Wobble wobble

YouRang87

YouRang87

Active Member
I've recently noticed and heard my chain wobbling left and right when looking down at my FD while riding. I can't hear it sitting down, while standing in a climbing position I hear it. I tightened the crank arms/made sure tight and all the bolts where the spider meets the chainring. This happens in both big n little chain rings and all gears. One thing I did notice is one of the bolts on the spider just keeps turning and turning. I don't know the proper name buts it's and Allen head on the outboard side and inboard side it's more of a washer that's no longer grabbing the chainring? Anyways I suspected a bent ring but it wobbles on both rings and doubt both are bent. It wobbles while sitting and standing but I hear it while standing as it ping pongs the FD. ANYONE have any advice to direction to point me in? Thanks!!! Ps everything is shifting great.
 
YouRang87 said:
I've recently noticed and heard my chain wobbling left and right when looking down at my FD while riding. I can't hear it sitting down, while standing in a climbing position I hear it. I tightened the crank arms/made sure tight and all the bolts where the spider meets the chainring. This happens in both big n little chain rings and all gears. One thing I did notice is one of the bolts on the spider just keeps turning and turning. I don't know the proper name buts it's and Allen head on the outboard side and inboard side it's more of a washer that's no longer grabbing the chainring? Anyways I suspected a bent ring but it wobbles on both rings and doubt both are bent. It wobbles while sitting and standing but I hear it while standing as it ping pongs the FD. ANYONE have any advice to direction to point me in? Thanks!!! Ps everything is shifting great.
Click to expand...

Check the back of the bike too.

Loose RD?

Cassette lock ring loose (play with cassette / free hub)?

Rear wheel not seated correctly?

If it's a FS, check linkage.

2c.
 
YouRang87 said:
One thing I did notice is one of the bolts on the spider just keeps turning and turning. I don't know the proper name buts it's and Allen head on the outboard side and inboard side it's more of a washer
Click to expand...

That's called a chainring bolt, and if it's stripped, that could definitely be your problem.
 
I little side to side motion isn't unusual. The cranks/chainrings/spider do flex to some degree. If everything is tight and not bent, there is nothing you can do.

The chainring bolt that is just spinning is a concern but likely not the cause of the problem. This tool is used to hold the slotted side while you turn the allen bolt on the outside. Watch your hands as this tool often slips and those chainring teeth are sharp. I have plenty of scars to prove that. Personally, I look for torx/allen chainring bolts so that I DO NOT have to use that crappy tool.
 
Same thing happened to me on a ride about a month ago, turns out all of my chainring bolts were loose and one was gone. Definitely invest in the tool and properly tighten the chainring and see if that helps!
 
This is the knuckle buster that Ben was talking about:
park_cnw1_nut_wrench_lg.jpg

The screwdriver types are bit safer and less likely to slip:

ice-toolz-chainring-bolt-tool-293-p.jpg
 
I'm going to tighten the loose chainring bolt first now that I understand how it goes together. I'm thinking I might get under the bike and see if leaving the chainring it wobbles as right now I only know it's wobbling returning to the chainring. I'm thinking juggernaut might be on to something and I will examine the rear as well. DOES anyone else agree that it's less likely both of my chainrings are bent? It's a road bike not a DH rig. I get some flex is normal but I think I have to much. I think maybe it's my FD positioning but if that were the case it be more constant and not once a revolution.
 
YouRang87 said:
I'm going to tighten the loose chainring bolt first now that I understand how it goes together. I'm thinking I might get under the bike and see if leaving the chainring it wobbles as right now I only know it's wobbling returning to the chainring. I'm thinking juggernaut might be on to something and I will examine the rear as well. DOES anyone else agree that it's less likely both of my chainrings are bent? It's a road bike not a DH rig. I get some flex is normal but I think I have to much. I think maybe it's my FD positioning but if that were the case it be more constant and not once a revolution.
Click to expand...

Yeah, it's highly unlikely that BOTH chainrings are bent... BUT.... Since they ARE basically bolted to each other. Loose chainring bolts would impact both.

Post back your findings.
 
Thankyou everyone, i shall have them tight and do a ride around dinner time. One thing I'm still scratching my head is how it's worse when I put a lot of power/stand on the pedals but the loose nut might do it, more torgue more pulling the chainrings in a poor manner.
 
YouRang87 said:
Thank you everyone, i shall have them tight and do a ride around dinner time. One thing I'm still scratching my head is how it's worse when I put a lot of power/stand on the pedals but the loose nut might do it, more torgue more pulling the chainrings in a poor manner.
Click to expand...

Consider the flex of the crank spindle. When under load, you cause things to bend. This is why we have evolved from old thin square taper spindles to the bigger BB30 spindles we see more commonly now. Outboard bottom bracket bearing are also intended to decrease spindle flex.
 
Tightened but it did not fix. I'm pretty sure it's aRD issue I thought I solved. No matter what tensions adjustments I make the chain meets my gears a hair off making a poping as it snaps In place. It's not bent. Back to the drawing board.
 
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