Re: [CR] Lengthening a fork steerer tube, how to?

(Example: Framebuilders:Mario Confente)

Date: Sun, 21 Oct 2007 08:55:40 -0500
To: Doug Fattic <fatticbicycles@qtm.net>
From: "Mark Stonich" <mark@bikesmithdesign.com>
Subject: Re: [CR] Lengthening a fork steerer tube, how to?
In-Reply-To: <C3405A6A.9C51%fatticbicycles@qtm.net>
References: <6A64CE2B-4DBE-43BB-81AA-A35CBC0C2587@mac.com>
cc: 'Classic Rendevous' <classicrendezvous@bikelist.org>

At 10/21/2007 01:22 AM -0400, Doug Fattic wrote:
>I don't think their is a risk of failure if the sleeve joining the 2 parts
>of the steerer is thick enough and long enough and perhaps tapered at the
>ends.

Doug Once I determine the angle of taper of the butted section of the existing steerer, I'll externally taper the sleeve to match. This will allow a longer sleeve and avoid a stress riser. Internally tapering the upper end of the sleeve is a given.

At 10/20/2007 09:34 PM -0700, James Valiensi wrote:
>Hullo,
>I would never lengthen a steerer tube. I'd replace it by removing the
>original one. Having this part of the bike fail is quite disastrous,
>and I would not take on the risk.

James, What failure mode do you envision? A properly chosen sleeve will be as strong as the steerer itself, so the steerer isn't going to snap in half at the joint unless it's poorly brazed or the sleeve creates a stress riser. Not a job for a newbie, but I've been brazing and machining since the '70s.

Mark Stonich;
     BikeSmith Design & Fabrication
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