getthething

I've got the stock IRO crank set and chainring and its pretty noisy. I can see that the chainring is at least warped (side to side) and may not be perfectly round. I'm looking for new chainrings that won't cause any chainline issues. 46t 130bcd. I'm also thinking about replacing my crankset altogether. Is the Sugino XD with sugino chainring any better than the stock IRO on a Mark V? I seem to be having trouble finding a crankset that claims to give a 42mm chainline with a 110mm BB, they usually recommend a 107mm BB. Am i going to have to replace my BB as well if i get a new crank set?

Sorry for the jumbled questions. I read an old thread on replacement chainrings for IRO cranks and didn't seem to find a conclusive answer

Just saw this post https://www.bikeforums.net/singlespeed-fixed-gear/429605-question-about-jamie-roy-chainrings.html which sort of answers my question

Cyclist0383

The IRO crank set is actually a very good crankset, especially for the cost. If you get an Sugino you will also need a new bottom bracket. Are you sure the noise is from the chainring and not something like a too tight chain?

getthething

Well, not 100% sure. I tried recentering the chainring which didn't help, the chain probably has about 1/2 inch play up and down. The fact that the chainring is warped doesn't really help its case though. So you suggest just picking up a new chianring? (if that in fact is causing the noise) Any particular rings that will be straight and round and not mess with my chainline?

Cyclist0383

I'd suggest you take it to a friend who is a decent mechanic before you go willy-nilly spending money trying to fix a problem you aren't 100% sure the cause of.

fixedup

I think the sugino zen messenger chainrings are 130bcd, my girlfriend has the messenger cranks and they're nice. If the chainring is warped then i'd replace it, no need to replace the whole crankset/bb unless you just want new cranks.

Cyclist0383

It's also 1/8" while his current setup is 3/32".

getthething

By "not 100% sure" I mean I'm probably 95% sure. What more could a decent mechanic do that I haven't tried? I'm also 95% sure that the cause is the warped ring. Thats probably something that should be straight.

Cyclist0383

Then any 46 tooth 130BCD 3/32" ring should work for you.

fixedup

not like he couldnt just get a 20 dollar bmx chain and a new cog? I didnt know the iro setup was 3/32, excuse my ignorance.

Cyclist0383

I think it would be better for him just to get the proper part in the first place......

ralphm2k

Andels. Ben's has them with a matte finish.
They come in wacky colors too.

Cyclist0383

That's the same crank as the IRO that he now has.

Cyclist0383

One last thought, if the crank is new and you didn't crash or drop your bike why don't you contact Tony at IRO for a warranty replacement ring? It's best to call him as email responses are spotty at best.

getthething

Good call. Hadn't really thought of that. Its only a couple months old. Maybe i'll give him a call.

operator

The iro crank is 130bcd. 3/32 chainrings are a dime a dozen. Cost you maybe $30-$50 for a good one at your lbs. Assuming that is really the problem anyways.