Hi Tom,
The Campy BMX group was Campagnolo's attempt to capitalize on the mid 1980s shift to BMX in the USA. Their marketing effort did not work as planned because there was no migration path for buyers to go from cheaper BMX parts to more expensive road bike parts.
The Campy BMX group appeared in the Campy 1982 Olympic Supplement catalog and listed component anodized colors as gold and metallic blue. The crankset used was 144 b-c-d made from Campy Pista track CNC machine designs with a 46T chainwheel, but was labeled as BMX instead of Pista. I own one of these gold colored cranks and use it on my criterium frameset. The colored hubs were not Pista high flange not low flange, but a hub size that is between those other dimensions. I don't know if these hubs used a standard size locknut. I am also unsure about the OEM BB size because I assembled mine with a true Pista BB set.
As far as rings, any 1/4 inch 144 bcd Campy, Sugino, or Gipiemme chainring will likely do. The original BMX chainrings were anodized which can be difficult to remove properly. As you are already aware, keep in mind that any 3/32 chain or chainrings will not work properly with a track hub and that a special size of track chain ring bolt is needed that differs from road chainring bolts. I currently run a 46 - 13 combo, but if you get other chainrings off ebay, there are a greater variety of chainwheel/cogs in mostly a siver aluminum color. Used ebay chainrings generally sell at auction from $10 USD to $30 USD. A complete new chainwheel set can be purchased from http://www.bicycleclassics.com for $120 (?) and a used ebay Campy BMX chainwheel set goes for approx $80 USD (as low as $65).
I hope this helps,
Steve Neago
Cincinnati, OH
> CR Listers:
>
> I don't know if this is on topic or not (well it is for me, as I plan on
> putting this on a Fixed project), but here goes:
>
> Any info on the Campagnolo BMX group, specifically the crankset? What
crank
> length, colors did they come in? Did it come with a BBset? what type- for
> American BBsets or 'euro' BBsets? BB threading? Are chainrings readily
> available? What is the bolt circle dia? What is the street price for a
good
> condition but used set without BBset? Are there any quirks I should be
> looking at, like cracks at the spider or taper?
>
> Your assistance and knowledge sharing would be appreciated. If you feel it
> is OT, please respond off list.
>
>
> Best Regards,
>
> Tom Martin
> Oakland CA