S and S Machine
Bicycle Torque Couplings (BTCs)
Your Travel Bike........Your Only Bike!
Titanium (visible
weld) BTC™ Specifications
New Design
Frame tube Tube Coupling
Diameter Wall thickness Weight
1 1/4" 31.7 mm .035" .89mm 4.37 oz 124 grams
1 1/4" 31.7 mm .039" .99mm 4.51 oz 128 grams
1 1/4" 31.7 mm .045" 1.14mm 4.73 oz 134 grams
1 1/4" 31.7 mm Machine to fit Variable weight
.017" to .045"
1 3/8" 34.9 mm .035" .89mm 4.80 oz 136 grams
1 3/8" 34.9 mm .038" .97mm 4.90 oz 139 grams
1 3/8" 34.9 mm Machine to fit Variable weight
.017" to .045"
1 1/2" 38.1 mm .032" .81mm 5.15 oz 146 grams
1 1/2" 38.1 mm .035" .89mm 5.29 oz 150 grams
1 1/2" 38.1 mm .039" .99mm 5.43 oz 154 grams
1 1/2" 38.1 mm Machine to fit Variable weight
.017" to .045"
1 3/4" 44.45 mm .045" 1.14mm 7.09 oz 201 grams
1 3/4" 44.45 mm Machine to fit Variable weight
.017" to .045"
2" 50.80 mm .035" .89mm 8.22 oz 233 grams
2" 50.80 mm .040" 1.01mm 8.40 oz 238 grams
2" 50.80 mm Machine to fit Variable weight
.017" to .045"
To calculate the weight increase resulting from adding couplings to
a frame subtract the weight of the The "machine to fit" or zero wall couplings are designed to be machined by the framebuilder on the outside of the coupling in the area that gets pressed into the tube. For example, the 1 1/4" "machine to fit" coupling will fit tubes with a wall thickness as thin as .017" or as thick as .045" or anything in between. (.43mm to 1.14mm).
Heat Hard. UTS .2% YS Elong
Part Name Material treat Rc ksi ksi % in 2"
Coupling Lugs 6AL/4V Ti - c35 145 132 14
Coupling Nut 17-4 PH SS H900 c44 200 185 14
Data shown above is believed to be representative but should not be used for design or application selection purposes. Specifications are subject to change without notice.
These photos show the coupling before being pressed into the tube.