Originally Posted by
One Wheel
I'll check the outer tubing dimensions this evening. The bike is a roughly 1972 Jupiter Beat Super Deluxe, which is not on that list. Every reference I can find to that brand and model mentions hexagonal tubing, but this has all round tubing. Paint and decals, except for the checkerboard stripes, are identical to
this one. As far as I can tell, I think all the original components match that one as well.
Edit: I don't have a better caliper handy. At the bottom of the lug, the R-L measurement is 1.114", about 3" below that at the top of the decal it measures 1.128".
On closer inspection, that slot does look a bit uneven. I bet it is supposed to have a bigger seatpost.
1mm change at the slot equals .3mm diameter change.....
a machinist' telescope gauge would be a handy tool for you, about now.... measuring a bit below the slot.
the thing i've run into while resizing seat tubes is that the slot only wants to bend in such a way that the spreading isn't evenly distributed in the diameter, and just partially flattens/straightens the tubing near the slot... i've had some better results by leaving the pinch bolt in place, but kinda loose, then spreading the slot some, then using a 1 inch or so tubing in the frame to pry and work the diameter more, etc... techniques can vary from material to material. just don't get in a huury or greedy with the effort... clamp ears have a nasty reputation for cracking!
on some frames, the material was very stretchy, so i over-bent the slot, then used vise grips to re-close the ears to a better place... they had been WAY over-pinched before i began repairing....
28.5 lb. puts that bike in the decent MTB weight class... very rideable!