U-bolt / tube clamp, with flattened wrap section

[spinningmagnets]

There are lots of developments going on right now. I am looking for search-terms and suppliers of U-bolts that wrap around cylindrical bicycle frame tubing. the conventional (round cross-section) U-bolt found in any hardware store will concentrate a tremendous amount of force onto a very thin section of the tube it is attached to (easily creating a crimp). I came across something an engineer wrote calling this "knife-edging".

My solution in the past was to slice a short section of steel pipe (strong, cheap, available) to act as a saddle. See the example in the pic below. notice the steel pipe section with rusty threads...

As much as that type of solution actually works, there is another option that might work "well enough". I was recently reminded that U-bolts exist with a flattened wrap section, and by having several of these, no "steel pipe section saddle" would be needed.



automotive U-joints u-bolt
automotive steering column u-bolt
"flat top" u-bolt
U type pipe clamp

here's one for 1-5/8 inch tube OD (1.625-inch/41.2mm)
http://www.nrs.com/product/1216/nrs-frame-u-bolt

The people for whom this is most useful will not need to have it explained to them. (i.e.)...if you have to ask what this is useful for, its really not for you. As an example, my current commuter has a seat-tube outer diameter (OD) of 1.25-inches, and the down-tube is 1.51...

 

[spinningmagnets]

McMaster-Carr is always a good place to start for this kind of thing. Here, a hard-plastic "bushing"? spreads out the load.

http://www.mcmaster.com/#u-bolts/=136tftt



Tube OD in inches,
1/8 - 0.125, 1/16 = 0.0625

0.812 - 13/16 (20.6mm)
0.875 - 7/8
1.000 - 1
1.062 - 1-1/16
1.250 - 1-1/4
1.312 - 1-5/16
1.375 - 1-3/8
1.687 - 1-11/16
1.875 - 1-7/8 (47.6mm)

 

[spinningmagnets]

Affordable aluminum tubing clamps (in a variety of styles) exist that attach accessories to motorcycle fork tubes



Tube diameter
32mm (1.26-inches)
33mm
35mm
36mm
37mm
38mm
39mm
40mm
41mm
43mm
45mm
46mm
47mm
49mm
50mm
54mm (2.125-inches)

 

[spinningmagnets]

There are accessories that are made to attach to bicycles. If you want to attach a common interface water bottle mount to

a handlebar, they can be had for $5 each,

for tubing OD 20mm-25mm (7/8ths, to one inch)

 

[spinningmagnets]

This is a "split ring pipe hanger" from a plumbing supply. Tube ODs are limited to common plumbing pipe ODs. If you add the search term "cushioned" then you get models that have a rubber sleeve between the clamp and the tube.

Also, if this type works for you, you can get a slightly larger size, and then wrap an old inner tube around your frame tubing to make a snug fit...the threaded hole (intended for all-thread) uses a common 3/8-16 threads.

3/4 inch
one inch
1-1/4
1-1/2
2-inch