Bicycle Mechanics - TA Chainring BCD Guide

The Co-op that I volunteer at had a 8 1/2 by 11 sheet of paper that had all of the various BCD's outlined. It was set up so you could just hold a crank or chain ring up to it and it would show you what BCD it was. It has grown legs and left the shop and we really miss it. Does anyone have an eletronic copy that they could post or email me?

Chris "at" sacbikekitchen "dot" org

Anyone?


Bump

Sheldon Brown's web site has a table of BCD's and the center-to-center distances for adjacent bolts but I've never seen a graphic you could just hold the chainring up to. I expect it was home made.

Check your QBP catalog, in the chiainring section.

We don't have the catalog, we operate on donations solely. I'll check with a local shop and their catalog.

We don't have the catalog, we operate on donations solely. I'll check with a local shop and their catalog.

I don't have an electronic version...but I have an original hardcopy. I use a Park chainring sizing tool now and have no use for it. You are welcome to it if you like. Just P.M. me the address and I will send it off. No postage needed. Just P.M. the addy and its on its way. Call it my donation.

Cavernmech to the rescue! Thanks again.

Measuring it is actually pretty simple.

I don't have an electronic version...but I have an original hardcopy. I use a Park chainring sizing tool now and have no use for it. You are welcome to it if you like.

How about scanning it and making it available online?

I'll scan it when I get it.

Measuring it is actually pretty simple.


I know but we have 30 or so volunteers and a crap load of chainrings and cranks. The measuring works for me at home in my garage but not in a crazy busy shop. This is a very simple way to organize things.

In case you are not well versed in the scanning arts, note that based on settings of the scanner, its software, paper sizes, etc. you could get a result that is slightly (or more) off in size from the original. To be sure, measure the bolt circle on the scan result.

Wait a minute ... ;)

[EDIT: I posted mine before yours was up. Ignore the last bit. :) ]

If you have FSA chain rings laying around, they print them on the back of the package. Or, like said before, QBP has one in the book.

Or perhaps just trace them onto a piece of paper and copy it (with the same caution for copies as for scans).