{"id":24859,"date":"2026-08-05T08:24:36","date_gmt":"2026-08-05T12:24:36","guid":{"rendered":"https:\/\/nuxx.net\/blog\/?p=24859"},"modified":"2026-08-05T08:24:36","modified_gmt":"2026-08-05T12:24:36","slug":"a-bicycle-troubleshooting-process-example","status":"publish","type":"post","link":"https:\/\/nuxx.net\/blog\/2026\/08\/05\/a-bicycle-troubleshooting-process-example\/","title":{"rendered":"A Bicycle Troubleshooting Process Example"},"content":{"rendered":"
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\"\"<\/a>
Slightly bent tooth on my Pivot Trail 429.<\/figcaption><\/figure>\n<\/div>\n\n\n

I like troubleshooting things. It’s basically what I do at my day job, and I’m kinda good at it. Sometimes I’m asked for illustrations of how I troubleshoot stuff, so I’m sharing this example of figuring out a noise on my Pivot Trail 429<\/a>‘s cassette that cropped up yesterday when riding at Poto<\/a> with some friends.<\/p>\n\n\n\n

I visualize this sort of troubleshooting as being shaped like a funnel. At first everything’s really broad and big and open, but with each step I (hope to) narrow things further and further until the potential is super narrow and pointing at the actual problem.<\/p>\n\n\n\n

When riding last night the noise started out sounding like a shifting problem. I didn’t feel it in the pedals (so it wasn’t ghost shifting), but it was an irritating click noise that seemed to only happen in my most frequently used gear. So, I kept riding, gathering a bit of data, so I could solve it later. Here’s the whole process broken down by question and finding.<\/p>\n\n\n\n

Q:<\/strong> What gear does this happen in?
A:<\/strong> Only the fourth from the largest cog.
Clues:<\/strong> Something might be wrong with this cog. Since it doesn’t affect other gears, it’s probably not cable tension (this affects shifting across all cogs). It could be a bent derailleur hanger, but this is a plastic UDH, and the problem didn’t happen when I last rode the bike in June, so it’s probably not that.<\/p>\n\n\n\n

The next day I put the bike in the work stand in the basement and got to looking at the problem.<\/p>\n\n\n\n

Q:<\/strong> Where is the noise coming from?
A:<\/strong> Cassette\/chain.
Clue:<\/strong> This means it’s probably not a jockey wheel \/ derailleur issue.<\/p>\n\n\n\n

Q:<\/strong> Does the problem cog have an even or odd number of teeth?
A:<\/strong> Even.
Note:<\/strong> With an even-toothed cog, teeth always align with inner\/outer plates on each revolution. With odd-toothed cogs, they alternate. Therefore on an even-toothed cog you may need to shift around the cassette and back before the issue will reproduce.

Q:<\/strong> Pedaling gently — forward and backward — and looking at the chain, does it jump or skip?
A:<\/strong> No.
Clue:<\/strong> This means it’s probably not a chain \/ stuck link problem. (Note that this chain is waxed, and it is a mountain bike, so after damp rides stuck links and corrosion can set in quickly.)<\/p>\n\n\n\n

Q:<\/strong> When slowly pedaling backwards, does the noise happen?
A:<\/strong> No.
Clue:<\/strong> Must be pedaled forward to repro. This points further to a tooth issue.<\/p>\n\n\n\n

Q:<\/strong> Slowly pedal forward, watching the chain links as they mesh with the cassette. Did this happen at a particular tooth?
A:<\/strong> Yes. Mark it with a sharpie.
Clue:<\/strong> Great! Now we know exactly which tooth. This could be the problem…<\/p>\n\n\n\n

Q:<\/strong> Does it happen only when that tooth is meshing with an inner or outer plate?
A:<\/strong> Yes, inner.
Clue:<\/strong> This tells me the tooth might be catching on the narrower plate.<\/p>\n\n\n\n

Q:<\/strong> Shift a few rings down the cassette to get the chain out of the way, then inspect and feel tooth for barbs\/damage.
A:<\/strong> None found.
Clue:<\/strong> Could be a bent\/misaligned tooth. If barb\/burr\/damage was found, that could cause the catching\/noise.<\/p>\n\n\n\n

Q:<\/strong> Using a straight-edge and your eyes, see if the overall cog is bent at this point.
A:<\/strong> Doesn’t seem to be. But tip of tooth does look a little bit out of line with the others.
Clue:<\/strong> Tooth could have become slightly bent… This can happen with mis-shifts, debris, etc.<\/p>\n\n\n\n

Action<\/strong>: Use a flat blade screwdriver braced against the inner part of the smaller cog to gently nudge the tip of this tooth inboard. (Not even enough to be visible.)<\/p>\n\n\n\n

Q:<\/strong> Shifting back to this cog, then shifting around a bunch, can the issue be reproduced anymore?
A:<\/strong> Nope! Seems like this sorted it out.
<\/p>\n\n\n\n

And… that’s it. Of course the issue shouldn’t be considered completely solved until after a test ride, but a simple change eliminating a noise is promising.<\/p>\n","protected":false},"excerpt":{"rendered":"

I like troubleshooting things. It’s basically what I do at my day job, and I’m kinda good at it. Sometimes I’m asked for illustrations of how I troubleshoot stuff, so I’m sharing this example of figuring out a noise on my Pivot Trail 429‘s cassette that cropped up yesterday when riding at Poto with some\u2026<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10,11],"tags":[],"class_list":["post-24859","post","type-post","status-publish","format-standard","hentry","category-cycling","category-making-things"],"_links":{"self":[{"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/posts\/24859","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/comments?post=24859"}],"version-history":[{"count":4,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/posts\/24859\/revisions"}],"predecessor-version":[{"id":24864,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/posts\/24859\/revisions\/24864"}],"wp:attachment":[{"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/media?parent=24859"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/categories?post=24859"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/tags?post=24859"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}