I'm thinking of selling a specialized 144mm forged crankset i have to a friend cross country who'd be using it for a fixie. with its original 107mm length single, I measure/calculate that the chain line will be 42mm if he puts a 1/8" (3mm thick) chainring on the inner side, and I gather thats standard for a track bike setup.

does anyone make any nice little streamlined spacer/washer/fittings for the outer side instead of just running short chainring bolts? seems like a lot of double -> fixie crank conversions work best on the inside space... an aluminum bit that was countersunk for a double chainring bolt and shaped approximately like a thimble in profile, and 3mm thick, would be sweet for this presumably common application. round off the outer edge of the curve....

I could try and draw a sketch of what I'm picturing, but I suck at art.

or would the 'cool' mod be to take my old 52T chainring and grind off the teeth so its a chainguard with his 46 or 48T mounted in the inner position?


said crankset with 52:42T rings

A lot of polo players make a chain guard out of another ring, but never that big of a difference in teeth. My polo set up has a 34 tooth ring and a grinded down 36 for the guard.

Not an expert, but from what I can find, I have seen mention of people taking a worn chain rings and cutting of the teeth to make a chainring. Alternately, one could take an old ring and cut the tabs off of the ring and profile them as trapezoidal shaped washers for the outside to act as fillers on the shelf. Do not know why someone could not do this. Aluminum is quite soft and very easy to work with. If you decide to cut it, mix up a little dishwashing soap (Dawn) and water to act as a lubricant on the blade.

You could try using a shorter bottom bracket spindle and putting the chainring on the outside. I say try, because not all cranksets and frames will work together that way. Worth a shot, though.

That said, I've wondered the same thing about spacers, but have been too lazy and ill-equipped to make my own. You get used to the "one chainring on the back" look fairly quickly, when it's the only option.

Your IRO is of such incredible value...I have no clue why no one is buying it.

a filed down 52 as a guard to a 48T shouldn't be that extreme. that picture shows a 52 with a 42. I figure the 48T's teeth are just about where the 52's solid ring is.


I've never heard of a standarad BB spindle shorter than 107mm. anyways, the axle and bearings that came with this specialized BB are made from some really nice metal, looks like high chrome tool steel thats been drop forged.

Just a bad time of year to be selling, I guess. Not even getting ridiculous lowball offers.

I love the thing, it just fits me so poorly. The top tube length is just right, but it's six or seven centimeters too low.

There are 103mm spindles, which might gives your friend a straight chainline but the arms might not clear the chain stays.

Argh, $200 for an IRO is already cheap enough and Chris King headset is a big bonus . You'd probably get more if you sold the headset separately but it really is none of my business.

That said, I hope you will be able to sell it soon.

Not sure about non-cartridge models like that, but Phil Wood has JIS and JIS low-profile (olde Dura-Ace style) starting at 103, and ISO/Campy at 102.

I intentionally priced it low and threw in the headset for quick sale. If I had any use for the headset, I would keep it, but somehow I've ended up with a stable of exclusively 1" threaded and threadless bikes. And I already have another King headset floating around in the parts drawer.

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