On 7/21/2019 10:21 AM, Doug Landau wrote:
When I try to braze the **** just runs away
That was on mild steel tho not bicycle tubing, I haven't tried on bicycle tubing, I guess I could and practice til I can, but that said:

how should I attach this rack to the head tube, to locate the rear of the top edge of the rack a few inches in front of the headtube?

https://tinyurl.com/y5dgsg56

https://www.bike-discount.de/en/buy/...yABEgI1xfD_BwE


I do think I could drill a hole without spidercracking it, but what then, other than brazing? Drill it for M4 or M5?
Is there stress on the headtube?
Does water already run thru there when it rains?

Forget this sillyness and just put one of those ubiquitous L-shaped silvery slotted soft steel strips under the brake mount nut?


For brazing, any intro welding/brazing/soldering textbook is
worth a half hour of your time.

Clean both pieces, use appropriate temperature flux (powder
flux which clings to a hot stick or sprinkled across the
area or a paste flux). Come in directly with your flame
where you want to start the tack, that is, not obliquely to
preheat as you would a gas weld. Once material flows on your
tack, pull your torch away. If piece is correctly positioned
and brazed, flow your joint starting somewhere else.
Practice iterations on scrap cannot be emphasized enough.

That said, leave the head tube alone. Your rack secures to
the fork. Connecting the rack to fork _and_ head tube means
you can't steer!

Typical mount is with a 6mm bolt through the hole in the
crown. If no hole, make one. Alternates are on the brake
boss or on the blade:

http://www.yellowjersey.org/photosfromthepast/kfbj2.jpg

http://www.yellowjersey.org/photosfr...st/guntrch.jpg

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971