Pop Pop Pop When Pedaling

[Buster1]

Has anyone ever experienced that? My '41 Westfield makes a pop pop pop sound when pedaling hard. It's quiet when pedaling lightly.

Yesterday I replaced the pedals from another bike, thinking the pedal bearings were acting up. That wasn't it, she still did it.

So I removed the chain (cleaned and re-lubed it) and disassembled the bottom bracket. Everything looked great in there. Re-assembled it all and adjusted the pre-load a tad lighter/looser, as well as the final BB nut. The final nut over the cover plates and it's tightness seemed to have some impact on how smoothly she pedals.

Anyway, my test ride was MUCH smoother after all this. Is this a common issue? Was my pervious pre-load just too tight?

Thank you.

 

[rustjunkie]

Are the chain, chain ring, and cog original to the bike?

 

[Joe Buffardi]

Sounds like chain bind

 

[Obi-Wan Schwinnobi]

I find on the skip tooth that if the rear cog is shark finned it will cause a grinding popping sound sensation whilst pedaling underload.

 

[rustjunkie]

http://sheldonbrown.com/chains.html

http://sheldonbrown.com/brandt/chain-care.html

 

[pedal4416]

Is it a morrow rear hub? I've noticed if they make a popping noise it means they are assembled wrong.

 

[redline1968]

It's the bearings in the hub. they are too tight. If you lift the wheel and spin them they should spin freely without wobble for more than 2 or 3 revolutions. Front, rear and the crank hangar also. Grease them and adjust them to spin easily.

 

[militarymonark]

sounds like a bent chainring, I get the same sound on a couple of my bikes.

 

[Buster1]

Thanks for helping me try to diagnose this guys. I appreciate it. Though it does appear that I have just about every possible part of the drivetrain listed above as the culprit!

Let me see if I can answer a few of the questions above.

- The Chainring is not original. The Chain and Cog/Hub ARE original. (even has the wider Westfield chain)
- The chain is in excellent condition, all rollers turn easily and there are zero binds or issues with the chain (that I can note)
- I will examine for rear shark-finned cog, but I believe it is okay.
- Thank you for the links!
- It's a ND model D hub, hand turning it and such provides a very smooth action. Turns easily and seems to be 'normal.'

I do feel like it was the BB being too tight. Now with the looser/lighter pre-load almost all of the popping is gone, but I need to give her a better ride test to see.

 

[bricycle]

That looks like one of those "repop" chainwheels. Maybe they were made wrong?