Chain Ring prob?

Having trouble with what I assume are tight spots in the chain. I’ve looked at older posts and been to sheldons website but maybe someone can give me a hint.

I had been riding my bike for a while with no problems, then one day i just started feeling this grinding sensation through the pedals around the same spot every rotation. So first I lubed the chain up nice, still there, then I thought the chain ring wasn’t on properly so I followed sheldon’s instructions on how to adjust the chain ring.
Afterwards the chain was a little looser and it felt fine. But after a flat the other day i tighten the chain up, with about two centremtrs of travel and I can feel the grinding when the pedals are under a bit of pressure, its fine when I’m spinning.

Any suggestions?

  1. Rotate the wheel till the chain gets tight, re-adjust from this point.

  2. Spin the chainring around one or two holes.

  3. Buy a new bike :wink:

you might have bent the crank spider (happened to me)
Flip the bike over. get a ruler/tyre lever/whatever and place it across your chain stays. Basically what you’re trying to do is make sure all the arms of the spider are the same distance from your chain stays (thus ensuring that none of the arms are bent).

thanks… ill check out the spider and give rotating the ring around a bit. cheers

I have felt that before…it’s almost like a vibration at a certain point.

You are right, it’s a tight spot in the chain. In my experience, it works itself out after a while.

quite often if you just bolt on the front chainring it wont be concentric.

if you are getting mild tight and loose spots it could be worth trying just nipping up the chainring studs, fitting the chain and rear wheel, and then when you get to the tight spot, tap on the ‘front’ of the chainring with a block of wood or a mallet, this will move the chainring ‘back’ slightly and help to eliminate tight spots.

keep doing this until you achieve a happy medium in chain tension and then finish tightening up the chainring studs so that it wont move again. This will get the chainring as concentric as possible.

hope that helps…


its a long shot but maybe when you got the flat and weren’t looking someone fitted one of these

Ok, shifted the ring around two and tried removing the tight spots as suggested but it still feels a little weird when the chain is anything but kinda slack.
I check out the chain ring, spider and sprocket and all are straight, but I did notice as the chain goes around that it is ‘bent’ in a section, not a tight link but like a faint z when looking down the chain line… could this be the cause?

Buy a new chain :slight_smile:

nah i think ill just invest in a hammer… cause i can use that to repair other issues that may arise with my bike

Gotta love percussive maintenance

When you break a chain, to add or remove links or whatever, and then you relink it, if you give it a quick reef back and forth (stressing the point you just relinked) it loosens it up a bit and restores it to something close to its original state - in regard to that kink in your chain line, my guess is you’ve either done this too much, or not enough.

“Madam, you’re either beating that child too much, or not enough.”

If the sensation is at the same point in a pedal stroke it is not likely to be the chain. Front sprocket, spider, pedal or the bottom bracket has a flat bearing… From suffering them all I would run with the flat bearing.

I have had a spin of the pedals with out the chain on and the chain ring looks straight and i cant feel the roughness then, should I be able to feel a flat bearing when ever I spin the pedals?
The roughness is around the same spot when I’m pedalling but its not every rotation, or i cant feel it every rotation…
im starting to think its from a bend chain and a shit front chain ring that is no where near circular