaging, the reputation of my colleagues, and by extension, my own professional career.