Randy,
I am in the process of building a bentech type recumbent with SWB and
under seat steering. I used the rear diamond off a ten speed and I used a 20"
BMX front fork. The head tube is as you say threadless. Actually mine is
threaded and my sons bike which we are also building is threadless. I machined
myself a nice billet threaded cap for mine and cut the long threaded shank down
a bit and with the factory bearing preload nut and washers under my cap all is
well. As far as my sons, we used the factory threadless fork and bearings, and
the gooseneck used the type of handlebar assembly that incorporates a socket
head cap screw down thru the head tube into the gooseneck shaft angled offset
internal clamp(does that make sense). I helped him machine a cap that closely
fit the od of the fork shaft and had a countersunk hole for the SHCS to go into.
Then we machined a small steel disk that fit tightly into the ID of the front
fork headtube shaft and threaded it for the SHCS. Then we tig welded it into
place down inside the tube a bit. All you do is stick the bearings on the bottom
of the shaft, install the fork into the headtube of the bikes frame, drop the
upper bearing on the shaft, slide down the upper race, then install the washer
and the cap we machined and stick the shcs down thru the cap and thread it into
the welded in disk and adjust to proper bearing preload. Worked out real nice
and has a clean look. Mine has a small threaded hole in it that is going to
accept a kinda small dash board that will hold my computer and possibly a small
water bottle on the back of it as well as someday a GPS unit. I am not a
professional bike mechanic but I play one on TV so I am not up on all the jargon
for some of these items but I hope this helps nonetheless...

Pete Matos


>
> From: "Randy" <utahsailing@...>
> Date: 2007/01/16 Tue PM 05:49:23 EST
> To: bentechriders@yahoogroups.com
> Subject: [bentechriders] head tube
>
> Hello everyone, I am getting all of my parts togetherfor a swb under
> frame steering bent. I have a question regaurding the steer tube. I
> want to get a bmx 20" front fork with v brake lugs. the problem i see
> is the head tube is threadless 1"1/8. I was wondering if anyone has
> used this size steer tube? Randy
>
>
>