Author Topic: Chainring out of round  (Read 820 times)

JonB

  • Granny Ring ... Yes Please!
Chainring out of round
« on: June 12, 2019, 09:00:17 am »
A few months back I snapped my Condor branded Sugino crank and replaced it with a Stronglight 2000. It's probably done around 2000km since I've had it including an audax SR series. I've had trouble tensioning the chain, I get tight spots and loose spots but more recently the problem has become more pronounced such that I don't really feel it's rideable; to get the chain to run without binding creates a lot of slack. I can't work out whether I've become more sensitive to it or if it's got worse.
- I changed the chain recently and struggle to see how that could affect it but I am wondering?
- The chainring is very snug on the crank and so there is no scope for the Sheldon Brown loosen a bit and tap to get in the right spot.
- Just buy a new chainring, maybe a Velo Solo? Is there a danger of the problem being with the crank, I haven't got a spare chainring of the same BCD to try.
- I don't really want to buy a new crankset but will do if it's the best course of action ...
Any thoughts welcome ....

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Re: Chainring out of round
« Reply #1 on: June 12, 2019, 09:22:03 am »
JonB don’t bother changing the chainring, if mine is anything to go by I bought and fitted a Stronglight Chainset and had the same problem. Changed the chainring in an attempt to improve with no success. New chain new cog at ever increasing cost, the result non. Now via a relative I have access to Engineering Measuring equipment. The results showed eccentricity at the bolt holes of 10-15 thou, the only solution I could arrive at would be to remove the fitted nuts and use standard. Then to use Sheldon Browns chain tension solution.
That would be a fairly destructive process so as of yet I haven’t had the balls.
Boots an Spurs

Re: Chainring out of round
« Reply #2 on: June 12, 2019, 09:48:26 am »
Jon I have the Stronglight on the Rourke and had the same problem, I worked out which part of the spider was "high" and took a file to it, a bit drastic with a new chainset but it solved the problem. The chainring now has a small amount of movement so you can use the Sheldon trick. Good luck!

JonB

  • Granny Ring ... Yes Please!
Re: Chainring out of round
« Reply #3 on: June 12, 2019, 12:20:15 pm »
Thanks both ... good info and advice  :thumbsup:

Re: Chainring out of round
« Reply #4 on: June 12, 2019, 02:30:22 pm »
Yep.. had same issue

Re: Chainring out of round
« Reply #5 on: June 12, 2019, 08:23:43 pm »
Been looking for a new chainset as my square tapered holes have worn out on mine as the chainset has probably been over tightened !! 

So any suggestions on what s best to buy ?

Re: Chainring out of round
« Reply #6 on: June 12, 2019, 11:05:38 pm »
I think I notice the slack more since I heard it was a phenomenon. I really only notice it when I'm off the bike and cleaning/oiling the chain, or when I'm on the bike and momentarily relax or start looking for play.

It's a bit of a faff when I have to refit the back wheel, because I have to account for the play, which means accepting a slack point. But I have just learned to live with it: it doesn't really affect my cycling.

L'enfer, c'est les autos.

DaT

Re: Chainring out of round
« Reply #7 on: June 13, 2019, 05:26:45 am »
Been looking for a new chainset as my square tapered holes have worn out on mine as the chainset has probably been over tightened !! 

So any suggestions on what s best to buy ?
My Dura ace 7710 chainring/BB/crank seems perfect. This is both with a DA cog and also an EAI gold medal one.

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Re: Chainring out of round
« Reply #8 on: June 13, 2019, 11:57:21 am »
Jon I have the Stronglight on the Rourke and had the same problem, I worked out which part of the spider was "high" and took a file to it, a bit drastic with a new chainset but it solved the problem. The chainring now has a small amount of movement so you can use the Sheldon trick. Good luck!
Mine fits tightly into fitted the captive nuts in crankset ( they have enough protusion to enter chainring), so does not that apply to yours ?
Boots an Spurs

Re: Chainring out of round
« Reply #9 on: July 07, 2019, 09:46:45 pm »
You can centre the chainring a bit by loosening the spider bolts and tapping the ring towards the rear wheel to relieve tight spots.  With patience this can improve an eccentric chainring enough to make it acceptable.  My TA Alize cranks and 47T TA chainring are a bit meh, but I built up a fixie for a friend using Sugino RD cranks and a TA chainring (same type of TA track ring, but 49T this time) and it was pretty much perfect.

High-end track kit tends to be the roundest.
Never tell me the odds.