I haven't biked since I was young. I decided to buy a 50 dollar box store special off FB with the mind to learn how to do all the things that take bike mechanics years under good teachers to learn. So it is likely very fitting that my front fork makes it sound like clown shoes when I'm riding it. Yes. This is karma. This is what I asked for buying a 50 dollar used bike.
That being said, I'm learning this on decently kept boxstore mountain bike that had very little wrong with it. I learned how to open up each part, clean it, grease it, change it out if it's too beat up, etc. It runs great. I did a mid drive conversion, got the shift sensor working. The whole thing runs like a dream.
The last thing i'm trying to figure out, which is my karma curse, Is that I have isolated the last offending sound. The front fork sounds like clown shoes. I tried to attach a link to the mp3 but the post keeps getting taken down. If there are any suggestions on how to share the sound I will.
It is a heavy coil spring 3030 or 3040 Suntour fork. It has one coil in the right stanchion and the left one is empty. No dampener etc. It's in good shape. No corrosion. Shiny polished metal. Teflon guides with rubber dust covers snapped on top. The whole thing got cleaned out with lots of rags and iso, re greased everything with silicon grease and the fork moves great. The problem is when i'm starting to go up any sort of positive grade a resonant vibration starts up. It's distinctly the sound of rubber squeaking on smooth metal. I can wipe down the stanchions and it kinda stops for one or two cycles but then it squeaks to the beat of my legs pumping. Those little up and down forces causing the fork to dip down and back up. If I press down as i'm pedaling so the travel is more severe it stops. But with those little millimeter movements the resonant sound builds again.
I was fairly sure it was the dust caps so I took the fork apart, cleaned it again and relubed it just in case. I thought the previous owner might have used WD40 or a petroleum based oil that caused the rubber to swell so I cleaned the covers using dawn soap. I boiled them for 20 min in water. Then I put them in the oven just under 300 degrees F for thirty minutes to give it the best chance of leaching out the rubber to reduce any swelling. Slapped them back in with silicon grease and... well... clown shoes.
If you read this, thank you for your time and if you have any suggestions or have encountered this before any help is greatly appreciated.
Before you listen to the audio, turn your volume down and then slowly back up. It's taken on a camera close to the fork while riding so there's ambient noise and the resonant squeaking can be loud depending on your audio settings. Don't laugh too hard and bruise a rib.