Tight spots on chain / chainring.

I’ve noticed that I seem to have tight spots on the chain tension on my Malvern Star. It’s very noticable when pedalling. I recently swapped out the BB and cranks for Ofmega track cranks and I have swapped the chain ring twice and I still seem to get it.

I tried the Sheldon Brown method with loosening the bolts and retightening them in the correct order, but it doesn’t seem to do anything.

Could it have anything to do with the chain? It’s one of these KMC chains.

But I’m sure it’s the chainring / cranks.

Highly likely its the chain. I had the same problem and swapped the chain and now there are no dramas.

To be sure, take the chain off and spin the cranks around as if you life depended on it.

Look at it from behind, and see if there any “Jumps” in the chainring. If there are, then the chainring is not round and you should get another one or try making it sit better on the spiders. If not, its most probably that your chain has just worn unevenly thus producing tight and loose spots.

ahh teh ol’ tighty loosey,

you can also try doing the chainring studs up to about 80% tight, pausing the drivetrain in the ‘tight spot’ and then giving the chainring some taps with a block of wood from the front end of the bike(while the chain is still on). Give it a spin, and see if the chainring is more concentric on the crank.

I’m guessing Sheldons method would be quite similar in trying to achieve ultimate concentricity in the chainrings fit on the crank.

p.s. it could be an issue at the hub, where the rear cog/hub isn’t centered but highly unlikely.

I’ve had it on all my SS & fixed bikes. I just don’t worry about it.

More likely to be your chainring - might be slightly ‘egg’ shaped rather than completely circular - not a problem with cycleunderground/fyxo chainrings.


go a touch less chain tension

Well, it is an Aerospoke hub… :expressionless:

And Alex, It’s kinda loose now, Don’t wanna drop a chain brakeless.

If your chain was ‘kinda loose’ you wouldn’t have a problem tight spots.

If the chainring doesn’t fit snuggly on the spider - and it is a good quality chainring, i.e. round, slip pieces of paper into the gaps between the chainring and spider, evenly until you can’t fit any more pieces in. Then tighten your bolts - that’ll help centre the ring.

To check that your chain is not too loose (and yours isn’t if you are feeling tight spots) pick the back wheel up, crank the pedals up to speed, then pick up the whole bike so that it’s horizontal and shake the shit out of it. This is a pretty standard way to check that your chain won’t fall off.

sounds like the spider is not round

you can either fiddle the mounting per the above or just get a crankset with more precise maching eg s75/da

I’m leaning more twards the chainring than the crank being not round.

When I was running these cranks on a different bike with a different chainring and a different rear hub, I didn’t have this problem.

are you using a quality chainring? a s75 or da will be pretty good, cheaper ones ive found are not usually very round at all

by round i mean the crank to chainring interface as well as the actual teeth area

when you checked with another chainring was it a good one or a cheapy?

So far I’ve used Campy (3/32"), Sugino 75, SR (Suntour?) (both 1/8") and TA (3/32").

No problems with the SR and Sugino, the TA and Campy give me tight spots.

Can’t really drop $$$ on a new chainring right now. I need a 42t or 44t. Unless I swap a buch of cogs and stuff around, which I can’t be bothered doing.

if you used a s75 and there were no tight spots, then there’s your answer :wink:

Yeah, but it gave me 80" and 1 skid spot!

My new fuji has an ‘egged’ chainring so i just ordered new one from cycleunderground…
can’t wait

sell me some stuff to pay for your new chainring


1 Campy Record cone for $100.

1 bent in half samson frame $0

is that a threat…? :smiley:

i had a similar prob’ a while back when i regreased hub and didn’t set axle back to original mark…had two hubs apart at once and must of swapped axles. doh! made a hell of a racket.