[sub6]

Okay. I just tried to mount a 22t compact 5-bolt chainring onto a compact spider. It simply would not fit. After assuring myself that I was not insane, I measured the chainring with EXTREME care. Every measurement I take comes out at a 56mm BCD, which explains why it wouldn't go onto the spider (a proper 58mm).

What the hell? Has anybody every seen this, or heard of one? Or why the hell someone would create such a beast?

The ring is black steel, the only markings on the ring are "466" and "22" - I know what one of those means......

EDIT: Before you oooold guys start spouting off, I found the answer. Anybody wants to know, it's here: http://www.hcor.net/postt12808.html - and for extra credit, I showed my work.......

 

[speedbump]

I know the answer, but I'm 34. Am I an "old guy"?

 

[oldfart]

I'll be 46 in a few weeks *sigh* I had that Suntour Microdrive on a XC pro group a loooong time ago. I forgot that Suntour used that different small ring bolt size. Shimano copied Suntour with their compact drive but I don't know why they didn't adopt the same diameter bolt pattern for the small. At one time you could get 20 tooth grannys for compact Shimano.

That first mocrodrive effort was the worst shifting set up I ever had. But it helped me win races because I had to adjust the rear cable tension as I rode to make it work at one end of the block so I tended to ride in too big a gear sometimes and just jam. Sold it off fast along with the most fragile bike I ever owned too. Klein Pinnacle. I went through 3 of those in less than a year.