Originally Posted by
Andrew R Stewart
Francis- wish I could be 100% in agreement. I've used Var, Eldi, Campy, Park and other threading dies/tool holders many times. With many different lubes from various cutting fluids to simple oils. My experiences have been inconsistent at best.
Now I know that you (Bicycle Research) use to offer cutting tool classes BITD. I'd love to learn the subtleties. But I also know that most common steerer dies are at best chasers, not cutters. And that single pointing (which is beyond my skill set) is the best way to thread a steerer.
So I'm all ears to your methods. f you wish we can take this off list. Andy.
To clear up a few misconceptions, the most important of which is that while I taught the subject over a number of years until the decline in road bikes and the related frame prep ended the market, I'm not affiliated with Bicycle Research, which was Don Milburger's company out in Concord Ca.
To my knowledge, all production fork threading is done with dies or releasing die heads, and nobody has single-pointed a steerer thread in production since something short of forever.
The dies sold in the bike trade, including those from Campy, Silva and Cobra are made of HSS and designed for cutting new thread. I believe that the Park dies should be also, but am not sure. Some of the other dies sold for the job were not HSS but could still cut new thread, but with shortened die life.
I suspect that the idea that the dies sold for the job were only suited for chasing originated from people who couldn't do the job successfully and, like the proverbial carpenter, blamed the tools.
Lastly, the role of cutting oil is critical to the success of the job since modern steerers are made of CroMo at a temper and grain structure that makes it more difficult tho thread than most materials. Also, since this material tends to make long, stringy chips which can easily load up and become a problem, skill in working with the material and process are important.
I'm thinking of offering my old course if there's enough demand now that I'm out of the distribution business and have the time, not to mention that the dough would also be nice.