[CR]High Flange/mid flange/low flange

(Example: Humor:John Pergolizzi)

Date: Thu, 13 Sep 2007 07:17:31 -0700 (PDT)
From: "Tom Dalton" <tom_s_dalton@yahoo.com>
To: bikestuff@nonlintec.com, Classic Rendezvous <classicrendezvous@bikelist.org>
Subject: [CR]High Flange/mid flange/low flange

Steve Maas wrote:

The main advantage is that the high-flange hubs are really cool looking. I have yet to hear of a credible, significant technical advantage. I have heard some claims that are incorrect. In particular, spoke length and angle are no different from short-flange hubs, unless radial spoking is used, which is a bad idea in any case.

Steve,

I agree with the first point, the main advantage of high flange is looks, especially from the perspective of most of us on this list. If high flange hubs end up on the wrong bike the looks are also the main drawback. This said, there are differences between high and low flange hubs. They may not meet your standards for significance, or even credibility, but the two that come to mind are as follows: 1) More spoke angulation, and 2) the final cross (on tangentally laced wheels) is closer to the rim. I have no idea where I picked up the silly term "angulation," and I think it bears explanation. What I'm refering to is the fact that the spokes on a high flange hub start at a closer radial distance from the rim, but approximatley the same lateral distance from the hub centerline when compared to low flange. As a result, the lateral component of spoke tension is higher, for a given tension along the spoke. This is why the Campy Record high-low actually makes some sense. It brings the obliquity of the left and right sides closer to even as compared to either a low or a high flange hub.

On the second matter, for a given spoke pattern, the final cross is closer to the rim when you use a high flange hub. This leaves a shorter span of spoke between the last point at which the spoke gets support from the spoke it crosses, and where it meets the rim. I doubt this makes much difference, but there's a better chance that it will if the spokes are tied and soldered, as is typical with track wheels.

You are incorrect that high and low flange wheels use the same spoke length except in cases where the spoking is radial. The correct spoke length typically differs, irrespective of cross pattern, but can be the same under specific conditions.

As for radial spoking, I'd say it qualifies as a "bad idea" to about the extent that low or high flange hubs are better or worse than one another. It's just another example of a wheel configuration that has had it's significance seriously overblown. The only real issue with radial is that it overloads the hub flange and can lead to early flange failure. Obviously you need at least one tangental side on a rear wheel. A friend did the "experiment" of building a full radial rear, and while it was rideable, it had a lot of windup.

Tom Dalton Bethlehem, PA USA

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