Paultso

I got some old campy pista cranks that i want to use but the chainring is 151. All NOS ones are extremely expensive.

Would it be possible for me to buy a 144 bcd track chainring and drill the prexisinting holes into ovals so that theyll fit?

Squirrelli

Unless you are super precise when you are drilling the holes...otherwise it is better off buying a new set of cranks.

TejanoTrackie 

Good luck with that. Unless you have access to a cnc machine, you'll end up with something that isn't concentric and / or loose and won't stay tight. Furthermore, the bolts will only contact a half circle and might bend or split the chainring. Anyways, you can get NOS 151 bcd Campy track chainrings for about the same money as modern Campy, Shimano, Sugino from places like Velomine >>> https://cgi.ebay.com/ws/eBayISAPI.dll...=263602_263622

Squirrelli

Also, using a 151 bcd crankset will limit the choice of gear inches you are able to use.

TejanoTrackie 

Not really. Other than a 42T or 43T, all other sizes are available.

rustybrown

Nawww, bad idea bro-bro.

Squirrelli

Oh, I thought the difference would be larger...

evilcryalotmore

The lug pattern is easy to dril.. Get a hunter and a laser.

CharneK

njs-keirin.blogspot.com has some 151's for 58usd. I don't know what shipping is like from them or whether or not the are reliable but...

Paultso

dang brahs, looks like i'll have to shell out some dough for this vintage crap. i would just sell the cranks but i spent the weekend polishing em to a mirror finish blang blang biatches

Squirrelli

CharneK

If you feel like getting nostalgic they do have quite the inventory of used NJS partage.

Ragooch

It's actually not that big a deal to do, although a vertical mill (not a CNC machine!) or a drill press should be used. Some old-timers do this to Campy 44T 144bcd rings to use on 151 road cranks, as originall 144bcd 44T's are really expensive! Way more than the Pista stuff.

If you have 151bcd ring to use as a pattern to transfer on to the 144bcd ring it's really a pretty straight forward job.

Paultso

couldnt i just use a dremel bit and gradually ovalized the holes?

ianjk

you need round holes for the round bolts.

Batavus

Oh my god, is it that difficult?

https://www.cycleunderground.com.au/chainringdesigns.htm

scroll down; choose from 12 designs, 3 or 4 mm plate, 3/32 or 1/8, plain finish, polished or anodized.


simplest version costs 50 bucks and shipping is ultracheap. I had mine shipped to the Low Countries for something like 5 dollars.

Hirohsima

Word of caution. I bought some of their rings. Soft. Pretty. But soft.

Batavus

Oh, well that wasn't my experience and I had a ring made from the thinner 3 mm plate, coincidentally also a 151 bcd ring.

Hirohsima

Mine was the thicker plate. 500 miles on my SS, and I saw visible deformation of the teeth. Such that, if I were to move the chain over 1-tooth the inner-plates would bind up on the deformed teeth. I had to file then down gently. Still works... now looking again for more back-up rings.

Batavus

That doesn't sound good... I should say that I didn't put a lot of miles on it before I sold it to fund other projects, probably less than 500 miles. They do call it 'armour plate' aluminum. Thinking of having them make a ring for my Stronglight 49d crankset, may have to rethink.