My eccentric creaks, what should I do?
Hold on a minute
We have one of the busiest repair shops in the industry, and we solve more bottom bracket creaks than you can shake a stick at. The first thing we've learned is to eliminate the easy things first so we don't go chasin' a rabbit down the wrong hole and come up empty.
Every year we have a few customers email us to help them solve a bb creak. Most of the time we get it solved before ever addressing the eccentric itself. There are several places that a bottom bracket creaking noise can come from that we need to eliminate first. These are things that happen to bicycles with or without eccentrics in them and we see every day in the repair shop here in Seattle. I apologize in advance if you've already done all of these things, but we do need to eliminate them as a possibility first. If one of these things is creaking, no amount of work on the eccentric will solve the creak.
The cause for the common creak
- 1.) The threads of the pedal spindles should have grease on them before the pedals are threaded into the crank arms. We have several bikes each year come in to our repair shop with creaks that are solved simply by removing the pedals and greasing the threads. Apparently, a lot of people install their pedals without greasing the threads. If you're unsure about yours, remove, grease and re-install your pedals.
- 2.) Still creaking? The bottom bracket cups themselves are a common source of creaks as well. Bottom bracket threads should also be greased and installed tightly just like the pedals. Some manufacturers skip this procedure and rely on the dealer to remove, grease, and re-install the bottom bracket cups during assembly. Some mechanics skip the procedure and it results in creaks every time. If you're unsure about yours...you'll want to remove, grease the threads, and reinstall your bb cups.
- 3.) The creaking persists you say? Crank arms creaking on the spindle is probably the 3rd most likely cause of a bottom bracket creak. It is important that there is grease on the threads of the bolts that secure the arms to the spindle or it will be a source of creaking. Most manufacturers do not grease them during manufacturing because they expect the dealer to do this during assembly. Not every dealer does this. I recommend checking them for grease, and tightening them to the manufacturer's recommended torque (or really tight if you don't have the specifications at your disposal).
Still creaking!!? The spindle itself may or may not require grease before installing the arms. Square tapered spindles should NOT be greased, but installed tightly and checked frequently (if there is grease on them, it should be wiped off before installation). Splined bottom bracket spindles (Mega-Exo, Octalink, etc...) require grease most of the time. We find that a lot of these spindles will creak without grease on them. Also, if there are binder bolts on the left crank arm, the threads of those bolts need to be greased and tightened frequently. Again, these are things that the manufacturer expects that the dealer will do.
The cause for the eccentric creak
If the above things are all properly done, and your bike still has a bottom bracket creak, then it may be in the eccentric, and almost always (but not always) has to do with improper installation and can be easily corrected.
- 4.) The eccentric can creak if installed improperly, or installed without grease in the appropriate areas. In our repair shop I can count on one hand the number of creaks that have come in that ended up being the actual eccentric, but we are very thorough when we install them. Unfortunately, a lot of bicycle manufacturers overseas are not as thorough, and some dealers are not aware that there is a procedure to installing the eccentric just as there is for the bottom bracket etc...
We have changed our assembly procedure to include greasing everything during the eccentric assembly process, but that affects the parts manufactred in 2010 and going forward.
Over time, especially in bad weather, the grease will get old or just 'go away'. You'll want to grease the ebb occasionally.
If you are unsure about the installation of your Bushnell ebb, you'll want to follow the instructions linked here (456k download) to ensure that it is greased properly and installed properly. Make sure to have plenty of your favorite beverage on hand as it helps cut down on swearing during the procedure. A list of recommended beverages can be provided by request.
5.) "The Torture Never Stops" Uneven bolt threading: I have recently had a customer who had creaking problems that we could not resolve so I sent him a new Bushnell ebb. When he sent his old one back to me it became obvious why he could not resolve his creak. The 'wedges' were threaded on to the 'bolt' different distances creating an unbalanced pressure situation. He has no problems with the new one I sent him, so it must've been his problem.
To the right is a picture of his ebb the way it came back to us
Make sure your wedges are NOT like this
- "Creaking....Still????" I guess karma got you this time. What have you been up too? Whatever it is, we're still going to help you out. Just shoot me an email and we'll get it solved for you.
Thanks for reading