For starters, I’m new to road bikes. I was riding and practicing switching gears when suddenly I hear a clunk and then the pedals seemed to just disconnect from the drive train. Hoping it’s not an expensive repair.
by powfacekillah
For starters, I’m new to road bikes. I was riding and practicing switching gears when suddenly I hear a clunk and then the pedals seemed to just disconnect from the drive train. Hoping it’s not an expensive repair.
by powfacekillah
8 Comments
[deleted]
Its broken
Take that crank arm off and see if you can see why the chainrings are no longer firmly attached to shaft in the center
Chance are you need a new crankset. Used ones of that quality are pretty inexpensive. Sometimes bike stores have boxes of pull off items from people upgrading new bikes.
On those cranks, the chainwheels are swaged onto the crank.
This joint has failed.
You could upgrade your cranks, but you would have to do your BB at the same time.
(Adding: unless you can find some cottered cranks. They are scarce these days.)
You could take a chance with a big hammer and see if it holds.
As others have said, the crank set is no longer a single piece.
Options:
Bash the crank arm and chain ring with an appropriate tool to re-establish the join. – requires metal work skills.
Braze the pieces together. – needs someone who knows how to braze.
Weld the pieces together. – needs a welder and a welder.
Find a suitable replacement. – needs persistence and some luck.
Replace the BB and crank set completely- probably the quickest and easiest.
A fantastic opportunity to replace those awful cottered cranks with something good.
That’s a [cottered crank](https://sheldonbrown.com/cotters.html), something that hasn’t regularly been on bikes made in the last 50 years. Take it to a shop and ask how much to fix it. “Fixing” it is likely going to entail installing a completely new bottom bracket and crankset. It may cost more than that bike is worth.
Trying to fix it yourself is going to be challenging.
The front fell off
The other comments are good and accurate advice. I was wondering what brand of bike it is.
I have a French road bike from the 70’s with the same drivetrain, and it’s a pain in the ass to source parts because back then the French used different measurements than everyone else. Your LBS may be more knowledgeable about that. If it’s not a French manufacturer, then ignore me.