Mechanics and the almighty test ride

With my newest custom build, I went full hype and had a frame built with the not-so-common T47 BB standard to match up with a BB30 through-axle crankset (SRAM Force in this instance). I figured it would be a win-win, offering the threaded, groan-free goodness of a traditional English set up but with the performance bump of the stiffer, lighter BB30 through-axle crankset. I was wrong and have dealt with the constant headache of tinkering with it, and felt compelled to give this short write up is to extoll the virtues of the test ride, a necessary cooperative of mechanics [another lengthier post on bad design is in the pipeline].

Having run a bike shop with a couple of minion mechanics at my disposal I obviously had a system for how the operation runs. This included starting and completing a repair with a test ride. Every instance in which a customer had wheeled out the door and made it but a few blocks before coming back asking after the same issue was often linked to the failure to perform a test ride (or perform the test ride correctly). And here’s why:

Test riding a bike is the fundamental “testing” portion of the design engineering process. Basic bike mechanics benefit from following this regimented cycle of problem-solving. One of the biggest mistakes people make is accepting a mechanical solution in the stand. You don’t ride your bike suspended from a stand, so this environment for testing is unrealistic and oftentimes produces unrealistic results. You have to double check.

It seems complicated to think of making a quick fix on your bike in context of the design engineering method but it’s simple. You have a problem. You think of a solution. You implement the solution. You test it. Most importantly you ask the basic question: Did the solution work? If yes, you’re golden. If no, the process dictates you return to step two: Thinking of a solution. A test ride gives you a clear yes or no. More importantly if it’s a no, you get an idea whether whatever you did improved, worsened or most painfully had no impact on original issue.

Test riding and discovering you’ve had absolutely no impact on the bike is easily the most frustrating thing, especially if you’re a bit green. But this is another area in which a test ride excels in informing the rider what the hell might actually be going on. The reason being is that oftentimes a mechanic will go at it wrong from the first step of the design engineering process: Determining the problem. You could go blue in the face, applying the process of thinking and implementing solutions, but if you’re not addressing the root problem then you’re getting no where.

This is the very reason I always required mechanics to test ride a bike before setting in to fix an issue. As a wrench, the most pernicious problem is encountering false positives.

Say for instance you get on your bike and you hear a clicking sound sometimes. You notice it occasionally then start playing with how you ride your bike and what behaviors create this creaking sound. Sitting down in a low gear, there’s nothing. Standing up on the pedals, there’s nothing. Sitting down in a high gear alone produces a regular creak. What could it be? The sound is beneath you. Maybe it’s the pedals, the crank, or the BB?

These are all common problem areas that share a positive correlation in this case. However it’s an incomplete look. There are dozens of moving parts on a bike that are at the whim of different forces you apply while riding. In this case it could just be the saddle rails have worn in their fixtures on the shell or your stem faceplate bolts are a little loose or your back wheel is nearly undone. A quick test ride is the quickest means of diagnosis (and it’s also important to remind that you should never take an unsolicited outside opinion at face value).

A test ride is the perfect opportunity to exert a variety of forces on your bike. Done preemptively this will help diagnose an issue, or after the fact give you an opportunity to see where a repair has failed and what may be done to correct it. So praise be to the almighty (test ride).

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